Microbiota-derived short-chain fatty acids mediate the effects of dengzhan shengmai in ameliorating cerebral ischemia via the gut-brain axis

Ethnopharmacological relevance: Dengzhan shengmai (DZSM) formula, composed of four herbal medicines (Erigeron breviscapus, Panax ginseng, Schisandra chinensis, and Ophiopogon japonicus), is widely used in the re-covery period of ischemic cerebrovascular diseases; however, the associated molecular mechanism remains unclear.Aim of the study: The purpose of this study was to uncover the links between the microbiota-gut-brain axis and the efficacy of DZSM in ameliorating cerebral ischemic diseases. Materials and methods: The effects of DZSM on the gut microbiota community and bacteria-derived short-chain fatty acid (SCFA) production were evaluated in vivo using a rat model of cerebral ischemia and in vitro through the anaerobic incubation with fresh feces derived from model animals. Subsequently, the mechanism underlying the role of SCFAs in the DZSM-mediated treatment of cerebral ischemia was explored. Results: We found that DZSM treatment significantly altered the composition of the gut microbiota and markedly enhanced SCFA production. The consequent increase in SCFA levels led to the upregulation of the expression of monocarboxylate transporters and facilitated the transportation of intestinal SCFAs into the brain, thereby inhibiting the apoptosis of neurocytes via the regulation of the PI3K/AKT/caspase-3 pathway. The increased intestinal SCFA levels also contributed to the repair of the 2VO-induced disruption of gut barrier integrity and inhibited the translocation of lipopolysaccharide from the intestine to the brain, thus attenuating neuro-inflammation. Consequently, cerebral neuropathy and oxidative stress were significantly improved in 2VO model rats, leading to the amelioration of cerebral ischemia-induced cognitive dysfunction. Finally, fecal microbiota transplantation could reproduce the beneficial effects of DZSM on SCFA production and cerebral ischemia.Conclusions: Our findings suggested that SCFAs mediate the effects of DZSM in ameliorating cerebral ischemia via the gut microbiota-gut-brain axis.

Automated summary

This study revealed that the Dengzhan shengmai (DZSM) formula improves cerebral ischemic diseases by regulating the gut microbiota and their production of short-chain fatty acids (SCFAs). DZSM treatment altered the gut microbiota composition and enhanced SCFA production, leading to the inhibition of neurocyte apoptosis and the improvement of cerebral neuropathy and oxidative stress. Additionally, DZSM repaired gut barrier integrity, reduced endotoxin translocation, and attenuated neuro-inflammation.