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International Journal of Phytomedicine and Phytotherapy

Investigation of nootropic potential of ethanol extract of Elettaria cardamomum Maton fruit (Cardamom): a spice of India

Abstract

Background

Cognitive impairment mainly affects learning and problem solving abilities of the person. Traditional medicines, due to fewer side effects, more efficacy and lesser cost are still the choice of treatment in India. The main objective of the present study is to explore the nootropic potential of ethanol extract of Elettaria cardamomum Maton fruits. The present study was conducted by using exteroceptive behavioral models like elevated plus maze, passive avoidance apparatus and object recognition task at doses 100, 300 and 500 mg/kg.

Results

Ethanol extract of E. cardamomum fruits significantly decreased transfer latency and increased step down latency and discrimination index respectively when compared to normal control groups. Piracetam and diazepam exhibited respective rise and fall in memory of the animals. The effect of plant extract on total serum cholesterol, acetylcholinesterase and malondialdehyde were more effective at two higher doses. However, it decreased serum glucose levels insignificantly whereas a significant rise in brain GSH levels was observed with increasing dose of the extract.

Conclusions

The study concludes that the nootropic effect of ethanol extract may be attributable to its anti-oxidant, anti-cholinesterase and cholesterol as well as glucose lowering potential.

Background

Alzheimer’s disease (AD), one of the most common cognitive disorders, characterized by progressive neurodegeneration, prevails in around 35 million people worldwide, of which 4.5 million Americans are affected annually [1]. However, the estimated figure for AD patients in India is less than 3.5 million, which is relatively smaller as compared to United States of America [2]. Oxidative stress is a major implication to these disorders as it plays a vital role in various pathological events such as mutagenesis, aging and neurodegenerative disorders [3]. Moreover, neuromodulators, diverse neurotransmitters and receptor systems are included in the cognitive viz., acetylcholine, nor-epinephrine, dopamine, serotonin, GABA and histamine [4, 5].

Piracetam is the chiefly used nootropic agent [6], along with aniracetam, pramiracetam [7] and choline esterase inhibitors like donepezil which are primarily being used for enhancing mood, gastro protective memory and behavior. However, due to side effects their use has been limited [8, 9]. According to World Health Organization (WHO), more than 3.3 billion people are resident of developing countries and rely on traditional herbal medicines for their primary healthcare needs [10]. Ayurveda, the oldest Indian medical system in the world, reports a group of plants called ‘medhyas’ which possess neuromodulatory activity, of which, Shankhapushpi (leaf), Jataamansi and Ashwagandha, are the most extensively used plants [11].

Elettaria cardamomum Maton (Zingiberaceae), commonly referred to as Cardamom in English and Choti ilaichi in Hindi is a widely accepted condiment which is commonly used for culinary purposes throughout India [12, 13]. It contains cineole (present in volatile oil) and borneol compounds [14] but apart from its aromatic character it also possesses anti-inflammatory, anti-cancer [15], anti-oxidant, analgesic, antispasmodic [16], antibacterial [17], gastro protective and anti-ulcerogenic activities [18, 19].

The present work was designed to justify the traditional use of E. cardamomum as neuropharmacological agent since no such reports had been reported in the literature. The study was attempted to corroborate the effectiveness of Indian traditional herbal plant E. cardamomum for the treatment of memory enhancement. Additionally, the study may be extended to delineate the possible mechanistic pathway responsible for memory enhancement so that an effective drug molecule can be evaluated.

Materials and methods

Plant material

Selection and identification of plant material

The plant Elettaria cardamomum, used in the present study has been selected by meticulous literature analysis of classical text books, peer reviewed papers and scientific databases. The fresh fruits of cardamom were procured from Kurukshetra, Haryana, India. The authentication of collected sample was done by Dr. H.B. Singh, Chief Scientist & Head, Raw Materials Herbarium and Museum (RHMD), National Institute of Science Communication and Information Resources (NISCAIR), New Delhi (Ref. NISCAIR/RHMD/Consult/2011-12/1939/239). Collected fruits were cleaned thoroughly in order to prevent any contamination.

Preparation of the extract

Seeds of cardamom were separated from undesirable materials using oscillating shakers. The dried plant material was ground to powder of 60 mesh size by using hand mill. The coarse powder (1200 gm) thus obtained was placed in soxhlet’s extractor and exhaustedly extracted using ethanol (60–80˚C). The crude ethanol extract of Elettaria cardamomum (EEC) was concentrated at 40˚C using a Rota evaporator. The crude extract (135 gm) thus obtained was labeled and preserved in a freezer at -20˚C until further use. The extractive value (11.25 % w/w) was found by using the formula= (Crude extract obtained /Total powder taken)x100.

