Phenobarbital enhances the aldehyde dehydrogenase activity of rat hepatocytes in vitro and in vivo

Aldehyde dehydrogenase (ALDH) was measured in primary cultures of hepatocytes obtained with collagenase perfusion from livers of Long-Evans rats. After seven days in culture, basal ALDH activity, protein content and DNA content are significantly decreased. Exposure of the cultures to phenobarbital (PB, 3 mM in the media) does not prevent the decrease of DNA content, although it keeps protein at relatively higher levels. The activity of ALDH is not only preserved, but also significantly enhanced, when propionaldehyde, phenylacetaldehyde, benzaldehyde and D-glucuronolactone are used as substrates and NAD as the coenzyme. A relative increase of activity is also noted when ALDH is measured with benzaldehyde and NADP. Treatment of Long-Evans animals with PB (1 mg/ml, in drinking water for 2 weeks) leads to similar relative increases of the ALDH activity. In absolute values, however, enzyme activities found after in vivo treatment with PB are higher, compared to those obtained after in vitro exposure. These results show that ALDH activity can be greatly enhanced by PB in primary hepatocyte cultures, free from any indirect endogenous influences.     

Sansanmycin A对铜绿假单胞菌体内外抗菌活性的初步研究

目的评价sansanmycin A对临床分离铜绿假单胞菌的体内、外抗菌活性。方法体外试验以微量肉汤稀释法测定sansanmycin A同时对照10种药物对150株铜绿假单胞菌的最低抑菌浓度(MIC),以平皿计数法测定最低杀菌浓度(MBC);半体内试验以微量稀释法测定sansanmycin A的血清抑菌活性(SBS)和血清杀菌活性(SBA)。结果 Sansanmycin A对铜绿假单胞菌体外抗菌活性与哌拉西林相似,其MIC50和MBC50分别为8和16μg/mL,MIC范围为2~>512μg/mL,MBC范围为2~>512μg/mL,头孢曲松和替卡西林对铜绿假单胞菌的MIC50和MBC50较sansanmycin A高2~4倍。Sansanmycin A对铜绿假单胞菌显示浓度依赖性杀菌作用。Sansanmycin A对铜绿假单胞菌峰时SBS和SBA中位数分别为1:256和1:128。结论 Sansanmycin A对铜绿假单胞菌显示较强的体外和体内杀菌活性,有进一步研究和开发的价值。     

In vitro synergistic activity of NCL195 in combination with colistin against Gram-negative bacterial pathogens

In this study, the potential of using the novel antibiotic NCL195 combined with subinhibitory concentrations of colistin against infections caused by Gram-negative bacteria (GNB) was investigated. We showed synergistic activity of the combination NCL195 + colistin against clinical multidrug-resistant GNB pathogens with minimum inhibitory concentrations (MICs) for NCL195 ranging from 0.5–4 μg/mL for Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa, whereas NCL195 alone had no activity. Transmission electron microscopy of the membrane morphology of E. coli and P. aeruginosa after single colistin or combination drug treatment showed marked ultrastructural changes most frequently in the cell envelope. Exposure to NCL195 alone did not show any change compared with untreated control cells, whereas treatment with the NCL195 + colistin combination caused more damage than colistin alone. Direct evidence for this interaction was demonstrated by fluorescence-based membrane potential measurements. We conclude that the synergistic antimicrobial activity of the combination NCL195 + colistin against GNB pathogens warrants further exploration for specific treatment of acute GNB infections.     

