Mechanisms of actions of some bioactive anti-diabetic principles from phytochemicals of medicinal plants: A review

Diabetes is both an endocrine and a metabolic disease affecting large numbers of individuals worldwide. The use of natural products such as herbs in the management of diseases dates back to the prehistoric era. Herbal therapy presents a less adverse side effect when compared with the synthetic orthodox counterpart. The phytochemical components of medicinal plants have been credited for the efficacy of herbal formulations. The aim of this study is to review some common anti-diabetic plants which have been tested experimentally using recent diabetes marker parameters and to highlight the bioactive anti-diabetic principles isolated from their phytochemicals. In addition, anti-diabetic compounds isolated in the process of research in our laboratory have been cited in the review. Such keywords like anti-diabetic medicinal plants, mechanism of actions, phytochemicals, alloxan, streptozotocin, glycosylated haemoglobin, were used on different search engines to generate secondary data used in this review. Data obtained indicated that various phytochemical components of anti-diabetic herbs such as the flavonoids, saponins, tannins, alkaloids, glycosides, terpenes, were responsible for the said anti-diabetic activities of the plants. The data equally revealed that these phytochemicals acted in diverse mechanisms to bring about their activities. From the data obtained, it was concluded that phytochemicals from anti-diabetic medicinal plants/herbs are pivotal in the production of marketable novel and efficacious anti-diabetic drug in future.