Synergistic effects of Zinc oxide nanoparticles and conventional antibiotics against methicillin resistant Staphylococcus aureus

Background: Methicillin resistance in Staphylococcus aureus (MRSA) is creating crises in therapeutic options for the treatment of S. aureus associated infections, worldwide. Nevertheless, Zinc oxide nanoparticles (ZnO-NPs) are providing a source of an attractive broad-spectrum antibiotic. The aim of the present study was to investigate the synergistic effects of ZnO-NPs and antibiotics against mecA positive MRSA isolates.Methods: Antibiogram of S. aureus was determined by Kirby Baur disc diffusion assay. The minimum inhibitory concentration (MIC) of antibiotics and ZnO-NPs was determined by using the broth dilution method. The mecA gene in S. aureus was detected by PCR amplification with gene specific forward and reverse primers. The effects of subinhibitory concentration of ZnO-NPs on conventional antibiotics was determined by combined disk diffusion assay.Results: Out of two hundred clinical specimens, twenty-eight showed the growth of S. aureus. Antibiogram of the isolates showed that S. aureus have acquired resistance to the majority of the conventional antibiotics. However, no isolate showed resistance to vancomycin. The confirmed methicillin resistant S. aureus isolates were sensitive to ZnO-NPs. The antibacterial activity of ZnO-NPs appeared in a dose and time dependent manner since higher dose produced stronger effects in two hours than the effects produced from lower dose in three hours. Furthermore, ZnO-NPs enhanced the antibacterial activity of levofloxacin significantly (p < 0.001).Conclusions: S. aureus has acquired strong resistance to multiple antibiotics. ZnO-NPs have potential synergism with levofloxacin antibiotic against the multiple drug resistant S. aureus including MRSA.    Keywords: Levofloxacin; Synergism; Combinational therapy; MRSA

Dolastane diterpenoids from the brown alga Dictyota indica

From the acetone extract of Dictyota indica, three new dolastane diterpenoids have been isolated together with the previously known amijiol. Their structures have been established on the basis o spectral data, in comparison with known related compounds

Spectroscopic and Substitution Kinetic Studies of Hexacyanoferrate(II) Complexes byEDTA Catalysed with Mercury(II)

Kinetics and mechanism of substitution of cyanide ion in hexacyanoferrate(II) by EDTA catalysed by mercury(II) has been studied spectrophotometrically at 365 nm in potassium hydrogen phthalate buffer of pH = 5.0 and ionic strength, I = 0.1 M, maintained by (KNO3) at 25 °C. Effect of the pH and concentration of the EDTA, [Fe(CN)4-6] on the rate of reaction has been studied. The kinetics and mechanism of the reaction has been shown through dissociative mechanism. The mechanism of ligand substitution in the complex together with the kinetic data has been shown. The catalytic activity of mercury(II) has also been studied as a function of its concentration. The maximum reaction product was detected at pH = 5 after which a decline in absorption occurs followed by precipitation. It is an inexpensive method to identify and remove the cyanide ion in solution even in very low concentration of the order of 10-4 M

Fatty acid and phenolic profile of oil and mineral composition of green unripe and purple ripe olives (Olea ferruginea)

AbstractThe present study aimed to explore fluctuations in fatty acids and phenolic profiles of olive oil extracted from fruits of Olea ferruginea Royle harvested at green raw and purple ripe stages from the district Zhob, Balochistan, Pakistan. First, fruit sampling was conducted on 26th June when green olives appeared on trees; second, purple ripe olives were picked on 26th August. Due to very small size and large pit size, oil is extracted without de-pitting the fruit. High-performance liquid chromatography–mass spectrometry (HPLC-MS) system was used for fatty acid and phenolic profiling of both oil samples. Results showed that fatty acid composition of oil extracted from raw green and ripe purple olives falls in the normal range set for purity criteria for olive oils and olive pomace oils by International Olive Council 2019 except for behenic, caprylic, capric and lauric in both oils and oleic acid and linoleic acid of oil extracted from raw green olives which do fall in standard ranges. Fatty acid composition of the olive oil showed that the oil is rich in monounsaturated fatty acids (range 50.71% in oil of green olives and 58.77% in oil of ripe purple olives), polyunsaturated fatty acids (range 30.45% in oil of raw green olives and 19.32% in oil of ripe purple olives) and saturated fatty acids (range 15.27–18.58% in olive oil obtained from raw green and ripe purple olives). SFAs showed least variation with ripening stages. There was high concentration of total phenolics in oil obtained from green raw olives (33.41 mg kg−1) as compared to oil of ripe purple olives (18.49 mg kg−1). The present study revealed that alpha, beta, gamma and delta tocopherols showed a uniform trend along with ripening of olive fruit, i.e. there is a clear decline in total tocopherol content of olive oil obtained from ripe purple olives. Green raw olives showed high values of α-tocopherol (192.47 mg kg−1), β + γ-tocopherols (233.65 mg kg−1) and δ-tocopherol (1087.48 mg kg−1). The present work concludes that ripening of olive fruit affects chemical composition of olive oil

<i>In vitro</i> growth inhibition and cytotoxicity of <i>Euphorbia caducifolia</i> against four human cancer cell lines and its phytochemical characterisation

<p>Several <i>Euphorbia</i> species have been used in folklore as cancer remedies, however, scientific studies on the cytotoxicity (<i>in vitro</i> studies) of <i>Euphorbia caducifolia</i> are lacking. In present study, anticancer potential of <i>E. caducifolia</i> aerial parts ethanol extract and its fractions were evaluated against human lung (NCI-H460), breast (MCF-7), prostate (PC-3) and cervical (HeLa) cancer cell lines, using sulphorhodamine-B <i>in vitro</i> cytotoxicity (<i>in vitro</i> studies) assay. The ethanol extract demonstrated growth inhibitory effect against all aforementioned cancer cell lines with IC₅₀, 19–135 μg/mL and LC₅₀, ~220 μg/mL, and its petroleum ether fraction obtained on bioactivity guided fraction showed highest activity with IC₅₀, 28–70 μg/mL and LC₅₀, 71 μg/mL against NCI-H460 and MCF-7 cell lines. Its phytochemicals were analysed by gas chromatography–mass spectrometry (GC-MS). The present study provides scientific justification for its traditional use against cancer.</p