Quorum sensing (QS) plays an important role in virulence of Pseudomonas aeruginosa, blocking of QS ability are viewed as viable antimicrobial chemotherapy and which may prove to be a safe anti-virulent drug. Bioactive components from Piper betle have been reported to possess antimicrobial ability. This study envisages on the anti-QS properties of ethanolic extract of P. betle leaf (PbLE) using P. aeruginosa PAO1 as a model organism. A marked reduction in swarming, swimming, and twitching ability of the bacteria is demonstrated in presence of PbLE. The biofilm and pyocyanin production also shows a marked reduction in presence of PbLE, though it does not affect the bacterial growth. Thus, the studies hint on the possible effect of the bioactive components of PbLE on reducing the virulent ability of the bacteria; identification of bioactive compounds should be investigated further.Electronic supplementary materialThe online version of this article (doi:10.1007/s13205-015-0348-8) contains supplementary material, which is available to authorized users.

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Background: The purpose of this study is to evaluate the effect of green synthesized silver nanoparticles on postharvest physiology of cut flower in relation to improvement of its vase life as well as keeping quality of the flowers taking gladiolus cut spikes as a model. Results: The synthesized Piper betle mediated silver nanoparticles (PbSNPs) were characterized by using UVvisible spectroscopy and transmission electron microscopy studies. It was revealed that PbSNPs ranges from 30 to 50 nm in diameter and spherical in shape. The experiments were conducted to study the effect of PbSNPs on post-harvest physiology, vascular blockage, prolonging vase life, and keeping the quality of cut spike of gladiolus. The treatment consisted of six vase solutions, viz. distilled water (control), 4% sucrose (T 1 ), 4% sucrose + 100 ppm 5-SSA (T 2 ), 4% sucrose + 2 ppm PbSNPs (T 3 ), 4% sucrose + 4 ppm PbSNPs (T 4 ), and 4% sucrose + 6 ppm PbSNPs (T 5 ). Experimental outcomes depicted that T 4 vase solution gives the best results in all the aspects statistically compared to its positive control (T 2 ). The results also show PbSNPs in vase solution might have played a significant role for scavenging the reactive oxygen species by inducing antioxidant enzyme system at the time of senescence, leading to a decrease in lipid peroxidation and increase in the membrane stability.Conclusions: This study revealed that application of T 4 vase solution helps to maintain spikes fresh and dry weight, reduce the vascular blockage, improve the antioxidative defense, and stabilize the membrane integrity that leads to delay senescence.

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SummaryThe effective potentiality of anticancerous drugs, namely, cisplatin, etoposide and vinblastine, as well as the ethanolic extract of Piper betle L. leaves, is evaluated (concentrations used: 0.001, 0.01, 0.1, 1.0 and 10.0 µM for vinblastine; 25, 50, 75, 100, 125 and 150 µM for other test materials) on germinating grass pea (Lathyrus sativus L.) seedlings in relation to radicle length and mitotic index. Furthermore, inhibition in the frequency of dividing polyploid cells induced due to prior treatments of colchicine (0.5%, 8 h) and in vitro callus growth are also assessed following treatments with different concentrations of the test materials. The objective of the present study is to determine the effectivity of the test materials on a plant species with the view to develop a plant system (convenient to use and cost effective) as a model for preliminary screening of novel anticancerous drugs as well as plant extract(s) possessing such potentiality for further exploration.

Background: Etoposide is one of the most potential anti-cancerous drugs that targets topoisomerase II (topoII) and inhibits its activity by ligation with the DNA molecule. Results: In silico study confirmed that the etoposide-binding sites of topoII are conserved among the plants and human. The efficacy of the drug on plant system was initially assessed using germinated grass pea (Lathyrus sativus L.) seedlings (in vivo) in relation to radicle length and mitotic index. The callus system (in vitro) was also used to elucidate the effect of etoposide on callus growth kinetics. Furthermore, it was observed that etoposide able to inhibit the division of polyploid cells induced by colchicine treatment (0.5%, 8 h). To determine the molecular interaction, topoII was isolated from young grass pea leaves using polyethylene glycol fractionation and ammonium sulphate precipitation followed by column chromatography on CM-Sephadex (C-25). The plasmid linearization assays by isolated plant topoII in the presence of etoposide significantly revealed the functional similarity of plants and human topoII. Results indicated that the effect of etoposide on plant topoII is significant. Conclusions: This study may pave the way to develop a plant-based assay system for screening the topoisomerase targeted anti-cancerous drugs, as it is convenient and cost-effective.

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The effect of alkylating anti-cancerous drugs oxaliplatin and carboplatin were assessed on germinating seedlings of Lathyrus sativus L. Concentrations used for oxaliplatin were 1 µM, 10 µM, 20 µM and 30 µM respectively; and 100 µM, 200 µM, 300 µM and 400 µM for carboplatin. The radicle length and mitotic index decreased with the increasing concentration of the drugs. Polyploidy was induced on germinating roots by pre-treatment (8 h) with 0.5% colchicine. The inhibitory effect of the drugs on the induced polyploidy was evident with the increasing doses of the drugs. In vitro callus growth in different doses of the drugs in media was measured by taking the weight and area of the callus. The objective of the work was to assess the effectiveness of alkylating drugs on the plant-based model to develop a plant-based model system for the primary screening of anti-cancerous drugs.