Chemical constituents and strong larvicidal activity of Solanum xanthocarpum among selected plants extracts against the malaria, filaria, and dengue vectors.

BACKGROUND & OBJECTIVES: The role of mosquitoes is instrumental in the transmission of various diseases. Mosquitoe-borne diseases account for a significant share of the global burden of total infectious diseases. Vector control is the principal method for the control of these mosquito-borne diseases. Plant-derived insecticides serve as an effective alternative to chemical insecticides. The present study has been undertaken to assess the larvicidal potential of methanol and petroleum ether extracts of leaves of Solanum xanthocarpum, Parthenium hysterophorus, Manihot esculenta, and Chamaecyparis obtusa. METHODS: Larvicidal activity was tested against the early four-stage instar larvae of laboratory-reared susceptible strains of the malaria vector, Anopheles stephensi, dengue fever vector, Aedes aegypti, and the lymphatic filariasis vector, Culex quinquefasciatus at 20 to 120 ppm concentrations. Further, liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectroscopy (GC-MS) analyses were carried out to identify the bioactive compounds present in the methanolic leaf extracts of Solanum xanthocarpum for designing a larvicidal product in future. RESULTS: After 72 h of exposure high larvicidal activities were observed in methanolic and petroleum ether leaves extract of S. xanthocarpum against An. stephensi, Ae. aegypti and Cx. quinquefasciatus. The larvicidal activities for methanol and petroleum ether leaf extract of S. xanthocarpum with LC50 = 09.201 and 12.435 ppm and LC90 = 21.578 and 27.418 ppm for An. stephensi; LC50 = 11.450 and 10.026 ppm and LC90 = 26.328 and 22.632 ppm for Ae. aegypti and LC50 = 12.962 and 13.325 ppm and LC90 = 26.731 and 30.409 ppm for Cx. quinquefasciatus, respectively, were found to be most effective. GC-MS analysis revealed 43 compounds, amongst these phytol (13.09%), 3-allyl-2-methoxy phenol (9.55%), (9Z, 12Z)-9, 12-octadecadienoyl chloride (7.93%), linoleic acid (5.45%), alpha-tocospiro B (5.08%) and hexadecanoic acid (4.35%) were identified as major compounds. INTERPRETATION & CONCLUSION: Present work showed that leaf extracts of S. xanthocarpum are a source of potential natural candidate that possess several phytochemicals which can be explored further for the development of ecologically safer mosquito control products.

Mosquito larvicidal potential of Solanum xanthocarpum leaf extract derived silver nanoparticles and its bio-toxicity on non-target aquatic organism.

BACKGROUND & OBJECTIVES: Mosquitoes are insects of public health importance that act as a vector to transmit various vector-borne diseases in humans including dengue, malaria, filariasis and yellow fever. The continually employed synthetic insecticides have developed resistance in mosquitoes. Nano-based botanical insecticides can be considered as the best alternative due to several advantages like being simple, non-pathogenic, biodegradable and safe to the environment. The present work reported the maximum larvicidal potential of green synthesized silver nanoparticles (AgNPs) derived from the leaf extract of Solanum xanthoearpum against the third instar larvae of Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus over its crude leaf extract. METHODS: The synthesis of AgNPs was done by adding leaf extract into silver nitrate solution in a conical flask. The characterization of AgNPs was done using different techniques such as UV-Vis, SEM, TEM, XRD, DLS and SAED. FT-IR analysis was done to find out the compound responsible for bio-reduction of silver nitrate. Larvicidal activity of AgNPs was checked against An. stephensi, Ae. aegypti, and Cx. quinquefasciatus according to WHO standard protocol and toxicity was evaluated against Poecilia reticulate. RESULTS: A change in colour was observed indicating the synthesis of AgNPs which was further confirmed by a strong surface plasmon resonance peak at 421nm under the UV-Vis spectrum. SEM and TEM micrographs exhibited that the most common shape of AgNPs was spherical. XRD spectrum showed crystalline nature of silver nanoparticles. FT-IR spectrum showed the presence of various functional groups such as carboxyl and hydroxyl which might be responsible for bio-reduction and capping of silver nanoparticles. Further, silver nanoparticles were very effective against An. stephensi, Ae. aegypti, and Cx. quinquefasciatus with LC50 and LC90 values of 1.90, 2.36, 2.93, 3.82, 4.31 and 7.63 ppm, respectively, as compared to aqueous leaf extract after 72 h of exposure and were non-toxic against non-target organism P. retieulata. Interpretation & eonelusion: From the above finding, it can be concluded that fabricated AgNPs can be promising eco-friendly tools for controlling mosquito vectors.

Role of Various Gene Expressions in Etiopathogenesis of Type 2 Diabetes Mellitus.

