Isolation and characterization of a lytic bacteriophage against Pseudomonas aeruginosa.

In recent years, the use of bacteriophages (or 'phages') against multidrug-resistant (MDR) bacteria including Pseudomonas aeruginosa has drawn considerable attention, globally. In this work, we report the isolation and detailed characterization of a highly lytic Pseudomonasphage DRL-P1 isolated from wastewater. Under TEM, DRL-P1 appeared as a member of the phage family Myoviridae. DRL-P1 featured rapid adsorption (~ 5 min), short-latency (~ 30 min), and large burst size (~ 100 PFU per infected cell). DRL-P1 can withstand a wide temperature range (4 °C to 40 °C) and pH (5.0 to 10.0) conditions. The 66,243 bp DRL-P1 genome (MN564818) encodes at least 93 ORFs, of which 36 were functionally annotated based on homology with similar phage proteins available in the databases. Comparative analyses of related genomes suggest an independent evolutionary history and discrete taxonomic position of DRL-P1 within genus Pbunavirus. No toxin or antibiotic resistance genes was identified. DRL-P1 is tolerant to lyophilization and encapsulation techniques and retained lytic activity even after 18 months of storage. We also demonstrated decontaminating potentials of DRL-P1 in vitro, on an artificially contaminated cover-slip model. To the best of our knowledge, this is the first Pbunavirus to be reported from India. Our study suggests DRL-P1 as a potential candidate for various applications.

Antifertility activity of Thevetia peruviana (Pers.) K. Schum leaf in female Sprague-Dawley rat.

OBJECTIVES: Thevetia peruviana (Pers.) K. Schum. (Apocynaceae) is known to possess cardioactive glycoside such as thevetin A, thevetin B, neriifolin, peruvoside, thevetoxin, and ruvoside. Traditionally, T. peruviana leaves are used as abortifacient. The aim of the present study is to evaluate antifertility potential of T. peruviana leaves. SUBJECTS AND METHODS: Cardiac glycoside freed leaves of T. peruviana were extracted with methanol using maceration method. The dried cardiac glycoside-free methanolic extract of T. peruviana leaves (TPL-Me-G) was screened for phytoconstituents and evaluated for its effect on estrogen-primed female Sprague-Dawley rat uterus model. It was further studied for effects on the estrous cycle, implantation, and effect on estrogen and progesterone. STATISTICAL ANALYSIS USED: Statistical analysis was done by ANOVA followed by Dunnett's t-test. RESULTS: Alkaloids, flavonoids, essential oils, carbohydrates, and amino acids were found to be present in the glycoside-free extract. Thin-layer chromatography (TLC) in n-butanol: acetone: water (4:1:5) revealed the presence of quercetin and kaempferol. The presence of flavonoids (quercetin 0.0326% and kaempferol 0.138% on dry weight basis) was reconfirmed by high-performance TLC analysis. The extract was able to induce uterine contractions (EC50, 0.170 mg/ml) in a dose-dependent manner. Further investigation showed significant (P < 0.001) extension of estrous cycle and anti-implantation activity of the extract by reduction of the progesterone level. CONCLUSIONS: Methanolic extract of T. peruviana leaves (TPL-Me-G) containing quercetin 0.0326% and kaempferol 0.138% possesses a significant (P < 0.001) antifertility potential by virtue of decreasing the progesterone level.

Phytochemical investigation and pharmacognostic standardization of Cissampelos pareira root.

BACKGROUND: In ethno-medicinal practices, the roots of Cissampelos pareira(Patha) are used in the treatment of various ailments related to urinary problems and skin infections, and in tumorinhibitor activity, antibacterial, antimalarial, diuretic activity,anticonvulsant activity etc., The main problem encountered in standardization of Ayurvedic drugs is proper identification of the source plant. MATERIALS AND METHODS: The macroscopic features of each anatomical component have been observed by a high-resolution camera. The moisture content, total ash, acid-insoluble ash, and water-alcohol and ether extractive values of the powdered sampleswere determined by the method as per WHO guidelines. The phytochemical investigation of the methanolic extract of Cissampelos pareira root was performed by the standard chemical ltests and by TLC on silica gel G using solvent systems proposed by Harborne. RESULT: The microscopic characteristics showed the wavy epidermis with unicellular trichomes. Lignified xylem vessels, radial medullary rays, and prismatic calcium oxalate crystals had also been found. Phytochemical screening revealed that the Cissampelos pareira root extract contains terpenoids, alkaloids, tannins, amino acid proteins, and carbohydrates. Alkaloids and essential oil were detected in TLC of the Cissampelos pareira root extract developed using blends of methanol:concentrated ammonia (200:3) and n-butanol:acetone:water (3:1:1) and benzene:ethyl acetate:formic acid(9:7:4) as solvent systems for alkaloid whereas chloroform(100%), benzene (100%), chloroform:benzene(1:1),and ether:benzene(1:1) as solvent systems for essential oil. CONCLUSION: These findings will be useful toward establishing pharmacognostic standards on identification, purity,quality, and classification of the plant, which is gaining relevance in plant drug research.