Investigation and characterisation of phenolic compounds that can be effectiveness of prevention of hyperglycemia and diabetic complications in some plants

Diabetes mellitus is multifactorial and chronic disease which is characterized with hyperglycemia and insulin resistance. Because of increasing numbers of people exposed to the disease in the world population, preventing the formation of the disease and developing new treatments has become a necessity. In recent years, there is an increased interest in the study of compounds from many natural sources that can be used in diabetes treatment. The therapeutically active compounds obtained from natural sources are advantageous in terms of low toxicity, high stability in physiological conditions instead of those of synthetic origin and they have various chemical structures for the design of new drugs. For this purpose, many plant extracts have been investigated for their phytochemical and biological activity and there are a number of studies that focus on polyphenolic compounds. Phenolic compounds are very effective and are being discussed because they cause some health problems when the dosage is not adjusted or taken as supplement. The aim of this study is that investigation of phytochemical tests, phenolic compound contents, antioxidant activity and various biological activities related to diabetes and characterisation of Hibiscus sabdariffa L., Hypericum sp., Calendula sp. and Prunus laurocerasus L. extracts. It has been observed that all plant extracts are rich in phenolic compounds. Antioxidant activity, lipoxygenase and α-amylase inhibition in Hibiscus sabdariffa L extracts; antioxidant and deglycation activity, inhibition of α- glucosidase and dipeptidyl peptidase 4 in Hypericum sp. extracts; Antioxidant and metal chelating efficacy in Calendula sp. extracts; The effects of antioxidant, metal chelating and reducing activity, α-glucosidase, α-amylase and dipeptidyl peptidase 4 were observed in Prunus laurocerasus L. extracts. In conculision, in each plant extract, multiple biological activities associated with diabetes and its complications, can be the source of potential drug effects in the prevention of diabetes and its complications. It is clear that it is necessary to carry out in vitro and in vivo kinetic studies of these plant extracts.