Antioxidant, antibacterial, anti-inflammatory, and anticancer activities of the methanol extract from Manilkara zapota leaves collected in Vietnam

Manilkara zapota, a member of the Sapotaceae family, is a well-known and widely distributed plant with various applications in traditional medicine. However, the number of studies about the bioactivities of the leaf extract from this species in Vietnam is limited. This study showed that the methanol leaf extract of M. zapota contained relatively high contents of antioxidant compounds, including polyphenols and flavonoids (197.48 ± 2.08mg GAE/g extract and 39.04 ± 0.36mg QE/g extract, respectively). The extract exhibited high antioxidant properties, demonstrated by its potent free radical scavenging activity (IC50 of DPPH assay: 2.71 ± 0.11 μg/mL) and its high total antioxidant capacity (218.91 ± 7.84mg AAE/g extract). Additionally, the extract showed a practical anti-bacterial effect against Bacillus cereus, Staphylococcus aureus, and Shigella boydii, with their inhibitory halos ranging from 8.00 - 11.33mm. The extract also exhibited a significant anti-inflammatory potential (IC50: 0.107 ± 0.008 mg/mL). Furthermore, its anti-cancer activities against two cancer cell lines representing soft-tissue sarcoma (RD) and liver (HepG2) cancers were also demonstrated (IC50: 260.27 ± 3.17 and 164.41 ± 1.83 μg/mL, respectively). This is the first study to report the inhibitory effect on protein denaturation and anticancer ability on soft-tissue sarcoma cells of the methanol leaf extract of M. zapota. These findings highlight M. zapota as a potential candidate for pharmaceutical research and development, particularly for its antioxidant, anti-inflammatory, and anticancer properties.