A Comparative Study on the Effect of Combined Methanolic Leaf Extracts of <i>Vernonia amygdalina</i> and <i>Gongronema latifolium</i> and Metformin on the Pancreatic beta cells of Streptozocin Induced Diabetic Wistar Rats


  • Mfon Isua Akpaso University of Calabar, Calabar, Nigeria
  • A. O. Igiri
  • P. A. Odey




Diabetes mellitus, metformin, Vernonia amygdalina, Gongronema latifolium, pancreatic beta cells


The effects of  methanolic leaf extracts of Vernonia amygdalina (VA) (Bitter leaf) and Gongronema latifolium (GL) (Utazi) and metformin on the histology and the DNA of the pancreas of streptozocin (STZ) induced diabetic rats were investigated in this study. 24 male albino rats which were divided into four groups of six rats each were used for this work: A (Normal control) and B (Diabetic control) received tap water, C received 5mg/kg of Metformin daily, D received combined extract of VA and GL, 400mg/kg twice daily. Groups B – D animals were induced for diabetes by intraperitoneal injection of 45mg/kg of Streptozocin, Following sacrifice, the pancreas and blood were collected for histopathological and biochemical studies. The results revealed normal exocrine and endocrine pancreas in group A. In group B, the pancreatic islets cells were shrunken with signs of degeneration and inflammation. In the group that received metformin, the islet appeared shrunken. In group D, the pancreas showed prominent and normal acinar and islet cells, suggestive of a possible regeneration. Feulgen’s reaction showed damage to the DNA of group B which was almost completely reversed in group D. The blood glucose in group B was significantly higher (P<0.05) compared to group A. In all the treatment groups, the blood glucose was significantly reduced (p<0.05) compared to group B.  Administration of methanolic leaf extracts of Vernonia amygdalina and Gongronema latifolium especially in combination restores pancreatic beta cells damaged by STZ compared to metformin. 

Author Biography

Mfon Isua Akpaso, University of Calabar, Calabar, Nigeria

I am a senior lecturer in Department of Human Anatomy, Faculty of Basic Medical Sciences, University of Calabar.


American Diabetes Association . Diagnosis and classification of diabetes mellitus. Diabetes Care. 37: (Supplement 1), 2014

Fox, I. S. Human physiology. 8th Edition. New York. Mc Graw Hill. Pp 615-618, 2004

Larsen, P. R., Kronberg, H. M. & Schlomo, M (2003). Williams Textbook of Endocrinology.10th Edition. St. Louis. Mo: WB Saunders. Pp 1427-1468, 1485-1504

Armstrong, C. Standards of Medical care for patients with Diabetes. American Family physician. 74(5): 871- 874, 2006

Tiwari, A. K & Rao J.M. Diabetes Mellitus and multiple therapeutic approaches of phytochemicals: present status and future prospects. Current science. 83(1) 30-37, 2002

Bnouham, M., Ziyyat, A., Mekhfi, H., Tahri, A & Legssyer, A. Medicinal plants with potential antidiabetic activity- A review of ten years of herbal medicine research (1990-2000). International Journal of Diabetes & Metabolism, 14: 1-25, 2006

Odugbemi, T. A textbook of Medicinal plants from Nigeria. Lagos: University of Lagos Press. Pp 542 – 612, 2008

Akah, P., Njoku, O., Nwanguma, A & Akinyuli, D. Effect of aqueous leaf extract of Vernonia amygdalina on blood glucose and triglyceride level of alloxan-induced diabetic rats. Animal Research International, 1(2): 90-94, 2004

Akpaso, M. I., Atangwho, I. J., Akpantah, A., Fischer, V., A, Igiri, A.O & Ebong, P. E. Effect of combined leaf extracts of VA and GL on the pancreatic beta-cells of STZ induced Diabetic wistar rats. British Journal of Medicine and medical research, 1(1) 22-34, 2011

Farombi, E. O. African Indigenous plants with chemotherapeutic potentials and biotechnological plants with production of bioactive prophylactic agents. African journal of Biotechnology, 2(12) 662-671, 2003

Atangwho, I. J., Ebong, P. E., Eteng, M. U., Eyong, E. U., & Obi, A. U. Effects of Vernonia amygdalina Del Leaf on kidney function of diabetic rats. International Journal of pharmacology, 3(2), 143-148, 2007

Ugochukwu, N. H & Babady, N. E. Antihyperglycaemic effect of aqeous and ethanolic extracts of Gongronema latifolium leaves on glucose and glycogen metabolism in livers of normal and streptozocin induced diabetic rats. Life science.73(150):1925-1938, 2003

Ogundipe, O. O., Moody, J. O., Akinyemi, T. O & Raman, A. Hypoglycaemic potentials of methanolic extracts of selected plant foods in alloxanised mice. Plant food and Human Nutrition, 55(3): 1-7, 2003

Szkudelski, T. The mechanism of alloxan and streptozocin action in Beta cells of the rat pancreas. Physiology Research, 50:536-546, 2001

Lenzen, S. The mechanism of alloxan and STZ induced diabetes. Diabetologia. 51: 216-226, 2008

Ugoanyanwu, F. O., Mgbeje, B. I., Igile, G. O & Ebong, P. E. The flavonoid rich fraction of Vernonia amygdalina Leaf extract reversed diabetes induced hyperglycaemia and pancreatic beta cell damage in albino Wistar rats. World Journal of Pharmacy and Pharmaceutical Sciences. 4(10): 1788-1802, 2015

