In vitro antioxidant effects of dichloromethane –methanol leaf blend extracts of Clutia abyssinica and Maytenus obscura

Abstract

Oxidative stress is a state of imbalance between free radicals and antioxidants in the body. It is the main cause of several disease conditions such as diabetes, different types of cancers, cardiovascular diseases, inflammation and aging. Oxidative stress is managed by use of antioxidants which can be obtained in the diet or given as supplements. Antioxidants are substances with the ability to prevent oxidation of other molecules in the body by free radicals. Antioxidants react with free radicals making them stable and reducing their ability to react with different cell components. The treatment of oxidative stress has been confined to use of synthetic supplements, which are unaffordable to most Kenyans and are known to possess side effects. This has led to increased demand for herbal products with antioxidant properties that have little side effects, are affordable and more readily available. Different plants that are used as medicinal plants have been tested for antioxidant activity such as Strychnos henningsii and Rosemarinus officinalis. Clutia abyssinica and Maytenus obscura though traditionally used, have not been scientifically proven and documented. This study evaluated the in vitro antioxidant potential of Dichloromethane: Methanolic extracts of Clutia abyssinica and Maytenus obscura. Different antioxidant assays were done including free radical scavenging activity by using 1,1 –Diphenyl-2-Picrylhydrazyl (DPPH), total ferric reducing power and hydrogen peroxide scavenging activity. The DCM: MeOH extracts of both plants demonstrated a significant level of DPPH scavenging activity with the highest percentage of 80%, 82.57% and 91.77% for C. abyssinica, M. obscura and ascorbic acid respectively. Ascorbic acid demonstrated the lowest value of IC50 of 0.044 and 0.087, 0.065 for C. Abyssinica and M. Obscura respectively. They also demonstrated reducing power that increased with increase in concentration. Different levels of hydrogen peroxide scavenging activity were also demonstrated by the extracts depending on the concentration. There were significant differences between the extracts and the standard. The DCM: MeOH extracts of C. abyssinica and M. obscura demonstrated significant antioxidant activity. The DCM: MeOH extracts of C. abyssinica and M. obscura can therefore be an alternative source of antioxidants for management of different problems that rise due to oxidative stress. The present study, therefore, scientifically validates and supports the traditional use of C. abysssinica and M. obscura in the management of oxidative stress