Oxidative Stress Research Centre, Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, Bellville 7538, South Africa.
J Photochem Photobiol B. 2011 May 3;103(2):126-39. doi: 10.1016/j.jphotobiol.2011.02.020. Epub 2011 Mar 5.
The possible mechanism of photoprotection by polyphenolic extracts of honeybush and the two most abundant polyphenols found in honeybush, hesperidin and mangiferin were determined using a mouse model. Ethanol: acetone soluble extracts and pure honeybush compounds were applied topically to the skin of SKH-1 mice before daily exposures to ultraviolet B (UVB) (180 mJ/cm²) for 10 days. The honeybush extracts reduced signs of sunburn, such as erythema, peeling and hardening of the skin and also significantly (P < 0.05) reduced edema, epidermal hyperplasia and the induction of cyclooxygenase-2 (COX-2), ornithine decarboxylase (ODC), GADD45 and OGG1/2 expression. The fermented honeybush extract significantly (P < 0.05) reduced lipid peroxidation and depletion of the antioxidant enzymes catalase and superoxide dismutase. Hesperidin and mangiferin were less effective. These results show that extracts of honeybush and to some extent, hesperidin and mangiferin, renders protection against UVB-induced skin damage. The mechanisms investigated suggest that honeybush extracts protected the skin via modulation of induced-oxidative damage, inflammation and cell proliferation. Other specific biological properties such as modulation of signaling pathways could also be involved.
采用小鼠模型，确定了霍桑蜂蜜茶多酚提取物以及在霍桑蜂蜜茶中含量最丰富的两种多酚化合物——橙皮苷和芒果苷的防晒作用的可能机制。将霍桑蜂蜜茶的乙醇:丙酮可溶性提取物和纯化合物局部应用于 SKH-1 小鼠皮肤，然后每天接受 180mJ/cm² 的紫外线 B（UVB）照射 10 天。霍桑蜂蜜茶提取物减轻了晒伤迹象，如红斑、皮肤剥落和硬化，还显著（P<0.05）减少了水肿、表皮增生以及环氧合酶-2（COX-2）、鸟氨酸脱羧酶（ODC）、GADD45 和 OGG1/2 的诱导表达。发酵的霍桑蜂蜜茶提取物显著（P<0.05）减少了脂质过氧化和抗氧化酶过氧化氢酶和超氧化物歧化酶的消耗。橙皮苷和芒果苷的效果则不那么显著。这些结果表明，霍桑蜂蜜茶提取物和在一定程度上橙皮苷和芒果苷，可提供对 UVB 诱导的皮肤损伤的保护。所研究的机制表明，霍桑蜂蜜茶提取物通过调节诱导的氧化损伤、炎症和细胞增殖来保护皮肤。其他特定的生物学特性，如信号通路的调节，也可能参与其中。
