Antibacterial activity of some actinomycetes from Tamil Nadu,India

Objective:To isolate novel actinomycetes and to evaluate their antibacterial activity.Methods:Three soil samples were collected from Vengodu(village)in Kanchipuram district,Tamil Nadu,India.Actinomycetes were isolated using serial dilution and plating method on actinomycetes isolation agar.Results:Totally 35 isolates were obtained on the basis of colony characteristics on actinomycetes isolation agar.All the isolates were screened for antibacterial activity by cross streak method.Medium and optimization of day were done for the potent strains using Nathan's agar well diffusion method.Isolation of bioactive compounds from significant active isolates was done by using different media.The most active isolate VAS 10 was identified as Actinobacterium Loyola PBT VAS 10(accession No.JF501398)using 16s rRNA sequence method.The hexane,ethyl acetate,dichloromethane and butanol extracts of VAS 10 were tested against bacteria.The maximum antibacterial activity was observed in dichloromethane and ethyl acetate;maximum zones of inhibition were observed against Enterococcus durans.The rRNA secondary structure and the restriction sites of Actinobacterium Loyola VAS 10 were predicted using Genebee and NEBCutter online tools respectively.Conclusions:The present study showed that among the isolated actinomycetes,Actinobacterium Loyola PBT VAS 10(accession No.JF501398)showed good antibacterial activity against the tested bacteria.

Isolation and identification of alkaloids and anthocyanins from flower and bulb of Lycoris radiata using HPLC and LC-ESI-MS

Three anthocyanins (cyanidin 3-diglucoside, cyanidin 3-sambubioside and cyanidin 3-glucoside) together with eleven known alkaloids (lycoricidine, hipppeastrine,O-Demethyllycoramin, lycoricidinol, galanthine, lycorine, lycorenine, lycoramine, galanthamine, homolycorine and pretazettine) were identified in the flower and bulb of Lycoris radiata using high-performance liquid chromatography coupled with UV detection and electrospray ionization mass spectrometry. Anthocyanins play a major role in protecting plant’s DNA from the UV spectrum of sunlight and also in attracting insects for the purpose of pollination. Thus, knowledge on the contents and types of anthocyanins of L. radiata will help to evaluate the adaptive evolution of flowers and provide useful information for the ornamental breeding.

Macleaya cordata extract alleviated oxidative stress and altered innate immune response in mice challenged with enterotoxigenic Escherichia coli

This study examines the effects of dietary Macleaya cordata extract(MCE) on bacterial burden and resistance to enterotoxigenic Escherichia coli(ETEC) in ICR mice. ICR mice were randomly distributed into one of the following groups:(i) basal diet;(ii)basal diet with 200 mg kg–1 MCE;(iii) basal diet challenged with ETEC;and(iv) basal diet with 200 mg kg–1 MCE and challenged with ETEC. Following a 7-day period of pre-treatment, CTRL-ETEC and MCE-ETEC mice were subjected to oral infection using 5×108 E. coli SEC 470. The results showed dietary 200 mg kg–1 MCE markedly reduced intestinal ETEC burden(P<0.05) and the disease-associated mortality was significantly alleviated in the MCE treated group(P<0.05). In addition,dietary MCE markedly alleviated ETEC-induced oxidative stress, evidenced by the lowered methane dicarboxylic aldehyde(MDA) abundance and enhanced activities of catalase and glutathione peroxidase(P<0.05). Furthermore, MCE mice exhibited higher immune activity, which might have further mediated ETEC infection. These results indicate MCE plays a preventative role with respect to ETEC infection. Future research should aim to develop MCE as a therapeutic approach to the promotion of intestinal health and a safeguard against ETEC infection.