Skip to main content
Clinical Phytoscience

International Journal of Phytomedicine and Phytotherapy

Download PDF
  • Original contribution
  • Open access
  • Published:

Comparative studies on the hypoglycemic and antioxidant activities of Vernonia amygdalina delile and Baccharoides tenoreana olive in alloxan-induced hyperglycemic rats

Clinical Phytoscience volume 7, Article number: 91 (2021) Cite this article

Abstract

Background

Vernonia amygdalina is a bitter culinary vegetable known to possess anti-diabetic principle. Baccharoides tenoreana belonging to the same species as V. amygdalina, is also used in cooking soup and it is comparatively non-bitter. However, its glycemic properties have not been studied. This study becomes imperative to find out if B. tenoreana possesses hypoglycemic and antioxidant properties and how it compares with V. amygdalina. Should B. tenoreana be better than V. amygdalina, it should be preferable since it is non-bitter and can comfortably be taken compared to V. amygdalina. This study investigated the comparative hypoglycemic and antioxidant potentials of V. amygdalina (VA) and B. tenoreana (BT).

Methods

Thirty male Albino wistar rats assigned into six groups of five rats per group were used for the study. Diabetes was induced in groups B-F rats by a single intraperitoneal injection of alloxan monohydrate at 160 mg/kg. Groups C-E rats were treated with VA (200 mg/kg), BT (200 mg/kg) and combination of VA & BT (100 mg/kg each) respectively. Group F rats were administered glibenclamide (2 mg/kg) whereas groups A and B rats were given distilled water. All treatments were through the oral administration, once daily for 21 consecutive days. Fasting blood glucose (FBG) levels were determined after 1 h, 3 h, 6 h, 24 h, 7 days, 14 days and 21 days while lipid profile, in vivo antioxidant and pancreatic histomorphology were assessed on day 21 post-treatment.

Results

The VA-treated rats recorded marginally reduced FBG, malondialdehyde and low-density lipoprotein levels when compared to the counterpart treated with BT. The high-density lipoprotein values were significantly higher in VA-treated rats than in BT-treated rats. The histomorphology of the pancreas of VA-treated rats expressed more islet cells compared to the counterpart treated with VT.

Conclusion

Both VA and BT exhibited hypoglycemic and antioxidant activities with varying potencies.

Introduction

V. amygdalina Del is popularly called bitter leaf in English language due to its bitter nature. The “sweet” variant of bitter leaf is called B. tenoreana Oliv and it is a native of Africa [1]. It is less bitter in taste when compared to V. amygdalina and can be chewed raw as vegetable or sliced for direct use in soup without prior squeeze washing. These culinary shrubs share a lot of botanical, nutritional and medicinal features in common and are distributed across tropical African countries where they are used in preparing delicious bitter leaf soup. They belong to the family Asteraceae or Compositae [2]. In Igbo, southeastern Nigeria, they are known as “onugbu” while Hausas, northern Nigerians call it “shuwakaa”. In Yoruba, western part of Nigeria, it is referred to as “Ewuro” [3].

Researchers have reported on various medicinal properties of V. amygdalina. It is used for treating gastrointestinal disorders, malaria and diabetes in folkloric medicine [4]. The hypolipidemic, hepatoprotective, hypoglycemic, and antioxidant activities of V. amygdalina have earlier been reported [5,6,7]. The antimicrobial activities of B. tenoreana, have been extensively studied [8]. However, the glycemic effect of B. tenoreana has not been fully investigated [9].

Diabetes mellitus is a metabolic and a debilitating endocrine disorder occasioned by hormonal dysregulation. Features of diabetes mellitus include hyperglycemia, dyslipidemia, polyuria and polydipsia consequent upon lack of insulin or non-sensitivity of cells to available insulin [10]. Based on aetiology, diabetes mellitus is traditionally classified as insulin-dependent diabetes mellitus (IDDM) or type 1 and Non-insulin dependent diabetes mellitus (NIDDM) or type 2 [11, 12]. Experimentally, diabetes is induced by the use of alloxan monohydrate or streptozotocin. These compounds generate free radicals which are known to destroy the beta cells of the islet of Langerhans that are responsible for insulin production. Lack of insulin production therefore occasions hyperglycemia [13]. Oxidative stress occurs when there is imbalance between the productions of free radicals and the body’s ability to fight them off [14]. Too high levels of oxidative stress maybe a precursor to multiple diseases in which diabetes is one of them [15].

