Chemical composition and anti-diabetic activities in two novel accessions of Cinnamon (Cinnamomum zeylanicum) leaves grown in Sri Lanka

Abstract

Diabetes Mellitus is a major health concern in many countries. Although there are many synthetic drugs to manage diabetes, most of them are associated with many side effects. Hence there is attention to the use of natural herbs with fewer side effects as an alternative. In this study the hypoglycemic properties, biological activities and chemical composition of leaves of two new Cinnamomum zeylanicum accessions (Sri Wijaya and Sri Gemunu) were investigated using spectrometric techniques. Ethanolic extracts of the two accessions were tested for alpha-amylase inhibitory activity (IC50 of Sri Gemunu 0.0565 ± 0.0013 mg/mL, IC50 of Sri Wijaya 0.1136 ± 0.0011 mg/mL), alpha-glucosidase inhibitory activity (IC50 of Sri Gemunu 0.0347 ± 0.0002 mg/mL, IC50 of Sri Wijaya 0.0884 ± 0.0002 mg/mL), total phenolic content (20.60 ± 0.01 mg Gallic acid equivalents.g-1of Sri Gemunu, 6.07 ± 0.01 mg Gallic acid equivalents.g-1 of Sri Wijaya), total flavonoid content (72.02 ± 0.02 mg quercetin equivalents.g-1of Sri Gemunu, 23.59 ± 0.02 mg quercetin equivalents.g-1 of Sri Wijaya), total proanthocyanidin content (0.60 ± 0.05 g catechin equivalents.g-1of Sri Gemunu, 0.15 ± 0.05 g catechin equivalents.g-1 of Sri Wijaya) and DPPH radical scavenging activity (IC50-58.18 ± 2.53 μg/mL of Sri Wijaya, IC50-69.60 ± 5.48 μg/mL of Sri Gemunu). GC-MS analysis and HPLC analysis indicated that both accessions were rich in eugenol and cinnamaldehyde. According to the results of this study, the ethanolic extract of Sri Gemunu Cinnamomum zeylanicum accession leaves displayed better anti-diabetic properties than the leaves of Sri Wijaya.