Bisdemethoxycurcumin-mediated Attenuation of Apoptosis Prevents Gentamicin-induced Ototoxicity in Mouse Cochlear UB/OC-2 Cells.

BACKGROUND/AIM: Gentamicin has been widely prescribed since the last two decades despite its ototoxicity and nephrotoxicity. Bisdemethoxycurcumin (BDMC) is an affordable and safe curcuminoid with medicinal properties. We aimed to understand the effects of BDMC on the gentamicin-induced hair cell damage in mouse cochlear UB/OC-2 cells, in order to elucidate the therapeutic potential of BDMC against gentamicin-induced ototoxicity. MATERIALS AND METHODS: We quantified the cell membrane potential and examined the regulators and cascade proteins in the intrinsic pathway of hair cell apoptosis. Mouse cochlear UB/OC-2 cells were treated with BDMC before exposure to gentamicin. The effects of BDMC on hair cell viability, mitochondrial function, and apoptosis-related proteins were examined by flow cytometry, western blot, and fluorescent staining. RESULTS: Our results revealed that BDMC reversed gentamicin-mediated cycle arrest at the G2/M phase, stabilizing the mitochondrial membrane potential, decreasing cleaved caspase proteins, and successfully reversing hair cell apoptosis. CONCLUSION: BDMC is a potential agent for reducing gentamicin-induced ototoxicity.

Ameliorative effect of taxifolin on gentamicin-induced ototoxicity via down-regulation of apoptotic pathways in mouse cochlear UB/OC-2 cells.

BACKGROUND: Taxifolin is a flavanonol with efficacious cytoprotective properties, such as anti-inflammatory, antioxidant, anticancer, hepatoprotective, and nephroprotective effects. However, the potential protective effects of taxifolin against gentamicin-induced ototoxicity have not been confirmed. In this study, the possible mechanisms underlying the effects of taxifolin on gentamicin-induced death of UB/OC-2 cochlear cells were investigated. METHODS: Mouse cochlear UB/OC-2 cells with or without taxifolin pretreatment were exposed to gentamicin, and the effects on cytotoxicity, reactive oxygen species (ROS) production, mitochondrial permeability transition, and apoptotic marker expression were examined using biochemical techniques, flow cytometry, western blotting, and fluorescent staining. RESULTS: Little or no apparent effect of taxifolin on cell viability was observed at concentrations less than 40 µM. Further investigations showed that gentamicin significantly inhibited cell viability in a concentration-dependent manner. Pretreatment with taxifolin attenuated gentamicin-induced lactate dehydrogenase release, as well as cellular cytotoxicity. In addition, taxifolin significantly prevented gentamicin-induced cell damage by decreasing ROS production, stabilizing mitochondrial membrane potential, and downregulating the mitochondrial pathway of apoptosis. CONCLUSION: In summary, pretreatment with taxifolin is effective for mitigating gentamicin-induced apoptotic cell death mediated by the mitochondrial pathway. Our data suggest that taxifolin provides a new approach to combat gentamicin-induced ototoxicity.

Effects of Water Extract of Cynanchum paniculatum (Bge.) Kitag. on Different Breast Cancer Cell Lines.

Cynanchum paniculatum (Bge.) Kitag. (CP) is an important medicinal herb used in Chinese herbal medicine, with a variety of biological activities including anticancer property. In this study, we explored the water extract of CP, for its anticancer effects against breast cancer cells with different mutation types. Cells were grouped as untreated (Control); CP direct treatment (dir-CP); Conditioned medium from CP treated (sup-CP), and untreated cells (sup-Control). Effects of dir-CP and sup-CP were compared to corresponding untreated cells on cytotoxicity, cell migration, and protein expression (cleaved caspase-3, caspase-9, and MMP-2 and 9). CP treatment showed time-dependent decrease in cell number of MDA-MB-231 and SK-Br-3 (both ER(-) PR(-)), while the decrease in cell number was not as significant in MCF-7 and ZR-75-1 cells (both ER(+) PR(+)). sup-CP treatment inhibited the cell migration of MDA-MB-231 and MCF-7 (Her2(-)) in a 24 h scratch assay. Our data suggested that ER(-) PR(-) cells are more sensitive to the CP in terms of direct cytotoxicity, which is not regulated by caspase-3. CP inhibited the migration of the two Her2(-) cells, and this correlated with MMP-2 regulation. The migration of ER(-) PR(-) cells was more sensitive to conditioned medium with CP treatment than to direct CP, and this is not regulated by MMP-2. Our data suggested that CP has anticancer potential on various breast cancer cells through different mechanisms and is specifically effective in inhibiting the migration of the triple negative MDA-MB-231. Our data provide insight into the mechanism of CP against breast cancer progression and would benefit the medical practitioners in better management with CP usage.

