Protective Effect Of Salvia Plebeia R. Br Ethanol Extract On UVB-induced Skin Photoaging In Vitro And In Vivo

Salvia plebeia R.Br(SP)belongs to the genus Salvia in the labiaceae family.Its main components are flavonoids,phenylpropanoids and hemiterpenoids.Studies have shown that it has anti-inflammatory,antioxidant,antibacterial and antiviral pharmacological effects.Studies have shown that SP significantly inhibit mitogen activated protein kinase,NF-κB,Akt and other proteins in synovial fibroblasts stimulated by tumor necrosis factor-α,and significantly inhibit the progression of inflammation.However,there are few studies on photodamage of SP,and then the study mainly took SP as the research object to explore its protective effect and mechanism against UVB irradiated skin photodamage.Objective: To investigate the protective effect and mechanism of SP on human epidermal immortalized keratosis(HaCaT)cells induced by ultraviolet ray(UVB)and skin photodamage in Kunming mice.Methods: The main active components of SP were analyzed by HPLC.The antioxidant activity of SP was determined by 2,2-diphenyl-1-picrylhydrazyl(DPPH)method for phenyl-1-picrylhydrazyl.WST-8(CCK-8)colorimetry was used to determine the effects of SP and hyperplantin(HP)on cell proliferation.By establishing mouse ear swelling model induced by xylene and mouse foot swelling model induced by carrageenan,the anti-inflammatory of SP and plananthine were tested.Intracellular reactive oxygen species(ROS)were analyzed by flow cytometry.By ELISA kits cells malondialdehyde(MDA),interleukin 6(IL-6)and matrix metalloproteinase-1(MMP-1)precursor,collagen(Pro-Col1)and β-galactose glucoside enzyme(SA-β-Gal)level;Mouse model of photodamage was established,and H&E staining and Masson staining were used to observe the epidermal morphology of skin tissue and the changes of Collagen fibers in dermis,and the levels of matrix metalloproteinase 1(MMP-1)and collagen 1 in skin tissue were detected by immunohistochemistry.Using molecular docking technology forecast of UVB induced HaCaT photodamage targets,and combined with protein immunoblot method(Western Blot)detection to research protective effect of SP by investigateing MAPK/AP-1,TGF-β/Smad and Nrf2/NQO-1/HO-1 pathway.Results: DPPH and inflammation model showed that SP had strong antioxidant capacity and anti-inflammatory effect.CCK8 assay showed compared with UVB group,30 μg/m L SP group and 10 μM HP group could significantly enhance the cell proliferation activity of UVB-irradiate HaCaT cells.30 μg/m L SP group and 10 μM HP could inhibit the intracellular ROS and MDA levels,and decrease the IL-6,MMP-1,and SA-β-Gal(all P < 0.05),and improve the expression level of collagen(all P <0.05).The photodamage mouse model showed that the back skin of Kunming mice showed different degree of photodamage after ultraviolet radiation.Compared with model control group,skin epidermal thickness,collagen 1 content in skin tissue and matrix metalloproteinase expression level in SP group and HP group were significantly decreased(all P < 0.05).In addition,molecular docking results showed that: HP has strong binding activity on ERK and JNK in MAPK,and WB results also showed that 30 μg/m L SP group and 10 μM HP group could also inhibit p-38,ERK and JNK proteins in MAPK pathway,c-Fos and c-Jun in AP-1 pathway,Smad 7 protein in TGF-β pathways,and promote Nrf2 pathway to promote the synthesis of collagenConclusion: SP and HP showed the photoprotection by inhibiting the MAPK/AP-1 pathways,activating the TGF-β/Smad and Nrf2 signaling pathways.