Biotransformation of osthole by Alternaria longipes.

The biotransformation of osthole (1) by Alternaria longipes was carried out, and five transformed products were obtained in the present research work. Based on their extensive spectral data, the structures of these metabolites were characterized as 4'-hydroxyl-osthole (2), 4'-hydroxyl-2',3'-dihydroosthole (3), 2',3'-dihydroxylosthole (4), osthole-4'-oic acid methyl ester (5), and osthole-4'-oic acid glucuron-1-yl ester (6), respectively. Among them, products 5 and 6 were new compounds.

Ferritinophagy activation and sideroflexin1-dependent mitochondrial iron overload contribute to patulin-induced cardiac inflammation and fibrosis.

Patulin (PAT) is a mycotoxin that is commonly present throughout the ecosystem where fungi grow and mainly contaminates food, soil, and water. PAT was found to be cardiotoxic in previous studies. However, the detailed mechanism has not been fully elucidated. The present study aimed to explore the role and underlying mechanism of ferroptosis in PAT-induced cardiac injury. Here, we confirmed in vivo and in vitro that ferroptosis is involved in PAT-induced myocardial inflammation and fibrosis. Mice exposed to PAT (1 and 2 mg/kg body weight/day for 14 days) exhibited myocardial inflammation and fibrosis along with disrupted iron homeostasis, elevated lipid peroxidation, depletion of glutathione peroxidase 4, and abnormal mitochondrial morphology. When primary neonatal rat cardiomyocytes (NRCMs) and H9c2 cells were exposed to PAT, ferroptosis was initiated in a dose-dependent manner, and this process could be significantly attenuated by ferrostatin-1. Mechanistically, we found that nuclear receptor coactivator (NCOA) 4, a master regulator of ferritinophagy, bound to and degraded ferritin in response to PAT treatment, thereby releasing large amounts of ferrous iron and further leading to sideroflexin (SFXN) 1-dependent mitochondrial iron overload. Conversely, knockdown of NCOA4 or SFXN1 with small interfering RNAs could effectively ameliorate ferroptotic cell death, cellular or mitochondrial iron overload and lipid peroxides accumulation. Furthermore, myocardial inflammation and fibrosis in PAT-exposed mice was alleviated by the mitochondrial iron chelator deferiprone. Overall, our findings underscore that ferritinophagy activation and SFXN1-dependent mitochondrial iron overload play critical roles in PAT-induced myocardial ferroptosis and consequent cardiotoxicity.

[Mechanism of the apoptosis of rat pancreas islet ß cell strain (INS-1 cells) induced by sodium arsenite].

OBJECTIVE: To study mechanism of the apoptosis of rat pancreas islet ß cell strain (INS-1 cells) induced by sodium arsenite. METHODS: INS-1 cells were exposed to sodium arsenite at the different concentrations. MTT assay was used to detect the viability of INS-1 cells. The potentials on mitochondrial membrane and lysosome membrane of INS-1 cells were determined with the fluorescence spectrophotometer. The apoptotic levels of INS-1 cells exposed to sodium arsenite were observed by a fluorescence microscope and flow cytometry. RESULTS: After exposure to sodium arsenite, the viability of INS-1 cells significantly decreased with the doses of sodium arsenite. At 24 h after exposure, the OD values of the mitochondrial membrane potentials declined observably with the doses of sodium arsenite (P < 0.01). At 48 h after exposure, the OD values of the lysosome membrane potentials significantly increased with the doses of sodium arsenite (P < 0.01). At 72 h after exposure, the apoptotic cells were observed under a fluorescence microscope and enhanced with the doses of sodium arsenite. The apoptosis cells with light blue, karyopyknosis, karyorrhexis, apoptotic body and chromatin concentration appeared. The results detected with flow cytometry indicated that after exposure, the apoptotic INS-1E cells significantly increased with the doses of sodium arsenite. CONCLUSIONS: The sodium arsenite can induce the apoptosis of INS-1 cells through the mitochondria-lysosome pathway.

[Effects of sodium arsenite on catalase in human keratinocytes].

OBJECTIVE: To evaluate the effects of sodium arsenite on the activity, the mRNA and the protein expression of CAT in human keratinocyte cell line (HaCaT). METHODS: The activity of catalase (CAT) was detected by ultraviolet direct velocity assay. RT-PCR was used to detect the mRNA expression of CAT and Western blotting was conducted to detect the protein expression of CAT. RESULTS: If the cells were treated with higher than 5.0 micromol/L sodium arsenite, the activity, mRNA and protein expression of CAT were decreased significantly and in a dosage dependent fashion (P < 0.05). CONCLUSION: CAT is inhibited by sodium arsenite in the transcription, translation and activity levels.