Conventionally, management of diabetes mellitus involves modifications of life style such as avoiding smoking, engaging in exercise and regulation of diet [16]. The uses of orthodox anti-diabetic drugs and medicinal hypoglycemic herbs have also been advocated as potent means of managing diabetes mellitus [17]. However, the complicated mode of intake and deleterious side effects associated with orthodox anti-diabetic drugs have discredited and discouraged their use [18]. The use of medicinal herbs or plants has been advocated due to their wide safety margin [19]. Vegetables with hypoglycemic potentials are gaining attention by the day.

There is dearth of researched information on the comparative strengths of hypoglycemic and antioxidant activities of the two variants- V. amygdalina and B. tenoreana. This study, therefore aims to investigate and compare the hypoglycemic and antioxidant potentials of these two culinary vegetables and any beneficial therapeutic effect of combining both of them.

Materials and methods

Chemicals and reagents

Chemicals and reagents used in this study includes: Alloxan monohydrate (Sigma Aldrich, UK); Superoxide dismutase (SOD) kit (Merk KGaA Darmstadt, Germany); Catalase kit (Hardy diagnostics, Santa Maria, California); Malondialdehyde kit (Eagle Biosciences, Armherst, New Harmshire, Germany); Gluthathione kit (Randox Laboratories, Crumlin, County Austrim, UK) and Glibenclamide (Hovid Hong Kong). All chemicals are of analytical grades.

Plant collection and extraction

V. amygdalina and B. tenoreana leaves were purchased during rainy season (July, 2020) from Ogige market, Nsukka and identified at Bioresources Development and Conservation Programme (BDCP), Aku road, Nsukka, Enugu state, Nigeria. The Voucher Specimens (V. amygdalina: INTERCEDD/041 B. tenoreana: INTERCEDD/2619) were kept at the herbarium. Nsukka is located between latitude 6o 5′ and 6o 24′ north and longitude 7o 23′ and 7o 45′ east in the south-east geopolitical zone [20]. The leaves were air-dried and pulverized into powder after removal of any foreign matter. Cold maceration method of extraction using distilled water was used. The pulverized materials were soaked in a distilled water for 48 h with intermittent shaking after every 2 h. Thereafter, they were filtered using NO1 Whiteman filter paper to obtain the filtrate (aqueous extract). The aqueous extracts were lyophilized and placed in airtight amber colored sample bottles and stored in refrigerator at 4 °C pending use.

The aqueous leave extracts of VA and BT gave a yield of 12.4 g (6.20% w/w) and 12.7 g (6.35% w/w) respectively.

Animals

Thirty (30) male Albino wistar rats aged between 7 and 9 weeks (160–190 g) were used for the study according to Aba and Edeh [15]. They were obtained from the animal house of the Department of Veterinary Physiology and Pharmacology, University of Nigeria Nsukka. The animals were acclimatized for two weeks during which they were kept in a stainless wire mesh cage and fed with Vital® feed grower and clean water ad libitum. The experimental design used in this study was approved by the Faculty of Veterinary Medicine Institutional Animal Care and Use Committee with the approval number: FVM-UNN-IACUC-2020-0266.

Experimental design

The thirty (30) male Albino wistar rats were assigned into six (6) groups of five (5) rats per group. Diabetes was induced in rats assigned to groups B-F by intraperitoneal injection of 160 mg/kg of alloxan monohydrate following 16 h fasting while rats in group A served as normal control. Upon establishment of diabetes (FBG > 126 mg/dl), the rats were treated as follows (Table 1):

Table 1 Showing the treatment regimen for various groups
Full size table

All treatments were made daily for 21 days through the oral route. The fasting blood glucose (FBG) levels were assessed every 1 h, 3 h, 6 h, 24 h, 7 days, 14 days and 21 days using Accu-Chek glucometer. At the end of 21 days duration of the study, samples were collected for analyses.

Sample collections

The whole blood sample for assessment of FBG was collected by tail snip while blood samples for serum biochemical (Total cholesterol, triacylglycerol, high density lipoprotein, superoxide dismutase, reduced glutathione, catalase and malondialdehyde) determinations were via the retrobulbar plexus of the medial canthus of the eye. The blood samples were centrifuged at 10, 000 g for 10 min. Thereafter, the sera for determination of serum biochemical parameters were decanted. The rats were humanely euthanized using chloroform and the pancreas harvested for histopathology studies.

