Ameliorating effect of Trigonella foenum-graecum L. (fenugreek) extract tablet on exhaustive exercise-induced fatigue in rats by suppressing mitophagy in skeletal muscle

OBJECTIVE

Trigonella foenum-graecum L. (fenugreek) is widely used as a leafy vegetable and spice in China and North Africa. Recent studies have reported that fenugreek can reduce fatigue; however, its antifatigue mechanism remains unclear. Therefore, this study aimed to investigate the potential antifatigue effects of fenugreek extract (FE) on mitophagy and the underlying mechanisms.

MATERIALS AND METHODS

We evaluated the potential effects of FE tablet on an exhaustive exercise-induced fatigue (EEF) rat model. Oxidative stress indicators and fatigue biomarkers in the serum and skeletal muscle were detected. Mitophagy and mitochondrial morphology were observed using transmission electron microscopy. The expression levels of mitochondrial autophagy-related proteins were detected using western blot and immunofluorescence.

RESULTS

Compared with the model group, FE enhanced the activities of the antioxidant enzymes superoxide dismutase and glutathione peroxidase as well as total antioxidant capacity; however, it decreased the level of malondialdehyde in the serum and skeletal muscle after a 7-day treatment. Moreover, certain indicators of mitochondrial function, such as reactive oxygen species levels, ATP levels, cellular and mitochondrial Ca2+ levels, and ATPase activity, were significantly improved in the FE group compared with the model group. Finally, we found that mitophagy was induced by exhaustive exercise and inhibited by FE. Regarding mitochondrial autophagy-related proteins, the expression levels of LC3B, FUNDC1, PGAM5, PARKIN, and PINK1 in the skeletal muscle tissue were increased in the EEF group compared with the control group. After administration of FE and a positive control drug, a significant reversal in the expression of the above-mentioned proteins was noted.

CONCLUSIONS

Our findings demonstrate that FE exerted antifatigue effects in the EEF rat model by regulating the mitophagy-related FUNDC1/LC3B signaling pathway rather than the PINK1/PARKIN signaling pathway.

CircRNA ZNF609 promotes growth and metastasis of nasopharyngeal carcinoma by competing with microRNA-150-5p

OBJECTIVE

This study aims to explore the biological function of circular RNA ZNF609 (circ-ZNF609) in regulating the occurrence and progression of nasopharyngeal carcinoma (NPC), and to investigate the possible underlying mechanism.

PATIENTS AND METHODS

The expression levels of circ-ZNF609, microRNA-150-5p and Sp1 in NPC tissues and normal nasopharyngeal epithelial tissues were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Circ-ZNF609 expression was silenced in NPC cell lines (5-8F and HONE-1). Cellular behaviors of NPC cells were determined using Cell Counting Kit-8 (CCK-8), wound healing and transwell assay. The binding relationship among microRNA-150-5p, circ-ZNF609 and Sp1 was detected by Dual-Luciferase reporter gene assay. In addition, the protein expression of Sp1 after altering expression of circ-ZNF609 or microRNA-150-5p was detected by Western blot.

RESULTS

The expression levels of circ-ZNF609 and Sp1 in NPC tissues were markedly higher than those of normal nasopharyngeal epithelial tissues. However, the expression of microRNA-150-5p was significantly lower in NPC tissues. The knockdown of circ-ZNF609 in NPC cells 5-8F and HONE-1 significantly inhibited the proliferative, migratory and invasive behaviors of NPC cells. Meanwhile, microRNA-150-5p knockdown in NPC cells showed the opposite effect on cellular behaviors of NPC cells. Dual-Luciferase reporter gene assay revealed that circ-ZNF609 could bind to microRNA-150-5p, and Sp1 was a target gene of microRNA-150-5p. Western blot results showed that circ-ZNF609 could stabilize the expression of Sp1, while microRNA-150-5p degraded Sp1 expression. Furthermore, the knockdown of Sp1 in NPC cells reversed the carcinogenic effect of circ-ZNF609.