2,3,4',5-Tetrahydroxystilbene-2-O-ß-D-Glucoside (THSG) Activates the Nrf2 Antioxidant Pathway and Attenuates Oxidative Stress-Induced Cell Death in Mouse Cochlear UB/OC-2 Cells.

Oxidative stress plays a critical role in the pathogenesis of hearing loss, and 2,3,4',5-tetrahydroxystilbene-2-O-ß-D-glucoside (THSG) exerts antioxidant effects by inhibiting reactive oxygen species (ROS) generation. With the aim of developing new therapeutic strategies for oxidative stress, this study investigated the protective mechanism of THSG in vitro using a normal mouse cochlear cell line (UB/OC-2). The THSG and ascorbic acid have similar free radical scavenger capacities. H2O2, but not THSG, reduced the UB/OC-2 cell viability. Moreover, H2O2 might induce apoptosis and autophagy by inducing morphological changes, as visualized by microscopy. As evidenced by Western blot analysis and monodansylcadaverine (MDC) staining, THSG might decrease H2O2-induced autophagy. According to a Western blotting analysis and Annexin V/PI and JC-1 staining, THSG might protect cells from H2O2-induced apoptosis and stabilize the mitochondrial membrane potential. Furthermore, THSG enhanced the translocation of nucleus factor erythroid 2-related factor 2 (Nrf2) into the nucleus and increased the mRNA and protein expression of antioxidant/detoxifying enzymes under H2O2-induced oxidative stress conditions. Collectively, our findings demonstrate that THSG, as a scavenging agent, can directly attenuate free radicals and upregulate antioxidant/detoxifying enzymes to protect against oxidative damage and show that THSG protects UB/OC-2 cells from H2O2-induced autophagy and apoptosis in vitro.

Sesamin reduces acute hepatic injury induced by lead coupled with lipopolysaccharide.

BACKGROUND: In this study, we investigated the potential anti-inflammatory and antioxidative effects of sesamin on acute liver injury. Lead (Pb) causes oxidative damage and enhances the effects of low-dose lipopolysaccharide (LPS), inducing acute hepatic injury in rats. METHODS: Male Sprague-Dawley rats were given intraperitoneal injections of Pb acetate (5 mg/kg) and LPS (50 µg/kg) to induce liver injury, and we tested the effects of oral administration of sesamin (10 mg/kg) on liver damage. To assess the extent of acute hepatic injury in the rats, we measured the anti-inflammatory and antioxidant markers and relevant signaling pathways: serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), C-reactive protein (CRP), reactive oxygen species (ROS), tumor necrosis factor (TNF)-α, interleukin (IL)-1, IL-6, nitric oxide (NO), and cyclooxygenase-2 (COX-2), inducible NO synthase (iNOS) levels, mitogen-activated protein kinases (MAPKs), c-Fos, and GADD45ß. RESULTS: Sesamin significantly decreased the serum AST, ALT, and CRP levels in the rat model. In the Pb and LPS-stressed rats, sesamin administration reduced the serum levels of TNF-α, IL-1, IL-6, NO, and ROS generation, and liver tissue expressions of c-Jun N-terminal kinase (JNK), p38 MAPK, GADD45ß, COX-2, and iNOS. CONCLUSION: Collectively, these results demonstrate that sesamin is associated with antioxidant and anti-inflammatory activity. The observed effect of scavenging of ROS and NO and inhibiting the production of proinflammatory cytokines may be achieved through the suppression of COX-2, iNOS, and MAPK pathways in the acute hepatic injury rats.

