An Overview on the Zoonotic Aspects of COVID-19.

Disruption of pristine natural habitat has a strong positive correlation with this increase in pandemics and thus, the zoonotic aspects are the most important part to uncover scientifically. On the other hand, containment and mitigation are the two basic strategies to stop a pandemic. The route of infection is of utmost importance for any pandemic and often left behind in combating the fatalities in real time. The increase in recent pandemics, from ebola outbreak to ongoing COVID-19 havoc, exerts implicit significance in the search of zoonotic transmissions of the diseases. Thus, a conceptual summary has been made through this article in understanding the basic zoonotic mechanism of the disease COVID-19 based on available published data and schematic presentation has been drawn on the route of transmission, so far discovered.

Phytoextracts as Antibacterials: A Review.

Botanicals have been cultured to flavour food, to treat health disorders and to put a stop to diseases caused by various microorganisms. The awareness of curative features of different medicinal plants has been spread among human communities. The application of herbal products as antimicrobial agents may be a better choice for the extensive and imprudent use of synthetic antibiotics. World Health Organization recommended traditional medicines as the safest remedies for the treatment of diseases of microbial origin. The plant extracts are generally nonhazardous, available in plenty at reasonable prices, biodegradable, eco-friendly and sometimes show broad-spectrum activities against different microorganisms. The current knowledge on plant extracts, phytochemicals and their antibacterial activity, target specific mechanism of action, solvents deployed during extraction, properties of an active ingredient isolated may help in biological control of bacteria. Antimicrobial properties of different plant parts, which act in a low dose, have been organised separately for easy understanding.

Larvicidal activity of phytosteroid compounds from leaf extract of Solanum nigrum against Culex vishnui group and Anopheles subpictus.

BACKGROUND: Vector control is facing a menace due to the appearance of resistance to synthetic insecticides. Insecticides of plant origin may provide appropriate substitute biocontrol techniques in the future. The present study was carried out to investigate the bio control potentiality of active ingredient isolated from chloroform: methanol (1:1 v/v) extract of mature leaves of Solanum nigrum L. (Solanaceae) against early 3rd instar larvae of Culex vishnui group (comprising of Cx. vishnui Theobald, Cx. pseudovishnui Colless and Cx. tritaeniorhynchus Giles) and Anopheles subpictus Grassi. S. nigrum is a common plant distributed in many parts of India with medicinal properties. METHODS: Bioactive compound isolated from chloroform: methanol (1:1 v/v) extract of mature leaves of S. nigrum was (25, 45, 60 mg/L) tested against early 3rd instar larvae of Cx. vishnui group and An. subpictus. The lethal concentration was determined by log probit analysis. The chemical nature of the active substance was also evaluated following gas chromatography-mass spectroscopy (GC-MS) and infrared (IR) analysis. The compound was also studied on non target organisms such as Daphnia sp. and Diplonychus annulatum. RESULTS: TLC spot having Rf value of 0.94 (Rf = 14.1/15 = 0.94) showed larvicidal activity. In a 72 h bioassay experiment, mortality rate at 60 mg/L was significantly higher (P < 0.05) than those at 25 and 45 mg/L against early 3rd instar. Result of log-probit analysis (at 95% confidence level) revealed that LC50 and LC90 values gradually decreased with the exposure period showing the lowest value at 72 h of exposure. A clear dose-dependent mortality was observed, as the rate of mortality (Y) was positively correlated with the concentration (X) having regression coefficient value close to one in each case. The compound was found to be eco-friendly as it did not show any adverse effect to the studied non target organisms. Chemical characterization (GC-MS and IR analyses) of the active ingredient revealed the presence of phytosteroid compounds responsible for mosquito larvicidal activity. CONCLUSION: Leaf extract of S. nigrum has great potential as bio control agent against Cx. vishnui group and An. subpictus. In near future the isolated bioactive phytochemical could be used as a source of an effective mosquitocidal agent.