MICROSCOPIC CHARACTERISTICS, HPTLC PROFILING, AND EVALUATION OF ANTIOXIDANT, TYROSINASE INHIBITORY, AND ANTI-INFLAMMATORY ACTIVITIES OF EURYA NITIDA KORTH. LEAF EXTRACTS

Tóm tắt

The microscopic study, high performance thin layer chromatography (HPTLC) profile, antioxidant, tyrosinase inhibitory properties, and anti-inflammatory properties of n-hexane, ethyl acetate (EtOAc), n-butanol (n-BuOH), water, and methanol (MeOH) extracts of Eurya nitida Korth. leaf were investigated for the first time. Besides total phenolic content (TPC) and total flavonoid content (TFC), the antioxidant determinations encompassed 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, total antioxidant capacity (TAC), ferric reducing antioxidant power (FRAP), and reducing power (RP). EtOAc extract exhibited the most potent radical scavenging capacities for DPPH (IC₅₀ = 11.10 ± 0.18 µg/mL), ABTS (IC₅₀ 7.63 ± 0.04 µg/mL), RP (OD_0.5 78.65 ± 0.63 µg/mL), FRAP (320.31 ± 14.34 mg AAE/g), TAC (123.2 ± 3.88 mg AAE/g), as well as significantly high TPC (292.41 ± 2.47 mg GAE/g) and TFC (76.30 ± 9.87 mg QE/g). Moreover, the EtOAc extract was found to possess the strongest anti-tyrosinase activity (37.96 ± 0.80% inhibition at 1000 µg/mL) among all tested samples. In addition, anti-inflammatory properties were also evaluated. Among all extracts, the EtOAc extract showed the highest inhibition of nitric oxide (NO) production in LPS-activated RAW 264.7 macrophages (IC₅₀ 25.62 ± 1.38 μg/mL), without showing cytotoxicity. In conclusion, Eurya nitida Korth. leaf presents a promising source of natural products for therapeutic applications in mitigating oxidative stress and anti-inflammation.