Animals

Swiss albino mice of either sex weighing 18–22 gm (aged 10–12 weeks) were used, which were kept in Animal House, Institute of Pharmaceutical sciences, Kurukshetra University, Kurukshetra. They had free access to water and food and were subjected to the natural dark-light cycle at the interval of 12 h. They were acquainted to the laboratory environment for a minimum period of one week before carrying out the cognitive studies. All experiments were performed from 09 a.m. to 04 p.m. during the day. Institutional Animal Ethics Committee (IAEC) (Reg. No 562/02/a/CPCSEA) approved the experimental protocol (No. 340 A/18) of the present study and animals were treated according to the guidelines of CPSCEA, Ministry of Forest and Environment, Government of India.

Drugs, chemicals and instruments

Piracetam (UCB India Ltd., India), diazepam (Calmpose, Ranbaxy, India), ethanol (SD Fine Chemicals Pvt. Ltd.), acetylthiocholine iodide, 5,5’-dithiobis-2-nitrobenzoic acid (DTNB), thiobarbituric acid (TBA) (Himedia Co. Ltd., India), cholesterol diagnostics kit (Erba diagnostics Mannheim GmbH Mallaustr, Germany), glucose diagnostic kit (Bayer diagnostic, Gujarat, India), U.V. Spectrophotometer (Systronics UV-Spectrophotometer 2202, Systronic India Ltd, India), Rota evaporator (Heidolph Labrota 4011 digital, Germany), Centrifuge machine (R-8 C, Mumbai) and auto analyzer (ERBA Chem-7, Raj Biosis Private Limited, India), Soxhlet’s extractor (Laborate Technocracy, Ambala, Haryana, India). All the other chemicals and solvents used in the present study were of analytical grade.

Initial phytochemical tests

Chemical tests were carried out on ethanol extract for the qualitative determination of phytochemical constituents as described by Khandelwal [20].

Acute toxicity studies

Guidelines (No. 423) of Organization for Economic Cooperation and Development (OECD) were followed to detect the possibility of acute toxicity in laboratory animals. The animals were treated with EEC at the following four doses (5, 50, 300 and 2000 mg/kg). The treated animals were kept under continuous supervision for behavioral and autonomic profiles or any signs of toxicity during this period.

Vehicle

Plant extract (EEC) was suspended in 2 % (w/v) gum acacia at the time of administration and was administered per oral to animals. Diazepam and piracetam were dissolved in normal saline and injected by intraperitoneal route.

Drug protocol

100, 300 and 500 mg/kg of EEC was given via oral gavage to different groups of mice for twelve days to perform various memory models and for biochemical estimations. Piracetam (400 mg/kg, i.p.), used as reference standard was given as positive control and was injected for 12 successive days. All control groups received normal saline for 12 days. After 1.5 h of the last dose of EEC, diazepam (1 mg/kg, i.p.) was administered to experimental animals to induce amnesia. 45 min after the diazepam was injected into the animals, they were subjected to exposure of training session. The retention of memory was measured after 24 h (13th day) of extract administration.

Exteroceptive behavioral studies

Elevated plus maze activity [21]

An elevated plus maze stood 25 cm above the ground had two open arms (16 cm × 5 cm) and two covered arms (16 cm × 5 cm × 15 cm). These arms were projected from a platform located in the center (5 cm × 5 cm). The test consisted of placing the mice on the extreme end of the open arm and measuring the time taken by it to move from there into any of the arm which was covered, by making use of its four paws termed as, Transfer Latency (TL). If the mice could reach to one of the covered arm of the platform before 90 s, the time it took to do so was recorded, else it was placed towards the covered arm and time taken to do so was assigned as 90 s. 10 s after the TL was recorded on the first day, each animal was transferred to its case and was again placed on the same platform after 24 h to record the retention of this learned task (memory). TL of the first and second day could become the measurement of parameters for acquisition and retrieval respectively, with a condition that each mouse has to be used once.

Passive avoidance paradigm activity [21]

A passive avoidance apparatus based on the principle of negative reinforcement is designed to measure the long term memory of mice. The apparatus is designed in the form of a rectangular box with its three sides made up of wood and fourth one of Plexiglass. The bottom consisted of a wooden platform in the center (10 cm×7 cm×1.7 cm) surrounded by a steel grid in all the four sides to deliver a current (20 V, AC). The mice were placed in the center of the bottom of the box and box was illuminated with a 15 W electric bulb and the Step Down Latency (SDL) was recorded. SDL is the time that a mouse takes to change its position from the central wooden platform to the grid with all its paws on it. Mice with the SDL of 2–15 s in the first test were chosen for the second trial which was performed 90 min after the first one. Mice with SDL less than 60 s were placed on the second wooden platform for another 15 s. Those mice which did not change their position from the platform to the grid within 60 s were removed from the central wooden platform and were placed into the same box on the central platform after 24 h of the first trial maintaining same environment except for the flow of (20 V, AC) current into the grid in the bottom.

