考察异橙黄酮(Isosinensetin,ISO)经皮给药对D-半乳糖(D-gal)诱导的皮肤衰老小鼠的抗衰老和抗氧化功效。将小鼠分为6组(n=12):分别为C组、D-gal组、D-gal+L-ISO组、D-gal+M-ISO组、D-gal+H-ISO组和D-gal+H-ISO+ML385组。在小鼠背部连续6周皮下注射1 g/ (kg·d)的D-gal建立皮肤衰老小鼠模型。D-gal注射当天开始,C组和D-gal组小鼠背部脱毛区域涂抹雪花膏,D-gal+L-ISO组、D-gal+M-ISO组和D-gal+H-ISO组小鼠分别涂抹50,100和200 mg/kg的异橙黄酮乳膏。D-gal+H-ISO+ML385组小鼠涂抹200 mg/kg的异橙黄酮乳膏,并腹腔注射30 mg/ (kg·d)核因子E2相关因子2(Nrf2)抑制剂ML385。涂抹量为2 mg/cm2。经皮给药6周后,检测小鼠的体重、皮肤含水量、皮肤抗氧化指标、羟脯氨酸(HYP)和透明质酸(HA)水平。采用苏木素伊红(HE)染色观察皮肤形态。采用RT-qPCR检测皮肤中COL1A1、COL3A1、基质金属蛋白酶(MMP)-1和MMP-3的转录水平。采用Western blotting检测皮肤中Nrf2(细胞核)、Kelch样ECH相关蛋白1(Keap1)和血红素加氧酶-1(HO-1)的蛋白水平。结果显示,3个剂量的异橙黄酮经皮给药均升高了皮肤衰老小鼠的皮肤含水量,改善了皮肤形态,升高了超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)水平,降低了丙二醛(MDA)水平,升高了HYP和HA水平,升高了COL1A1和COL3A1转录水平,降低了MMP-1和MMP-3转录水平,升高了Nrf2(细胞核)和HO-1蛋白水平,降低了Keap1蛋白水平(P<0.05)。ML385减弱了异橙黄酮的抗衰老及抗氧化功效(P<0.05)。总之,异橙黄酮经皮给药通过激活Nrf2通路提高D-gal诱导的皮肤衰老小鼠的抗衰老和抗氧化能力。
The study aimed to investigate the anti-aging and antioxidant effects of isosinensetin (ISO) on skin aging mice induced by D-galactose (D-gal). The mice were divided into 6 groups (n=12): C group, D-gal group, D-gal+L-ISO group, D-gal+M-ISO group, D-gal+H-ISO group and D-gal+H-ISO+ML385 group. The skin aging mouse model was established by subcutaneous injection of D-gal of 1 g/ (kg·d) into the back of mice for 6 weeks. From the day of D-gal injection, mice in C group and D-gal group were applied with snow cream on their back depilation area, while mice in D-gal+L-ISO group, D-gal+M-ISO group and D-gal+H-ISO group were applied with 50, 100 and 200 mg/kg isosinensetin cream, respectively. The mice in D-gal+H-ISO+ML385 group were applied with 200 mg/kg isosinensetin cream and intraperitoneally injected with 30 mg/(kg·d) nuclear factor E2 related factor 2 (Nrf2) inhibitor ML385. The application amount was 2 mg/cm2. After 6 weeks of transdermal administration, the body weight, skin water content, skin antioxidant index, hydroxyproline (HYP) and hyaluronic acid (HA) levels were measured. The skin morphology was observed by HE staining. The transcriptional levels of COL1A1, COL3A1, matrix metalloproteinase (MMP) -1 and MMP-3 in skin were detected by RT-qPCR. The protein levels of Nrf2 (nucleus), Kelch-like ECH associated Protein 1 (Keap1) and heme oxygenase-1 (HO-1) in skin were detected by Western blotting. The results show that all three doses of isosinensetin increases skin water content, improves skin morphology, increases superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) levels, decreases malondialdehyde (MDA) levels, increases HYP and HA levels, increases COL1A1 and COL3A1 mRNA levels, decreases MMP-1 and MMP-3 mRNA levels, increases Nrf2 (nucleus) and HO-1 protein levels, and decreases Keap1 protein levels in skin aging mice (P<0.05). ML385 attenuates the anti-aging and antioxidant effects of isosinensetin (P<0.05). In short, transdermal administration of isosinensetin can improve the anti-aging and antioxidant ability of D-gal-induced skin aging mice by activating Nrf2 pathway.