Effects of Acupuncture, Tuina, Tai Chi, Qigong, and Traditional Chinese Medicine Five-Element Music Therapy on Symptom Management and Quality of Life for Cancer Patients: A Meta-Analysis.

CONTEXT: Most cancer patients suffer from both the disease itself and symptoms induced by conventional treatment. Available literature on the clinical effects on cancer patients of acupuncture, Tuina, Tai Chi, Qigong, and Traditional Chinese Medicine Five-Element Music Therapy (TCM-FEMT) reports controversial results. OBJECTIVES: The primary objective of this meta-analysis was to evaluate the effect of acupuncture, Tuina, Tai Chi, Qigong, and TCM-FEMT on various symptoms and quality of life (QOL) in patients with cancer; risk of bias for the selected trials also was assessed. METHODS: Studies were identified by searching electronic databases (MEDLINE via both PubMed and Ovid, Cochrane Central, China National Knowledge Infrastructure, Chinese Scientific Journal Database, China Biology Medicine, and Wanfang Database). All randomized controlled trials (RCTs) using acupuncture, Tuina, Tai Chi, Qigong, or TCM-FEMT published before October 2, 2014, were selected, regardless of whether the article was published in Chinese or English. RESULTS: We identified 67 RCTs (5465 patients) that met our inclusion criteria to perform this meta-analysis. Analysis results showed that a significant combined effect was observed for QOL change in patients with terminal cancer in favor of acupuncture and Tuina (Cohen's d: 0.21-4.55, P < 0.05), whereas Tai Chi and Qigong had no effect on QOL of breast cancer survivors (P > 0.05). The meta-analysis also demonstrated that acupuncture produced small-to-large effects on adverse symptoms including pain, fatigue, sleep disturbance, and some gastrointestinal discomfort; however, no significant effect was found on the frequency of hot flashes (Cohen's d = -0.02; 95% CI = -1.49 to 1.45; P = 0.97; I(2) = 36%) and mood distress (P > 0.05). Tuina relieved gastrointestinal discomfort. TCM-FEMT lowered depression level. Tai Chi improved vital capacity of breast cancer patients. High risk of bias was present in 74.63% of the selected RCTs. Major sources of risk of bias were lack of blinding, allocation concealment, and incomplete outcome data. CONCLUSION: Taken together, although there are some clear limitations regarding the body of research reviewed in this study, a tentative conclusion can be reached that acupuncture, Tuina, Tai Chi, Qigong, or TCM-FEMT represent beneficial adjunctive therapies. Future study reporting in this field should be improved regarding both method and content of interventions and research methods.

[Oxidative stress induced by NaAsO2 in HaCaT cells].

OBJECTIVE: To study the level of oxidative stress induced by sodium arsenite (NaAsO2) in HaCaT cells. METHODS: The AlamarBlue assay was used to evaluate the viability of HaCaT. The level of ROS was detected by staining. cells with DCFH-DA. The contents of reduced (GSH) and oxidated (GSSG) glutathione were detected with the fluorescent method. The apoptosis and necrosis rates were counted based on the PI staining. RESULTS: The reduction of AlamarBlue increased in the cells treated at dose of 0.001 -1 micromol/L NaAsO2 and decreased in the cells treated at doses of over 10 micromol/L NaAsO2. The fluorescent density of DCF significantly increased in all experimental groups, the contents of GSH and GSSG increased in groups higher than that of 1 micromol/L and higher than that of 5 micromol/L respectively. The apoptosis and necrosis rates were increased markedly at dose of 20 micromol/L. CONCLUSION: Arsenic could induce enhancive ROS in HaCaT. At low levels of arsenic the proliferation of HaCaT was stimulated while at high levels of arsenic was inhibited. The increase in contents of GSH and GSSG could be associated with the excessive ROS and with detoxification in HaCaT.

Citreoviridin induces ROS-dependent autophagic cell death in human liver HepG2 cells.

Citreoviridin (CIT) is one of toxic mycotoxins derived from fungal species in moldy cereals. Whether CIT exerts hepatotoxicity and the precise molecular mechanisms of CIT hepatotoxicity are not completely elucidated. In this study, the inhibitor of autophagosome formation, 3-methyladenine, protected the cells against CIT cytotoxicity, and the autophagy stimulator rapamycin further decreased the cell viability of CIT-treated HepG2 cells. Knockdown of Atg5 with Atg5 siRNA alleviated CIT-induced cell death. These finding suggested the hypothesis that autophagic cell death contributed to CIT-induced cytotoxicity in HepG2 cells. CIT increased the autophagosome number in HepG2 cells observed under a transmission electron microscope, and this effect was confirmed by the elevated LC3-II levels detected through Western blot. Reduction of P62 protein levels and the result of LC3 turnover assay indicated that the accumulation of autophagosomes in the CIT-treated HepG2 cells was due to increased formation rather than impaired degradation. The pretreatment of HepG2 cells with the ROS inhibitor NAC reduced autophagosome formation and reversed the CIT cytotoxicity, indicating that CIT-induced autophagic cell death was ROS-dependent. In summary, ROS-dependent autophagic cell death of HpeG2 cells described in this study may help to elucidate the underlying mechanism of CIT cytotoxicity.