Object recognition task [22]

This test is carried out to determine the object recognition ability of mice after a given period of time. An open circular field of height 400 mm and diameter 480 m was used to determine the ability of mice to recognize the object. Three non-identical objects (sphere, cylinder and cone) made up of aluminum and which were neither could be moved by mice nor could be used by them to hide behind, were implied. The objects did not have any natural significance and were novel for the mice. The mice were put face to face with two objects in the first trial (T1) and the third object in the trial meant for recognition trial (T2). To vanish the familiar odor, the objects were washed with tap water and detergent after each trial was performed. In the first two days the mice were put in the apparatus twice a day, 3 min in the morning and 3 min in the afternoon preceding it so that they become familiar with the environment within. Two objects were placed equidistant from the mice within the apparatus, the mice having its face towards the wall in front of the person performing the trial. Maximum time taken for the experiment was 3 min. Pairs of two trials T1 and T2 were done to train the animals, the second trial being done after the first one after one hour. The first experimental trial was designed in two ways that the two identical objects A1 and A2 were placed at the symmetrical position 120 mm away from the center of the apparatus towards the wall. The second trial T2 consisted of placing two different objects, one novel one and the other identical tool that in T1, at the same position where the identical objects were placed in T1 trial. The time taken by mice to identify the object identical to that placed in trial T1 was noted. If the animals take more time to differentiate between the two objects or to identify the familiar objects, it indicates reduced recognition memory. The mouse is said to explore the objects if it directs its nose to the object at a distance of not more than 2 cm and/or touching the object with muzzle. However, if the mouse sits on the object it is not said to explore it.

Biochemical estimations

Collection of blood and brain samples [21]

On the last day of the study, the animals were anesthetized, following which they were sacrificed, 1.5 h after the last dose of control/standard drugs or extract was given to them. The animals were sacrificed using cervical dislocation under light chloroform anesthesia, their whole brain was removed consciously from skull and the blood of their trunk was collected. Total cholesterol and blood glucose level of mice were determined after centrifugation of blood at 3000 rpm for 15 min, to obtain its plasma followed by its chemical analysis.

Brain homogenate was prepared by homogenizing the weighed fresh whole brain in a glass homogenizer at -20˚C in an ice bath, in 10 times (w/v) of sodium phosphate buffer (0.1 M, pH 7) as a medium. Brain malondialdehyde (MDA) level, acetyl-cholinesterase (AChE) activity and glutathione (GSH) levels were estimated by centrifugation of the homogenate at 3000 rpm at 40˚C for 10 min and analyzing the resultant cloudy supernatant.

Estimation of brain AChE activity

The method demonstrated by Ellman et al., 1961 with slight modification was used for brain AChE activity. DTNB solution was prepared fresh (10 mg DTNB in 100 ml of Sorenson phosphate buffer, pH 8.0) and was added to 0.5 ml of the cloudy supernatant up to 25 ml in a volumetric flask. After pipetting 4 µl twice in two test tubes and adding 1 ml of substrate solution (75 mg of acetylcholine iodide per 50 ml of distilled water) in both of them and two drops of eserine solution into one of them and incubating for 10 min at 30˚C, they were subjected to colorimetric analysis. The DTNB was reduced to thionitobenzoic acid by some chemicals in the brain homogenate and non-enzymatic hydrolysis of substrate due to which yellow color was obtained. The instrument was calibrated and the alteration in absorbance per min was measured at 420 nm [23, 24].

Estimation of total cholesterol levels [25]

Serum total cholesterol was estimated by CHOD-PAP method (Allain et al., 1974). To prepare the standard and test solutions 20 µl of standard cholesterol and serum were mixed with 1000 µl of the working reagent. Blank was prepared by adding 20 µl of distilled water to 1000 µl of working reagent. After incubating both standard and test solutions at 37˚C for 10 min, the auto-analyzer was used to measure the absorbance at 510 nm and 630 nm (Filter 1 and Filter 2) against the blank.

Quantitative estimation of glucose in the blood [26]

Blood glucose level was estimated by GOD-POD method using semi auto-analyzer. The standard and test sample were prepared by respectively mixing 10 µl of standard glucose and serum with 1000 µl of the working reagent. The blank was prepared by mixing together 10 µl of distilled water and 1000 µl of working reagent. After incubating these solutions for 1/4 h at 98.7˚F they were analyzed through the UV-visible Spectrophotometer, the absorbance being measured at 510 nm and 630 nm (Filter 1 and Filter 2).

Estimation of brain MDA level [27]

Lipid peroxidation is measured with the help of MDA, a thiobarbituric acid reactive substance (TBARS) using UV-visible Spectrophotometric method. 500 µl of thiobarbituric acid (TBA) reagent, 1.5 ml of 15 % trichloroacetic acid (TCA) and 500 µl supernatant of tissue homogenate were mixed using 10 ml screw-cap pyrex centrifuge tube and the mixture was heated on water bath for 3/4 h and cooled in an ice bath subsequently and the extraction of chromogen was carried out by adding 3 ml of n-butanol and centrifuging the mixture. The pink colored organic phase thus obtained was analyzed spectrophotometrically taking 512 nm as ƛmax. ε = 1.56 × 105 M− 1 cm− 1 formula was used to calculate the quantity of lipid peroxidation which was expressed as nmol of MDA per g of wet tissue.

