Danshen modulates Nrf2-mediated signaling pathway in cisplatin-induced renal injury.

Danshen, an efficacious agent for cardiovascular diseases, has been found to play an essential role in kidney injury. In the present study, the effect of Danshen on cisplatin-induced renal dysfunction was investigated in a mouse model. Danshen was administered to mice at a dose of 3 g/kg 4 days before and 3 days after cisplatin treatment. A single intraperitoneal injection of 20 mg/kg cisplatin was used to induce nephrotoxicity. The mice were sacrificed 72 h after cisplatin intoxication. Biochemical parameters including serum creatinine and blood urea nitrogen were analyzed. Histopathological changes of kidney tissues were detected using HE staining. Antioxidant enzymes (GSH-Px and SOD) and peroxidative product (MDA) were detected. Protein expressions of Nrf2 and its target genes including HO-1 and NQO1 were measured by Western blotting. The results showed that pretreatment with Danshen significantly reduced serum creatinine and blood urea nitrogen in the cisplatin-treated mice. Histopathological examination showed that Danshen mitigated the renal damage induced by cisplatin. Moreover, Danshen restored the activities of antioxidant enzymes (GSH-Px and SOD) and normalized the MDA contents in renal tissues. Western blotting revealed that Danshen enhanced the expressions of Nrf2 and its target genes in cisplatin-exposed mice. It was suggested that Danshen protects against the cisplatin-induced renal impairment in the mice, which is potentially associated with the upregulation of Nrf2-mediated signaling pathway.

Ethanol Extract of Fructus ligustri lucidi Increased Circulating 1,25(OH)2D3 Levels, but Did Not Improve Calcium Balance in Mature Ovariectomized Rats.

Our previous studies found that different extracts or fractions of Fructus ligustri lucidi (FLL) played different roles in altering the regulation of bone and mineral metabolism in different animal models. The present study was designed to compare the actions of FLL ethanol (EE) and water extracts (WE) on bone and mineral metabolism in a 6-month-old mature ovariectomized (OVX) rat model. Our results showed that FLL extracts did not significantly improve systematic Ca balance in mature OVX rats. However, EE, but not WE treatment, significantly increased serum 1,25(OH)2D3 levels in mature OVX rats. An in vitro study using human proximal tubule (HKC-8) cells showed that EE, but not WE, significantly enhanced renal 25-dihydroxyvitamin D3-1[Formula: see text]-hydroxylase (1-OHase) mRNA expressions and simultaneously repressed renal 25-dihydroxyvitamin D3-24-hydroxylase (24-OHase) mRNA expressions. Further investigation indicated that EE could significantly induce the protein expression of 1-OHase, but did not alter 24-OHase expression in HKC-8 cells. Our results demonstrated that EE increased circulating 1,25(OH)2D3 levels in OVX rats, possibly via upregulation of renal 1-OHase expressions in renal proximal tubule cells. Our study indicates that FLL is a natural oral agent that could directly regulate renal vitamin D metabolism in vivo and in vitro.

A High-Saturated-Fat, High-Sucrose Diet Aggravates Bone Loss in Ovariectomized Female Rats.

BACKGROUND: Estrogen deficiency in women and high-saturated fat, high-sucrose (HFS) diets have both been recognized as risk factors for metabolic syndrome. Studies on the combined actions of these 2 detrimental factors on the bone in females are limited. OBJECTIVE: We sought to determine the interactive actions of estrogen deficiency and an HFS diet on bone properties and to investigate the underlying mechanisms. METHODS: Six-month-old Sprague Dawley sham or ovariectomized (OVX) rats were pair fed the same amount of either a low-saturated-fat, low-sucrose (LFS) diet (13% fat calories; 15% sucrose calories) or an HFS diet (42% fat calories; 30% sucrose calories) for 12 wk. Blood, liver, and bone were collected for correspondent parameters measurement. RESULTS: Ovariectomy decreased bone mineral density in the tibia head (TH) by 62% and the femoral end (FE) by 49% (P < 0.0001). The HFS diet aggravated bone loss in OVX rats by an additional 41% in the TH and 37% in the FE (P < 0.05). Bone loss in the HFS-OVX rats was accompanied by increased urinary deoxypyridinoline concentrations by 28% (P < 0.05). The HFS diet induced cathepsin K by 145% but reduced osteoprotegerin mRNA expression at the FE of the HFS-sham rats by 71% (P < 0.05). Ovariectomy significantly increased peroxisome proliferator-activated receptor γ mRNA expression by 136% and 170% at the FE of the LFS- and HFS-OVX rats, respectively (P < 0.05). The HFS diet aggravated ovariectomy-induced lipid deposition and oxidative stress (OS) in rat livers (P < 0.05). Trabecular bone mineral density at the FE was negatively correlated with rat liver malondialdehyde concentrations (R(2) = 0.39; P < 0.01). CONCLUSIONS: The detrimental actions of the HFS diet and ovariectomy on bone properties in rats occurred mainly in cancellous bones and were characterized by a high degree of bone resorption and alterations in OS.

Combination treatment with Fructus Ligustri Lucidi and Puerariae radix offsets their independent actions on bone and mineral metabolism in ovariectomized rats.

OBJECTIVE: The aim of this study was to evaluate the efficacy of Fructus Ligustri Lucidi (FLL) and Puerariae radix (PR) combination treatment in bone and mineral metabolism in ovariectomized (OVX) rats in our search for an alternative regimen for the management of postmenopausal osteoporosis. METHODS: Six-month-old OVX rats were used as postmenopausal osteoporotic models, and PR water extract (PR) and FLL water extract (WE) were added to commercial diets individually or in combination and administered to OVX rats for 12 weeks. Bone properties, calcium and phosphorus absorption, and bone biochemical markers were measured to investigate the potential interactions between the actions of PR and the actions of WE on bone and mineral metabolism in OVX rats. RESULTS: Long-term treatment with PR did not significantly improve bone properties but greatly ameliorated the secondary hyperparathyroidism induced by ovariectomy in the animals. WE significantly enhanced the intestinal calcium absorption rate and decreased the enlarged trabecular bone surface at the site of metaphysic tibia in OVX rats. However, the positive effects of WE or PR alone on bone and mineral metabolism were diminished when OVX rats were cotreated with WE and PR. CONCLUSIONS: The combination of these two herbs offsets their independent actions on bone and mineral metabolism in vivo. The results of the present study could provide insights to medical professionals to further their understanding of the potential negative impact of herb-herb interactions when a combination of herbal mixtures is used for the management of osteoporosis.