Discovery of synthetic penaeidin activity against antibiotic-resistant fungi

Penaeidins are antimicrobial peptides from shrimp that are constituted by divergent classes of peptide isoforms in an individual organism. Penaeidin sequence variation suggests functional diversity in the host and promises differential activities if applied to treat infections in humans. We have synthesized isoform 4 of penaeidin class 3 from the Atlantic shrimp, Litopenaeus setiferus, by native ligation using three peptide segments. Our synthesis approach led to the discovery of an irreversible side reaction that was successfully suppressed, a discovery, which has particular relevance to the synthesis of cysteine-rich peptides. The antimicrobial activity of full-length penaeidin and the N-terminal proline-rich domain of this isoform were compared with the corresponding peptides of penaeidin class 4 isoform 1 using a wide range of bacteria and fungi. New aspects of penaeidin function are reported that include activity against fungi of the phylum Basidiomycota (Cryptococcus strains), activity against fungi that are pathogenic to humans and effectiveness in the context of antibiotic resistance mechanisms (Cryptococcus and Candida spp.). The proline-rich domain of penaeidin class 4 shows the highest relative antimicrobial activity, while exhibiting no cytotoxicity to human monocytes, and therefore stands out as a potential peptide therapeutic.     

A novel valproic acid prodrug as an anticancer agent that enhances doxorubicin anticancer activity and protects normal cells against its toxicity in vitro and in vivo

The poor survival of patients with malignant gliomas, underscores the need to develop effective treatment modalities for this devastating disease. Epigenetic agents used in combination with chemotherapy provide a promising approach to evoke synergistic cytotoxicity in glioblastomas. Previously we have described the cytotoxic synergy between a butyric acid prodrug and radiation in glioblastoma cell lines and the potentiation of radiation efficacy in glioma xenografts. Herein, we describe and compare the activities of AN446 (valproyl ester-valpramide of acyclovir) a novel histone deacetylase inhibitor (HDACI) to the previously described AN7 a HDACI prodrug of butyric acid. In various cancer cell lines, AN446 was a ∼2–5-fold more potent anticancer agent HDACI than AN7. While AN446 augmented the anticancer efficacy of doxorubicin (Dox) it also reduced the Dox toxicity in non-cancerous cells. The interaction between AN446 and Dox in U251 and in 4T1 cell lines was synergistic in inducing cytotoxicity. We examined the concomitant physical and molecular changes in the tumor and heart of glioblastoma xenografts treated with AN446, AN7, Dox and the combination of the prodrugs with Dox. A weekly dose of 4 mg/kg Dox, caused toxicity in mice whereas AN446 (25 mg/kg) or AN7 (50 mg/kg) administered thrice weekly, did not. When Dox was administered with AN446 or AN7, the prodrugs ameliorated the decline in body weight, prolonged the time to failure and increased anticancer efficacy. Thus, the combination of Dox with AN446 or AN7 could add safety and efficacy to future treatment protocols for treating glioblastoma and other cancers.     

Potent antibacterial activity of halogenated compounds against antibiotic-resistant bacteria

Common Gram-positive clinical pathogens are showing an increasing trend for resistance to conventional antimicrobial agents. New drugs with potent antibacterial activities are urgently needed to remediate this problem. Halogenated compounds isolated from several species of the red algae genus Laurencia were examined for their antibacterial activity against 22 strains of human pathogenic bacteria, 7 strains of which were antibiotic-resistant bacteria. Four phenolic sesquiterpenes and a polybrominated indole showed wide spectra of antibacterial activity against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant Streptococcus pneumoniae, and vancomycin-resistant Enterococcus faecalis and E. faecium (VRE). In addition, laurinterol and allolaurinterol displayed potent bactericidal activity against three strains of MRSA at 3.13 microg mL(-1), and three strains of vancomycin-susceptible Enterococcus, at 3.13 microg mL(-1) and 6.25 microg mL(-1), respectively.     

Protective activity of pyridinium salts against soman poisoning in vivo and in vitro

The protective effects of a series of pyridinium salts against soman poisoning were studied using female mice. From the most active compound, 130 nmoles/kg (i.m.) reduced the toxic effect of a LD₉₅ of soman (s.c.) down to the 50 per cent mortality level. The compounds with protective activity in vivo were able to protect acetylcholinesterase (AChE) from soman in vitro. The protective efficiency was evaluated by comparing the rates of AChE inhibition in the absence and in the presence of 1 mM pyridinium salt. The most effective substances decreased the inhibition rate down to about $\text{1}\text{100}$ of the unprotected value. Additionally, the influence of these compounds upon the acetylcholine hydrolysis by AChE was investigated. A striking correlation exists between the protective efficiencies in vitro and the competitive inhibition constants of the pyridinium salts.     

