Solvent-Dependent Phytochemical Profile, Antihyperglycaemic Activity and Oral Toxicity of Gossypium herbaceum L. Leaf Extracts: An Integrated in vitro and in vivo Study in Wistar Rats

Ethnopharmacological Relevance: Gossypium herbaceum L. (Malvaceae) is traditionally used in parts of Nigeria to manage diabetes and other ailments, yet integrated evidence on solvent-dependent phytochemistry, antidiabetic efficacy, and safety of its leaves remains limited.

Aim

To comparatively evaluate aqueous and 70% ethanolic leaf extracts of G. herbaceum for phytochemical composition, α-amylase and α-glucosidase inhibitory activities, antihyperglycaemic efficacy, and acute and repeated-dose oral toxicity. Materials and Methods: Mature leaves were authenticated, shade-dried, powdered, and extracted by maceration with distilled water or 70% ethanol. Qualitative phytochemical screening employed standard methods. Enzyme inhibition was assessed against α-amylase and α-glucosidase using acarbose as a reference. Diabetes was induced in male Wistar rats with streptozotocin (40 mg/kg, i.p.). Animals received vehicle, diabetic-control treatment, glibenclamide (5 mg/kg), aqueous extract (400 mg/kg), or ethanolic extract (400 mg/kg) orally for 28 days (n = 6). Fasting blood glucose and body weight were monitored. Acute toxicity was evaluated in female rats at 2000 mg/kg according to OECD 423, while 28-day toxicity was assessed at 100, 300, and 1000 mg/kg/day using clinical, haematological, biochemical, and histopathological endpoints.