Optimization of extraction of flavonoids from Lonicera rupicola and analysis of its effects in resisting inflammation, relieving pain, enhancing immunity, and inhibiting pyroptosis / 中国中药杂志

ABSTRACT

The present study optimized the extraction of flavonoids from Lonicera rupicola Hook. f. et Thoms(LRH) and explored its pharmacological effects, such as resisting inflammation, relieving pain, enhancing immunity, and inhibiting pyroptosis, aiming to provide data support and scientific basis for the development and utilization of LRH. Response surface methodology(RSM) was applied to optimize the extraction of flavonoids from LRH based on the results of single-factor experiments. Anti-inflammatory and analgesic effects of LRH flavonoids were evaluated via inflammation and pain models in mice, such as xylene-induced ear swelling, carrageenan-induced footpad swelling, writhing caused by acetic acid, and paw licking. The effect of LRH flavonoids on the carbon clearance index of monocytes and serum immunoglobulin A(IgA) and IgM levels was analyzed on the immunosuppression model induced by cyclophosphamide in mice. The anti-oxidative effect in vivo of LRH flavonoids on liver superoxide dismutase(SOD), catalase(CAT), and malondialdehyde(MDA) levels was determined based on the chronic/subacute aging model in mice induced by D-galactose. The levels of cysteinyl aspartate specific proteinase-1(caspase-1), interleukin-1β(IL-1β), and IL-18 in the supernatant of J774 A.1 mononuclear phagocytes were detected to evaluate the effect of LRH flavonoids on the pyroptosis of mononuclear phagocytes in mice induced by the combination of lipopolysaccharide(LPS) and adenosine triphosphate(ATP). Meanwhile, the effect of LRH flavonoids on the cAMP-PKA signaling pathway was also explored. The optimum conditions for the extraction of LRH flavonoids are listed below extraction temperature of 65 ℃, the ethanol concentration of 50%, extraction time of 60 min, a material-liquid ratio at 1∶25, and the yield of LRH flavonoids of 0.553%. RSM determined the multiple quadratic regression equation model of response value and variables as follows the yield of LRH flavonoids=0.61-0.48A+0.1B+0.029C-0.014D+0.32AB+0.04AC-0.012AD-0.02BC+0.037BD-0.031CD-0.058A~2-0.068B~2-0.069C~2-0.057D~2. LRH flavonoids could effectively inhibit ear swelling and footpad swelling, reduced acetic acid-induced writhing, and delayed the paw licking response time in mice. Additionally, LRH flavonoids could improve the carbon clearance index in immunosuppressed mice, potentiate the activities of SOD and CAT and reduce MDA levels in the liver of aging mice induced by D-galactose, and effectively inhibit macrophage pyroptosis by decreasing the levels of caspase-1, IL-1β, and IL-18. The results reveal that LRH flavonoids possess excellent pharmacological activities such as resisting inflammation and oxidation, relieving pain, and enhancing immunity. They can inhibit pyroptosis by enhancing the cAMP-PKA signaling pathway. The results of this study can underpin the pharmacological research, development, and utilization of LRH.