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Melaleuca polandii, commonly known as "Gold-tipped Bottlebrush", is widely grown in Indian gardens and parks as an ornamental plant. In the present study, the chemical composition, antioxidant, antimicrobial and cytotoxic activities of M. polandii leaf essential oil (MPLEO) have been investigated. GC-MS analysis of MPLEO isolated from plants grown along the coastal plains of Eastern India revealed the presence of 50 constituents with α-pinene (46.17%), 3Z-hexenyl acetate (10.10 %), α-terpineol (5.43%), limonene (3.63%) and ρ-cymene (2.44 %) as the major constituents. MPLEO exhibited moderate antioxidant capacity in DPPH, ABTS and Reducing ability assays with IC50 values of 7.94 ± 0.34 μg/mL, 5.71 ± 0.21 μg/mL and EC50 7.09 ± 0.35 μg/mL, respectively. Of the 5 bacterial strains tested, the EO exhibited highest sensitivity against Bacillus subtilis with the ZOI of 12.66 ± 0.57 mm and strong antimicrobial activity against Staphylococcus saprophyticus with MIC value of 6.25 μg/mL. MPLEO exhibited significant cytotoxic effects against Human alveolar lung adenocarcinoma (A549), Human hepato-cellular carcinoma (HepG2), Human cervix adenocarcinoma (HeLa) and normal Human Embryonic Kidney cell (HEK-293) as evaluated through MTT assay with IC50 values of 9.5 ± 0.38 μg/mL, 22.73 ± 0.95 μg/mL, 20.41 ± 0.82 μg/mL and 237.68 ± 9.26 μg/mL, respectively. The findings of the present study demonstrated that MPLEO could be considered as a potential bioresource having applications in pharmaceutical industries as an antibacterial and antiproliferative agent. [ABSTRACT FROM AUTHOR]

Inside the biological milieu, nanoparticles with photocatalytic activity have potential to trigger cell death non‐specifically due to production of reactive oxygen species (ROS) upon reacting with biological entities. Silver nanoparticle (AgNP) possessing narrow band gap energy can exhibit high light absorption property and significant photocatalytic activity. This study intends to explore the effects of ROS generated due to photocatalytic activity of AgNP on antimicrobial and cytotoxic propensities. To this end, AgNP was synthesized using the principle of green chemistry from the peel extract of Punica granatum L., and was characterized using UV–Vis spectroscope, transmission electron microscope and x‐ray diffraction, and so forth. The antimicrobial activity of AgNP against studied bacteria indicated that, ROS generated at AgNP interface develop stress on bacterial membrane leading to bacterial cell death, whereas Alamar Blue dye reduction assay indicated that increased cytotoxic activity with increasing concentrations of AgNP. The γH2AX activity assay revealed that increasing the concentrations of AgNP increased DNA damaging activity. The results altogether demonstrated that both antimicrobial and cytotoxic propensities are triggered primarily due interfacial ROS generation by photocatalytic AgNP, which caused membrane deformation in bacteria and DNA damage in HT1080 cells resulting in cell death. [ABSTRACT FROM AUTHOR]

Bacopa monnieri (L.) Wettst is a very high-value medicinal plant that is commonly used for improving cognitive functions. However, the availability of very limited information on the drying method of B. monnieri has prompted to optimize a suitable drying method. The present study therefore aimed to evaluate the influence of the following six drying treatments on the quality of B. monnieri sample: microwave drying at 300 W and 600 W, hot air-drying at 50EC and 70EC, solar drying, and freeze-drying (FD). The quality attributes of the dried samples were comparatively analyzed in terms of color, total color difference, moisture content, water activity (a w), antioxidant activity, and bacoside A and bacopaside I content. The results of this study showed significant differences (P < 0.05) among the different drying methods in International Commission on Illumination (CIE) parameters, namely lightness index (L*), red-green index (a*), and yellow-blue index (b*), ΔE and a w values. Among the samples dried with the six drying methods, freeze-dried B. monnieri samples had an attractive color with the lowest total color difference value (11.415%), a w value (0.15%), and maximum bacoside A (3.389%) and bacopaside I (0.620%) content. Moreover, Fourier transform infrared spectroscopy (FT-IR) analysis showed no major difference in the functional groups in B. monnieri samples processed by the different drying methods. Considering the retention of quality after drying, FD was found to be very effective for future large-scale production of good quality dried B. monnieri products. [ABSTRACT FROM AUTHOR]