Estimation of brain reduced GSH level [28]

20 % TCA was added to the supernatant homogenate and proteins were separated from it by centrifugation. 3 ml of phosphate buffer (pH 8.4), and 2 ml of DTNB was added to 0.25 µl of this supernatant. The yellow colored solution thus obtained was analyzed spectrophotometrically using 412 nm as ƛmax against a blank, within 15 min. ε = 13.6 × 103 M− 1 cm− 1 formula expressed as nmol/g of wet tissue was used to calculate GSH content.

Statistical analysis

The data was analyzed by the One way ANOVA followed by Dennett multiple comparison tests. Mean ± SEM were used to express all the outcomes. The critical range for significant difference between two groups of observations was taken as p < 0.05. All the treated groups were compared with the respective control groups.

Results

Preliminary phytochemical screening

The preliminary phytochemical screening of EEC showed the presence of various phytoconstituents as summarized in the Table 1.

Table 1 Preliminary phytochemical investigation of EEC

Acute toxicity studies

EEC administered at the dose levels (5, 50, 300 and 2000 mg/kg) produced no signs of toxicity when administered orally. Even the highest dose of extract did not show any toxic symptoms. Also, no mortality was seen in any animal at all these doses of EEC.

Elevated plus maze model

On the first day (12th day of treatment) TL reflected learning behavior, whereas on the next day (13th day of the treatment) TL reflected retention of information (Fig. 1). Effective memory retrieval was indicated by a decrease in TL values of retrieval test as compared to the acquisition session and vice-versa. EEC (at all doses) and piracetam treatment exhibited a significant (p < 0.05) decrease in TL indicating improvement in learning and memory as compared to the control animals. The effect was highest with piracetam treatment. EEC showed fall in TL in a dose dependent manner, however the effect was more profound at 500 mg/kg dose. Diazepam treatment showed increase in TL in both the sessions i.e., learning and memory, in comparison to vehicle control.

Fig. 1
figure1

Effect of EEC on transfer latency (TL) using elevated plus maze model. 

All values are mean ± SEM (n = number of animals in each group). Data was analyzed using one-way ANOVA followed by Dunnett test. *** p < 0.001, ** p < 0.01 and * p < 0.05 vs. normal control group

Passive avoidance paradigm activity

Increase in SDL value indicated improvement of memory whereas low SDL value represented memory impairment. EEC increased SDL in animals as compared to vehicle control groups dose dependently however, the effect was more at doses 300 and 500 mg/kg (Fig. 2). Diazepam treated mice showed a decrease in SDL indicating amnesic activity whereas piracetam revealed increase in SDL and exhibited maximum improvement when compared to all other groups.

Fig. 2
figure2

Effect of EEC on step down latency (SDL) using passive avoidance paradigm.

All values are mean ± SEM (n = number of animals in each group). Data was analyzed using one-way ANOVA followed by Dunnett test. *** p < 0.001, ** p < 0.01 and * p < 0.05 vs. normal control group

Object recognition task

Increase in DI indicated enhanced recognition memory. EEC administered orally for 12 days increased the DI indicating improvement in memory of mice at higher doses i.e., 300 and 500 mg/kg (Fig. 3). Diazepam produced impairment in memory as indicated by reduced DI whereas piracetam revealed increase in the DI when compared to the normal control.

Fig. 3
figure3

Effect of EEC on discrimination index (DI) using object recognition task

All values are mean ± SEM (n = number of animals in each group). Data was analyzed using one-way ANOVA followed by Dunnett test. *** p < 0.001, ** p < 0.01 and * p < 0.05 vs. normal control group

Biochemical parameters

Estimation of AChE activity

Acetylcholine pathway is considered as the most important conduit in regulation of memory functions. EEC produced significant reduction in brain AChE activity in dose dependent manner as compared to normal control group, when measured using Ellman’s kinetic colorimetric method. Interestingly, EEC at 100 and 300 mg/kg showed insignificant results whereas at 500 mg/kg, it produced a significant (p < 0.01) fall in brain AChE activity (Table 2). Diazepam treated group increased AChE activity suggesting an impaired cholinergic system.

Table 2 Effect of EEC on biochemical parameters administered orally for 12 consecutive days

Effect on total cholesterol level

Piracetam and EEC (at all doses) showed a significant reduction in serum total cholesterol levels as compared to normal control treated mice when treated for 12 successive days (Table 2). The reduction was more in piracetam treated animals. The effect of EEC at dose 100 mg/kg was found to be less than the higher doses (300 and 500 mg/kg). But, diazepam treated animals exhibited an increase in cholesterol levels.

Effect on blood glucose level

The effects of EEC on serum glucose levels were found to increase but as evident from the Table 2, the effects were insignificant whereas the standard drug treated animals revealed a significant decrease in glucose levels. And similar to the effect on serum cholesterol level, diazepam control groups presented a marked increase in glucose levels.

Effect on brain MDA level

A reduction in brain MDA levels is a marker of enhanced memory protective activity. As evident from Table 2, EEC at highest dose 500 mg/kg showed significant though slight decrease in the MDA levels when compared to normal control group. However, the results were insignificant for EEC at doses 100 and 300 mg/kg. The negative control group (diazepam) showed increase in levels of brain MDA. Piracetam on the other hand, unexpectedly increased brain MDA levels.

