ABSTRACT
Objective: Rehmanniae Radix has been traditionally used to treat diabetes. Catalpol (CAT) and stachyose (STA) are two of the main bioactive compounds in Rehmannia Radix and found to have similar therapeutic effects on diabetes and its complications. In this paper, we aimed to investigate whether there were synergistic therapeutic effects of CAT and STA on diabetes. Methods: Streptozotocin (STZ) with the feeding of high-sugar-high-fat diet (HFD) was applied to induce diabetic C57BL/6 mice. STZ-HFD induced diabetic mice were then divided into model and six medical-treated groups: metformin (MET), STA, CAT, and three combinations of CAT:STA (1:1, 1:2, 2:1). Blood, liver, and kidney samples were isolated after six-week oral administration for biochemical assays of serum lipids, the indicators of kidney and liver functions and HE staining for liver tissues. Results: It turned out that CAT, STA and their three combinations (1:1, 1:2, 2:1) could effectively control body weight, blood glucose, kidney weight and liver weight index, and well regulate levels of TC, HDL-c, TG, ALT, and TBA. In addition, CAT and its combination with STA at the ratio of 2:1 could significantly improve albumin content, compared to that in model group. STA and CAT and their combinations showed the improvements on kidney function in terms of urinary creatinine (Ucr). However, there were no such consistent observations on serum creatinine (Scr) and creatinine clearance rate (Ccr). The combination of CAT and STA at the ratio of 1:1 exhibited the better adjusting effects on kidney weight and liver weight indexes and the levels of ALT, Ucr, Scr, and Ccr. Our results demonstrated that the combinations of CAT and STA especially 1:1 showed similar or better improvements on diabetes-associated complications, compared to the sole CAT or STA treatment. Conclusion: Thus, we concluded that there were synergistic therapeutic effects between CAT and STA on STZ/HFD-induced type 2 diabetes. This project provided insights and technical supports for the innovation of discovering bioactive constituents in Rehmannia Radix and studying its integrative mechanism in curing diabetes.
ABSTRACT
Zebrafish of different strains with 5 dpf (5 days post-fertilization) were selected and fed with 0.2% high-fat diet for 8 h and 3% glucose solution for 16 halternatively during the day and night for 4 consecutive days. The zebrafish model was established and randomly divided into model group, Huangdi Anxiao Capsules (260 mg·L⁻¹) group and pioglitazone (32 mg·L⁻¹) group. The drug treatment groups were given the water-soluble drugs, with a volume of 25 mL, and incubated in a 28 °C incubator for 4 days. To detect the exposure to the corresponding drugs, the normal control group was set up. Thirty zebrafish were included in each group. The effect of Huangdi Anxiao Capsules on vascular wall thickness, fluorescence intensity of islet beta cells, fluorescence intensity of macrophages, and blood flow velocity of zebrafish were detected. The expressions of vascular endothelial growth factor (vegfaa) and angiotensin converting enzyme (ACE) were detected by RT-PCR. The results showed that compared with the model group, Huangdi Anxiao Capsules can significantly reduce the thickness of the blood vessel wall, increase the fluorescence intensity of islet β cells and macrophages, increase the blood flow velocity in vivo, and decrease the ACE and vegfaa expressions in zebrafish. It is suggested that Huangdi Anxiao Capsules may alleviate zebrafish vascular lesions by regulating the expressions of ACE and vegfaa.