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Parkinson's disease (PD) is a progressive neurodegenerative disease associated with loss of dopaminergic neurons in the substantia nigra pars compacta. Although aging is the primary cause, environmental and genetic factors have also been implicated in its etiology. In fact, the sporadic nature of PD (i.e., unknown etiology) renders the uncovering of the exact pathogenic mechanism(s) or development of effective pharmacotherapies challenging. In search of novel neuroprotectants, we showed that butyrate (BUT), a short-chain fatty acid, protects against salsolinol (SALS)-induced toxicity in human neuroblastoma-derived SH-SY5Y cells, which are considered an in-vitro model of PD. Dihydromyricetin (DHM), a flavonoid derived from Asian medicinal plant, has also shown effectiveness against oxidative damage and neuroinflammation, hallmarks of neurodegenerative diseases. Here we show that pretreatment of SH-SY5Y cells with DHM concentration-dependently prevented SALS-induced toxicity and that a combination of DHM and BUT resulted in a synergistic protection. The effects of both DHM and BUT in turn could be completely blocked by flumazenil (FLU), a GABAA antagonist acting at benzodiazepine receptor site, and by bicuculline (BIC), a GABAA antagonist acting at orthosteric site. Beta-hydroxybutyrate (BHB), a free fatty acid 3 (FA3) receptor antagonist, also fully blocked the protective effect of DHM. BHB was shown previously to only partially block the protective effect of BUT. Thus, there are some overlaps and some distinct differences in protective mechanisms of DHM and BUT against SALS-induced toxicity. It is suggested that a combination of DHM and BUT may have therapeutic potential in PD. However, further in-vivo verifications are necessary. [ABSTRACT FROM AUTHOR]

Toxicity induced by binge alcohol drinking, particularly in adolescent and young adults, is of major medical and social consequence. Recently, we reported that butyrate, a short chain fatty acid, can protect against ethanol (ETOH)-induced toxicity in an in vitro model. In this study, we sought to evaluate the potential effectiveness of dihydromyricetin (DHM), a natural bioactive flavonoid, alone or in combination with butyrate in the same model. Exposure of SH-SY5Y cells for 24 h to 500 mM ETOH resulted in approximately 40% reduction in cell viability, which was completely prevented by 0.1 μM DHM. Combinations of DHM and butyrate provided synergistic protection against alcohol toxicity. Whereas butyrate effect was shown to be mediated primarily through fatty acid receptor 3 activation, DHM protection appears to be mediated primarily via benzodiazepine receptor site of GABAA receptor. This is based on the finding that DHM's effect could be completely prevented by pretreatment with flumazenil, a selective antagonist at this site, but not by bicuculline, a selective antagonist at the actual GABAA receptor binding site. These findings suggest potential utility of DHM alone or in combination with butyrate against ETOH-induced toxicity. [ABSTRACT FROM AUTHOR]

Background: Cancer-induced bone pain (CIBP) is the pain caused by bone metastasis from malignant tumors, and the largest source of pain for cancer patients. miR-300 is an important miRNA in cancer. It has been shown that miR-300 regulates tumorigenesis of various tumors. Purpose: This study aims to investigate the role of miR-300 in CIBP and its underlying molecular mechanisms in vitro and in vivo. Methods: We constructed CIBP model in rats and investigated the mechanism through which miR-300 affects CIBP. We first examined expression level of miR-300 in CIBP rats and then tested the effect of its overexpression. Next, we identified the target of miR-300 using TargetScan analysis and double luciferase assay. Finally, we studied genetic interactions between miR-300 and its target and their roles in CIBP. Results: We found that miR-300 was downregulated in CIBP rats. Overexpression of miR-300 significantly attenuated cancer-induced neuropathic pain (p < 0.01). Furthermore, TargetScan analysis and double luciferase assay show High Mobility Group Box 1 (HMGB1) is a target of miR-300. Notably, HMGB1 is overexpressed in CIBP rats, while up-regulation of miR-300 significantly suppresses expression of HMGB1 (p < 0.01). Moreover, knockdown of HMGB1 by siRNA significantly relieves cancer-induced neuropathic pain in rats (p < 0.01). On the other hand, HMGB1 overexpression partially blocked the effect of miR-300 on cancer-induced nerve pain. Conclusion: miR-300 relieves cancer-induced neuropathic pain by inhibiting HMGB1 expression. These results may be beneficial for the treatment of CIBP in clinical practice. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the cytotoxic effects of ampelopsin sodium (Amp-Na) and carboplatin (CBP) used alone or in combination on human non-small cell lung cancer (NSCLC) cells SPC-A1 in vitro and its related mechanism. Methods: Cytotoxic effects were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. The synergistic effects of the drugs were calculated with coefficient of drug interaction (CDI). Cell cycle was determined by flow cytometry (FCM). The levels of p53, p21, cyclinE, cyclinD1, and phosphorylated cyclin-dependent kinase-2 (p-CDK2) were evaluated by Western blot. Results: Amp-Na (6.25-200 μg/mL) and CBP (3.13-100 μg/mL) alone exhibited prominent cytotoxic activity in a concentration-dependent manner on SPC-A1 cells with 50% inhibitive concentration values of 57.07±14.46 and 34.97±6.30 μg/mL, respectively. Drug combinations were associated with significantly higher cytotoxic effects than each drug alone ( P<0.05 or 0.01). The CDI analysis confirmed the synergy of Amp-Na and CBP on inhibiting cancer cell viability across a wide concentration range (CDI <1). FCM and Western blot showed that synergistic cytotoxic effects of Amp-Na and CBP were related to G arrested which mainlym ediated by p 21 through the inhibition of CDK2 activity independent of the p53 tumor suppressor pathway. Conclusions: Amp-Na exhibits anticancer activities and enhances the antitumor activities of CBP through up-regulation of p21 and inhibition of CDK2 activity in human NSCLC cells SPC-A1. These results suggest that Amp-Na may be applied to enhance the anticancer action of CBP. [ABSTRACT FROM AUTHOR]