Effect on brain reduced GSH level

When the animals were treated with EEC (at all doses), a rise in GSH was observed in a dose dependent manner which infers its ameliorative action on memory and learning. However, in diazepam treated animals GSH level was found to be reduced (Table 2).

Discussions

In India, despite its high population, AD is found to be less prevalent, may be due to regular intake of some nutrients [4, 22]. Epidemiological studies suggested that high peripheral cholesterol pools increases vulnerability to AD [29, 30] and the countries with high calorie diet shows higher propensity to AD [31]. Histologically, extracellular protein deposits (β- amyloid plaques) in blood vessels and intraneuronal neurofibrillary tangles are manifested in AD. Increased Aβ in cellular and animal models of AD was found to be correlated with accumulation of abnormally high cholesterol level [32, 33]. Similarly, some research investigations revealed that hyperglycemia and hypoinsulinaemia could increase the neuronal damage produced by hypoxia, hypoglycemia or β-amyloid depositions [34]. Interestingly, EEC treated animals exhibited significant reduction in both serum cholesterol and glucose levels as compared to control groups. So, E. cardamomum may be regarded as a potential anti-Alzheimer candidate.

Memory impairments are allied to selective and irreversible deficiency in cholinergic transmission in brain. Also, senile dementia of AD is characterized by enhanced cholinergic loss and decreased choline acetyltransferase activity [22, 35]. Therefore, cognitive impairment is associated with disturbed cholinergic function. In our research, EEC decreased the brain AChE level dose dependently which may be the reason for improvement in memory and learning of experimental animals.

Activation of GABA-A and GABA-B receptors are documented to be involved in the processes of learning and memory [36]. BZD receptor agonists like alprazolam and diazepam have been shown to induce anterograde amnesia in rodents [37, 38] and humans [39] which may be responsible for the accessory symptoms of AD whereas GABA-A antagonist, bicuculline when injected prior to training enhanced memory in chicks [40] and rats [41]. Diazepam produced significant and comparable amnesia in mice in the present study.

Reactive oxygen species (ROS) and other oxidative metabolic byproducts have been shown to be neurotoxic [42, 43] and aged rats showed improvement in cerebellar physiology and motor learning when administered anti-oxidant rich diets [44]. MDA is a reactive electrophilic aldehyde which is produced as a result of lipid peroxidation of polyunsaturated lipids by ROS in an organism. It serves as a biological marker of oxidative stress as high levels of MDA are an indication of increased oxidative stress [45, 46]. Similarly, reduced GSH in brain is a marker of augmented oxidation reactions. GSH is a cellular thiol present in mammalian cells in concentrations upto 12 mM. GSH system is an antioxidant cellular defense system against ROS and its hindrance can lead to various deleterious effects including cessation of cell proliferation [47]. Since EEC considerably decreased the MDA and increased GSH levels, it can be inferred that EEC exhibits potent anti-oxidant activity. Also the surplus presence of flavonoids in EEC (as concluded from the preliminary phytochemical studies) further confirms this theory as flavonoids are known to possess potent anti-oxidant activity [48].

Inflammation (a consequence to oxidative stress [49]) may predispose to AD and its progression over age. Indomethacin, a potent non-steroidal anti-inflammatory agent augmented memory protection against electroconvulsive shock induced retrograde amnesia and amyloid deposits in the brain [50, 51]. Therefore, anti-inflammatory action of E. cardamomum, as documented by Majdalawieh and Carr, 2010, may also be attributable to the observed memory enhancing activity [15]. Thus, a combination of anti-oxidant, anti-inflammatory, antistress and neuroprotective task of E. cardamomum could all be leading to the memory enhancing effect.

EEC contains various chemical constituents like flavonoids, glycosides, alkaloids, triterpenoids and steroids. Memory enhancing effect of extract may be due to combined effect of various constituents present in the plant. Flavonoids have been reported to give protection against the memory impairment related to aging as well as associated with AD induced dementia [52]. Alkaloids act as nootropics either through inhibition of AChE [53] or by potentiating the GABA level [54]. The memory improving effect of E. cardamomum may be due to presence of alkaloids, flavonoids and other anti-oxidants.

Conclusions

In conclusion, the present work gives preliminary data that the EEC possess potent nootropic principles, which enhances memory that may be attributable to its anti-inflammatory, anti-oxidant and neuroprotective activities. Also, its peripheral cholesterol and glucose lowering tendency suggests its potential to decrease progression of cognitive impairment. The findings of this study suggests that E. cardamomum may be used for the development of a new herbal derived medicament in the treatment of diverse cognitive disorders. However, further insight into the molecular details could explain the possible mechanism of action and the active principle responsible for the exhibited activity.

Availability of data and materials

Data and materials will be provided on request.

