Some Antioxidant Properties of Components from the Flower of Ochna integerrima and Their Beneficial Effects on HaCaT Keratinocytes and in Silico Analysis on Tyrosinase

Abstract

Four compounds, luteolin (1), 6‐γ,γ‐dimethylallylquercetin 7‐O‐β‐D‐glucopyranoside (2), 6‐γ,γ‐dimethylallylkaempferol 7‐O‐β‐D‐glucopyranoside (3), and 6‐γ,γ‐dimethylallyldihydrokaempferol 7‐O‐β‐D‐glucoside (4), were isolated for the first time from AcOEt extract of the O. integerrima flower. We then evaluated the antioxidant effects of AcOEt, butanol, and MeOH extracts and their effects on H2O2 against oxidative stress in HaCaT keratinocyte cell lines. Furthermore, 2,2‐diphenyl‐1‐picrylhydrazyl hydrate (DPPH⋅) radical scavenging activities of 1–4 were determined and their mechanisms of action on tyrosinase were predicted by in silico studies. The results revealed that the AcOEt extract and 1–3 exhibited good DPPH⋅ radical scavenging activity. Furthermore, this extract also had a significant protective effect against H2O2‐induced oxidative stress in HaCaT cells. In silico studies indicated that the activity of 1–3 may be due to tyrosinase inhibition with MM‐GBSA free binding energies of −78.9, −70.1, and −71.1 kcal mol−1, respectively, compared to 4 with an energy −56.9 kcal mol−1.

Antioxidant, Anti‐Skin‐Aging, Anti‐Inflammatory, and Anti‐Acetylcholinesterase Activities of Rourea oligophlebia Extracts

“…The negative correlations were demonstrated by the low IC 50 value of the antioxidant assay and the high values of TPC and TFC. [26] In the present study, TPC was negatively and significantly correlated with ABTS * + and DPPH * + , RP capacities and a positive correlation with FRAP capacity. In contrast, the correlations between TFC and radical scavenging activity were very poor.…”

“…The Pearson test was examined to figure out the correlations between TPC, TFC, and free radical scavenging activity. The negative correlations were demonstrated by the low IC 50 value of the antioxidant assay and the high values of TPC and TFC [26] . In the present study, TPC was negatively and significantly correlated with ABTS⋅ + and DPPH⋅ + , RP capacities and a positive correlation with FRAP capacity.…”

Thử nghiệm hoạt tính sinh học của hai hợp chất flavonol glucoside phân lập được từ nhị hoa mai vàng

“…Với hàm lượng flavonoid lớn và đa dạng từ flavon, flavonol, flavan, biflavon, glycoside tương ứng, chi mai có tính kháng oxy hóa nổi bật . Tại Thái Lan, một nghiên cứu về hoạt tính sinh học công bố chi tiết dịch chiết ethanol của loài Ochna intergerrima có khả năng kháng oxy hóa mạnh (Buranasudja et al, 2022). Tại Việt Nam, chỉ có một ít công trình nghiên cứu về phân lập thành phần hóa học của loài mai vàng này.…”