PHYTOCHEMICAL EVALUATION, ANTIOXIDATIVE PROPERTIES OF ESSENTIAL OIL FROM H. verticillata LEAF AND ITS EFFECT ON CARBOHYDRATE METABOLISING ENZYMES RELEVANT TO TYPE 2 DIABETES MELLITUS

Abstract

Oxidative stress is key to the progression of diabetic complications. Plants derived essential oils have been shown to possess promising glucose modulating and antioxidant effects resulting from their rich content of phytochemicals. In the present study, essential oil extracted from Hyptis verticillata leaf (HVEO) was investigated for its phytochemical and anti-oxidative properties as well as its effect on carbohydrate metabolising enzymes relevant to type 2 Diabetes Mellitus. GCMS analysis revealed that 9, 12-octadecadienal, 2,4-Di-tert-butylphenol, Decyl prop-1-en-2-yl ester, palmitic acid vinyl ester, oleic acid, palmitoleic acid and 3-Eicosene were some of the bioactives contained in HVEO. Further, the inhibitory effect of HVEO on carbohydrate metabolising enzymes was estimated using ?-amylase and ?-glucosidase inhibiting assays while total antioxidant capacity as well as its inhibitory effect on FRAP, DPPH, hydroxyl radical and lipid peroxidation was evaluated. From the results, HVEO moderately inhibited ?-amylase and ?-glucosidase compared to acarbose, while presenting a higher scavenging capacity on DPPH and hydroxyl radicals in comparison to gallic acid and A. muricata essential oil. Also, HVEO potently inhibited lipid peroxidation by deceasing MDA levels. In conclusion, the antioxidant activity of HVEO together with the observed moderate inhibitory effect on glucose metabolising enzymes may have resulted from its rich phytochemicals contents and maybe part of the mechanisms for which HVEO could be explored in the management of oxidative stress and diabetic related complications.