Abbreviations

EEC:

Ethanol extract Elettaria cardamomum

AD:

Alzheimer’s disease

AChE:

Brain Acetylcholinesterase

MDA:

Malondialdehyde

GSH:

Glutathione

TL:

Transfer Latency

SDL:

Step Down Latency

DI:

Discrimination Index

IAEC:

Institutional Animal Ethics Committee

CPCSEA:

Committee for the Purpose of Control and Supervision on Experiments on Animals

SEM:

Standard error of Mean

ANOVA:

Analysis of Variance

References

  1. 1.

    Hebert LE, Scherr PA, Bienias JL, Bennett DA, Evans DA. Alzheimer disease in the U.S. population: prevalence estimates using the 2000 census. Arch Neurol. 2003;60(8):1119–22.

    PubMed  Article  PubMed Central  Google Scholar 

  2. 2.

    Vas CJ, Pinto C, Panikker D, Noronha S, Deshpande N, Kulkarni L, Sachdeva S. Prevalence of dementia in urban population. Int Psychogeriatr. 2001;13(4):439–50.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  3. 3.

    Federico A, Cardaioli E, Pozzo P Da, Formichi P, Gallus GN, Radi E. Mitochindria, oxidative stress and neurodegeneration. J Neurol Sci. 2012;322(1-2):254-62.

  4. 4.

    Natalie CT, Taylor JR. Molecular mechanisms of memory reconsolidation. Nat Rev Neurosci. 2007;8:262–75.

    Article  CAS  Google Scholar 

  5. 5.

    Palmer MA, Stratmann GC, Procter AW, Bowen DM. Possible neurotransmitter basis of behavioral changes in Alzheimer’s disease. Ann Neurol. 1988;23(6):616–20.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  6. 6.

    Cumin R, Bandle EF, Gamzu E, Haefely EW. Effects of the novel compound aniracetam (Ro-13-5057) upon impaired learning and memory in rodents. Psychopharmacology. 1982;78(2):104–11.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  7. 7.

    Blazer DG, Federspiel CF, Ray WA, Schaffner W. The risk of anticholinergic toxicity in the elderly: a study of prescribing practices in two populations. J Gerontol. 1983;38(1):31–5.

    PubMed  Article  PubMed Central  Google Scholar 

  8. 8.

    Rogers SL, Farlow MR, Doody RS, Mohs R, Friedhoff LT. A 24 week, double blind, placebo-controlled trial of donepezil in patients with Alzheimer’s disease. Donepezil Study Group Neurology. 1998;50(1):136–45.

    CAS  Google Scholar 

  9. 9.

    Nabeshima T. Behavioral aspects of cholinergic transmission: Role of basal forebrain cholinergic system in learning and memory. Prog Brain Res. 1993;98:405–11.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  10. 10.

    Davidson HI. Ecological ethnobotany: stumbling towards new practices and paradigms. MASA J. 2000;16(1):1–13.

    Google Scholar 

  11. 11.

    Kulkarni R, Girish KJ, Kumar A. Nootropic herbs (Medhya Rasayana) in Ayurveda: An update. Pharmacogn Rev. 2012;6(12):147–53.

    PubMed  PubMed Central  Article  Google Scholar 

  12. 12.

    Kaushik P, Goyal P, Chauhan G. In vitro evaluation of antibacterial potential of dry fruit extract of Elettaria cardamomum Maton (Choti Elaichi). Iran J Pharm Res. 2010;9(3):287–92.

    PubMed  PubMed Central  Google Scholar 

  13. 13.

    Kokate CK, Purohit AP, Gokhale GB. A Textbook of Pharmacognosy. 45th ed. Pune: Nirali Prakashan. 2010;1.31–1.32.

  14. 14.

    Dhulap S, Anita M, Hirwani RR. Phyto-pharmacology of Elettaria cardamomum. Phcog Rev. 2008;2(4):27–35.

    CAS  Google Scholar 

  15. 15.

    Majdalawieh AF, Carr RI. In vitro investigation of the potential immunomodulatory and anticancer activities of Black Pepper (Piper nigrum) and cardamom (Elettaria cardamomum). J Med Food. 2010;13(2):371–81.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  16. 16.

    al-Zuhair H, elSayeh B, Ameen HA, et al. Pharmacological studies of cardamom oil in animals. Pharmacol Res. 1996;34(1–2):79–82.

    CAS  PubMed  Article  Google Scholar 

  17. 17.

    Islam MS, Rahman MA, Sheikh MI, Mostafizur R, Jamal MAHM, Firoz A. In vitro antibacterial activity of methanol seed extract of Elettaria cardamomum (L.) Maton. Agric Conspec Sci. 2010;75:113–7.

    Google Scholar 

  18. 18.

    Jamal A, Javed K, Aslam M, Jafri MA, et al. Gastroprotective effect of cardamom Elettaria cardamomum Maton fruit in rats. J Ethnopharmacol. 2006;103:149–53.

    CAS  PubMed  Article  Google Scholar 

  19. 19.

    Khan MB, Hoda MN, Yousuf S, Ishrat T, Ahmad M, Ahmad AS, Alavi SH, Haque N, Islam F. Prevention of cognitive impairments and neurodegeneration by Khamira Abresham Hakim Arshad Wala. J Ethnopharmacol. 2006;108:68-73. https://doi.org/10.1016/j.jep.2006.04.012.

