Prenatal exposure to corn oil, CMC-Na or DMSO affects physical development and multi-organ functions in fetal mice.

Corn oil, sodium carboxymethyl cellulose (CMC-Na), and dimethyl sulfoxide (DMSO) are widely used as solvents or suspensions in animal experiments, but the effects of prenatal exposure to them on fetal development have not been reported. In this study, Kunming mice were given a conventional dose of corn oil (9.2 g/kg·d), CMC-Na (0.05 g/kg·d) or DMSO (0.088 g/kg·d) during gestation days 10-18, and the pregnancy outcome, fetal physical development, serum phenotype, and multi-organ function changes were observed. The results showed that corn oil decreased serum triglyceride level in males but increased their serum testosterone and CORT levels, and affected female placenta and female/male multi-organ functions (mainly bone, liver, kidney). CMC-Na increased female/male body lengths and tail lengths, decreased serum glucose and total cholesterol levels in males as well as increased their serum LDL-C/HDL-C ratio and testosterone level, decreased female serum bile acid level, and affected male/female placenta and multi-organ functions (mainly bone, liver, hippocampus). DMSO decreased male body weight and serum glucose level, decreased male/female serum bile acid levels, and affected male/female placenta and multi-organs functions (mainly bone, hippocampus, adrenal gland). In conclusion, prenatal exposure to a conventional dose of corn oil, CMC-Na or DMSO could affect fetal physical development and multi-organ functions, and has the characteristics of "multi-pathway, multi-organ and multi-target". This study provides the experimental basis for the rational selection of solvents or suspensions in pharmacology and toxicology studies.

Protective effect of sinomenine on cartilage degradation and chondrocytes apoptosis.

Sinomenine (SIN), an alkaloid extracted from the stem of the Chinese medicinal plant sinomenium acutum, has been used for treating rheumatoid arthritis. But little is known whether SIN has a protective effect on osteoarthritis (OA). In this study, we investigated the protective effect of SIN on IL-1beta-induced proteoglycan degradation and apoptosis in rabbit articular cartilage and chondrocytes. Treatment with 10 ng/ml IL-1beta increased the level of glycosaminoglycan (GAG) released into the culture media, and up-regulated the activity and mRNA expression of matrix metalloproteinase 13 (MMP-13) and down-regulated the activity and mRNA expression of tissue inhibitor of metalloproteinase 1 (TIMP-1) in cartilage explants, as confirmed by the methods of GAG quantitation, MMP-13/TIMP-1 enzyme-linked immunosorbent assay (ELISA) and real-time quantitative RT-PCR. Treatment with 10 ng/ml IL-1beta resulted in marked apoptosis in chondrocytes, as demonstrated by decreased cell viability, occurrence of DNA laddering and increased caspase-3 activity and annexin V binding of phosphatidylserine. However, simultaneous treatment with SIN (10, 50 or 250 microM) inhibited the GAG release and the activity and mRNA expression of MMP-13, and enhanced the activity and mRNA expression of TIMP-1 in a dose-dependent manner in cartilage explants. Furthermore, DNA fragment, caspase-3 activity and apoptosis rate were down-regulated, and cell viability was up-regulated dose-dependently in chondrocytes. Thus, SIN has the protective capacity to antagonize cartilage degradation and chondrocyte apoptosis, which suggest that SIN may act as an agent for pharmacological intervention in the progress of OA.

The protective effect of tetramethylpyrazine on cartilage explants and chondrocytes.

AIMS OF STUDY: Ligusticum wallichi Franchat (chuanxiong) is a very common traditional Chinese herbal medicine in China. Tetramethylpyrazine (TMP) is a major active ingredient extracted from Ligusticum wallichi Franchat. We investigated the protective effect of TMP on interleukin-1ß (IL-1ß) induced proteoglycan (PG) degradation and apoptosis in rabbit articular cartilage and chondrocytes. MATERIALS AND METHODS: Rabbit articular cartilage explants and chondrocytes were cultured with 10 ng/ml IL-1ß for 72 h in the absence or presence of various concentrations of TMP (50, 100 or 200 µM). Cartilage and chondroprotective effects of TMP were determined by evaluating (1) the degree of PG degradation by measuring the amount of glycosaminoglycan (GAG) released into the culture media with 1,9-dimethylmethylene blue (DMMB) assay in cartilage explants; (2) gene expression of MMP-3 and TIMP-1 by real-time quantitative reverse transcription-polymerase chain reaction analysis in cartilage explants; (3) chondrocytes viability with MTT assay; (4) the production of intracellular reactive oxygen species (ROS) with laser scanning confocal microscopy (LSCM). Anti-apoptotic effects of TMP were determined by measuring (1) apoptosis with flow cytometric analysis; (2) mitochondrial membrane potential assay with LSCM; (3) caspase-3 activity with special assay kit. RESULTS: IL-1ß treatment increased the level of GAG released into the culture media, and induced the gene expression of MMP-3 and inhibited the gene expression of TIMP-1 in cartilage explants. Moreover, IL-1ß treatment decreased the cell viability and mitochondrial membrane potential, and enhanced the level of intracellular ROS, apoptosis rate, and caspase-3 activity in chondrocytes. However, simultaneous treatment with TMP attenuated the IL-1ß-induced cartilage and chondrocyte destruction in a dose-dependent manner. TMP showed the decrease of GAG degradation and MMP-3 mRNA production, and the enhancement of TIMP-1 mRNA production in cartilage explants. TMP also increased the cell viability in chondrocytes. Furthermore, TMP inhibited the chondrocytes apoptosis through suppression of ROS production, maintaining of mitochondrial membrane potential and downregulation of caspase-3 activity. CONCLUSION: These results demonstrate that TMP has the cartilage and chondroprotective effect, which suggest that TMP could act as an agent for pharmacological intervention in the progress of OA.

Effects of 18alpha-glycyrrhizin on the pharmacodynamics and pharmacokinetics of glibenclamide in alloxan-induced diabetic rats.

This paper investigated the effects of 18alpha-glycyrrhizin (18alpha-GL) on the pharmacodynamics and pharmacokinetics of glibenclamide in experimental diabetic rats. 18alpha-GL (25 mg/kg) and/or glibenclamide (1 mg/kg) were given to alloxan-induced diabetic rats for consecutive 5 days. When the rats were co-treated with 18alpha-GL and glibenclamide, fasting plasma glucose concentration was further reduced, plasma insulin content and liver glycogen level were increased markedly as compared with glibenclamide-treated animals. Meanwhile, in co-treated group, elimination rate constant (Ke) of glibenclamide was reduced while peak plasma concentration (C(max)), area under the plasma concentration vs time curve (AUC(0-14 h)) and elimination half-life (T(1/2Ke)) were increased significantly vs glibenclamide alone administered rats. The activities of hepatic CYP3A and the markers of liver injury, plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST), were significantly decreased in rats treated with 18alpha-GL alone and in combination with glibenclamide. Results of immunohistochemistry showed that 18alpha-GL improved the effects of glibenclamide on the pathological morphology of pancreatic islet beta cells and the intensities of positive immunostaining for insulin. Our results revealed that 18alpha-GL led to the enhancement of the hypoglycemic effect of glibenclamide by inhibiting the activity of CYP3A; on the other hand, 18alpha-GL protected the pancreatic islet beta cells and liver from damage in diabetes which suggested that 18alpha-GL might be beneficial as an adjuvant drug of glibenclamide in a proper dose, especially to the diabetic patients associated with liver dysfunction.