Anti-tumorigenic activity of sophoflavescenol against Lewis lung carcinoma in vitro and in vivo

This study examined the in vitro cytotoxic activity and in vivo antitumor activity as well as intracellular apoptotic capacities of a prenylated flavonol, sophoflavescenol from Sophora flavescens, to evaluate prospective anti-tumorigenic drugs, and antitumor potential. In addition, the in vitro antioxidant and anti-inflammatory capacities were evaluated. Despite the small effect on human breast adenocarcinoma (MCF-7), sophoflavescenol showed cytotoxicity against human leukaemia (HL-60), Lewis lung carcinoma (LLC), and human lung adenocarcinoma epithelial (A549) cells. Interestingly, it also exerted potent in vivo antitumor activity by tumor growth inhibition in the LLC tumor model as well as apoptotic activity by caspase-3 activation in HL-60 cells. In addition, it exhibited potent antioxidant activities in 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radicals and lipid peroxidation assays. Sophoflavescenol exerted notable anti-inflammatory activity by inhibiting nitric oxide generation and tert-butylhydroperoxide-induced ROS generation rather than inhibiting nuclear factor kappa B activation in RAW 264.7 cells. The findings show that the antioxidant, anti-inflammatory, and apoptotic activities of sophoflavescenol might contribute to the antitumor activity without severe side effects, highlighting its potential for chemoprevention and/or anticancer drugs due to multi-effective targets in almost all stages of tumorigenesis, including initiation, promotion, and progression.     

The reported in vitro anti-estrogen pentachloronitrobenzene enhances the estrogenic activity of estradiol in vivo in the rat

Pentachloronitrobenzene (PCNB) has been shown to inhibit foci-formation for MCF-7 cells in vitro (Zou, E., Hatakeyama, M., Matsumra, F., 2002. Foci-formation of MCF-7 cells as an in vitro screening method for estrogenic chemicals. Environ. Toxicol. Pharmacol. 11, 71) This effect was referred to as representing an anti-estrogenic property of PCNB. However, we have found no evidence that PCNB acts as either an estrogen or an anti-estrogen, either in vitro or in vivo. The assays conducted were binding to human and rat estrogen receptors (ER), a hER yeast trans-activation assay, the immature rat uterotrophic assay and a pubertal female rat assay. Nonetheless, when PCNB was evaluated as a possible anti-estrogen against estradiol in the immature rat uterotrophic assay, it enhanced, rather than reduced the activity of estradiol. Absence of an effect by PCNB on the uterotrophic activity of diethylstilbestrol suggests that the effect with estradiol was related to alteration of its metabolism. However, PCNB was not hepatotoxic and failed to inhibit cytochrome P450 or estradiol sulphotransferase. Pentachlorophenol, a major metabolite of PCNB, was inactive as an estrogen and failed to enhance the uterotrophic activity of estradiol.     

The activity 'in vitro' of trospectomycin against high-level antibiotic-resistant enterococci

Trospectomycin, a new aminocyclitol antibiotic, was uniformly active against 69 isolates of enterococci with high-level resistance to steptomycin (54 isolates), gentamicin (27 isolates), ampicillin (19 isolates), ciprofloxacin (17 isolates), vancomycin (3 isolates), or teicoplanin (3 isolates). In time-killing studies, trospectomycin alone demonstrated no bactericidal activity. No synergistic interaction was demonstrated when trospectomycin was combined with ampicillin, vacomycin or ciprofloxacin.     

In vitro and ex vivo activity of thioridazine derivatives against Mycobacterium tuberculosis

Thioridazine (TZ) has previously been shown by us to have in vitro and ex vivo activity against antibiotic-susceptible and multidrug-resistant Mycobacterium tuberculosis (MDRTB). Because current therapy of MDRTB is highly problematic even when all five 'first line of defence' drugs are employed, there is a need for effective antituberculosis drugs. New derivatives of TZ were synthesised and their in vitro activity against a reference strain of M. tuberculosis was evaluated with the aid of the BACTEC 460 system. Derivatives that presented significant activity were evaluated by ex vivo studies and were shown to enhance the killing of intracellular M. tuberculosis.     

