BackgroundScreening of the ethnobotenical plants is a pre-requisite to evaluate their therapeutic potential and it can lead to the isolation of new bioactive compounds.MethodsThe crude extracts and fractions of six medicinal important plants (Arisaema flavum, Debregeasia salicifolia, Carissa opaca, Pistacia integerrima, Aesculus indica, and Toona ciliata) were tested against three Gram positive and two Gram negative ATCC bacterial species using the agar well diffusion method.ResultsThe crude extract of P. integerrima and A. indica were active against all tested bacterial strains (12-23 mm zone of inhibition). Other four plant's crude extracts (Arisaema flavum, Debregeasia salicifolia, Carissa opaca, and Toona ciliata) were active against different bacterial strains. The crude extracts showed varying level of bactericidal activity. The aqueous fractions of A. indica and P. integerrima crude extract showed maximum activity (19.66 and 16 mm, respectively) against B. subtilis, while the chloroform fractions of T. ciliata and D. salicifolia presented good antibacterial activities (13-17 mm zone of inhibition) against all the bacterial cultures tested.ConclusionThe methanol fraction of Pistacia integerrima, chloroform fractions of Debregeasia salicifolia &Toona ciliata and aqueous fraction of Aesculus indica are suitable candidates for the development of novel antibacterial compounds.

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Citrus black rot disease being caused by Alternaria citri is a major disease of citrus plants with 30–35% economic loss annually. Fungicides had not been effective in the control of this disease during last few decades. In the present study, antifungal role of green synthesized zinc oxide (ZnO) and copper oxide (CuO) nanoparticles (NPs) were studied against Alternaria citri . Alternaria citri was isolated from disease fruits samples and was identified by staining with lacto phenol cotton blue. Furthermore, CuO and ZnO NPs were synthesized by utilizing the lemon peels extract as the reducing and capping agent. Nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. From the XRD data, the calculated size of CuO NPs was to be 18 nm and ZnO NPs was16.8 nm using Scherrer equation. The SEM analyses revealed the surface morphology of all the metal oxide NPs synthesized were rounded, elongated and or spherical in the shape. The zone of inhibition was observed to be 50 ± 0.5 mm by CuO NPs, followed by 51.5 ± 0.5 mm by ZnO NPs and maximum zone of antifungal inhibition was observed to be 53 ± 0.6 mm by mix metal oxide NPs. The results of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the synthesized nanoparticles showed that at the certain concentrations (80 mg ml −1 ), these NPs were capable of inhibiting the fungal growth, whereas above that specified concentrations (100 mg ml −1 ), NPs completely inhibited the fungal growth. Based on these findings, the green synthesized NPs can be used as alternative to fungicide in order to control the citrus black rot disease.

The emergence of multidrug resistance in pathogenic bacteria limits the utilization of available antibiotics. The development of alternate options to treat infectious diseases is the need of the day.The present study was aimed to synthesize, characterize and evaluate the bioactive properties of silver nanoparticles. Endophytic bacterium Bacillus cereus (MT193718) isolated from Berberis lycium was used to synthesize biocompatible silver nanoparticles. Antibacterial properties of AgNPs were evaluated against clinically isolated multidrug-resistant strains of Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae . AgNPs indicated significant antibacterial activity against S. aureus and K. pneumoniae f with a zone of inhibition of 17 and 18 mm at a concentration of 1000 µg/ mL with minimum inhibitory concentration of 15.6 and 62.5 µg/mL respectively. Significant antioxidant activity with an IC50 value of 9.5 µg/mL was recorded. Biosynthesized AgNPs were found compatible with red blood cells at a concentration of 31.5 µg/ml with no clumping of erythrocytes. The study suggested that AgNPs synthesized by the endophytic bacterium Bacillus cereus are biologically active and can be used as antioxidant and antibacterial agents against drug-resistant bacteria.

Pistacia integerrima Stew. ex Brand (Anacardiaceae) is an ethanobotanically important plant species traditionally used in the treatment of chronic wounds, jaundice, dysentery, etc. The crude extract from Pistacia integerrima and its fractions were tested for cytotoxic activity against Michigan Cancer Foundation-7 human breast cancer cell line. We have also investigated that crude stem extract of this plant also exhibits the antitumour as well as antifungal potential activities. Moreover, we have also studied that the crude extract inhibited Michigan Cancer Foundation-7 cell viability in a dose-dependent manner; the poor toxicity (1.6%) at 10 μg/ml to moderate toxicity (55.4%) at 100 μg/ml. The IC50 values calculated were 90.9 μg/ml. The ethyl acetate and chloroform fractions at a concentration of 200 μg/ml showed ~100 and 97.4% inhibition against Michigan Cancer Foundation-7 cell line, respectively. The crude methanol extract also showed good antitumour (IC50 125 ppm) activity, but weak antifungal activity. These findings reveal that the ethyl acetate and chloroform fractions of Pistacia integerrima are potent cytotoxic fractions, and could be an alternate candidate for the development of novel biologically active compounds.