Protective effect of a sesamin derivative, 3-bis (3-methoxybenzyl) butane-1, 4-diol on ischemic and hypoxic neuronal injury.

BACKGROUND: Stroke is one of the leading causes of neuronal death. Sesamin is known for neuroprotection by its antioxidant and anti-inflammatory properties but it lacks blood-brain barrier (BBB) activity. A panel of sesamin derivatives was screened and 3-bis (3-methoxybenzyl) butane-1,4-diol (BBD) was selected for high BBB activity and tested for its neuroprotective effect. METHODS: The focal cerebral ischemia of Sprague-Dawley rats and hypoxia models of murine BV-2 microglia or PC12 cells under oxygen/glucose deprivation were used for in vivo and in vitro test, respectively. Lipid peroxidation and superoxide dismutase (SOD) activity from the ischemic brain were tested and reactive oxygen species (ROS), cytokine production, prostaglandin (PGE2) and related signaling pathways from hypoxic cells were examined by ELISA or Western blot assay, respectively. RESULTS: BBD showed a protective effect when given 90 min after the focal cerebral ischemia. It also reduced lipid peroxidation and preserved SOD activity from the ischemic brain. The mechanism of BBD was further confirmed by attenuating ROS, cytokine production, and PGE2 release from hypoxic BV-2 or PC12 cells. BBD significantly reduced hypoxia-induced c-Jun N-terminal kinases (JNK) and modulated AKT-1 and caspase-3 (survival and apoptotic pathways) in BV-2 cells, and inhibited hypoxia-induced JNK and cyclooxygenase-2 activation in PC12 cells. CONCLUSIONS: The neuroprotective effect of BBD on ischemia/hypoxia models was involved with antioxidant and anti-inflammatory effects. The result would help the development of new CNS drug for protection of ischemia/hypoxia injury.

Immunomodulatory effect of chinese herbal medicine formula sheng-fei-yu-chuan-tang in lipopolysaccharide-induced acute lung injury mice.

Traditional Chinese medicine formula Sheng-Fei-Yu-Chuan-Tang (SFYCT), consisting of 13 medicinal plants, was used to treat patients with lung diseases. This study investigated the immunoregulatory effect of SFYCT on intratracheal lipopolysaccharides- (LPS-) challenged acute lung injury (ALI) mice. SFYCT attenuated pulmonary edema, macrophages, and neutrophils infiltration in the airways. SFYCT decreased inflammatory cytokines, including tumor necrosis factor- α (TNF α ), interleukin-1 ß , and interleukin-6 and inhibited nitric oxide (NO) production but increased anti-inflammatory cytokines, interleukin-4, and interleukin-10, in the bronchoalveolar lavage fluid of LPS-challenged mice. TNF α and monocyte chemotactic protein-1 mRNA expression in the lung of LPS-challenged mice as well as LPS-stimulated lung epithelial cell and macrophage were decreased by SFYCT treatment. SFYCT treatment also decreased the inducible nitric oxide synthase expression and phosphorylation of nuclear factor- κ B (NF- κ B) in the lung of mice and macrophage with LPS stimulation. SFYCT treatment dose dependently decreased the LPS-induced NO and reactive oxygen species generation in LPS-stimulated macrophage. In conclusion, SFYCT attenuated lung inflammation during LPS-induced ALI through decreasing inflammatory cytokines production while increasing anti-inflammatory cytokines production. The immunoregulatory effect of SFYCT is related to inhibiting NF- κ B phosphorylation.

The Chinese Herbal Medicine Formula Sheng-Fei-Yu-Chuan-Tang Suppresses Th2 Responses and Increases IFN γ in Dermatophagoides pteronyssinus Induced Chronic Asthmatic Mice.

