Dendrobium Mixture Ameliorates Diabetic Nephropathy in db/db Mice by Regulating the TGF-β1/Smads Signaling Pathway

Impact of baicalin and components of Scutellaria baicalensis on renal fibrosis of diabetic kidney disease

Background

Fibrosis is key in the development and progression of diabetic kidney disease (DKD). Baicalin (BA), wogonin (WGN), and wogonoside (WGS) have renoprotective effects. The mechanism of alleviation of DKD progression, by improving renal fibrosis, is unclear. This study aimed to investigate the mechanisms and effects of a Scutellaria baicalensis Georgi. (Lamiaceae) mixture (MIX, WGN:BA:WGS = 4:2:1) on DKD in a spontaneous DKD model.

Methods

Male db/m mice were controls, and db/db mice were diabetes models. Both groups received daily oral gavage of normal saline. Treatment groups received daily oral gavage of BA or MIX (20 mg/kg) for 10 weeks. Biochemical indicators and kidney lesions were assessed. Fibrosis-related proteins were detected by immunoblotting, immunohistochemistry, and real-time fluorescence quantitative PCR.

Results

MIX significantly reduced body weight (40.97 ± 1.43 vs. 42.26 ± 1.60), improved insulin sensitivity (63.70 ± 8.98 vs. 109.48 ± 0.69), lowered the renal hypertrophy index (19.81 ± 2.86 vs. 28.94 ± 0.256), and decreased blood urea nitrogen levels (7.57 ± 0.79 vs. 9.57 ± 0.38) and the urine protein/creatinine ratio (0.50 ± 0.06 vs. 0.80 ± 0.18). MIX also enhanced lipid profiles and renal function by improving renal tubular dilation, restoring renal structures, and reducing glomerulosclerosis, basal membrane thickening, and glycogen deposition. These effects were achieved by reducing the protein and gene expression of collagen II (Col-II), connective tissue growth factor, and collagen I (Col-I).

Conclusion

MIX inhibits the transforming growth factor-β/Smads signaling pathway, thus alleviating renal fibrosis, and can be used to develop a treatment for DKD.

Dendrobium mixture ameliorates hepatic injury induced by insulin resistance in vitro and in vivo through the downregulation of AGE/RAGE/Akt signaling pathway

Dendrobium mixture (DM) is a patented Chinese herbal medicine which has been shown to ameliorate type 2 diabetes mellitus (T2DM) with non-alcoholic fatty liver disease (NAFLD) in vivo and in vitro. We aimed to investigate the underlying mechanism of DM as a therapeutic agent in attenuating liver steatosis in relation to type 2 diabetes mellitus (T2DM). DM (16.2 g/kg/d) was administered to db/db mice for 4 weeks. The db/m mice and db/db mice in the control and model groups were given normal saline. Additionally, DM (11.25 g/kg/d) was administered to Sprague-Dawley (SD) rats, and the serum was collected and used in an experiment involving palmitic acid (PA)-induced human liver HepG2 cells with abnormal lipid and glucose metabolism. In db/db mice, the administration of DM significantly alleviated liver steatosis, including histological damage and cell apoptosis. DM was found to prevent the upregulation of the RAGE and AKT1 proteins in liver tissues. The underlying mechanism of DM was further studied in PA-induced HepG2 cells. Post-DM administration serum from SD rats reduced lipid accumulation and regulated glucose metabolism in HepG2 cells. Consequently, it inhibited RAGE/AKT signaling and restored autophagy activity. The upregulated autophagy was associated with the mTOR-AMPK signaling pathway. Furthermore, post-DM administration serum reduced apoptosis of hepatocytes in PA-induced HepG2 cells. Our study supports the potential use of DM as a therapeutic agent for the treatment of NAFLD in T2DM. The mechanism underlying this therapeutic potential is associated with the downregulation of the AGE/RAGE/Akt signaling pathway.

Research Progress of Chinese Herbal Medicine Intervention in Renal Interstitial Fibrosis

Chronic kidney diseases usually cause renal interstitial fibrosis, the prevention, delay, and treatment of which is a global research hotspot. However, no definite treatment options are available in modern medicine. Chinese herbal medicine has a long history, rich varieties, and accurate treatment effects. Hitherto, many Chinese herbal medicine studies have emerged to improve renal interstitial fibrosis. This paper reviews the mechanisms of renal interstitial fibrosis and recent studies on the disease intervention with Chinese herbal medicine through literature search, intend to reveal the importance of Chinese herbal medicine in renal interstitial fibrosis. The results show that Chinese herbal medicine can improve renal interstitial fibrosis, and the effects of Chinese herbal medicine on specific pathological mechanisms underlying renal interstitial fibrosis have been explored. Additionally, the limitations and advantages of Chinese herbal medicine in the treatment of renal interstitial fibrosis, possible research directions, and new targets of Chinese herbal medicine are discussed to provide a basis for studies of renal interstitial fibrosis.

Antidiabetic Activity of Hydromethanolic Extract of Crude Dorstenia barnimiana Root: Validation of In Vitro and In Vivo Antidiabetic and Antidyslipidemic Activity

Background

Despite modern therapeutic armamentaria, DM remains a 21st-century public health menace. Novel phytomedicines are a rapidly expanding focus of research. The juice of Dorstenia barnimiana roots has long been used for the treatment of diabetes mellitus in traditional Ethiopian medicine, but its efficacy has not been supported by in vitro or in vivo scientific study. To investigate this, the present work was performed.

Methods

In this experimental study, simple random sampling was applied. Healthy male mice were used in normoglycemic and oral glucose-tolerance test (OGTT) models. Streptozotocin (IP, 150 mg/kg)–administered diabetic male mice were utilized. Animals were randomly divided into five groups of six each. Group I received 10 mL/kg distilled water, groups II–IV received 100 (DB100), 200 (DB200), and 400 (DB400) mg/kg crude extract, respectively, and group V received glibenclamide 5 mg/kg. A sham group (group VI) was added that received 10 mL/kg distilled water. All treatments were given orally. FBG, serum-lipid profiles, and body-weight changes were then measured. In vitro α-amylase inhibitory activity was also evaluated.

Results

The doses were atoxic up to 2,000 mg/kg. There was α-amylase inhibition activity of 67.52% at 500 μg/mL with an IC₅₀ of 4.595 μg/mL. The OGTT revealed an antihyperglycemic effect of the crude extract. This was not attributed to a hypoglycemic side effect. In the diabetic mouse model, it shrank FBG levels remarkably. There were also significant reductions in serum TC, TGs, VLDL-C, and LDL-C. Nevertheless, HDL-C and body-weight levels returned.

Conclusion

The present study confirmed the safety and promising in vivo antidiabetic and antidyslipidemic activity of D. barnimiana, thus corroborating the traditional claim.