CONCLUSIONS

Highly expressed circ-ZNF609 adsorbs microRNA-150-5p to upregulate Sp1 expression, thereby promoting the proliferation and metastatic ability of NPC cells.

[Efficacy and safety of endonasal phototherapy in the treatment of adult allergic rhinitis: A Meta-analysis]

Objective:To perform a systematic review of the efficacy and safety of endonasal phototherapy in the treatment of AR, and to provide evidence of evidence-based medicine for clinical application. Method:Databases were from PubMed, Embase, Cochrane Library, Chinese Academic Journal Full-text Database (CNKI) and Wanfang database. A randomized controlled trial (RCT) or clinical study literature on intranasal phototherapy for adult AR is available, and the deadline is March 2017. Based on the literature inclusion and exclusion criteria, the related literatures were selected and the quality was evaluated by using the Cochrane inclusion bias assessment table. Meta-analysis was performed with Revman 5.3 software. For continuous outcomes, the weighted mean difference (WMD) and its 95% confidence intervals (CI) were calculated, forest maps and funnel plots were drew. For uncontinuous outcomes, the odds ratio (OR) and its 95%CI were calculated, and forest maps and funnel plots were drew. The efficacy included total nasal symptom scores (TNSS), rhinoconjunctivitis quality of life questionnaire (RQLQ) and palate itching scores, and the safety was assessed by incidence rate of severe drying and mild drying of nasal mucosa. Result:A total of 12 articles were selected, including 5 RCT and 7 clinical studies, and there were 615 adult AR patients. The Meta-analysis shows that endonasal phototherapy significantly reduced the TNSS, RQLQ and palate itching scores, the incidence rate of mild drying of nasal mucosa was higher in comparison with pretreated values, and the difference was statistically significant (P<0.05). The rate of severe drying of nasal mucosa was higher, but the difference was not statistically significant (P>0.05). It also shows that endonasal phototherapy significantly reduced the TNSS, RQLQ and palate itching scores, and the rate of mild drying of nasal mucosa was higher in comparison with placebo and antihistamines groups, and the difference was statistically significant. The rate of severe drying of nasal mucosa was higher, but the difference was not statistically significant. Conclusion:Endonasal phototherapy can improve the symptoms of TNSS, RQLQ and palate itching score in patients, and the safety is also confirmed.Patients who are not satisfied with symptom relief may choose to use it.

Genome-wide analysis of DNA methylation variations caused by chronic glucolipotoxicity in beta-cells

There is a growing body of literature suggesting the role of interactions between genes and the environment in development of type 2 diabetes mellitus (T2DM). However, the interplay between environment and genetic in developing and progressing T2MD is not fully understood. To determine the effects of high-glucose-lipid on the status of DNA methylation in beta cells, and clarify the mechanism of glucolipotoxicity on beta-cell deterioration, the DNA methylation profile was detected in beta-cells cultured with high-glucose-lipid medium.We utilized a high throughput NimbleGen RN34 CpG Island & Promoter Microarray to investigate the DNA methylation profile in beta-cells cultured with high-glucose-lipid medium. To validate the results of microarray, the immunoprecipitation (MeDIP) PCR was used to test the methylation status of some selected genes. The mRNA and protein expression of insulin and Tcf7l2 in these cells were quantified by RT-PCR and western blot, respectively.We have identified a lot of loci which experienced aberrant DNA methylation in beta-cells cultured with high-glucose-lipid medium. The results of MeDIP PCR were consistency to the microarray. An opposite regulation in transcription and translation of Tcf7l2 gene was found. Furthermore, the insulin mRNA and protein expression in beta-cells also decreased after cultured with high-glucose-lipid medium compared with the control cells.We conclude that chronic glucolipotoxicity could induce aberrant DNA methylation of some genes and may affect these genes expression in beta-cells, which might contribute to beta-cell function failure in T2DM and be helpful to explain, at least partially, the mechanism of glucolipotoxicity on beta-cells deterioration.

