Mechanism of Modified Tianwang Buxindan on Skin of Sleep-deprived Mice Through PI3K/Akt/Nrf2 Signaling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo observe the effect of modified Tianwang Buxindan （MTBD） on the skin of sleep-deprived （SD） mice and investigate its mechanism. MethodSixty 2-month-old female Kunming mice were randomly divided into a blank group， a model group， a vitamin C （VC， 0.08 g·kg-1）， and MTBD low-， medium-， and high-dose groups （6.5， 12.5， 25 g·kg-1）. Except for the blank group， the other groups were subjected to SD mouse model induction （using multiple platform water environment method for 18 hours of sleep deprivation daily from 15：00 to next day 9：00）， continuously for 14 days， and caffeine （CAF， 7.5 mg·kg-1） was injected intraperitoneally from the 2nd week onwards， continuously for 7 days. While modeling， the blank group and the model group were administered with normal saline （0.01 mL·g-1）， and the other groups received corresponding drugs for treatment. On the day of the experiment， general observations were recorded （such as body weight， spirit， fur， and skin）. After sampling， skin tissue pathological changes were observed under an optical microscope using hematoxylin-eosin （HE） and Masson staining methods. Skin thickness and skin moisture content were measured. Biochemical assay kits were used to detect skin hydroxyproline （HYP） content， skin and serum superoxide dismutase （SOD） activity， and malondialdehyde （MDA） content. Enzyme-linked immunosorbent assay （ELISA） was used to detect serum interleukin （IL）-6， tumor necrosis factor （TNF）-α， and IL-1β levels in mice. Western blot was used to detect skin tissue type Ⅰ collagen （ColⅠ）， type Ⅲ collagen （ColⅢ）， phosphatidylinositol 3-kinase （PI3K）， phosphorylated （p）-PI3K， protein kinase B （Akt）， p-Akt， nuclear factor E2-related factor 2 （Nrf2）， heme oxygenase （HO）-1， and nuclear factor （NF）-κB protein expression. ResultCompared with the blank group， the model group showed varying degrees of changes. In general， signs of aging such as reduced body weight （P<0.01）， listlessness， dull fur color， and formation of wrinkles on the skin appeared. Tissue specimen testing revealed skin thinning， flattening of the dermoepidermal junction （DEJ）， and reduced collagen fibers under the optical microscope. Skin thickness and moisture content decreased， skin tissue HYP content significantly decreased （P<0.01）， skin and serum SOD activity significantly decreased （P<0.01）， and MDA content significantly increased （P<0.01）. Serum IL-6， TNF-α， and IL-1β levels significantly increased （P<0.01）. Skin ColⅠ， ColⅢ， p-PI3K/PI3K， p-Akt/Akt， Nrf2， and HO-1 protein expression significantly decreased （P<0.05， P<0.01）， and NF-κB expression increased （P<0.01）. Compared with the model group， the VC group and the MTBD low-dose group showed increased skin moisture content， HYP content， SOD activity， and ColⅠ， ColⅢ， p-PI3K/PI3K protein expression （P<0.05， P<0.01）， and decreased serum MDA content （P<0.05）. In addition， a decrease in serum IL-6 and IL-1β levels was detected in the MTBD low-dose group （P<0.05）， while the above indicators in the MTBD medium- and high-dose groups improved （P<0.05， P<0.01）. ConclusionSleep deprivation accelerates the aging process of the skin in SD model mice. MTBD can improve this phenomenon， exerting anti-inflammatory and antioxidant effects， and its mechanism of action may be related to the activation of the PI3K/Akt/Nrf2 signaling pathway.