Yeast exposure in the preparation of steamed rehmannia root improving its effects on alloxan-induced diabetic rats

Yunvjian Improves Glucose and Insulin Function in Diabetic Rats by Regulating Gastric Emptying Function

BACKGROUND

Diet acts on the human body through digestion in the stomach and absorption in the intestines. Thus, the emptying of the stomach should be the focus of the research mechanism of the combined medicine and food treatment of diabetes. The emptying function of the stomach and the secretion of related hormones may be the key points of traditional Chinese medicine. In the clinic, Yunvjian is a famous traditional Chinese formula for preventing and curing diabetes. However, the pharmacological action and mechanism of Yunvjian are also need to be probe.

OBJECTIVE

To assess the effect of Yunvjian on glucose, insulin level and gastric emptying function and related hormones on high-fat diet combined with STZ-induced diabetic rats.

METHODS

High-fat diet combined with STZ was used to construct type 2 diabetes mellitus (T2DM) rats model and received a 4-week Yunvjian administration. The animals were divided into 6 groups, respectively, as the Control group, the DM group, the DM + Acarbose group, the DM + YNH group, and the DM + YNL group. Radionuclide single-photon emission computed tomography (SPECT) technology was used to observe the gastric emptying rate and half-empty time; blood was took to test fasting insulin, and then the insulin resistance index (HOMA-IR) was calculated; HE staining was performed to detect islets and gastric antrum, immunohistochemical staining was performed to detect the number and morphology of pancreatic β cells and gastric antrum Cajal cells, and the average optical density was calculated; the expression of ghrelin hormone in gastric antrum and serum was detected by ELISA and immunofluorescence; the expression of GHRS mRNA in gastric antrum was detected by RT-PCR method.

RESULTS

Yunvjian could significantly improve the glucose level and insulin function of rats. Compared with the DM group, Yunvjian was beneficial to low fasting blood glucose (FBG) (P < 0.01), increased glucose tolerance, and improved islet function at the same time (P < 0.05). At the same time, compared with the DM group (25.02 ± 0.05, 44 ± 12.33), the emptying rate of the DM + YNH group was significantly faster (64.98 ± 0.12), and the half row time was shortened (26 ± 8.29, P < 0.05). The gastric ghrelin levels in each group of Yunvjian increased with different degrees compared with the DM group (616.2 ± 26.23), especially in the DM + YNH group (863.51 ± 23.76, P < 0.01). Correspondingly, the expression of gastric GHSR mRNA in the DM + YNH and DM + YNL groups increased significantly compared with the DM group (P < 0.01).

CONCLUSIONS

Yunvjian can effectively control glucose and improve islet function, which may be closely related to its influence on gastric emptying function and related hormone secretion regulation.

Steamed root of Rehmannia glutinosa Libosch (Plantaginaceae) alleviates methotrexate-induced intestinal mucositis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Intestinal mucositis induced by chemotherapy is a severe clinical problem in cancer patients that currently lack effective interventions. In traditional Chinese medicine, chemotherapeutic toxicity is diagnosed as Qi and Yin deficiency, and steamed rehmannia root (SRR) is frequently prescribed to these patients. Whether SRR can prevent the adverse effects remains to be confirmed experimentally. The present study used a rat model to investigate potential efficacy and action mechanisms of SRR in attenuating the adverse effects caused by chemotherapy.

MATERIALS AND METHODS

Intraperitoneal injection of a single dose of anti-metabolite methotrexate (MTX, 25mg/kg) was given to adult Wistar rats, which also received oral gavage of water or SRR (1.08g/kg twice daily 3 days before and 4 days after MTX treatment), or calcium folinate (CF, a clinically used MTX antidote as a comparison, at 1mg/kg twice daily 36h after MTX treatment), or SRR and CF in combination. Animals were sacrificed 4 days after MTX treatment. Complete blood cell counting was carried out. Jejunum was analyzed histologically for mucosal damage, immunohistochemically for proliferating cell nuclear antigen (PCNA), and biochemically for thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH), as well as for tumor necrosis factor alpha (TNF-α).

RESULTS

MTX treatment led to weight loss, leucopenia, polycythemia, increase in large thrombocyte ratio, intestinal villus atrophy, crypt loss and reduction in PCNA positive crypt cells, increases in mucosal TBARS and TNF-α and decrease in GSH. All these alterations were inhibited by SRR administration except leucopenia, and the effects of CF or CF plus SRR supplementation were found to be inferior to those of SRR.

CONCLUSIONS

SRR can alleviate MTX-induced gut mucositis, which may be achieved by inhibiting MTX-induced oxidative stress and inflammatory response. These findings support the application of SRR in chemotherapy but not the combined application of SRR and CF.