Evaluation of Anti-Hyperglycaemic Potential of Allium Cepa, Coffee and Oxidative Stress

Allium cepa Linn, botanicals, Liliaceae (family) commonly known as onion, and coffee are special delicacies, and conventional as functional foods that contain physiologically active ingredients that for centuries have been exploited as folk remedies for the treatment of diseases. The present study was conducted to evaluate the therapeutic efficacies and the possible participation of oxidative stress of Nigerian Allium cepa and coffee such as antioxidant, antihyperglycaemic, hypoglycaemic, hyperglycaemic in normal experimental wistar rats. Materials and Methods: qualitative phytochemical screening of hydromethanolic extract of Allium cepa was carried out for the identifications of the phytoconstituents. Hydromethanolic extract of Allium cepa 100mg kg -1, vitamin E 400mg kg -1, and coffee 500mg kg-1, combinations of Allium cepa and coffee and vitamin E and coffee respectively, administered orally to each group of rats daily. During the experimental periods glucose concentrations were estimated at baseline 0 (time of treatment ingestion), age 21 and 42 days respectively, with corresponded oxidative stress markers - superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH) and malondialdehyde (MDA) analyzed at age 42 days. Results: Result ranked time-dependent (in days) glucose lowering potential of treatments as: - Allium cepa + coffee > Allium cepa > vitamin E > coffee + vitamin E; with corresponded up regulated of SOD, CAT, GPx and GSH and reduced MDA. Conversely, coffee and control group (normal rats) significantly in time – dependent, raised blood glucose level with corresponded increase in MDA with respect to other biomarkers, suggesting lipid peroxidation oxidative stress induced impairment of cellular antioxidant protective system. Conclusion: It can be concluded that synergistic effect, presence of the additive bioactive phytoconstituents, and/or antioxidant efficacies or both, and potentiation action of several compounds in Allium cepa and coffee combined , over time, offer the intrinsic antioxidant defence system much better defensive mechanism to protect against free radicals, and alleviate the toxic effects of accumulation of reactive oxygen species (ROS); thence providing protective mechanisms against the development of elevated blood sugar levels. Evidently, Allium cepa and coffee combined is efficacious and potent hypoglycemic agent, which could be beneficial as a dietary supplement for prevention, treatment or management of raised blood glucose levels or diabetes.