Avijit Mazumder

Antimicrobial potentiality of Phyllanthus amarus against drug resistant pathogens

The antimicrobial potentiality of the methanolic extract of Phyllanthus amarus (Family: Euphorbiaceae) was studied against some drug resistant pathogenic bacterial strains by disc diffusion and agar dilution method. The extract showed significant concentration-dependent antibacterial activity particularly against gram-negative microbes. The study illustrated the claim of the usefulness of the plant in dysenteric and diarrheal infections and also suggested its use in fever. The antibacterial action was mainly due to the isolated phyllanthin.

In vitro antimicrobial and antioxidant activities of anthrone and chromone from the latex of Aloe harlana Reynolds.

In the search for new antimicrobial and antioxidant compounds from plants, the latex of the medicinal plant Aloe harlana Reynolds from Ethiopia was subjected to bioassay‐guided fractionation, which led to the isolation of two known compounds, anthrone (aloin) and chromone (7‐O‐methylaloeresin A). The latex and its two constituents were assessed for their possible antimicrobial activities against 23 bacterial and four fungal strains using the disc diffusion method and their antioxidant activity by two complementary test systems, namely 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2‐deoxyribose degradation assay methods.

Pharmacological studies on Buchanania lanzan Spreng.-A focus on wound healing with particular reference to anti-biofilm properties

OBJECTIVE To evaluate the wound healing activity of the methanolic root extract of Buchanania lanzan Spreng. (B. lanzan), with a focus on antimicrobial and anti-biofilm properties. METHODS The extract was evaluated for its wound healing properties (excision and incision models) as evident from the analysis of tensile strength and wound contraction. The extract was also screened for antibacterial properties against different Gram positive and Gram negative bacterial strains. B. lanzan was also studied for its effect on biofilm formation and disruption of preformed biofilms. The synergistic effect of B. lanzan was determined in combination with gentamicin. RESULTS Topical application of B. lanzan (10% w/w ointment) significantly increased (40.84%) the tensile strength in the incision wound model. B. lanzan also showed significant wound healing activity in excision model and such significant activity was observed from the 9th day. Whereas Soframycin displayed significant wound healing activity from the 6th day. It was found that root extracts of B. lanzan revealed significant inhibition against all tested pathogens. B. lanzan displayed antimicrobial activity against Gram positive (MIC 0.625 mg/mL) and Gram negative (MIC 0.625-1.25 mg/mL). B. lanzan was able to reduce biofilm formation and also caused disruption of preformed biofilms in a manner similar to ciprofloxacin. However, gentamicin was found to be ineffective against biofilms formed by Gram negative organism. According to the fractional inhibitory concentration index, B. lanzan displayed synergistic activity when it was combined with gentamicin. CONCLUSIONS From this study it may be concluded that the root extract of B. lanzan revealed significant wound healing potential, which was supported and well correlated with pronounced antibacterial activity of the tested plant parts.

Isolation, structural elucidation and in vitro antioxidant activity of compounds from chloroform extract of Cedrus deodara (Roxb.) Loud.

This study was designed to isolate, characterise and explore in vitro antioxidant potential of compounds from the chloroform extract of Cedrus deodara wood belonging to Pinacae family. We have investigated the in vitro free radical scavenging activity of isolated compounds by measuring total antioxidant capacity (TAC) and reducing power ability. From the chloroform extract five sesquiterpenes namely atlantone, himaphenolone, atlantolone, deodardione and atlantone-2,3-diol were identified. Himaphenolone and deodardione from the chloroform extract of this plant have been isolated for the first time. A marked dose-dependent reducing power and strong TAC were found in favour of himaphenolone and atlantone-2,3-diol, respectively. Moreover, deodardione and atlantolone also exhibit good antioxidant potentials. However, atlantone has showed least antioxidant activity. In conclusion, the chloroform extract of C. deodara exhibited significant antioxidant potential mainly due to the presence of sesquiterpenes which may be responsible for various pharmacological activities of this plant.

Evaluation of the wound healing property of Commiphora guidottii Chiov. ex. Guid.

BackgroundThe traditional use of the oleo-gum-resin of Commiphora guidottii Chiov. ex. Guid., which is commonly called scented myrrh, for topical treatment of wound is well documented. The major objective of the present study was to investigate the essential oil and resin obtained from C. guidottii for their potential wound healing properties. Due to their influence on the wound healing process, the anti-inflammatory and antimicrobial activities of scented myrrh have also been investigated.MethodsPowdered oleo-gum-resin of C. guidottii was steam-distilled to obtain essential oil, and the resin was extracted from the marc with MeOH and filtered. The TLC fingerprint profile of the resin has been recorded by using silica gel GF254 as stationary phase. The essential oil components were identified and quantified by GC-MS. Ointments prepared from the essential oil (4 % v/w) and the resin (5 % w/w) were used for wound healing activity tests. Toxicity of the formulated ointments was investigated according to Draize skin irritation test. Acute anti-inflammatory effect in mice was evaluated using carrageenan induced mouse hind paw oedema model. Antimicrobial activity tests were carried out using disk diffusion and broth dilution techniques against 21 pathogenic bacterial and 4 fungal strains.ResultsOintment formulations of both the oil and resin were found to be non-irritant at the concentrations used and showed significant (p < 0.05-0.001) increase in wound contraction rate, shorter epithelization time and higher skin breaking strength as compared to the negative control. Overall, the antibacterial and antifungal activities of the oil and resin were comparable with the standard antibiotics ciprofloxacin and griseofulvin, respectively.ConclusionThe results confirm that scented myrrh possesses genuine wound healing activity supporting the traditional use of the plant.