Low-level sodium arsenite induces apoptosis through inhibiting TrxR activity in pancreatic ß-cells.

In our previous study, we reported that sodium arsenite induced ROS-dependent apoptosis through lysosomal-mitochondrial pathway in pancreatic ß-cells. Since the thioredoxin (Trx) system is the key antioxidant factor in mammalian cells, we investigate whether the inhibition of Trx system contributes to sodium arsenite-induced apoptosis in this study. After treatment with low-level (0.25-1µM) sodium arsenite for 96h, the thioredoxin reductase (TrxR) activity was decreased significantly in pancreatic INS-1 cells. Following with the inactivation of TrxR, ASK1 was released from combining with Trx, which was evidenced by increased levels of ASK1 in sodium arsenite-treated INS-1 cells. Subsequently, activated ASK1 accelerated the expression of proapoptotic protein Bax and reduced the expression of anti-apoptic protein Bcl-2. Finally, low-level sodium arsenite induced apoptosis via caspase-3 in INS-1 cells. Knockdown of ASK1 alleviated sodium arsenite-induced apoptosis. In summary, the precise molecular mechanisms through which arsenic is related to diabetes have not been completely elucidated, inactivation of Trx system might provide insights into the underlying mechanisms at the environmental exposure levels.

Sodium arsenite induces ROS-dependent autophagic cell death in pancreatic ß-cells.

Inorganic arsenic is a worldwide environmental pollutant. Inorganic arsenic's positive relationship with the incidence of type 2 diabetes mellitus arouses concerns associated with its etiology in diabetes among the general human population. In this study, the inhibitor of autophagosome formation, 3-methyladenine, protected the cells against sodium arsenite cytotoxicity, and the autophagy stimulator rapamycin further decreased the cell viability of sodium arsenite-treated INS-1 cells. These finding suggested the hypothesis that autophagic cell death contributed to sodium arsenite-induced cytotoxicity in INS-1 cells. Sodium arsenite increased the autophagosome-positive puncta in INS-1 cells observed under a fluorescence microscope, and this effect was confirmed by the elevated LC3-II levels detected through Western blot. The LC3 turnover assay indicated that the accumulation of autophagosomes in the arsenite-treated INS-1 cells was due to increased formation rather than impaired degradation. The pretreatment of INS-1 cells with the ROS inhibitor NAC reduced autophagosome formation and reversed the sodium arsenite cytotoxicity, indicating that sodium arsenite-induced autophagic cell death was ROS-dependent. In summary, the precise molecular mechanisms through which arsenic is related to diabetes have not been completely elucidated, but the ROS-dependent autophagic cell death of pancreatic ß-cells described in this study may help to elucidate the underlying mechanism.

Perfluorooctane sulfonate blocked autophagy flux and induced lysosome membrane permeabilization in HepG2 cells.

Perfluorooctane sulfonate (PFOS) is an emerging persistent organic pollutant widely distributed in the environment, wildlife and human. In this study, as observed under the transmission electron microscope, PFOS increased autophagosome numbers in HepG2 cells, and it was confirmed by elevated LC3-II levels in Western blot analysis. PFOS increased P62 level and chloroquine failed to further increase the expression of LC3-II after PFOS treatment, indicating that the accumulation of autophagosome was due to impaired degradation rather than increased formation. With acridine orange staining, we found PFOS caused lysosomal membrane permeabilization (LMP). In this study, autophasome formation inhibitor 3-methyladenine protected cells against PFOS toxicity, autophagy stimulator rapamycin further decreased cell viability and increased LDH release, cathepsin inhibitor did not influence cell viability of PFOS-treated HepG2 cells significantly. These further supported the notion that autophagic cell death contributed to PFOS-induced hepatotoxicity. In summary, the data of the present study revealed that PFOS induced LMP and consequent blockage of autophagy flux, leading to an excessive accumulation of the autophagosomes and turning autophagy into a destructive process eventually. This finding will provide clues for effective prevention and treatment of PFOS-induced hepatic disease.