  20. 20.

    Khandelwal KR. Practical Pharmacognosy, Techniques and Experiments. 8th ed. India: Nirali Prakashan; 2007. pp. 149–53.

    Google Scholar 

  21. 21.

    Vasudevan M, Parle M. Antiamnesic potential of Murraya koenigii leaves. Phytother Res. 2008;23:308–16.

    Article  CAS  Google Scholar 

  22. 22.

    Jessberger S, Clark RC, Broadbent NJ, Clemenson GD, Consiglio A, Lie DC, Squire LR, Gage FH. Dentate gyrus-specific knockdown of adult neurogenesis impairs spatial and object recognition memory in adult rats. Learn Mem. 2009;16:147–54.

    PubMed  PubMed Central  Article  Google Scholar 

  23. 23.

    Ellman GL, Courtney DK, Andres V, Featherstone RM. A new and rapid colorimetric determination of acetylcholinesterase activity. Biochem Pharmacol. 1961;7:88–95.

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  24. 24.

    Voss G, Sachsse K. Red cell and plasma cholinesterase activities in microsamples of human and animal blood determined simultaneously by a modified acetylthiocholine/DTNB procedure. Toxicol Appl Pharmacol. 1970;16:764–72.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  25. 25.

    Allain CC, Poon LS, Chan CSG, Richmond W, Paul CF. Enzymatic determination of total serum cholesterol. Clin Chem. 1974;20(4):470–5.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  26. 26.

    Miksch R, Wiedemann G. Blood sugar determination with the GOD- POD-ABTS method using uranylactate for deproteinization. Z Med Labortech. 1973;14(1):27–33.

    CAS  PubMed  PubMed Central  Google Scholar 

  27. 27.

    Ohkawa H, Ohishi N, Yagi K. Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction. Anal Biochem. 1979;95(2):351–8.

    CAS  Article  Google Scholar 

  28. 28.

    Ellman GL. Tissue sulfhydryl groups. Arch Biochem Biophys. 1959;82(1):70–7.

    CAS  Article  Google Scholar 

  29. 29.

    Solomon A, Kivipelto M, Wolozin B, Zhou J, Whitmer RA. Mildlife serum cholesterol and increased risk of Alzheimer’s and vascular dementia three decades later. Dement Geriatr Cogn Disord. 2009;28:75–80.

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  30. 30.

    Roher AE, Kuo YM, kokjohn KM, Emmerling MR, Gracon S. amyloid and lipids in the pathology of Alzheimer’s disease. Amyloid Int exp Clin Invest. 1999;6:136–45.

    CAS  Google Scholar 

  31. 31.

    Kalmijn S, Launer LJ, Ott A, Witteman JC, Hofman A, Breteler MMB. Dietary fat intake and the risk of incident dementia in Rotterdam study. Ann Neurol. 1997;42(5):776–82.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  32. 32.

    Puglielli L, Tanzi RE, Kovacs DM. Alzheimer’s disease: the cholesterol connection. Nature Neurosci. 2003;6:345–51.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  33. 33.

    Mori T, Paris D, Town T, Rojiani A, Sparks D, Delledonne A, Crawford F, Abdullah LI, Humphrey JA, Dickson DW, et al. Cholesterol accumulation in senile plaques of Alzheimer’s disease patient and in transgenic APP(SW) mice. J Neuropathol Exp Neurol. 2001;60:778–85.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  34. 34.

    Messier C, Gagnon M. Glucose regulation and cognitive functions: relation to Alzheimer’s disease and diabetes. Behav Brain Res. 1996;75(1–2):1–11.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  35. 35.

    Parle M, Dhingra D, Kulkarni SK. Neuromodulators of learning and memory. Asia Pac J Pharm. 2004;16:89–99.

    CAS  Google Scholar 

  36. 36.

    Zarrindast MR, Bakhsha A, Rostami P, Shafaghi B. Effects of intrahippocampal injection of GABAergic drugs on memory retention of passive avoidance learning in rats. J Psychopharmacol. 2002;16(4):313–19.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  37. 37.

    Preston C, Ward C, Lines CR, Poppleton P, Haigh JRM, Traub M. Scopolamine and benzodiazepine models of dementia: cross-reversals by RO 15-1788 and physostigmine. Psychopharmacology (Berl). 1989;98:487-94. https://doi.org/10.1007/bf00441947.

  38. 38.

    Singh N, Sharma A, Singh M. Possible mechanism of alprazolam-induced amnesia in mice. Pharmacology. 1998;56(1):46–50.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  39. 39.

    Lister RG. The amnesic action of benzodiazepines in man. Neurosci Biobehav Rev. 1985;9:87–94.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  40. 40.

    Clements MP, Bourne RC. Passive avoidance learning in the day-old chick is modulated by GABAergic agents. Pharmacol Biochem Behav. 1996;53(3):629–34.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  41. 41.

