Comparative Hepatoprotective Activity of Vernonia amygdalina Leaf Solvent Extracts in Alloxan-Induced Diabetic Rats

Abstract

The associated abnormalities in carbohydrate metabolism and insulin synthesis elicit hyperglycemia with symptoms such as polyphagia, polydypsia, polyuria, glucosuria, and lethargy. 9 Diabetic mortality and morbidity arise from associated macrovascular degeneration in older people. 10 Several other factors such as hyperlipidemia and antioxidant depletion are implicated in the pathogenesis of diabetes and attendant complications. 11 A variety of therapeutic approaches have been applied, including dieting and the use of oral hypoglycemic agents. Currently, available management options involve monotherapy or a combination of drugs to achieve better glycemic control. The incidence of type 2 diabetes mellitus is widely managed using Metformin, a biguanide antihyperglycaemic agent, which normalizes glycemia. 9 Recently, advocacy for the application of readily available plant products in diabetes management has been on the increase; this is attributable to cost-effectiveness and reduced side effects. Consequently, herbal remedies have been widely researched to provide alternative or complementary drugs or adjuvants to improve diabetes management. 12 V. amygdalina is a shrub of the Asteraceae family. It typically thrives in the African tropic; attaining a height of 2-6m at maturity with petiolate small evergreen leaves. Leaf shapes are elliptic with a diameter of about 6 mm. It is widely known as "bitter leaf" due to its astringent bitter taste associated with anti-nutritional factors and phytochemicals. 13 In Nigeria, it is commonly used for its culinary and medicinal benefits and is known by names such as Onugbu, Ewuro, Chusar doki, and Etidot in Igbo, Yoruba, Hausa, and Efik languages. 14,15 Vernonia amygdalina leaf, stem, and bark are locally used in ethno-medicine for the management of fevers, stomach discomfort, diabetes, malaria, hiccups, and as a laxative. 16 The plant has been studied for its bioactive compounds and pharmacological properties; the works of Farombi and Owoeye, 14 and Ojimelukwe and Amaechi, 17 reported the phytochemicals profile to