Determination of serum biochemical parameters

The serum cholesterol was determined by cholesterol oxidase-peroxidase method [16]. The serum high density lipoprotein (HDL) was determined by the dextran sulphate-magnesium (II) precipitation method [21]. The triacylglycerol (TAG) values were determined by phosphate oxidase enzymatic method [22]. The very low-density lipoprotein (VLDL) was calculated by dividing the triacylglycerol by 5 while Friedwald formula was used to calculate the value of low-density lipoprotein (LDL) [23].

Superoxide dismutase activity was assayed by the method of Kakkar et al [24]. The activity of catalase was assayed by the method of Sinha [25]. The reduced glutathione level was determined by the method of Beutler and Kelley [26]. Lipid peroxidation was estimated by measuring spectrophotometrically, the level of the lipid peroxidation product, malondialdehyde (MDA) as described by Wallin et al [27].

The histopathology of the pancreas was processed according to Drury et al [28].

Data analysis

The data generated were analyzed with One-way Analysis of Variance (ANOVA) using SPSS version 20. The variant means were separated using Duncan’s Multiple Range test. P < 0.05 was accepted as being significant. Results were expressed as Mean ± Standard Error of the Mean (SEM) and presented in tables.

Results

Effect of aqueous leaf extract of V. amygdalina and B. tenoreana on the fasting blood glucose (FBG) levels of alloxan-induced diabetic rats

The fasting blood glucose (FBG) of rats treated with the aqueous extract of V. amygdalina (VA) was significantly (p < 0.05) lower than the diabetic untreated rats and compared very well with that of the normal control and those treated with glibenclamide, a known anti-diabetic drug on day 21 post treatment. The hypoglycemic activities of VA and B. tenoreana (BT) were comparable from 3 h post treatment (PT) up to 14 days PT but the FBG of the VA-treated rats were significantly (p < 0.05) lower than that of the VA & BT-treated rats (group E) on day 21 PT (Table 2).

Table 2 Effect of aqueous leaf extract of V. amygdalina and B. tenoreana on the fasting blood glucose (FBG) levels of alloxan-induced diabetic rats
Full size table

Percentage reduction in FBG levels of alloxan-induced diabetic rats treated with aqueous leaf extract of V. amygdalina and B. tenoreana

Results also indicated consistent reductions in FBG levels of VA and BT-treated rats from 1 h to 21 days PT with VA, BT and glibenclamide-treated rats recording 65.80%, 65.10% and 66.54% respectively (Fig. 1).

Fig. 1
figure 1

Percentage reduction in FBG levels of alloxan-induced diabetic rats treated with aqueous leaf extract of V. amygdalina and B. tenoreana. PT Post-treatment, h hour (s), D Day

Full size image

Effect of the aqueous leaf extract of V. amygdalina and B. tenoreana on the lipid panel of alloxan-induced rats

The lipid panel results showed that the high-density lipoprotein (HDL) values of the VA and glibenclamide-treated rats were comparable and significantly (p < 0.05) higher than that of the diabetic untreated group. Significant (p < 0.05) decreases in low density lipoprotein (LDL) values of all the extract-treated groups when compared to the diabetic untreated group were recorded. Triacylglycerol and total cholesterol levels for the extract-treated rats varied marginally (p > 0.05) when compared to that of the diabetic untreated group (Table 3).

Table 3 Effect of the aqueous leaf extract of V. amygdalina and B. tenoreana on the lipid panel of alloxan-induced rats
Full size table

Effect of the aqueous leaf extract of V. amygdalina and B. tenoreana on oxidative stress markers of alloxan-induced diabetic rats

The results of the effects of VA and BT aqueous extracts on oxidative stress markers indicated significant (p < 0.05) reductions in the malondialdehyde values of the rats treated with VA and glibenclamide compared to the diabetic untreated group. The catalase activities and the reduced glutathione values of all the extract and glibenclamide-treated groups were significantly (p < 0.05) higher than those of the diabetic untreated group (Table 4).

Table 4 Effect of the aqueous leaf extract of V. amygdalina and B. tenoreana on oxidative stress markers of alloxan-induced diabetic rats
Full size table

Photomicrograph of the pancreas of diabetic rats treated with aqueous leaf extracts of V. amygdalina and B. tenoreana

The pancreas photomicrograph showed that all the treated groups demonstrated more islet cells compared to the diabetic untreated group which expressed scanty islet cells. However, islet cells were more preponderant in the groups treated with VA and glibenclamide when compared to BT-treated rats. The islet cells in the glibenclamide-treated rats compared very well with those of the normal control group (Fig. 2).

