Effects of N,N-dimethylformamide on behaviour and regeneration of planarian Dugesia japonica.

In this study, the toxicity, behavioural and regeneration effects of dimethylformamide (DMF) on planarian Dugesia japonica were investigated. One control and six different concentrations of DMF (10 ppm, 100 ppm, 500 ppm, 1000 ppm, 5000 ppm and 10,000 ppm) were used in triplicate. The results showed that the mortality was directly proportional to the DMF concentration and planarian locomotor velocity (pLMV) was significantly reduced by increasing the exposure time and DMF concentration. pLMV of D. japonica was significantly reduced at a lower concentration of 10 ppm after 7 days of continuous exposure to DMF. The recovery of the motility of planarians pretreated with DMF was found to be time- and dose dependent, all planarians had complete recovery in their motility after 48 h. The appearance of auricles in regenerating animals was easily affected by DMF exposure in comparison with the appearance of eyespot. The present results suggest that the intact adult mobility in the aquatic planarian D. japonica is a more sensitive biomarker than mortality, and the appearance of auricles in regenerating animals is a more sensitive biomarker than eyespot.

Berberine alleviates ischemic arrhythmias via recovering depressed I(to) and I(Ca) currents in diabetic rats.

The present study was designed to elucidate the potential mechanism underlying that berberine suppressed ischemic arrhythmias in a rat model of diabetes mellitus (DM). Streptozotocin (STZ)-induced diabetic rats were subjected to ischemia by the occlusion of left anterior descending (LAD) coronary artery. Berberine was orally administered for 7 days before ischemic injury in diabetic rats. Whole-cell patch-clamp was performed to measure the transient outward K⁺ current (I(to)) and L-type Ca²âº current (I(Ca)). Results showed that oral administration of berberine (100 mg/kg) attenuated ischemia-induced arrhythmias in diabetic rats. Berberine significantly shortened the prolonged QTc interval from 214 ± 6ms to 189 ± 5ms in ischemic diabetic rats, and also restored the diminished I(to) and I(Ca) current densities in the same animal model rats. In conclusion, the ability of berberine to protect diabetic rats against cardiac arrhythmias makes it possible to be a prospective therapeutic agent in clinical management of cardiac disease secondary to diabetes.

Berberine elicits anti-arrhythmic effects via IK1/Kir2.1 in the rat type 2 diabetic myocardial infarction model.

The purpose of this study was to explore the anti-arrhythmic mechanisms of berberine in diabetic rats with myocardial infarction. Sixty rats were divided into four groups: (1) normal control; (2) myocardial infarction group (MI); (3) Type 2 diabetes with myocardial infarction group (T2DM+MI); and (4) Type 2 diabetic with myocardial infarction berberine-treated group (BBR). Berberine (60 mg/kg/day) was administered after coronary artery ligation in the T2DM+MI group for 14 days. Currents were measured using whole-cell patch-clamp techniques. Western blot was performed for quantification of target proteins. The study showed that arrhythmias induced by myocardial infarction were aggravated in diabetic rats. Arrhythmia scores in the MI group were significantly higher than in the control group. Interestingly, the administration of berberine at a dose of 60 mg/kg/d recovered arrhythmia scores (P > 0.05). RMP (Resting membrane potential) which could be recovered by berberine (P < 0.05), was significantly reduced in both the infarction groups. I(K1) current and current density markedly decreased in the MI and T2DM+MI groups (P < 0.05) and could be reversed by berberine (P < 0.05). The relative expression of Kir2.1 in rats in the MI and T2DM+MI group were both significantly decreased (P < 0.05); berberine recovered depressed Kir2.1 to nearly normal levels. The results suggest that the effects of berberine on I(K1)/Kir2.1 may be an important mechanism for producing anti-arrhythmic effects.

Prevention of diet-induced obesity by safflower oil: insights at the levels of PPARalpha, orexin, and ghrelin gene expression of adipocytes in mice.

The aim of this study was to investigate the prevention of diet-induced obesity by a high safflower oil diet and adipocytic gene expression in mice. Forty 3-week-old C57BL/6 mice were randomly divided into three groups: control group (CON, 5% lard + 5% safflower oil), high lard group (LAR, 45% lard + 5% safflower oil), and high safflower oil group (SAF, 45% safflower oil + 5% lard). After 10 weeks, 10 mice of the LAR group were switched to high safflower oil diet (LAR-SAF). Ten weeks later, glucose tolerance tests were performed by intraperitoneal injection of glucose. Circulating levels of lipid and insulin were measured and white adipose tissues were taken for gene chip and reverse transcriptase-polymerase chain reaction analysis. The LAR group showed higher body weight, adiposity index, insulin, and lipids than the CON group (P<0.05). The body weight in the LAR-SAF group decreased after dietary reversal. The plasma biochemical profiles decreased in the LAR-SAF and SAF groups (P<0.05) compared with those of the LAR group. The blood glucose level of the LAR-SAF group was reduced during intraperitoneal glucose tolerance test compared with that of the LAR group. The LAR-SAF group had lower levels of Orexin and Ghrelin gene expression, whereas the level of PPARalpha gene expression was significantly enhanced compared with that of the LAR group. So, the SAF diet can alter adipocytic adiposity-related gene expression and result in effective amelioration of diet-induced obesity.