Penicacids E-G, three new mycophenolic acid derivatives from the marine-derived fungus Penicillium parvum HDN17-478.

Three new mycophenolic acid derivatives, penicacids E-G (1-3), together with three known analogues, mycophenolic acid (4), 4'-hydroxy-mycophenolic acid (5) and mycophenolic methyl ester (6), were isolated from a marine-derived fungus Penicillium parvum HDN17-478 from a South China Sea marine sediment sample. The structures of compounds 1-3 were elucidated by HRMS, NMR, and Mosher's method. Among them, compounds 1 and 2 were the first examples of mycophenolic acid analogs with a double bond at C-3'/C-4' position. The cytotoxicity of 1-6 was evaluated against the HCT-116, BEL-7402, MGC-803, SH-SY5Y, HO-8910 and HL-60 cell lines, and compounds 4 and 6 showed potent cytotoxicity with IC50 values ranging from 1.69 to 12.98 µmol·L-1.

Design of signal peptide bombyxin and its effect on secretory expression efficiency and levels of Helicobacter pylori urease subunit B in silkworm cells and larvae

This study employed a Bac-to-Bac/Bombyx mori bioreactor to mass-produce immunogenic urease subunit B (UreB) from Helicobacter pylori. The signal peptide bombyxin from B. mori was used to promote secretory expression to improve expression levels and was designed and integrated into the UreB gene to generate the Bacmid/BmNPV/(signal peptide)-UreB baculovirus expression system. To determine whether the bombyxin signal peptide resulted in secretory expression of recombinant UreB (rUreB) and to determine the secretory efficiency, we tested the secretory expression level of rUreB in Bm5 cells using ELISA. To further investigate whether secretory expression affected cell viability, cells were evaluated using 0.4% trypan blue staining, and Bacmid/BmNPV/UreB without the signal peptide served as a control. The above recombinant bacmid constructs were injected to silkworm larvae, and the secretory expression level of rUreB was detected using SDS-PAGE and semi-quantitative western blot analysis. The results indicated that the bombyxin signal peptide directed the secretory expression of rUreB and that this expression improved the viability of Bm5 cells. Moreover, the results showed that the expression level of rUreB was 1.5 times higher with the Bacmid/BmNPV constructs containing the bombyxin signal sequence than those without the signal sequence. These results demonstrate that secretory expression can enhance rUreB expression levels and is likely to aid in the large-scale expression and yield of rUreB in silkworm larvae.

In silico target fishing for the potential bioactive components contained in Huanglian Jiedu Tang (HLJDD) and elucidating molecular mechanisms for the treatment of sepsis.

The present study was designed to target fish for potential bioactive components contained in a Huang Lian Jie Du decoction (HLJDD) and identify the underlying mechanisms of action for the treatment of sepsis at the molecular level. he bioactive components database of HLJDD was constructed and the sepsis-associated targets were comprehensively investigated. The 3D structures of the PAFR and TXA2R proteins were established using the homology modelling (HM) method, and the molecular effects for sepsis treatment were analysed by comparing the bioactive components database and the sepsis targets using computational biology methods. The results of the screening were validated with biological testing against the human oral epidermal carcinoma cell line KB in vitro. We found that multiple bioactive compounds contained in the HLJDD interacted with multiple targets. We also predicted the promising compound leads for sepsis treatment, and the first 28 compounds were characterized. Several compounds, such as berberine, berberrubine and epiberberine, dose-dependently inhibited PGE2 production in human KB cells, and the effects were similar in the presence or absence of TPA. This study demonstrates a novel approach to identifying natural chemical compounds as new leads for the treatment of sepsis.

Protective effect of Lycium barbarum polysaccharides against doxorubicin-induced testicular toxicity in rats.