Fig. 2
figure 2

Photomicrograph of pancreas of: A = Group A rats (Normal control) showing well populated islet cells (arrows); B = Group B rats (Diabetic untreated) showing severely depleted islet cells. Arrows show areas devoid of cells. C = Group C rats (Diabetic + 200 mg/kg of Vermonia amygdalina) showing evidence of adequately populated islet cells (arrows). D = Group D rats (Diabetic + 200 mg/kg of Vermonia amygdalina) showing relatively moderate population of islet (arrows). F = Group F rats (Diabetic + 2 mg/kg glibenclamide) showing well populated islet cells (arrows). H&Ex 400

Full size image

Discussion

This study investigated the comparative strengths of the aqueous extracts of V. amygdalina (VA) Del and B. tenoreana (BT) Olive on their hypoglycemic and antioxidant potentials in alloxan-induced diabetic rats.

The fasting blood glucose (FBG) levels of the rats administered alloxan monohydrate increased significantly compared to the normal control rats. Hyperglycemia is usually seen following administration of diabetogenic compounds such as alloxan monohydrate. Alloxan monohydrate is capable of generating free radicals which destroy beta cells of the islets of Langerhans with attendant reduction in insulin production; consequently, leading to a spike in blood glucose levels [29]. Rats treated with the extracts (VA and BT) showed significant reductions in their FBG values compared to the diabetic untreated counterpart from 1 h to 21 days post treatment. Previous studies had also demonstrated hypoglycemic potentials of VA [30]. However, the VA-treated rats showed a better hypoglycemic potential compared to VA & BT-treated rats on day 21 post treatment. This observation could be attributed to probably an anti-nutritive factor which has been reported in VA [31]. VA contains antinutritional factor such as alkaloids, saponins, tannins, steroids, glucosides (Vernoniosides), flavonoids, glycosides (Vernomin) and sterols which cause its bitterness [32, 33]. This anti-nutritive principle is capable of reducing the potency when both extracts are combined as seen in group E rats.

The results of the lipid panel indicate significant changes in the high-density lipoprotein (HDL) and low-density lipoprotein (LDL) only. Rats treated with VA demonstrated significantly higher HDL values and lower LDL values compared to the negative control group and the BT-treated rats. This again, demonstrates an advantageous activity of VA over BT in the management of diabetes. The HDL cholesterol is usually referred to as “good cholesterol” because of its anti-atherogenic potentials. It is also involved in the reverse transport of cholesterol where it carries cholesterol from the peripheral tissues to the liver for excretion into the bile [34]. Conversely, LDL cholesterol transport cholesterol from the liver to the peripheral tissues thereby predisposing to atherosclerosis. Increased LDL and decreased HDL are common features of diabetes mellitus [35]. The results of this study on amelioration of dyslipidemia by the extract of VA are in agreement with the earlier submissions of Adaramoye et al [5].

Significant increases in the catalase activities and glutathione levels of the extract-treated group compared to those of the diabetic untreated group bear eloquent testimony to the in vivo antioxidant potentials of both VA and BT aqueous extracts. Catalase is an in vivo antioxidant saddled with the responsibility of decomposing hydrogen peroxide into water and molecular oxygen [7]. Deficiency of catalase has been reported in diabetic conditions [36]. Glutathione, on the other hand is a master antioxidant that takes part in so many cellular reactions such as drug detoxification, antioxidant defense of cells and even in cellular signaling [37]. Diabetes is one of the pathological conditions in which reduced glutathione deficiency is a feature [37]. This observation of VA improving in vivo antioxidant activities in diabetics had earlier been reported [7]. From these results, VA-treated rats appeared to be marginally better than those of the BT-treated group.

The pancreatic islet cells of the diabetic untreated group appeared scanty indicating depletion of the cells. This, most probably is as a result of the effects of alloxan monohydrate on the pancreas. Several studies have reported that alloxan monohydrate generates free radicals that cause degeneration and subsequent necrosis of pancreatic beta cells of the islets of Langerhans [38, 39]. However, both the extract-treated and glibenclamide-treated rats demonstrated relatively more numbers of pancreatic islet cells compared to the diabetic untreated group. This could mean that the extracts and glibenclamide facilitated repopulation of these alloxanized pancreases, following treatment.

