Potential anti-diabetic and anti-oxidant activity of essential oil of Zataria multiflora leaves
Phytochemicals show multiple beneficial effects in combating diabetes and diabetes-related complications. Agents with α-glucosidase inhibitory activity have been useful as oral hypoglycemic drugs for the control of hyperglycemia in patients with type 2 [1,2]. In this study, we examined the α-glucosidase, α-amylase and anti-oxidant activity of essential oil of air-dried Zataria multiflora leaves and its main constituent's carvacrol using an in vitro models. The essential oil of air-dried samples was obtained by hydrodistillation. The oil was analyzed by GC and GC-MS. Carvacrol (72.4–78.9%) was found the major compound. 2,2-diphenyl-1-picrylhydrazil (DPPH) was used to determined the anti-oxidant activity (RSC) by measuring the scavenging activity of examined essential oil. Enzyme inhibitory activities of carvacrol against rat intestinal α-glucosidase and porcine pancreatic α-amylase were done by standard methods. Effect of carvacrol on the in vitro free radical (DPPH) was 161.7 (µg/ml) while BHT was used as a positive control 19.8 (µg/ml). Carvacrol possessed the strong anti-amylase activity (AI index value=2.1±0.5; ˜ 71% of inhibition) and also possessed the moderate α-glucosidase inhibitory activity (α-GI index value=1.19±0.03; ˜35% of inhibition). The α-amylase activity was inhibited more than the α-glucosidase activity in the presence of carvacrol. Strong anti-oxidant activity and good α-amylase inhibitory activity among moderate α-glucosidase activity were found in essential oil of dried Zataria multiflora leaves. This preliminary observation will provide the basis for further examination of the suitability of Zataria multiflora as a medicinal supplement that contributes towards the treatment and prevention of diabetes.
Acknowledgements: 1. Tehran University of Medical Sciences and Pharmaceutical Sciences Research Center for financial support. 2. Mr. AS. Nasreldin Heidari
References: 1. Korreia, R.T.P. et al. (2004) Food Biochem. 28:419–434.
2. Mccue, P. et al. (2005) Food Biochem. 29:278–294