Protective effect of Ramulus Mori(Sangzhi)alkaloids tablets on obese mice and the impact of Ramulus Mori(Sangzhi)alkaloids tablets on gut microbiota

CAO Lei; WU Chunwei; CHEN Hailong; WANG Ruolin; PENG Jin; HE Ze

doi:10.3969/j.issn.1674-3806.2024.05.14

Abstract：Objective To explore the protective effect of Ramulus Mori(Sangzhi)alkaloids tablets(SZ-A)on obese mice and the impact of SZ-A on gut microbiota.Methods Male C57BL/6 mice of specific pathogen free(SPF)grade were selected and an obese mouse model was induced in these mice by feeding them with a high-sugar and high-fat diet for 12 weeks.The successfully modeled mice were randomly divided into model group(M group),positive control group(PC group),low-dose SZ-A group(SZ-L group),medium-dose SZ-A group(SZ-M group)and high-dose SZ-A group(SZ-H group),with 10 mice in each group.Additionally,10 normal mice were set as the blank group(N group).The PC group was given simvastatin suspension(2.6 mg/kg)by gavage.The SZ-L group,the SZ-M group and the SZ-H group were orally administered with SZ-A at doses of 20 mg/kg,40 mg/kg and 80 mg/kg,respectively.The N group and the M group were given equal volume of distilled water by gavage.All the groups were given intragastric administration once a day for 12 weeks.Lee's index,body mass,biochemical indicators,pathological change of inguinal white adipose tissues(iWAT),gut microbiota α and β diversity,and relative abundance of gut microbiota were compared among the groups.Results There were statistically significant differences in Lee's index,body mass,and serum total cholesterol(TC),triglyceride(TG),high-density lipoprotein cholesterol(HDL-C)and low-density lipoprotein cholesterol(LDL-C)levels among the groups(P＜0.05).Adipocytes in the N group were closely arranged,with a large number and small volume of adipocytes in the same field of view.The volume of adipocytes in the M group increased significantly.Compared with that in the M group,the volume of adipocytes in the PC group and the SZ-L group decreased slightly.The number of adipocytes in the SZ-M group and the SZ-H group increased obviously and the cell volume decreased obviously,tending towards those in the N group.The Ace index in the SZ-H group was significantly higher than that in the M group,the PC group and the SZ-L group(P＜0.05).The Chao index in the SZ-H group was significantly higher than that in the PC group and the SZ-L group(P＜0.05).The Shannon index in the SZ-H group was significantly higher than that in the M group,the PC group,the SZ-L group and the SZ-M group(P＜0.05).The Coverage index in each group approached 1.The results of PCoA analysis showed that the separation degrees of the N group,the M group,the PC group,the SZ-L group,the SZ-M group and the SZ-H group were relatively good,and the horizontal linear distance between the N group and the M group was relatively far,and the microbial community structure in the SZ-L group,the SZ-M group and the SZ-H group gradually tended towards that in the N group.The results of non-metric multidimensional scaling(NMDS)analysis showed a Stress value of 0.131.At the phylum level,compared with the M group,the SZ-H group exhibited significantly lower relative abundances of Firmicutes and Patescibacteria(P＜0.05),and significantly higher relative abundance of Bacteroidota(P＜0.05).At the genus level,compared with the M group,the SZ-H group showed signifi-cantly higher relative abundance of norank_f_Muribaculaceae(P＜0.05),and significantly lower relative abundances of unclassified_f_Lachnospiraceae,norank_f norank_o_Clostridia_UCG-014 and Desulfovibrio(P＜0.05).Conclusion SZ-A can partially resist the increase of body mass and the expansion of adipose tissues induced by a high-sugar and high-fat diet in obese mice,improves their lipid metabolism,enhances microbial species diversity,and increases the relative abundances of partial microbial species.