Conclusion

In conclusion, aqueous extracts of V. amygdalina and B. tenoreana have demonstrated potent hypoglycemic and antioxidant properties. V. amygdalina however, showed a better hypoglycemic effect when compared with B. tenoreana alone and when combined with B. tenoreana. It is therefore recommended that V. amygdalina or B. tenoreana be used alone but not in combination because combining them has no added advantage.

Mechanisms of action of the extracts as well as the active ingredients present in the extracts that produced hypoglycemic, antioxidant and antilipidemic effects observed in this study were not determined. Therefore, further studies to determine their mechanisms of action and active ingredients that produced these effects are necessary.

Availability of data and materials

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Abbreviations

VA:

Vernonia amygdalina

BT:

Baccharoides tenoreana

FBG:

Fasting blood glucose

NIDDM:

Non-insulin dependent diabetes mellitus

IDDM:

Insulin dependent diabetes mellitus

BDCP:

Bioresources development and conservation programme

HDL:

High density lipoprotein

LDL:

Low density lipoprotein

VLDL:

Very low density lipoprotein

TAG:

triacylglycerol

Chol:

Cholesterol

MDA:

malondialdehyde

SOD:

Superoxide dismutase

GSH:

Reduced glutathione

PI:

Post induction

PT:

Post treatment

H:

Hour

D:

Day

References

  1. Sobrinho CAN, de Souza EB, Fontenelle ROS. A review on antimicrobial potential of species of the genus Vernonia (Asteraceae). J Med Plant Res. 2015;9(31):838–50. https://doi.org/10.5897/JMPR2015.5868.

    Article  CAS  Google Scholar 

  2. Burkill HM. The useful plants of west tropical Africa. 2nd ed. United Kingdom: Royal Botanic Gardens, Kew; 2000.

    Google Scholar 

  3. Kadiri O, Olawoye B. Vernonia amygdalina: an underutilized vegetable with neutraceutical potentials-a review. Turkish J Agric Food Sci Technol. 2016;4(9):763–8. https://doi.org/10.24925/turjaf.v4i9.763-768.570.

    Article  Google Scholar 

  4. Farombi EO, Owoeye O. Antioxidant and chemopreventive properties of Vernonia amygdalina and Garcinia biflavonoid. Int J Environ Res Pub Health. 2011;8(6):2533–55. https://doi.org/10.3390/ijerph8062533.

    Article  Google Scholar 

  5. Adaramoye OA, Akintayo O, Achem J, Fafunso M. Lipid-lowering effects of methanolic extract of Vernonia amygdalina leaves in rats fed on high cholesterol diet. Vas Health & Risk Managt. 2008;4:235–41. https://doi.org/10.2147/VHRM.S2451.

    Article  Google Scholar 

  6. Minari JB. Hepatoprotective effect of methanolic extract of Vernonia amygdalina leaf. J Nat Prod. 2012;5:188–92.

    Google Scholar 

  7. Aba PE, Okenwa-Ani CP. Biochemical effects of methanolic extracts of Vernonia amygdalina and Gongronema latifolia on alloxan-induced diabetic rats. British J Pharmaceut Res. 2015;9:1–10.

    Google Scholar 

  8. Ogundare AV, Adetuyi FC, Akinyosoye FA. Antimicrobial activities of Vernonia tenoreana. Afr J Biotech. 2006;5:1663–8.

    Google Scholar 

  9. Taiwo IA, Odeigah PGC, Ogunkanmi LA. The glycemic effects of Vernonia amygdalina and Vernonia tenoreana with Tolbutamide in rats and the implications for the treatment of diabetes mellitus. J Sci Res Dev. 2008;11:122–30.

    Google Scholar 

  10. Lanza RP, Eeker DM, Kuhtreigber UM, Marsh JP, Ringelin J, Chink WL. Transplantation of islets using micro encapsulation: studies in diabetic rodents and dogs. J Mol Med. 2001;77(1):206–10. https://doi.org/10.1007/s001090050337.

    Article  Google Scholar 

  11. Tierney LM, Mcphee SJ, Papadakis MA. Current medical diagnosis and treatment. 3rd ed. New York: Lang Medical Books/McGraw-Hill; 2002.