Atangwho, I. J., Ebong, P. E., Egbung, G. E & Obi, A. U. Extracts of Vernonia amygdalina Del (African bitter leaf) can reverse pancreatic cellular lesion after alloxan damage in the Rat. Australian Journal of Basic and Applied sciences, 45 (5): 711-716, 2010

Gunton, J. E., Delhanty, P. J., Takashi, S & Baxter, R. C. Metformin rapidly increases insulin receptor activation in human liver and signals preferentially through insulin-receptor substrate 2. Journal of Clinical Endocrinology and Metabolism, 88: 1323-1332, 2003

Natali, A & Ferrannini, E. Effects of metformin and thiazolidinediones on suppression of hepatic glucose production and stimulation of glucose uptake in T2D: a systematic review. Diabetologia, 49: 434-441, 2006

Dufrane, D., Van Steenberghe, M., Guiot Y., Goebbels, R. M., Saliez, A & Gianello, P. STZ-induced diabetes in large animals (pigs, primates): role of GLUT 2 transporter and B- cell plasticity. Transplantation. 81: 36-45, 2006

Paik, S. G., Fleischer, N & Shin, S. I. Insulin – dependent diabetes mellitus induced by subdiabetogenic doses of STZ: obligatory role of cell mediated autoimmune processes. Proceedings of the National Academy of Science, USA. 77: 6129-6133, 1980

Ghiraldini, F. G., Crispim, A. C & Mello, M. Effects of hyperglycaemia and aging on nuclear sirtuins and DNA damage on mouse hepatocytes. Molecular Biology of the Cell Journal, 24 (15) 2476-76, 2013

Sharma, B., Kumar, S., Siddiqui, S., Ram, G & Chaudhary, M. Ameliorative effects of aqueous leaf extracts of aloe arboresiens on antihyperglycaemia and antihyperlipidaemia alterations in alloxan-induced diabetic mice. Journal of Investigational Biochemistry, 2(2): 71-76, 2013

Ebong, P. E., I. J Atangwho., E. U. Eyong., C. Ukere & A. U. Obi. Pancreatic Beta cell regeneration. A probable parallel mechanism of hypoglycaemic action of vernonia amygdalina and Azadirachta Indica. Proceedings of International neem conference, Kuming China. Nov, 11-12, pp. 83-89, 2006

Eurich, D. T., McAlister, F. A., Blackburn, D. F., Majumdar, S. R., Tsuyuki, R. T., Varney, J & Johnson, J. A. Benefits and harms of antidiabetic agents in patients with diabetes and heart failure: systematic review. British Medical Journal, 8;335 (7618): 497, 2007

Morebise, O. A review on Gongronema latifolium, an extremely useful plant with great properties. European

Journal of medicinal plants, 10(1):1-9, 2015

Parasuman. S., Dhanaraj, S & Thing, S.G. Polyherbal formulation: Concept of Ayuverda. Pharmacognosy Review, 8 (16) 73-80, 2014

Vasudevan, D. M and Sreekumari, S. Regulation of blood glucose, insulin and diabetes mellitus. Textbook of

Biochemistry for Medical students.6th edn. New Delhi: Jaypee Brothers Medical Publishers (P) Ltd. Pp 285 -290, 2011

Armstrong, C. Standards of Medical care for patients with Diabetes. American Family physician. 74(5): 871- 874, 2006

Buse, J. B., Plonsky, K. S & Burant, C. F (Eds). Type 2 Diabetes Mellitus. Williams textbook of endocrinology. Philadelphia: Elsevier/Saunders. Pp 1371 – 1435, 2011

Scott, G. The diabetic foot examination: A positive step in the prevention of diabetic foot ulcers and amputation.

Osteopathic Family Physician, 5 (2): 73–78, 2013

Jiaquan, X. U., Shery, L., Murphy, B. S., Kenneth, D., Kochanek, M. A., Brigham, A & Bastian, B. S. Deaths:

Final data for 2013. National vital statistics Report, vol 64(2), 2013

Guariguata, L., Whiting, D. R., Hambleton, I., Beagley, J., Linnekamp, U & Shaw, J. E. Global estimates for

diabetes prevalence for 2013- 2035. Diabetes Research and Clinical Practice. 103 (2): 137 -149, 2014

International Diabetes Federation.The Global Burden. IDF Diabetes, 6th edn. Brussels. Belgium:

www.diabetesatlas.org. Accessed on 22/3/16, 2013

Atangwho, I. J. Synergism, Polyvalence, and Polypharmacology: The Novel Nuggets of Modern Phytomedicine Research. Phytomedicine: Panacea for Healthcare Delivery in Nigeria. Calabar: University of Calabar Press. Pp 228 -239, 2015

Damasceno, D.C, Netto, A.O, Lessi, I.L, Calderon, M.P and Rudge, V.C. Streptozotocin- Induced Diabetes Models: Pathophysiological Mechanisms an Fetal outcomes. Biomed Research International Volume 2014, Article ID 819065, 2014




How to Cite

Akpaso, M. I., Igiri, A. O., & Odey, P. A. (2017). A Comparative Study on the Effect of Combined Methanolic Leaf Extracts of <i>Vernonia amygdalina</i> and <i>Gongronema latifolium</i> and Metformin on the Pancreatic beta cells of Streptozocin Induced Diabetic Wistar Rats. Asian Journal of Pharmacy, Nursing and Medical Sciences, 5(2). https://doi.org/10.24203/ajpnms.v5i2.4591