In vitro anti-diabetic effects and phytochemical profiling of novel varieties of Cinnamomum zeylanicum (L.) extracts

Background. Diabetes mellitus type 2 (DMT2) is a leading metabolic disorder in the world. Anti-diabetic actions of phytochemicals from various medicinal herbs have been explored as an alternative therapy in the management of DMT2 due to adverse effects of synthetic drugs used in allopathic medicine. alpha-amylase and alpha-glucosidase inhibitory potential and phytochemical profiling were investigated in aqueous extracts of two new Cinnamomum zeylanicum accessions, namely C. zeylanicum Sri Wijaya (SW), C. zeylanicum Sri Gemunu (SG) and commercially available C. zeylanicum (CC). Methods. Microwave Digestion (MD), Pressurized Water Extraction (PWE), Steam Distillation (SD), Solvent Extraction (SE), Decoction Water Extraction (DWE) and Infusion Water Extraction (IWE) methods were used to prepare Cinnamon quill extracts. Total phenolic content (TPC, Folin-Ciocalteu method) and Proanthocyanidin content (PC, vanillin assay), alpha-amylase and alpha-glucosidase inhibition of Cinnamon extracts were determined spectrophotometrically. The alpha-amylase and alpha-glucosidase inhibition were reported in terms of IC50 value. The phytochemical profiling was accomplished by GC-MS technique. Results and Discussion. Lowest IC50 values were observed in PWE and DWE of SW. The highest PC and TPC were also observed in PWE and DWE of SW. Pressured water and decoctions are promising methods for the extraction of antidiabetic constituents from cinnamon. Benzoic acid, cinnamyl alcohol, benzyl alcohol, and 4-Allyl-2,6-dimethoxyphenol were identified as major compounds in SW extracts. These compounds are believed to be responsible for strong enzyme inhibitory activity of the extracts. Conclusions. This is the first study to explore the use of pressured and decoctions water to extract anti-diabetic phytochemicals from cinnamon. The extensive metabolite profiling of novel SW and SG extracts and comparison of that with commercially available CC are reported for the first time in this study. The C. zeylanicum, SW accession holds some promise in the management of diabetes.