Puerarin inhibits cisplatin-induced ototoxicity in mice through regulation of TRPV1-dependent calcium overload.

Puerarin (PUE), a flavonoid derivative with vasodilatory effects found in the traditional Chinese medicine kudzu, has anti-sensorineural hearing loss properties. However, the mechanism of its protective effect against ototoxicity is not well understood. In this study, we used in vitro and in vivo methods to investigate the protective mechanism of puerarin against cisplatin (CDDP)-induced ototoxicity. We established an ototoxicity model of CDDP in BALB/c mice and assessed the degree of hearing loss and cochlear cell damage. We used bioinformatics analysis, molecular docking, histological analysis, and biochemical and molecular biology to detect the expression of relevant factors. Our results show that puerarin improved CDDP-induced hearing loss and reduced hair cell loss. It also blocked CDDP-induced activation of TRPV1 and inhibited activation of IP3R1 to prevent intracellular calcium overload. Additionally, puerarin blocked CDDP-stimulated p65 activation, reduced excessive ROS production, and alleviated cochlear cell apoptosis. Our study provides new evidence and potential targets for the protective effect of puerarin against drug-induced hearing loss. Puerarin ameliorates cisplatin-induced ototoxicity and blocks cellular apoptosis by inhibiting CDDP activated TRPV1/IP3R1/p65 pathway, blocking induction of calcium overload and excessive ROS expression.

The antiviral mechanism of the crude extract from the flowers of Trollius chinensis based on TLR 3 signaling pathway.

The effects of crude extract from the flowers of Trollius chinensis on expressions of mRNA and proteins related to vital genes (TLR 3, TBK 1, IRF 3 and IFN ß) in TLR 3 signaling pathway were investigated in the presence/absence of Polyinosinic acid-polycytidylic acid (PolyI: C) to ascertain the antiviral mechanism of these flowers. Real-time PCR and western blot were applied to determine the expressions of mRNA and proteins, respectively, and immunofluorescence assay was employed to study the effect on IRF 3 distribution between nuclei and cytoplasma. In the absence of PolyI:C, the crude extract reduced the mRNA expression of TLR 3, IRF 3 and IFN ß and the protein expression of TLR 3, and increased the protein expression of IRF 3 and the distribution of IRF 3 in nuclei. In the presence of PolyI:C, the extract reduced the mRNA and protein expressions of TLR 3 and the mRNA expression of IFN ß, meanwhile inhibited the translocation of IRF 3 into nuclei. The antiviral mechanism of the crude extract from the flowers of T. chinensis is to protect the host from inflammatory damage through intervening the TLR 3 signaling pathway and reducing the secretion of inflammatory factors.

Ursolic acid protects against cisplatin­induced ototoxicity by inhibiting oxidative stress and TRPV1­mediated Ca2+­signaling.

Cisplatin (CDDP) is widely used in clinical settings for the treatment of various cancers. However, ototoxicity is a major side effect of CDDP, and there is an associated risk of irreversible hearing loss. We previously demonstrated that CDDP could induce ototoxicity via activation of the transient receptor potential vanilloid receptor 1 (TRPV1) pathway and subsequent induction of oxidative stress. The present study investigated whether ursolic acid (UA) treatment could protect against CDDP­induced ototoxicity. UA is a triterpenoid with strong antioxidant activity widely used in China for the treatment of liver diseases. This traditional Chinese medicine is mainly isolated from bearberry, a Chinese herb. The present results showed that CDDP increased auditory brainstem response threshold shifts in frequencies associated with observed damage to the outer hair cells. Moreover, CDDP increased the expression of TRPV1, calpain 2 and caspase­3 in the cochlea, and the levels of Ca2+ and 4­hydroxynonenal. UA co­treatment significantly attenuated CDDP­induced hearing loss and inhibited TRPV1 pathway activation. In addition, UA enhanced CDDP­induced growth inhibition in the human ovarian cancer cell line SKOV3, suggesting that UA synergizes with CDDP in vitro. Collectively, the present data suggested that UA could effectively attenuate CDDP­induced hearing loss by inhibiting the TRPV1/Ca²+/calpain­oxidative stress pathway without impairing the antitumor effects of CDDP.

