Vol. 6, Issue 2, Part A (2024)

The significance of antioxidant properties in medicinal plants lies in their ability to combat detrimental free radicals, which are linked to various conditions like diabetes mellitus, cancer, atherosclerosis, and visual impairment. Tapinanthus preussii is a hemiparasitic epiphyte species of African mistletoe in the Loranthaceae family. It thrives mainly in the wet tropical biome across Southeast Nigeria to West Central Tropical Africa, showcasing diverse medicinal potentials. This study aimed to compare the total phenolic contents, flavonoid contents and various antioxidant capacities of Tapinanthus preussii crude leaf aqueous and ethanolic extracts. The choice of solvents was guided by the common practices of herbal remedy preparation in the region, ensuring the study's relevance and practical implications. The in-vitro evaluation included several electron transfer reactions (e.g. TAC, TEAC, FRAP, DPPH, hydroxyl radical scavenging, and nitric oxide radical scavenging assays). The analysis revealed significantly (p<0.05) higher total phenolic contents (1968.89 μg/ml GAE) and total flavonoid contents (13120.99 μg/ml QE) in the ethanolic extract compared to the aqueous extract (360.34 μg/ml GAE and 280.99 μg/ml QE respectively). The ethanolic extract exhibited significantly (p<0.05) higher TAC (1870.54 μg/ml AAE), FRAP (3372.99 μg/ml AAE), trolox equivalent antioxidant capacity (38363.64 ug/ml trolox) and reductive potential (09.59 μg/ml AAE) compared to the aqueous extract (497.10 μg/ml AAE, 2275.95 and 6415.5 ug/ml trolox μg/ml AAE, 04.07 μg/ml AAE respectively). These results highlights the superior antioxidant potential of the ethanolic extract, indicating ethanol as a more efficient solvent for extraction contributing to the plant's overall antioxidant capacity. In conclusion, the findings suggest that the ethanolic extract of Tapinanthus preussii leaves showed promising potential as a relatively effective solvent for extracting natural antioxidants. These antioxidants extracted from the plant may offer valuable natural compounds with applications in healthcare and medicine with therapeutic benefits against diseases associated with free radical damage.