Sheng-Fei-Yu-Chuan-Tang (SFYCT), a traditional Chinese medicine formula consisting of 13 medicinal plants, has been used in the treatment of asthma. This study demonstrated the immunoregulatory effect of SFYCT on chronic allergic asthma using the Dermatophagoides-pteronyssinus- (Der p-) challenged chronic asthmatic murine model. SFYCT decreased the airway hyperresponseness (AHR), pulmonary inflammatory cell infiltration, and airway remodeling in Der p mice. SFYCT treatment decreased Der p-induced total IgE and Der-p-specific IgG1 but not IgG2a/2b Ab titer in serum of Der p mice. SFYCT also decreased Th2 cytokines, IL-4, IL-5, and IL-13, but increased IFN- γ and IL-12 in the BALF of Der p mice. TGF- ß 1 and collagen production in the lung of mice were decreased by SFYCT. The mRNA expression of chemokine including Eotaxin, RANTES, and MCP-1 in the lung of Der p mice was decreased by SFYCT. In conclusion, the suppressed Der-p-induced airway inflammation, remodeling, and hyperresponseness in chronic asthma murine model are related to SFYCT inhibits Th2 responses, decreases chemokine expression and promotes IFN- γ and IL-12 production. SFYCT could show Der-p-induced Th2 responses to Th1 responses by increasing IFN- γ which is merit for clinical application on asthma patients.

Elephantopus scaber inhibits lipopolysaccharide-induced liver injury by suppression of signaling pathways in rats.

Elephantopus scaber (ES, Teng-Khia-U) has been traditionally used for the treatment of nephritis, pain, and fever; however, the direct evidence is lacking. We investigated the effect of ES on lipopolysaccharide (LPS) induced inflammation of BV-2 microglial cells and acute liver injury in Sprague-Dawley (SD) rats. Our results showed that ES reduced LPS-induced nitric oxide (NO), interleukin (IL)-1, IL-6, reactive oxygen species (ROS), and prostaglandin (PGE(2)) production in BV-2 cells. ES significantly decreased serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels in LPS-treated rats. Furthermore, the water extract, but not the ethanol extract, of ES dose-dependently inhibited LPS-induced JNK, p38 mitogen-activated protein kinases (MAPK), and slightly inhibited cyclooxygenase (COX-2) in BV-2 cells but decreased p38 MAPK and COX-2 expressions in the liver of LPS-treated rats. Taken together, these results indicate that the protective mechanism of ES involves an antioxidant effect and inhibition of p38 MAP kinase and COX-2 expressions in LPS-stressed acute hepatic injury in SD rats.

Enhancement of the release of inflammatory mediators by substance P in rat basophilic leukemia RBL-2H3 cells.

Substance P (SP), a neurotransmitter, may play an important role in neurogenic inflammation. Ginseng has been used extensively in traditional medicine; however, few studies were focused on their anti-allergic effect. Therefore, the effect and mechanism of ginsenoside Rb1 on the SP enhancement of allergic mediators were explored. In this study, SP and dinitrophenyl-bovine serum albumin (DNP-BSA) were used to activate rat basophilic leukemia (RBL)-2H3 cells. The cultured supernatants were assayed for histamine, leukotriene C(4)(LTC(4)) and interleulin-4 (IL-4) production. The mitogen-activated protein kinases (MAPKs) signaling pathway was determined by Western blotting analysis. We found that IgE/DNP-BSA, SP, ginsenoside Rb1, or MAPK specific inhibitors had no effect on cell viability and cytotoxicity. SP (30 microM) alone, did not induce histamine and LTC(4) release, but it enhanced allergen-induced histamine and LTC(4) release. In addition, SP significantly induced and enhanced allergen-activated IL-4. Ginsenoside Rb1 dose-dependently inhibited these effects. SP enhanced the allergen-activated ERK pathway in RBL-2H3 cells, and Rb1 effectively inhibited the ERK pathway activation. Although MAPK specific inhibitors suppressed LTC(4) and IL-4, only U0126 inhibited the SP enhanced histamine release. These results demonstrate that Rb1 dose-dependently inhibited SP enhanced allergen-induced mediator release and its mechanism was through the inhibition of the ERK pathway.