Anti-influenza A virus mechanism of three representative compounds from Flos Trollii via TLRs signaling pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Flos Trollii is the dried flowers of Trollius chinensis. It has been used as a traditional herbal medicine for the treatment of upper respiratory tract infection, tonsillitis and pharyngitis in China for a long history. Veratric acid, vitexin, and trolline are the representative compounds of phenolic acids, flavonoids and alkaloids in this herbal medicine. All of these three compounds show antiviral activity which is related to the efficacy of Flos Trollii. AIM OF THE STUDY: To investigate the anti-influenza A virus mechanism of the three representative compounds from the perspective of regulating TLRs signaling pathways, so as to understand the relevant efficacy of Flos Trollii. MATERIALS AND METHODS: Influenza A virus A/FM/1/47 (H1N1) and mouse peritoneal macrophages (RAW264.7) were used in the whole process of investigation. MTT assay was conducted to select the appropriate experimental concentrations of the three compounds on RAW264.7 cells. Western blot, RT-PCR, and ELISA assays were performed to determine the protein and mRNA expression of key factors and related inflammatory factors of TLRs signaling pathways. Griess method was employed to detect the production of NO. RESULTS: The three representative compounds reduced the inflammatory factors including NO, IL-6, and TNF-α and enhanced the production of IFN-ß through dynamically regulating the TLRs 3, 4 and 7 pathways. Veratric acid significantly down-regulated the protein expression of TLR3 and IRF3 as well as the mRNA expression of TBK1 and TRIF. Vitexin significantly down-regulated the protein expression of TBK1 and IRF3 as well as the mRNA expression of TLR3, TBK1, TRIF and IRF3 while up-regulated the protein expression of TLR4 and IKKα. Trolline significantly down-regulated the protein expression of TLR7 whereas significantly up-regulated the protein expression of TLR4, IKKα and TAK1. CONCLUSIONS: The three representative compounds from Flos Trollii play their parts in anti-H1N1 viral effect through partially down-regulating TLRs 3 and 7 pathways and up-regulating TLR4 pathway. They counteract the inflammatory injury caused by excessive production of NO, IL-1, IL-6, and TNF-α induced by virus infection and enhance the production of IFN-ß so as to eliminate the virus.

[Effect of electroacupuncture on neurological deficit and activity of TLR2/NF-κB signaling in ce-rebral ischemia /reperfusion injury rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on neurological behavior and activity of Toll-like receptor 2 / nuclear factor kappa B (TLR2/NF-κB) signaling of the ischemic cerebral area in cerebral ischemia-reperfusion injury (CIRI) rats, so as to explore its mechanisms underlying improvement of CIRI. METHODS: A total of 120 male SD rats were randomly divided into blank control, sham operation, model, EA and EA＋NF-κB inhibitor (Pyrrolidine Dithiocarbamate Hydrochloride, PDTC, EA＋PDTC) groups which were further divided into 3, 7, 14 and 28 d subgroups (n＝6 in each subgroup). The CIRI model was established by occlusion of the middle cerebral artery for 90 min, followed by reperfusion. EA (1－20 Hz, 6 V) was applied to "Shuigou" (GV26), "Neiguan" (PC6), "Sanyinjiao" (SP6) and "Weizhong" (BL40) for 30 min, once a day for 28 days. For rats of the EA＋PDTC group, PDTC solution (120 mg/kg) was intraperitoneally injected on the 3rd day after successful modeling and before EA intervention. The neurological deficit severity (Zea Longa score) was assessed 3, 7, 14 and 28 days after modeling. The expression levels of TLR2, Interleukin-1 receptor-associated kinase (IRAK) and NF-κB mRNAs in the ischemic penumbra region of brain tissue were detected by real-time fluorescence quantitative PCR. RESULTS: Following modeling, the neurological deficit scores were significantly increased from the 3rd day on after CIRI (P<0.05), the expression levels of TLR2 mRNA on day 3, 7, 14 and 28, and IRAK mRNA on day 3 and 7, as well as NF-κB mRNA on day 3, 7 and 14 were significantly up-regulated in the model group relevant to the blank control group (P<0.05). After EA intervention, the neurological deficit scores were significantly decreased in the EA group on day 3, 7 and 28 and in the EA＋PDTC group on day 3, 7, 14 and 28 in comparison with those of the model group (P<0.05). In addition, the expression levels of TLR2 mRNA and NF-κB mRNA on day 3, 7 and 14 in the EA group, and on day 3, 7, 14 and 28 in the EA＋PDTC group, IRAK mRNA on day 3 in the EA and EA＋PDTC group were significantly down-regulated (P<0.05), but those of IRAK mRNA on day 14 and 28 in the EA group were significantly up-regulated in comparison with those of the model group (P<0.05). The effect of the EA＋PDTC was obviously superior to that of simple EA in down-regulating the expression of TLR2 (on day 28), and IRAK (on day 3, 14, 28), and NF-κB (on day 3, 7 and 14) (all P<0.05). CONCLUSION: EA stimulation can improve the symptoms of neurological deficits in CIRI rats, which may be related to its effect in suppressing the expression of TLR2, NF-κB and IRAK mRNAs of the ischemic cerebral tissue, i．e., down-regulating the activity of TLR2/NF-κB signaling.

