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
Objective To evaluate Brachychiton acerifolius leaf extracts as antidiabetic potential agent and to identify the main active constituents using bioactivity guided fractionation. Methods In vitro antioxidant activity was evaluated for B. acerifolius different extracts using DPPH assay and vitamin C as control. Antidiabetic activity was then determined using STZ-induced rats treated daily with ethyl acetate and 70% ethanol leaf extracts for 4 weeks at a dose of 200 g/kg body weight against gliclazide reference drug. Blood glucose, α-amylase, lipid profile, liver function enzymes and oxidative stress markers were assessed along with histopathological study for liver and pancreatic tissues. Isolation and structural elucidation of active compounds were made using Diaion and Sephadex followed by spectral analyses. Results The results indicated that ethyl acetate and ethanol leaf extracts exhibited the strongest antioxidant activity compared to that of vitamin C (IC
ABSTRACT
Objective:To evaluate Brachychiton acerifolius leaf extracts as antidiabetic potential agent and to identify the main active constituents using bioactivity guided fractionation.Methods:In vitro antioxidant activity was evaluated for B.acerifolius different extracts using DPPH assay and vitamin C as control.Antidiabetic activity was then determined using STZ-induced rats treated daily with ethyl acetate and 70％ ethanol leaf extracts for 4 weeks at a dose of 200 g/kg body weight against gliclazide reference drug.Blood glucose,α-amylase,lipid profile,liver function enzymes and oxidative stress markers were assessed along with histopathological study for liver and pancreatic tissues.Isolation and structural elucidation of active compounds were made using Diaion and Sephadex followed by spectral analyses.Results:The results indicated that ethyl acetate and ethanol leaf extracts exhibited the strongest antioxidant activity compared to that of vitamin C (IC50 0.05,0.03 and 12 mg/mL,respectively).Both extracts showed potent anti-hyperglycemic activity evidenced by a significant decrease in serum glucose levels by 82.5％ and 80.9％ and α-amylase by 45.2％ and 53.6％,as compared with gliclazide 68％ and 59.4％,respectively.Fractionation of ethanol extract resulted in the isolation of 9 flavonoids including apigenin-7-O-α-rhamnosyl(1 → 2)-β-D-glucuronidc,apigenin-7-O-β-D-glucuronide,apigcnin-7-O-β-D-glucoside and luteolin-7-O-β-D-glucuronide.Conclusions:This study highlights the potential use of B.acerifolius leaf extract enriched in flavones for the treatment of diabetes that would warrant further clinical trials investigation.