[Effect of pulse current iontophoretic transdermal delivery of insulin on blood glucose in diabetic rats]

Iontophoresis of pulse current with various current intensity, frequency, on/off ratio and duration of treatment was used to facilitate the transdermal delivery of insulin in order to control blood glucose levels in diabetic rats. Male Sprague-Dawley rats were made diabetic by i.p. injection of streptozotocin (65 mg . kg-1 body weight). After two days, diabetic rats were anaesthetized with urethane (as 25% aqueous solution, 1.5 mg . g-1). Both the reservoir electrodes and the receptor electrodes were applied on the abdominal site of the diabetic rats. Iontophoresis was carried out using a prototype transdermal periodic iontophoretic system in order to provide the required direct current with desired pulse modes. The extent of reduction of blood glucose levels was found to be positively correlated with the current intensity, frequency and duration of treatment to some extent. But when the current intensity was over 0.8 mA/cm2 and the frequency was over 3000 Hz, the reduction of blood glucose levels did not continuously increase. Blood glucose levels were found to be better controlled when the on/off ratio of 1 : 1 was used.

[Effects of silybin on red blood cell sorbitol and nerve conduction velocity in diabetic patients]

The effects of silybin on red blood cell (RBC) sorbitol and nerve conduction velocity in 14 non-insulin dependent diabetic patients (female 9, male 5; average age 58.2 years) were reported. Their RBC sorbitol levels averaged 72.55 +/- 21.61 nmol/g.Hb, a value almost two times of non-diabetic controls (33.31 +/- 7.82 nmol/g.Hb). After 4 weeks of silybin (231 mg/d) therapy, RBC sorbitol dropped to 39.53 +/- 14.94 nmol/g.Hb, a highly significant reduction than that before silybin therapy. Silybin treatment had no effect on fasting blood glucose. In addition, silybin treatment slightly improved nerve conduction velocity, but statistically not significant. This report suggests that silybin may be a potent aldose reductase inhibitor, and valuable in the prophylaxis and treatment of diabetic complications.

Effects of nicotinamide on cardiac contraction force and slow inward current

The effects of nicotinamide (Nic) on cardiac contraction force and on slow inward current (Isi) in guinea pigs were studied with atrial strips and voltage clamp techniques. Verapamil (Ver), MnCl2, nifedipine (Nif), and propranolol (Pro) depressed markedly the positive inotropic effect induced by Nic in a noncompetitive manner. The pD2 values of Ver, MnCl2, Nif, and Pro were 6.19, 3.41, 5.00, and 6.43, respectively. The action of Nic was reduced by a low Ca2+ Tyrode solution and disappeared in a Ca(2+)-free solution. Nic 33 mmol.L-1 elevated the Isi from 6.5 +/- 1.3 microA to 10.3 +/- 2.2 microA. The results suggest that Nic promotes the Ca2+ influx and its site of action is different from that of both Pro and the calcium antagonists.

[Inhibition of aldose reductase by Chinese herbal medicine]

Seven Chinese herbal drugs were screened for experimental inhibition of lens aldose reductase activity, among which quercetin exhibited potent enzyme-inhibitory activities in vitro. Its IC50 value was 3.44 x 10(-7) mol/L. It may be helpful in the prophylaxis and treatment of diabetic complications.

[Effects of 2[p-(dimethylamino)styryl] pyridine methiodide on mouse and rabbit]

The effects of 2[p-(dimethylamino)styryl] pyridine methiodide on mouse and rabbit ECG and on the contraction of isolated rabbit atrial muscles were studied. DSPM produced long-lasting bradycardia and A-V block in a dose-dependent manner, but did not effect intraventricular conduction. DSPM antagonized the positive chronotropic and dromotropic effects of isoprenaline (Iso) in vivo, and antagonized the inotropic effects of Iso and CaCl2 non-competitively in vitro. The pD'2 were 4.49 and 4.52, respectively. It is suggested that DSPM may be a Ca2+ antagonist.