Pomegranate peel extract attenuates D-galactose-induced oxidative stress and hearing loss by regulating PNUTS/PP1 activity in the mouse cochlea.

Oxidative stress is considered to be a major contributor to age-related hearing loss (ARHL). Here, we investigated whether pomegranate peel extract (PPE) protected against hearing loss by decreased oxidative stress in the cochlea of D-galactose-induced accelerated aging mice. The aging mice exhibited an increase in hearing threshold shifts and hair cells loss, which were improved in the PPE-treated aging mice. The aging mice also exhibited an increase in 4-hydroxynonenal, the expression of protein phosphatase 1 nuclear targeting subunit (PNUTS), p53 and caspase-3, and a decrease in protein phosphatase 1 (PP1) and MDM2 in the cochlea. PPE treatment reversed the changes in aforementioned molecules. Our results suggested that PPE can protect against ARHL, the underlying mechanisms may involve in the inhibition of oxidative damage of cochlea, possibly by regulating PNUTS/PP1 pathway. The results from the present study provide a new therapeutic strategy to use PPE for prevention of ARHL.

FoxO3a plays a key role in the protective effects of pomegranate peel extract against amikacin-induced ototoxicity.

The use of amikacin (AMK) in present treatment strategies results in severe ototoxicity; however, the underlying molecular mechanisms of this toxicity remain unclear. In this study, we investigated the effectiveness of orally administered pomegranate peel extract (PPE), a strong antioxidant, as a protective agent against AMK-induced ototoxicity. To this end, PPE was orally administered to adult BALB/c mice for 5 days, and the mice were then concurrently treated with AMK (500 mg/kg/day for 15 consecutive days). Auditory threshold shifts induced by AMK were significantly attenuated. The results of immunohistochemical staining and western blot analysis revealed that PPE exerted its protective effects by by downregulating the phosphorylation of Forkhead box O3a (FoxO3a), an important transcription factor which is involved in the responses to oxidative stress. The results also showed that PPE treatment inhibited mitogen-activated protein kinase phosphorylation, prevented the activation of pro-apoptotic protein caspase-3, decreased the levels of apoptosis-inducing Bax protein, and increased the levels of the anti-apoptotic mediator, Bcl-2, induced by AMK in the mouse cochlea. Taken together, our experimental findings suggest that phosphorylated FoxO3a mediates AMK-induced apoptosis in BALB/c mice cochlea. PPE effectively attenuated oxidative stress and ototoxicity by regulating FoxO3a, and may thus prove to be beneficial in protecting auditory cells from ototoxic drugs.

[On-line monitoring of extraction process of danhong injection based on near-infrared spectroscopy].

OBJECTIVE: To establish a rapid quantitative analysis method for the quality control of Danhong injection extraction using near-infrared (NIR) spectroscopy. METHOD: Online collecting the NIR spectra during the mixed extraction process of Salvia miltiorrhiza and Carthamus tinctorius, partial least squares regression (PLSR) models were developed for the quality indicators rosmarinic acid (RA), salvia acid B (SaB), lithospermic acid (LA), hydroxysafflor yellow A (HSYA) and solid content (SSC), with HPLC and weight-loss method as reference methods. RESULT: The correlation coefficients of the cross validation for RA, SaB, LA, HSYA and SSC were 0.909 3, 0.915 2, 0.901 9, 0.747 7 and 0.931 4, respectively. And the root mean square errors of cross validation (RMSECV) were 0.012 1, 0.251, 0.017 7, 0.038 1 g x L(-1) and 0.359%, respectively. CONCLUSION: In this study, NIR spectroscopy was successfully applied to achieve the real-time determination of the contents of RA, SaB, LA and SSC, while the performance of the HSYA calibration model needed to be improved.

[Application of ultraviolet spectroscopy for rapid analysis in extraction process of danhong injection].

In this work, a rapid analysis method basing on ultraviolet spectroscopy was established for the determination of danshensu, protocatechuic aldehyde, rosmarinci acid, lithospermic acid and salvianolic acid B in the extraction process of Danhong injection. In the extraction process of Danshen and Honghua crude drugs, 44 extraction solution samples were collected and the contents of the five components were determined by HPLC analysis. The ultraviolet spectra of the samples were collected. Partial least square regression was used to establish the multivariate calibration models between the ultraviolet spectra and the contents of the five components. The results showed that the established models could predict the contents of the five components in the extraction solution accurately. The ultraviolet spectroscopy method established in this work can be used for rapid analysis of the intermediates of Danhong injection, which may be applied for the quality control in the manufacturing process.