The present study aimed to investigate whether Lycium barbarum polysaccharides (LBP) would protect against doxorubicin (DOX)-induced testicular toxicity. Male Sprague-Dawley rats were treated with distilled water (4 mL/kg) or LBP (200 mg/kg, p.o.) daily for 10 days and followed by saline (0.9 %, 10 mL/kg) or DOX (10 mg/kg) intravenous injection at day 7. Pretreatment with LBP ameliorated DOX-induced reduction in the testicular weights, sperm concentrations and percentage of motile sperms, as well as the increase in abnormal sperm rate. LBP administration to DOX-treated rats successfully reversed the changes in MDA and GHS-Px levels. Compared with the control, pretreatment with LBP significantly increased the plasma testosterone level in the LBP + DOX group. The histopathology examinations further confirmed that LBP effectively attenuated DOX-induced severe degenerative changes of seminiferous tubules. This study illustrated the capability of LBP in attenuating testicular oxidative stress and protecting testis-specific toxicity in DOX-exposed rats.

Angelica sinensis: a novel adjunct to prevent doxorubicin-induced chronic cardiotoxicity.

Doxorubicin is an anthracycline antibiotic agent used in the treatment of a variety of solid and haematopoietic tumours, but its use is limited by formation of metabolites that induce acute and chronic cardiac toxicities. Angelica sinensis has been widely used to treat cardiovascular and cerebrovascular diseases in China. In the present study, we used an in vivo mouse model to explore whether A. sinensis could protect against doxorubicin-induced chronic cardiotoxicity. Male ICR mice were treated with distilled water or water extraction of A. sinensis (15 g/kg, orally) daily for 4 weeks, followed by saline or doxorubicin (15 mg/kg, intravenously) treatments weekly. Cardiotoxicity was assessed by electrocardiograph, antioxidant activity in cardiac tissues, serum levels of creatine kinase, aspartate aminotransferase (AST) and histopathological change in cardiac tissues. A cumulative dose of doxorubicin (60 mg/kg) caused animal death and myocardial injury characterized by increased QT interval and decreased heart rate in electrocardiograph, decrease of heart antioxidant activity, increase of serum AST, as well as myocardial lesions. Pre-treatment with A. sinensis significantly reduced mortality and improved heart performance of the doxorubicin-treated mice as evidenced from normalization of antioxidative activity and serum AST, preventing loss of myofibrils as well as improving arrhythmias and conduction abnormalities. Furthermore, the in vitro cytotoxic study showed that A. sinensis did not compromise the antitumour activity of doxorubicin. These results suggested that A. sinensis elicited a typical cardioprotective effect on doxorubicin-related oxidative stress, and could be a novel adjunct in the combination with doxorubicin chemotherapy.

Protective effect of Lycium barbarum on doxorubicin-induced cardiotoxicity.

The objective of this work was to explore the hypothesis that Lycium barbarum (LB) may be protective against doxorubicin (DOX)-induced cardiotoxicity through antioxidant-mediated mechanisms. Male SD rats were treated with distilled water or a water extract of LB (25 mg/kg, p.o.) daily and saline or DOX (5 mg/kg, i.v.) weekly for 3 weeks. Mortality, general condition and body weight were observed during the experiment. DOX-induced cardiotoxicity was assessed by electrocardiograph, heart antioxidant activity, serum levels of creatine kinase (CK) and aspartate aminotransferase (AST) and histopathological change. The DOX group showed higher mortality (38%) and worse physical characterization. Moreover, DOX caused myocardial injury manifested by arrhythmias and conduction abnormalities in ECG (increased QT and ST intervals and ST elevation), a decrease of heart antioxidant activity, an increase of serum CK and AST, as well as myocardial lesions. Pretreatment with LB significantly prevented the loss of myofibrils and improved the heart function of the DOX-treated rats as evidenced from lower mortality (13%), normalization of antioxidative activity and serum AST and CK, as well as improving arrhythmias and conduction abnormalities. These results suggested that LB elicited a typical cardioprotective effect on DOX-related oxidative stress. Furthermore, in vitro cytotoxic study showed the antitumor activity of DOX was not compromised by LB. It is possible that LB could be used as a useful adjunct in combination with DOX chemotherapy.