COMPARATIVE ANTIOXIDANT AND ANTI-INFLAMMATORY POTENTIAL OF THE ETHYL ACETATE EXTRACT OF PARKIA BIGLOBOSA AND CYMBOPOGON CITRATUS LEAVES

Oxidative stress and inflammation are pivotal contributors to the pathogenesis of various chronic diseases, including cancer, cardiovascular diseases, neurodegenerative disorders, and metabolic disorders, highlighting the need for effective treatments. Natural products have garnered significant attention due to their potential to fight against oxidative stress and inflammation. This study undertakes a comprehensive comparative assessment of the antioxidant and anti-inflammatory potential of ethyl acetate extracts of Cymbopogon citratus and Parkia biglobosa leaves, traditionally utilized for their medicinal properties in African and Asian cultures. The bioactive compounds were extracted from both leaves using methanol, followed by fractionation using liquid-liquid chromatography with ethylacetate. The resulting fractions were subjected to in vitro assays, including total flavonoid content, 1, 1- diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity, hydroxyl radical scavenging activity, lipid peroxidation inhibition, protein denaturation inhibition, and inhibition of protease activity. The results demonstrated that both leaves possess significant antioxidant and anti- inflammatory activities, with Parkia biglobosa exhibiting superior potential in most assays. This was attributed to its higher total flavonoid content quercetin equivalent (QE) of 0.734mg/g and 0.166mg/g (QE) at 500µg/ml and robust free radical scavenging capabilities. Flavonoid content increased steadily with concentration for both extracts. Additionally, the results showed that the ethyl acetate extract of Parkia biglobosa has a significantly higher percentage DPPH radical scavenging activity than that of Cymbopogon citratus at the same concentration of 400µg/ml with maximum activities of 94.71% and 61.93% respectively. The DPPH radical scavenging activity of Parkia biglobosa extracts demonstrated a concentration-dependent increase, whereas Cymbopogon citratus extracts showed a concentration-dependent decrease. On the other hand, the results indicated that the ethyl acetate extract of Parkia biglobosa has a lower percentage hydroxyl radical scavenging activity than that of Cymbopogon citratus at the same concentration of 50µg/ml with maximum activities of 73.57% and 81.68% respectively. The percentage hydroxyl radical scavenging activities of both extracts notably decreased in a concentration-dependent manner. Moreover, the ethyl acetate extract of Parkia biglobosa exhibited higher percentage lipid peroxidation inhibition activity than that of Cymbopogon citratus, as deduced from their respective maximum inhibition of 46.96% and 10.98% at the same concentration of 50µg/ml. Remarkably, the ethyl acetate extract of Parkia biglobosa also exhibited higher protein denaturation inhibition activity 34.66% at 400µg/ml compared to Cymbopogon citratus 51.87% at 50µg/ml. However, the protein denaturation inhibition assay revealed no activity for Parkia biglobosa extracts across concentrations ranging from 50µg/mL to 150µg/mL. Conversely, the ethyl acetate extract of Cymbopogon citratus displayed higher inhibition of proteinase activity than that of Parkia biglobosa, with maximum inhibition of 68.61% and 79.89% at the same concentration of 50µg/ml. Cymbopogon citratus and Parkia biglobosa leaves are potential sources for natural products mitigating oxidative stress and inflammation-related disorders. This study provides a comprehensive comparative evaluation of their bioactive properties, underscoring the importance of preserving traditional knowledge and biodiversity. The findings contribute meaningfully to exploring their therapeutic potential for pharmaceutical, nutraceutical, and cosmeceutical applications. In conclusion, this study underscores the potential of Cymbopogon citratus and Parkia biglobosa as valuable natural resources for developing novel therapies against chronic diseases.