Antioxidant properties and phytochemical composition of Opuntia Ficus Indica used in the management of diabetes mellitus

Abstract

Opuntia ficus-indica has been extensively used over the past several years in traditional herbal medicine to treat various types of chronic diseases which are on the rise like diabetes mellitus due to the plant’s supposed protective activities and nutritional values. The leaves of this plant are the most widely used part in Uganda. However, the leaves of O. ficus-indica hardly bare any scientific evidence for their claimed healing properties. This study therefore aimed to evaluate the antioxidant properties and phytochemical composition of the aqueous, ethanolic and petroleum ether extracts of Opuntia ficus-indica used in the management of diabetes mellitus. The leaves of O. ficus-indica were purchased from Nakasero market in Kampala district and transported to the lab where they were cleaned, washed and later used fresh after extraction. This extraction was done using three solvents namely petroleum ether, distilled water and aqueous ether. The subsequent extracts were used in the calculation of percentage extraction yield, determination of phytochemical composition and antioxidant activity. The phytochemical composition was determined using conventional methods and qualitative phytochemical methods. The phytochemicals tested included saponins, alkaloids, flavonoids, phenols, tannins, glycosides, steroids, terpenoids and reducing sugars. Antioxidant activity was determined using the DPPH free radical scavenging assay. The study established that aqueous extract had the highest percentage yield (58.4966%) compared to the ethanolic and petroleum ether extracts. Out of the seven phytochemicals tested, the ethanol extracts exhibited five phytochemicals and had the majority which included phenols, saponins, terpenoids, flavonoids and tannins. The ethanol extract exhibited better antioxidant activity compared to that of the aqueous extract with a mean inhibitory concentration of (71.8137 ± 0.851 µg/ml) which was closer to that of the standard ascorbic acid (58.5696±0.118138 µg/ml). Therefore, the scientific community is advised to add Opuntia ficus-indica as a supplement to the diabetes mellitus regimen preferably using ethanol as an extract rather than water. It is recommended that further studies be done on the in-vivo antioxidant properties of Opuntia ficus-indica in the management of diabetes mellitus to justify an investment into supplement innovation with Opuntia ficusindica leaves at the centre of the innovation.