Antioxidant Potential of Methanol Extract of Xylopia aethiopica Leaves

Abstract

Background: Plants possess an array of phytochemicals and are mostly used in the treatment of diseases associated with high levels of reactive oxygen species (ROS). Xylopia aethiopica is a plant widely found in tropical Africa and used traditionally as spices in food and for the treatment of skin infection in Nigeria. The leaves are used in the management of boils, wounds, cough and menstrual pain in women. Objective: This study assessed the phytochemicals and antioxidant potentials of the methanol extract of X. aethiopica (MEXA) leaves. Methods: The leaves of X. aethiopica were extracted with methanol. Qualitative phytochemical screening, total phenolic and total flavonoid contents were determined. In vitro antioxidant potential of the methanol extract of X. aethiopica leaves was assessed by evaluating its reducing power, the extent of inhibition of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 1,1, Diphenyl 2, picrylhydrazyl (DPPH), hydroxyl (OH), nitric oxide (NO) and lipid peroxidation. Results: The result of the phytochemical screening of the MEXA leaves showed the presence of alkaloids, glycosides and polyphenols. Total phenolic and total flavonoid contents were 49.42±2.7 mg/GAE/100 g and 28.3±1.8 mg/QE/100 g, respectively. Also, the reducing power of MEXA leaves increased with increasing concentration of the extract. Furthermore, MEXA leaves significantly (p< 0.05) inhibited ABTS, DPPH, hydroxyl and nitric oxide radicals in a concentration-dependent manner. The extract also significantly (p<0.05) inhibited Fe2+-induced lipid peroxidation in a concentration-dependent manner. Conclusion: This study demonstrated that the methanol extract of Xylopia aethiopica leaves possesses potent phytochemicals which could significantly scavenge free radicals and may be useful in treatment of diseases associated with high levels of reactive oxygen species.