Synthesis, Characterization, and In Vitro Anticancer Evaluation of Novel 2,5-Disubstituted 1,3,4-Oxadiazole Analogue

In this series, we have synthesised a new 2,5-disubstituted 1,3,4-oxadiazole in search of potential therapeutics for cancer. The anticancer activities were evaluated on a panel of 60 cell lines by the National Cancer Institute according to its own screening protocol. Out of the 24 compounds, 11 were selected and evaluated via single high dose (10−5 M). In the next phase, two compounds have been selected for five-dose assay. The compounds 3-(5-benzyl-1,3,4-oxadiazol-2-yl)quinolin-2(1H)-one 18 (NSC-776965) and 3-[5-(2-phenoxymethyl-benzoimidazol-1-ylmethyl)-[1,3,4]oxadiazol-2-yl]-2-p-tolyloxy-quinoline 27 (NSC-776971) showed mean growth percentage of 66.23 and 46.61, respectively, in one-dose assay and their GI50 values ranging between 1.41–15.8 μM and 0.40–14.9 μM, respectively, in 5-dose assay.

Essential Oil of Plectranthus cylindraceus Hochst. ex. Benth from Ethiopia: Chemical Composition and Antimicrobial Activity

Traditionally Plectranthus cylindraceus Hochst. ex. Benth (Lamiaceae) is used as a disinfectant and for the treatment of various illnesses. Hydrodistillation of the fresh aerial part of P. cylindraceus collected in Ethiopia yielded 0.39 % (v/w) colourless oil with a strong but pleasant smell. Analysis of the oil by gas chromatography-mass spectrometry (GC-MS) afforded twenty-nine compounds which accounted for 95.26 % of the oil with two of the components yet to be identified. The oil was found to be rich in oxygenated monoterpenes (90.00 %), the major constituents being camphor (40.93 %) and 1,8-cineol (25.38 %). In vitro antimicrobial activity of the oil investigated by disc diffusion technique indicated that it was active against both Gram-positive and Gram-negative bacteria as well as some fungal strains. The activity of the oil was more prominent against several Gram-negative bacterial strains including Escherichia coli, Shigella spp and Vibro cholerae with a minimum inhibitory concentration (MIC) value of 25 μg/ml. Among the bacterial strains tested Shigella flexneri Type 6 was the most susceptible against which the oil displayed an MIC value of 10 μg/ml. The oil did also demonstrate a significant fungal inhibitory potency against Aspergillus niger and Candida albicans with an MIC value of 400 μg/ml. At similar concentrations, the oil and the standard antimicrobials used in this study exhibited comparable activities against the tested bacterial and fungal strains. Moreover, the mode of action of the oil was proved to be bactericidal and fungicidal. The study provides evidence for the broad-spectrum antimicrobial effect of P. cylindraceus essential oil, a possible justification for the traditional use of the plant in the treatment of skin, digestive, respiratory and inflammatory diseases which may be related to microbial infections.

In vivo antitussive potentiality of Lagerstroemia parviflora flower extract using a cough model induced by sulfur dioxide in mice.

The methanol extract of the flowers of Lagerstroemia parviflora Roxb (Family: Lythraceae) was investigated for its effect on a cough model induced by sulphur dioxide gas in mice. It exhibited significant antitussive activity when compared with the control in a dose-dependent manner. The extract (100, 200, 300 mg kg−1) showed maximum inhibition of cough reflex at 90 min after drug administration and the antitussive activity was comparable to that of codeine phosphate, a standard antitussive agent.

Evaluation of Antipyretic Potential of Lagerstroemia parviflora. Extract in Rats

Abstract The methanol extract of Lagerstroemia parviflora. Roxb leaves was tested for antipyretic effects on rats. The extract (200 and 300 mg/kg, p.o.) showed very significant reduction of yeast-induced pyrexia in rats with respect to the control group. The antipyretic activity of the extract was comparable to the standard prototype, paracetamol.

Updates on synthesis and biological activities of 1,3,4-oxadiazole: A review

ABSTRACT The new era of heterocyclic moieties which are developed in the decades plays a very important role in the treatment of various diseases. Among them are 1,3,4-oxadiazoles, a heterocyclic five-membered ring which plays an vital role in the development of newer medicinal compounds for treating various biological activities, such as proliferation of cells, tuberculosis, allergy, viral diseases, etc. The present review will summarize the various synthetic approaches which will be correlated with the biological activities so that the information in future may be used by many researches to give a path breaking lead in the field of medicinal chemistry. GRAPHICAL ABSTRACT