  12. Shoback D. Greenspan’s basic and clinical endocrinology. 9th ed. New York: McGraw Hill Medical; 2011.

    Google Scholar 

  13. Etuk EU. Animal models for studying diabetes mellitus. Asian J Exp Biol Sci. 2010;1:331–6.

    CAS  Google Scholar 

  14. Dewanjee S, Bose SK, Sahu R, Mandal SC. Antidiabetic effect of matured fruits of Diospyros peregrine in alloxan induced diabetic rats. Intern J Green Pharm. 2008;2(2):95–9. https://doi.org/10.4103/0973-8258.41179.

    Article  Google Scholar 

  15. Taniyama Y, Griendling KK. Reactive oxygen species in the vasculature. Hypertension. 2003;42(6):1075–81. https://doi.org/10.1161/01.HYP.0000100443.09293.4F.

    Article  CAS  PubMed  Google Scholar 

  16. World Health Organization. Regional Office for the Eastern Mediterranean. Management of diabetes mellitus: standards of care and clinical practice guidelines. 1994. https://apps.who.int/iris/handle/10665/116245

  17. Rose K, Itaikael DM, Judith K. Traditional medicine and its role in the management of diabetes mellitus: “patients and herbalist’s perspectives”. Evidence-Based Compl Alt Med. 2019;19:1–2.

    Google Scholar 

  18. Philomina G. Concerns regarding the safety and toxicity of medicinal plants- an overview. Appl Pharmaceut Sci. 2011;1:40–4.

    Google Scholar 

  19. Aba PE, Edeh MN. Age susceptibility of wistar rats to alloxan-induced diabetes: a paradox. Not Sci Biol. 2019;11(2):191–5. https://doi.org/10.15835/nsb11210438.

    Article  CAS  Google Scholar 

  20. Federal Republic of Nigeria Official Gazette. The Federal Government Printer. Lagos. 2007; FGP 95/62007/1000.

  21. Allain CC, Poon LS, Chan CSG, Richmond W, Fu PC. Enzymatic determination of serum total cholesterol. Clin Chem. 1976;20(4):470–5. https://doi.org/10.1093/clinchem/20.4.470.

    Article  Google Scholar 

  22. Albers JJ, Warnick GR, Cheung MC. Quantification of high-density lipoproteins. Lipids. 1978;13(12):926–32. https://doi.org/10.1007/BF02533852.

    Article  CAS  PubMed  Google Scholar 

  23. Bucolo G, David H. Quantitative determination of serum triglycerides by use of enzymes. Clin Chem. 1973;19(5):476–82. https://doi.org/10.1093/clinchem/19.5.476.

    Article  CAS  PubMed  Google Scholar 

  24. Friedewald WT, Levy RI, Fredrickson DS. Estimation of the concentration of low density lipoprotein cholesterol in plasma without use of the preparative ultracentrifuge. Clin Chem. 1972;18(6):499–502. https://doi.org/10.1093/clinchem/18.6.499.

    Article  CAS  PubMed  Google Scholar 

  25. Kakkar SB, Viswanathan P. A modified spectrophotometric assay of superoxide dismutase. Indian J Biochem Biophy. 1983;21:130–2.

    Google Scholar 

  26. Sinha AK. Colorimetric assay of catalase. Anal Biochem. 1972;47(2):389–94. https://doi.org/10.1016/0003-2697(72)90132-7.

    Article  CAS  PubMed  Google Scholar 

  27. Beutler E, Duron O, Kelly BM. Improved method for determination of blood glutathione. J Lab Clin Med. 1963;61:882–8.

    CAS  PubMed  Google Scholar 

  28. Wallin B, Rosengren B, Shertyer HG, Camejo G. Lipoprotein oxidation and measurement of thiobarbituric acid reacting substances formation in a single microfilter plate; its use for evaluation of antioxidants. Anal Biochem. 1993;288(1):10–5. https://doi.org/10.1006/abio.1993.1002.

    Article  Google Scholar 

  29. Drury RA, Wallington A, Cameroun SR. “In: Carlleton’s Histological Techniques”. New York. Oxford University press. 1967. P. 1–420.

  30. Szkudelski T, Kandulska K, Okulicz M. Alloxan in vivo does not only exert deleterious effects on pancreatic B cells. Physiol Res. 1998;47(5):343–6.

