Antihyperglycemic and Antioxidative Properties of Chromolaena odorata Leaf-Extract against Deleterious Effects of Diabetes and Mercuric Chloride-Induced Oxidative Stress in Wistar Rats
Ifeanyichukwu Maxwell Ama
*
Department of Anatomy, Ebonyi State University, Abakaliki, Ebonyi State, Nigeria.
Obinna Humphery Ekechi
Department of Anatomy, Federal University of Technology, Owerri, Imo State, Nigeria.
Genesis Izang
Department of Anatomy, David Umahi Federal University of Health Sciences, Ohaozara, Ebonyi State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Background: Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycaemia resulting from impaired insulin secretion, insulin resistance or both. Exposure to mercury, a highly toxic heavy metal, exacerbates diabetic complications through oxidative stress, inflammation and tissue damage. Medicinal plants rich in bioactive phytochemicals have gained attention as potential therapeutic agents against diabetes and heavy-metal toxicity. Chromolaena odorata is a medicinal plant widely used in traditional medicine because of its antioxidant, anti-inflammatory, antimicrobial and antidiabetic properties.
Objective: This study investigated the antihyperglycaemic and antioxidative properties of Chromolaena odorata leaf extract against deleterious effects of diabetes and mercuric chloride-induced oxidative stress in Wistar rats and also evaluated its phytochemical composition through qualitative and quantitative analyses.
Methods: Fresh leaves of Chromolaena odorata were collected, authenticated, dried, pulverised and extracted using graded concentrations of ethanol. Phytochemical screening was conducted using standard qualitative methods, while the major phytoconstituents and oxidative stress markers were quantified spectrophotometrically. Experimental diabetes was induced with a single dose of alloxan monohydrate (150 mg/kg body weight), and mercury toxicity was induced with HgCl₂ (3 mg/kg body weight daily for 14 days). A total of 36 male Wistar rats were randomly assigned to six groups (A-F), comprising six rats each. Fasting blood glucose levels were monitored weekly, and the study lasted for 31 days.
Results: Qualitative phytochemical analysis revealed the presence of flavonoids, alkaloids, tannins, saponins, phenols, terpenoids and glycosides. Quantitative analysis showed high concentrations of flavonoids and phenolic compounds. Administration of Chromolaena odorata leaf extract significantly reduced fasting blood glucose levels in diabetic and mercury-exposed rats (Groups D-F) compared with the untreated group (Group B); the extract also reduced the expression of oxidative biomarkers (P <.05).
Conclusion: Chromolaena odorata leaf extract exhibited significant antihyperglycaemic activity and restorative effects against mercury-aggravated diabetic complications. These effects may be attributed to its rich phytochemical constituents, particularly flavonoids and phenolic compounds, which possess antioxidant and free-radical-scavenging properties.
Keywords: Chromolaena odorata, diabetes mellitus, mercuric chloride, oxidative stress, alloxan, Wistar rats, antihyperglycaemic activity, antioxidant enzymes, phytochemicals, metformin