POLYPHENOLIC CONTENTS AND ANTIOXIDANT PROPERTIES OF SELECTED WILD EDIBLE FRUITS, AGAMSA (Carissa edulis (Forssk.) Vahl.) AND QOLAATTII (Mimusops kummel Bruce ex A. DC.) FROM ETHIOPIA

Abstract

Plants serve as valuable sources of therapy in both traditional and modern medicine. This study aimed to evaluate the antioxidant capacities of fruit extracts of Carissa edulis (Forssk.) Vahl. and Mimusops kummel Bruce ex A. DC. Dried fruits of both plants were extracted by macerating them in three different organic and aqueous solvents to quantify their polyphenolic content using spectrophotometric technique. The antioxidant capacities of the fruit extracts were assessed through DPPH, nitric oxide and H₂O₂ scavenging, as well as ferric ion-reducing power assays. Each experiment was conducted in triplicate. Results indicated that the total phenolic and flavonoid contents varied significantly (p < 0.05) among the different solvents, with values decreasing as polarity diminished. Notably, Mimusops kummel exhibited significantly (p < 0.05) higher polyphenolic content compared to C. edulis across all solvents tested. Antioxidant activity assessments revealed significant (p < 0.05) differences based on solvent type and extract concentration in DPPH scavenging activity. Methanolic extracts of both C. edulis and M. kummel demonstrated the highest DPPH scavenging activity when compared to extracts from other solvents and ascorbic acid, a standard antioxidant. In the nitric oxide scavenging assay, significant (p < 0.05) differences were also noted, with aqueous extracts of both plants showing the highest activity. Significant (p < 0.05) differences in antioxidant capacity were observed across solvents and extract concentrations for H₂O₂ scavenging as well. Ethyl acetate extracts exhibited superior activity compared to other solvents and the standard antioxidant BHT. Ferric ion-reducing power assays also revealed significant (p < 0.05) variations, with ethyl acetate extracts of C. edulis performing better than those from other solvents, while methanolic extracts were more effective for M. kummel. Overall, Mimusops kummel consistently showed higher polyphenolic content than C. edulis, correlating with their respective antioxidant capacities. This study highlights that both C. edulis and M. kummel are rich in polyphenols and possess considerable potential for scavenging reactive oxygen species, suggesting their potential utility in preventing degenerative diseases linked to oxidative stress.