Intestinal flora: A new target for traditional Chinese medicine to improve lipid metabolism disorders

Comprehensive evaluation of Dragon's Blood in combination with borneol in ameliorating ischemic/reperfusion brain injury using RNA sequencing, metabolomics, and 16S rRNA sequencing

Ischemia/reperfusion (IR) can induce deleterious responses such as apoptosis, inflammation, and oxidative stress; however, there are currently no efficient therapeutics to treat IR brain injury. Dragon's blood (DB) plays a significant role in treating ischemic stroke in China. Borneol (B) is an upper ushering drug that guides drugs to the target organs, including the brain. Therefore, we hypothesized that the combination of DB and B (DB + B) would provide cooperative therapeutic benefits for IR brain injury. To confirm this, we first investigated the protective effect of DB + B in an IR brain injury rat model using the modified neurological severity score (mNSS), infarction size measure, HE staining, and laser speckle contrast imaging. Then, we comprehensively evaluated the mechanism of DB + B in ameliorating IR brain injury based on RNA sequencing, serum untargeted metabolomics, and 16S rRNA sequencing. We have confirmed that DB + B enhanced the efficacy of the ischemic stroke treatment compared to DB or B alone for the first time. Our study provisionally confirms that the mechanism by which DB + B prevents IR brain injury is related to the maintenance of intestinal microecological balance and regulation of metabolic dysfunction, thereby suppressing inflammation and regulating immunity. DB + B may effectively regulate intestinal flora including o_Pseudomonadales, s_Bacteroides_caecimuris, o_unidentified_Bacilli, f-Pseudomonadaceae, and g-Pseudomonas, mainly regulate serum metabolites including improve the protective benefit of IR brain injury lysoPCs and lysoPEs, thus inhibiting TLR4/MyD88/NF-κB and IL-17 signing pathway to reduce inflammatory reactions. hat this mechanism is associated with the maintenance of intestinal flora balance and the regulation of metabolic dysfunction, thereby suppressing inflammation and regulating immunity. This provides scientific support for the clinical translation of DB + B in the prevention and treatment of ischemic stroke and establishes a basis for further investigation of its therapeutic mechanism.

[Yacon root extract improves lipid metabolism in hyperlipidemic rats by inhibiting HMGCR expression and activating the PPARα/CYP7A1/CPT-1 pathway]

OBJECTIVE

To investigate the effect of yacon root extract on lipid metabolism in rats with hyperlipidemia (HLP) and its underlying mechanisms.

METHODS

SD rat models of HLP induced by high- fat diet feeding for 8 weeks were randomized into the model group, fenofibrate treatment group (27 mg/kg), and yacon extract treatment groups at doses of 5, 2.5 and 1.25 g/kg (n=10). The rats were given corresponding drug treatments via gavage for 8 weeks. After the treatments, the rats were observed for body weight changes, liver coefficient, liver pathology, and serum levels of triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). The mRNA and protein expressions of HMGCR, PPARα, CYP7A1, and CPT-1 in the liver were detected using RT-qPCR and Western blotting.

RESULTS

Compared with those in the model group, the rats treated with fenofibrate and 5 g/kg yacon root extract showed significantly slower body weight gain and lower liver coefficient (P < 0.05) with lower serum levels of TG, TC, and LDL- C (P < 0.05) but higher HDL- C level (P < 0.05). The HLP rat models showed obvious fatty degeneration and vacuolar changes in the liver, which were significantly alleviated by fenofibrate treatment and by treatment with yacon root extract in a dose-dependent manner. Both fenofibrate and 5 g/kg yacon root extract significantly lowered the mRNA and protein expression levels of HMGCR (P < 0.001) and increased the expressions of PPARα, CYP7A1, and CPT-1 in the liver of HLP rats (P < 0.001).

CONCLUSION

Yacon root extract can reduce serum TG and TC levels in HLP rats possibly by inhibiting HMGCR expression and activating the PPARα/CYP7A1/CPT-1 signaling pathway, thereby promoting fatty acid β oxidation and bile acid metabolism.