To investigate the effect and mechanism of Toutongning Capsules(TTN) on a migraine rat model and lipopolysaccharide(LPS)-induced microglial cells.Methods:Twenty-one specific pathogen-free(SPF) grade male Sprague-Dawley(SD) rats were randomly divided into three groups according to a random number table:blank group,model group,and TTN treatment group(TTN group).Rats in the TTN group were administered TTN at 640 mg/kg by gavage,while those in the blank and model groups were given an equivalent volume of saline,once daily for 7 days.Thirty minutes after the last administration,the TTN and model groups received a subcutaneous injection of nitroglycerin injection at 10 mg/kg to induce a migraine model,while the blank group received a subcutaneous injection of saline.The serum levels of 5-HT and DA in brain tissues were measured using enzyme-linked immunosorbent assay(ELISA).LPS-induced microglial cells(BV2) were used to simulate central sensitization and were divided into a blank group,an LPS group,and high-and low-dose TTN treatment groups.The MTT assay was used to detect the effects of TTN and LPS on BV2 cell viability.Nitric oxide(NO) levels in the cell supernatant were detected using the nitrate reductase method,while brain-derived growth factor(BDNF),5-HT,interleukin-6(IL-6),and tumor necrosis factor-α(TNF-α) levels in the supernatant were measured using ELISA.Immunohistochemistry and Western blotting were used to detect the expression of Toll-like receptor 4(TLR4) and phosphorylated p65(p-p65) NF-κB proteins in BV2 cells.Results:The model group showed lower serum 5-HT and brain tissue DA levels(P<0.05),while the TTN group showed higher levels of these indicators(P<0.05).TTN(1.25 to 20 μg/mL) and LPS(1,2,4,and 8 μg/mL) had no significant effect on BV2 cell viability.Compared to the blank group,the LPS group had lower levels of BDNF and 5-HT in the cell supernatant(P<0.05) and higher levels of NO,IL-6,and TNF-α(P<0.05),as well as higher expression of TLR4 and p-p65 NF-κB proteins in cells(P<0.05).Compared to the LPS group,the TTN treatment groups had higher levels of BDNF and 5-HT in the cell supernatant(P<0.05),lower levels of NO,IL-6,and TNF-α(P<0.05),and lower expression of TLR4 and p-p65 NF-κB proteins in cells(P<0.05).Conclusion:Toutongning Capsules alleviate migraine symptoms in rats by inhibiting the TLR4/NF-κB signaling pathway,thereby reducing the inflammatory response induced by LPS in BV2 cells. |