Antifungal activity of a new benzothiazole derivative against Candida in vitro and in vivo

The antifungal activity of 6-amino-2-n-pentylthiobenzothiazole (APB) against 26 strains of the genus Candida in vitro was studied. Susceptibility of 17 strains was IC₅₀ ≤ 40 μmol/ml, of 7 strains IC₅₀ = 40−80 μmol/ml and of 2 strains IC₅₀ = 80−200 μmol/ml. Generalized candidosis of mice was treated with APB (doses 50, 100, 250 mg/kg) and ketoconazole (KET, 50 mg/kg of body weight). The optimal dose of APB was shown to be 100 mg/kg; 25% of mice survived after 14 days as compared to control animals. C. albicans was not found in the kidney of the sacrificed mice. 80% of mice survived after KET therapy. However, C. albicans was present in the kidney in an amount of 10⁵−10⁶ CFU/g of tissue. C. albicans did not reappear in the kidney 7 days after the discontinuation of APB treatment, but it was found there after KET therapy.     

Antivirulence activity of auranofin against vancomycin-resistant enterococci: in vitro and in vivo studies

Introduction: Vancomycin-resistant enterococci (VRE) are a leading cause of nosocomial infections because of the limited number of effective therapeutic options. In an effort to repurpose FDA-approved drugs against antibiotic-resistant bacteria, auranofin has been identified as a potent drug against VRE.Methods and ResultsThe present study determined that auranofin's antibacterial activity was not affected when evaluated against a higher inoculum size of VRE (~10⁷ CFU/mL), and auranofin successfully reduced the burden of stationary phase VRE cells via a time-kill assay. In addition, auranofin reduced VRE production of key virulence factors, including proteases, lipase and haemagglutinin. The promising features of auranofin prompted evaluation of its in vivo efficacy in a lethal mouse model of VRE septicaemia. All mice receiving auranofin at 0.125 mg/kg orally, 0.125 mg/kg subcutaneously (SC) or 0.0625 mg/kg (SC) survived the lethal VRE challenge. Additionally, auranofin was superior to linezolid, the current drug of choice, in reducing VRE burden in the liver, kidneys and spleen of mice. Remarkably, auranofin successfully reduced VRE below the limit of detection in murine internal organs after 4 days of oral or subcutaneous treatment.ConclusionThese results indicate that auranofin warrants further investigation as a new treatment for systemic VRE infections.     

Antiviral activity of diarylheptanoid stereoisomers against respiratory syncytial virus in vitro and in vivo

We previously showed that (5S)-5-hydroxy-7-(4-hydroxyphenyl)-1-phenylhept-3-one (AO-0011) and (5S)-5-methoxy-1,7-diphenylhept-3-one (AO-0016) isolated from Alpinia officinarum exhibited stronger anti-influenza virus activity and anti-respiratory syncytial virus (RSV) activity, respectively, than the other isolated diarylheptanoids. In this study, we synthesized an enantiomer (AO-0503) and racemate (AO-0504) of AO-0011 and an enantiomer (AO-0514) of AO-0016. The anti-RSV activities of the three stereoisomers (AO-0503, AO-0504, and AO-0514) and AO-0011 were examined in vitro and in vivo to evaluate the stereoisomeric effect on anti-RSV activity. In a plaque reduction assay using human epidermoid carcinoma cells, all four diarylheptanoids significantly exhibited anti-RSV activity, and AO-0514 and AO-0016 exhibited stronger anti-RSV activity than AO-0503, AO-0504, and AO-0011. In a murine RSV infection model, all four diarylheptanoids with anti-RSV activity in vitro were also significantly effective in reducing virus titers in the lungs of RSV-infected mice. In the histopathological analysis of RSV-infected lungs, the oral administration of even AO-0514, which showed the lowest reduction of virus titers in the lungs, was significantly effective in reducing the infiltration of lymphocytes and in reducing the interferon-γ level, which is a marker of severity of pneumonia due to RSV infection, in bronchoalveolar lavage fluids prepared from RSV-infected mice. Although the stereoisomeric effects of diarylheptanoids on anti-RSV activity varied moderately, all four diarylheptanoids examined were suggested to ameliorate pneumonia and have a potential anti-RSV activity in vivo. They are possibly mother compounds for the development of an anti-RSV drug in the future.     

