EFFECTS OF MANIHOT ESCULENTA LEAF ON EXPRESSION OF CATALASE GENE IN STREPTOZOTOCIN-TREATED RATS.

ABSTRACT Diabetes mellitus, a chronic metabolic disorder affecting over 500 million adults globally, is driven by hyperglycemia and oxidative stress, leading to complications like neuropathy and nephropathy via reactive oxygen species (ROS)-induced damage. This study investigates the effects of Manihot esculenta (cassava) leaf extracts on catalase (CAT) gene expression and activity in streptozotocin (STZ)-induced diabetic rats to explore their potential as an antioxidant and antidiabetic therapy. Cassava leaves, rich in flavonoids (e.g., quercetin), stilbenes, and saponins, were extracted using Soxhlet method (methanolic/aqueous) and screened for phytochemicals. Thirty Wistar rats were randomized into six groups (n=5): non-diabetic (water-treated, Blank Control, BC), STZ + metformin (5 mg/kg, Positive Control, PC), STZ-only (Negative Control, NC), and STZ + extract (100, 200, 400 mg/kg). Diabetes was induced with 60 mg/kg STZ, and treatments were administered orally for 21 days. Fasting blood glucose, antioxidant enzymes (CAT, SOD, GSH), lipid peroxidation (MDA), and CAT gene expression (via qPCR and agarose gel electrophoresis, normalized to GAPDH) were measured. STZ significantly increased glucose and MDA while suppressing CAT expression in NC (p < 0.001 vs. BC). Extracts dose-dependently reduced glucose and MDA, with 400 mg/kg (TC) fully restoring CAT expression to BC levels, surpassing metformin’s effect, likely via Nrf2-ARE activation and ROS scavenging. Pancreatic histology showed improved beta-cell integrity, and body weight stabilized in extract-treated groups, indicating metabolic benefits. These findings highlight Manihot esculenta leaf extracts as a potent, cost-effective adjunct for managing diabetes-related oxidative stress, with implications for ethnomedicine in tropical regions. Further studies on toxicity (e.g., cyanogenic glycosides) and specific phytochemical contributions are needed to advance therapeutic development.