    CAS  PubMed  Google Scholar 

  31. Nwanjo HU. Efficacy of aqueous leaf extract of Vernonia amygdalina on plasma lipoprotein and oxidative status in diabetic rat model. Niger J Physio Sci. 2005;20:39–42.

    CAS  Google Scholar 

  32. Ologunde MO, Ayorinde FO, Shephard RK, Afolabi OA, Oke OL. Sterols of seed oils of Vernonia galanensis, Amaratus cruentu, Amaratus caudatum, Amaratus hybridus and Amaratus shypoochrondriacus grown in the humid tropics. J food Agric. 1992;58(2):221–5. https://doi.org/10.1002/jsfa.2740580210.

    Article  CAS  Google Scholar 

  33. Butler GW, Bailey RW. Chemistry and biochemistry of herbage. 3rd ed. London: Academic Press; 1973.

    Google Scholar 

  34. Oboh G. Effect of blanching on the antioxidant property of some tropical green leafy vegetables. Food Sci Technol. 2005;38(5):513–7. https://doi.org/10.1016/j.lwt.2004.07.007.

    Article  CAS  Google Scholar 

  35. Barter P. CETP and atherosclerosis. Arterioscler Thromb Vasc Biol. 2000;20(9):2029–31. https://doi.org/10.1161/01.ATV.20.9.2029.

    Article  CAS  PubMed  Google Scholar 

  36. Aba PE, Asuzu IU. Effect of administration of methanol root bark extract of Cussonia arborea on serum lipid profile and oxidative biomarker parameters in alloxan-induced diabetic rats. Indian J Anim Res. 2019;53:1006–13.

    Google Scholar 

  37. Habib LK, Lee MTC, Yang J. Inhibitors of catalase amyloid interactions protect cells from β amyloid-induced oxidative stress and toxicity. J Biol Chem. 2010;285(50):38933–43. https://doi.org/10.1074/jbc.M110.132860.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Franco R, Schoneveld OJ. PappaA, Panayiotidis MI. The central role of glutathione in the pathophysiology of human diseases. Arch Physiol Biochem. 2007;113(4-5):234–58. https://doi.org/10.1080/13813450701661198.

    Article  CAS  PubMed  Google Scholar 

  39. Lensen S. Mechanism of alloxan and streptozocin-induced diabetes. Diabetologia. 2008;51(2):216–26. https://doi.org/10.1007/s00125-007-0886-7.

    Article  CAS  Google Scholar 

Download references

Acknowledgements

Authors acknowledge the assistances of the staff of the Department of Veterinary Physiology and Pharmacology and those of the Plant Science and Biotechnology.

Funding

No funding was received for this study.

Author information

Authors and Affiliations

  1. Department of Veterinary Physiology and Pharmacology, University of Nigeria, Nsukka, Enugu state, Nigeria

    Samuel Chijioke Attama, Patrick Emeka Aba & Isaac Uzoma Asuzu

  2. Department of Plant Science and Biotechnology, University of Nigeria, Nsukka, Enugu state, Nigeria

    Chinwe Uchechukwu Asuzu

Authors
  1. Samuel Chijioke Attama
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Patrick Emeka Aba
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Chinwe Uchechukwu Asuzu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Isaac Uzoma Asuzu
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

CU collected and extracted the plant material. SC carried out the experimentation while PE analyzed the data and drafted the manuscript. IU performed the literature review and supervised the entire process. The authors read and approved the manuscript.

Authors’ information

1Department of Veterinary Physiology and Pharmacology, University of Nigeria, Nsukka, Enugu state, Nigeria. 2Department of Plant Science and Biotechnology, University of Nigeria, Nsukka, Enugu state, Nigeria.

Corresponding author

Correspondence to Patrick Emeka Aba.

Ethics declarations

Ethics approval

All applicable international, national and or institutional guidelines for the care and use of animals were followed. The experimental design used in this study was approved by the Faculty of Veterinary Medicine Institutional Animal Care and Use Committee with the approval number: FVM-UNN-IACUC-2020-0266.

Consent for publication

Not applicable.

Competing interests

Authors declare no competing interest.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Attama, S.C., Aba, P.E., Asuzu, C.U. et al. Comparative studies on the hypoglycemic and antioxidant activities of Vernonia amygdalina delile and Baccharoides tenoreana olive in alloxan-induced hyperglycemic rats. Clin Phytosci 7, 91 (2021). https://doi.org/10.1186/s40816-021-00330-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s40816-021-00330-z

Keywords