Phytochemical Screening, Antioxidant Activity and Hypoglycemic Potential of Kenyan Aloe lateritia and Aloe secundiflora Extracts in Alloxan-Induced Diabetic Swiss Albino Mice

ABSTRACT

The aim of the study was to investigate the phytochemical constitution, antioxidant activity, hypoglycemic potential and safety of Aloe lateritia and Aloe secundiflora. Phytochemical screening was determined using standard procedures and Gas chromatography-mass spectrometry (GC-MS) analysis. 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was determined spectro-photometrically. Hypoglycemic studies involved daily administration of 200 mg/kg of metformin and 300 mg/kg of methanol and aqueous leaves extracts of A. lateritia and A. secundiflora to alloxan-induced diabetic mice for 21 days. The safety of the extracts was experimented using OECD protocol on Acute Oral Toxicity-Acute Toxic Class Method Test no. 423. The results showed the presence of hypoglycemic phytochemicals - phenols, saponins, alkaloids, flavonoids, tannins, anthraquinones, steroids and carbohydrates in both plants. Analysis by GC-MS determined the presence of phytochemicals in A. lateritia and A. secundiflora already established in other Aloe species. Aloe secundiflora extracts were decided to have higher free radical scavenging activity than A. lateritia extracts. Both A. lateritia and A. secundiflora aqueous and methanol extracts showed significant decreases in FBG levels when compared to the diabetic control group while there was no significant difference between A. secundiflora extracts and metformin-treated group at the end of the experiment (P<0.05). Aloe secundiflora methanol extracts achieved the highest percentage glycemic change among the extracts. All the extracts were not toxic at the tested levels. The hypoglycemic and antioxidant activities established in A. lateritia and A. secundiflora can be linked to the phytochemicals present.