    Luft T, Pereira GS, Cammarota M, et al. Different time course for the memory facilitating effect of bicuculline in hippocampus, entorhinal cortex, and posterior parietal cortex of rats. Neurobiol Learn Mem. 2004;82(1):52–6.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  42. 42.

    Sayre LM, Zagorski MG, Surewicz WK, Krafft GA, Perry G. Mechanisms of neurotoxicity associated with amyloid beta deposition and the role of free radicals in the pathogenesis of Alzheimer’s disease: a critical appraisal. Chem Res Toxicol. 1997;336:1216–22.

    Google Scholar 

  43. 43.

    Rogers EJ, Milhalik S, Ortiz, Shea TB. Apple juice prevents oxidative stress and impaired cognitive performance caused by genetic and dietary deficiencies in mice. J Nutr Health Aging. 2003;7:1–6.

    Google Scholar 

  44. 44.

    Bickford PC, Gould T, Briederick L, Chadman K, Polloch A, Young D, et al. Antioxidants-rich diets improve cerebellar physiology and motor learning in aged rats. Brain Res. 2000;886:211–7.

    Article  Google Scholar 

  45. 45.

    Pryor WA, Stanley JP. Letter: A suggested mechanism for the production of malondialdehyde during the autoxidation of polyunsaturated fatty acids. Nonenzymatic production of prostaglandin endoperoxides during autoxidation. J Org Chem. 1975;40:3615-7.

  46. 46.

    Farmer EE, Davoine C. Reactive electrophile species. Curr Opin Plant Biol. 2007;10:380-6.

  47. 47.

    Dringen R. Metabolism and functions of glutathione in brain. Prog Neurobiol. 2000;62(6):649–71.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  48. 48.

    Joharapurkar AA, Jambad SP, Wanjari MM, Umathe SN. In-vivo evaluation of antioxidant activity of alcoholic extract of Rubia cordifolia Linn and its influence on ethanol induced immunosupression. Indian J Pharmacol. 2003;35:232–6.

    Google Scholar 

  49. 49.

    Reuter S, Gupta SC, Chaturvedi MM, Aggarwal BB. Oxidative stress, inflammation, and cancer: How are they linked? Free Radic Biol Med. 2010;49:1603–16.

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  50. 50.

    Rao SK, Andrade C, reddy K, Madappa KN, Thyagarajan S, Chandra S. Memory protective effect of indomethacin against electroconvulsive shock induced retrograde amnesia in rats. Biol Psychia. 2002;51(9):770.

    CAS  Article  Google Scholar 

  51. 51.

    Stephan A, Laroche S, Davis S. Learning deficits and dysfunctional synaptic plasticity induced by aggregated amyloid deposits in the dentate gyrus are rescued by chronic treatment with indomethacin. Eur J Neurosci. 2003;17:1921-7.

  52. 52.

    Joseph JA, Shukitt-Hale B, Lau FC. Fruit polyphenols and their effects on neuronal signaling and behavior in senescence. Ann N Y Acad Sci. 2007;1100:470–85.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  53. 53.

    Abhijit D, Anuradha M. Plant-Derived Alkaloids: A Promising Window for Neuroprotective Drug Discovery. In: Discovery and Development of Neuroprotective Agents from Natural Products. 2018;237-320.

  54. 54.

    Cushnie TP, Cushnie B, Lamb AJ. Alkaloids: an overview of their antibacterial, antibiotic-enhancing and antivirulence activities. Int J Antimicrob Agents. 2014;44(5):377–86.

    CAS  PubMed  Article  PubMed Central  Google Scholar 

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Acknowledgements

The authors are thankful to Institute of Pharmaceutical Sciences, Kurukshetra University for providing the facilities to conduct this research work.

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Sapna Saini conducted all the experiments. Manjusha Choudhary supervised the experimental-work including selection of study, finalizing plan of work, in-vivo studies and interpretation of data. Ankur Garg did the writing and editing work. All the authors read and approved the final manuscript.

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Correspondence to Manjusha Choudhary.

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The experiments conducted on animals complied with ARRIVE guidelines and carried out in accordance with the committee formulated for the Breeding of the Experiments on Animals (Control and Supervision) Rules, 1998, which was amended in 2001 and then in 2006 and associated guidelines. Laboratory animals were duly approved from IAEC (Institutional Animal Ethical Committee) and obtained from Institutional central animal facility (Approval Letter no. 340 A/18) as per the guidelines of CPCSEA (Committee for the Purpose of Control and Supervision on Experiments on Animals) Govt. of India. The authors have obtained written informed consent to use the animals in the study from the owner of the animals. An ARRIVE checklist has been attached as a separate file regarding the ethics approval and consent to participate.

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Saini, S., Choudhary, M. & Garg, A. Investigation of nootropic potential of ethanol extract of Elettaria cardamomum Maton fruit (Cardamom): a spice of India. Clin Phytosci 7, 68 (2021). https://doi.org/10.1186/s40816-021-00300-5

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Keywords

  • Elettaria cardamomum
  • Memory
  • Cognitive impairment
  • Amnesia: Nootropics