The natural compound Cirsitakaoside enhances antiviral innate responses against vesicular stomatitis virus in vitro and in vivo

Cirsitakaoside, isolated and purified from the stems and leaves of Premna szemaoensis and Macaranga denticulata, is a natural compound with potential anti-inflammatory effects. However, the role of Cirsitakaoside in antiviral activity and the underlying mechanism remains largely unknown. In this study, we aimed to identify whether Cirsitakaoside has antiviral activity and investigated the underlying mechanisms. Mouse peritoneal macrophages were pretreated with Cir or DMSO, and then infected by Vesicular Stomatitis Virus (VSV) for indicated hours, Q-PCR and ELISA were used to detect the expression of interferons and pro-inflammatory cytokines, immunoblot assay were employed to investigate the involved signaling pathway in the antiviral effects of Cirsitakaoside. Furthermore, mice infected with VSV were used to investigate the antiviral activities of Cirsitakaoside in vivo. Our study demonstrated that Cirsitakaoside could promote type I IFN expression and inhibit pro-inflammatory cytokines such as IL-6 and TNF-α production in mouse peritoneal macrophages infected by VSV. Suppressive viral replication effects of Cirsitakaoside were observed on VSV-infected mouse peritoneal macrophages as well. Furthermore, Cirsitakaoside significantly increased the VSV-triggered phosphorylation of TBK1, IRF3 and reduced the phosphorylation of IκBα and p65 in mouse peritoneal macrophages. in vivo, the results showed that Cirsitakaoside-treated mice were more resistant to VSV infection by producing more IFN-β and less pro-inflammatory cytokines. Our study indicates that Cirsitakaoside is a good candidate for the treatment of viral infection and inflammation-related diseases.     

In vitro and in vivo biological activity of PEDF against a range of tumors

Background: Pigment epithelium-derived factor (PEDF) is an emerging anti-cancer agent that targets both tumor tissue and its supporting vasculature. These direct and indirect effects of PEDF have been examined in vitro and in vivo for a range of malignancies. Objective: This review seeks to present PEDF as a potential anti-cancer agent with applications across multiple malignancies. We refer closely to experimental methodology whilst still highlighting the clinical significance of PEDF in cancer, drawing on biological findings in vitro and in vivo. Methods: A Pubmed database search was performed limiting the scope of this discussion paper mainly to PEDF's biological role in cancer, specifically lung, breast, prostatic, ovarian and pancreatic carcinomas, melanoma, glioma and osteosarcoma. Conclusions: The biological roles of PEDF are diverse and multidimensional. As an anti-cancer agent, PEDF has great potential as a focused anti-neoplastic therapy against a variety of tumor types.     

Synergistic activity of isepamicin and beta-lactam antibiotics against Pseudomonas aeruginosa in vitro and in vivo

Synergistic activities of isepamicin (ISP) and a beta-lactam antibiotic such as piperacillin (PIPC) or cefotaxime (CTX) against Pseudomonas aeruginosa were demonstrated in vitro and in vivo. In vitro synergistic activity was observed when ISP was used together PIPC or CTX. The synergy observed in vitro was reproduced in vivo against experimental mouse infections, and a ISP-PIPC or a ISP-CTX combination showed significantly greater protective effects than individual antibiotics by themselves.     

氧化淀粉体内外实验的相关性及尿毒症的疗效

氧化淀粉是一种尿毒症辅助治疗剂。本文报告该药体内、外吸附氨的能力和临床应用。体外实验表明,1.0g氧化淀粉可吸附90mg氨,体内实验表明1.0g氨化淀粉每天可使大便中的氨增加83mg。两者的氨量极为接近。据42例临床尿毒症病例使用,显效率为52％,总有效率为76％,未发现有明显副作用。