**Author details**

genes relevant for the development of T2DM A number of candidate genes have been identified in humans and many phytochemicals/extracts from traditional medicinal plants that

Medicinal plants can delay or inhibit glucose absorption, facilitate the entry of glucose into cells such as muscle cells, or stimulate insulin secretion by the pancreas. It was reported that oral administration of the ethanolic extract of *Allium sativum* showed significant antidiabetic effect in normal and alloxan-induced diabetic rats and that this effect was probably mediated through the stimulation of insulin secretion from the pancreas [137]. Oral administration of *Gymnena sylvestre* to diabetic rats was reported to increase the number of pancreatic islet cells as well as insulin levels suggesting a possible repair or regeneration of the pancreas [138]. *In vitro* and *in vivo* studies showed that water soluble extracts of *Gymnena sylvestre* released insulin

Aqueous extract of unripe fruit of *Momordica charantia* showed partial stimulation of insulin release from isolated beta cells of obese hyperglycaemic mice which is an indication of its insulin releasing action as a result of perturbations of membrane functions [140]. *Parinari excelsa* showed hypoglycaemic effects due to its insulin secretory activity in diabetic animal models [141]. Epicatechin which is the active principle isolated from the bark of *Pterocarpus maruspium* showed protective and restorative effect on beta cells of diabetic subjects. This may

Aqueous extract of *Citrullus colocynths* showed a dose dependent increase in insulin released from isolated islets [142]. Immunohistochemistry studies [143] showed that the amount of insulin in beta cells of the islet of Langerhans is greater in *Citrullus colocynthis* treated rats when

A report on *in vitro* assays on some medicinal plants showed that they possess inhibitory activity on alpha glucosidase enzyme. In a study, thirty seven of forty-five samples examined showed IC50 values of between 2.33 *μ*g/mL and 112.02 *μ*g/mL, which were lower than that of acarbose (117.20 *μ*g/mL) [144]. Also, 80% ethanol extract from *Garcinia daedalanthera* Pierre. leaves (Clusiaceae), *Antidesma celebicum* leaves (Euphorbiaceae), *Amaracarpus pubescens,* (Rubiaceae), and *Willughbeia tenuiflora* leaves (Apocynaceae) had the highest *α*-glucosidase inhibiting activity with IC50 of 2.33 *μ*g/mL, 2.34 *μ*g/mL, 3.64 *μ*g/mL, and 8,16 *μ*g/mL respec‐ tively. Meanwhile, types of enzyme inhibition mechanism from *Garcinia kydia* leaves (Clusia‐ ceae), *Antidesma celebicum* leaves (Euphorbiaceae), and *Amaracarpus pubescens* leaves (Rubiaceae) were non-competitive inhibitor, competitive inhibitor, and mixed inhibitor

Diabetes mellitus and all its comorbidities constitute major causes of high economic loss which can in turn pose significant challenges to the economic development of developing

can target diabetogenic genes have also been identified [135,136].

probably due to the regeneration of pancreatic beta cells [139].

be due to its ability to regenerate beta cells [139].

compared with the control group.

152 Antioxidant-Antidiabetic Agents and Human Health

respectively.

**12. Conclusion**

Afolabi Clement Akinmoladun1\*, Ebenezer Olatunde Farombi2 and Oluwafemi Omoniyi Oguntibeju3

\*Address all correspondence to: akinmoladunfc@yahoo.com; acakinmoladun at futa.edu.ng

1 Phytomedicine, Drug Metabolism and Toxicology Unit, Department of Biochemistry, School of Sciences, The Federal University of Technology, Akure, Nigeria

2 Drug Metabolism and Toxicology Research Unit, Department of Biochemistry, College of Medicine, University of Ibadan, Nigeria

3 Oxidative Stress Research Centre, Department of Biomedical Sciences, Faculty of Health & Wellness Sciences, Cape Peninsula University of Technology, South Africa