CONTEXT: Diabetes is a metabolic disease, with high mortality, and is characterized by increased glucose levels in the blood occurring due to poor pancreatic insulin secretion or development of insulin resistance in the body. Type 2 DM (T2DM) represents 90% of diabetic cases, and its pathogenesis involves a genetic correlation with insulin resistance, ß-cell dysfunction, lifestyle, and environmental factors. OBJECTIVE: The current study intended to examine the pathophysiology of T2DM, including factors influencing insulin resistance and beta (ß)-cell dysfunction as well as the genetic factors that indicate susceptibility to T2DM. DESIGN: The research team performed a narrative review by searching the Mendeley, Science Direct, Medline, PubMed, Google Scholar, and Springer databases. The search used the keywords Diabetes, insulin secretion and environmental factor. SETTING: This study was take place in School of Pharmacy, Suresh Gyan Vihar University, Jaipur, India. RESULTS: The paraoxonase-1 gene Q192R and the L55M, INS-VNTR, and IL-38 gene alterations can result in insulin resistance while PAM variants and miR-132 and miR-18 expression can lead to ß-cell dysfunction. Palmitate-like FFA expression of mRNA MafA, and IRS-2 can lead to impairment of insulin secretion. CONCLUSIONS: T2DM is the most common metabolic disorder of the twenty-first century, and its incidence, complications, and morbidity increase every day. The examination of T2DM's pathophysiology and the literature review have revealed that it has a strong correlation with genetic defects.

The Impact of COVID-19 Pandemic Infection in Patients Admitted to the Hospital for Reasons Other Than COVID-19 Infection.

COVID-19 or SARS CoV-2 is a worldwide public health emergency. The first case of COVID-19 was described in Wuhan, China in December, 2019 and within a short time the infection had spread quickly to the rest of China and then the world. The COVID-19 pandemic has had a huge impact on patients who do not have COVID-19 but other diseases like cancer, diabetes, and many more non-communicable diseases; their care is compromised because of the pandemic. COVID-19 also poses a work-related health risk for healthcare workers who are treating patients with COVID-19, and many have themselves become infected. Healthcare workers involved in diagnosing and treating patients with COVID-19 should be evaluated for stress, anxiety and depression.

Biocontrol of mosquito vectors through herbal-derived silver nanoparticles: prospects and challenges.

Mosquitoes spread several life-threatening diseases such as malaria, filaria, dengue, Japanese encephalitis, West Nile fever, chikungunya, and yellow fever and are associated with millions of deaths every year across the world. However, insecticides of synthetic origin are conventionally used for controlling various vector-borne diseases but they have various associated drawbacks like impact on non-targeted species, negative effects on the environment, and development of resistance in vector species by alteration of the target site. Plant extracts, phytochemicals, and their nanoformulations can serve as ovipositional attractants, insect growth regulators, larvicides, and repellents with least effects on the environment. Such plant-derived products exhibit broad-spectrum resistance against various mosquito species and are relatively cheaper, environmentally safer, biodegradable, easily accessible, and are non-toxic to non-targeted organisms. Therefore, in this review article, the current knowledge of phytochemical sources exhibiting larvicidal activity and their variations in response to solvents used for their extraction is underlined. Also, different methods such as physical, chemical, and biological for silver nanoparticle (AgNPs) synthesis, their mechanism of synthesis using plant extract, their potent larvicidal activity, and the possible mechanism by which these particles kill mosquito larvae are discussed. In addition, constraints related to commercialization of nanoherbal products at government and academic or research level and barriers from laboratory experiments to field trial have also been discussed. This comprehensive information can be gainfully employed for the development of herbal larvicidal formulations and nanopesticides against insecticide-resistant vector species in the near future. Graphical abstract.

Larvicidal activity of Ricinus communis extract against mosquitoes.

BACKGROUND & OBJECTIVES: Vector control strategies play significant role in reducing the transmission of malaria, dengue and other vector-borne diseases. The control of vector population using synthetic insecticides has resulted in development of insecticide resistance and negative effects on humans and environment. The present investigation evaluated the larvicidal potential of methanol, dichloromethane and hexane extracts of leaves and seeds of Ricinus communis (castor) plant against the early IV instar larvae of the dengue vector, Aedes aegypti, and malaria vector, Anopheles culicifacies. METHODS: Plant extracts were screened for their efficacy against Ae. aegypti and An. culicifacies using WHO standard larval susceptibility test method. Dose response bioassay was performed to get lethal concentrations. Further, gas chromatography-mass spectroscopy (GC-MS) analysis was carried out to identify the bioactive chemical constituents of the extracts of R. communis. Toxicity of the extracts towards non-target organism, Poecilia reticulata was also evaluated. RESULTS: The leaf and seed extracts of R. communis showed significant mortality against the larvae of Ae. aegypti and An. culicifacies at concentrations of 31.25, 62.5, 125, 250, 500 ppm; and 2, 4, 8, 16, 32, 64 ppm, respectively. At 24 h of the exposure period, the larvicidal activities were highest for the methanol extract of seeds with LC50 15.52 and 9.37 ppm and LC90 45.24 and 31.1 ppm for Ae. aegypti and An. culicifacies, respectively. The methanol extract of seeds and leaves was found to be safe towards non-target organism, P. reticulata. The GC-MS profile showed that seed extracts were having higher concentration of stigmasterol (7.5%), ß-sitosterol (11.48%), methyl linoleate (2.5%), vitamin E (11.93%), and ricinoleic acid (34%) than the leaf extracts. INTERPRETATION & CONCLUSION: The seed extract of R. communis has better larvicidal activity than the leaf extract and can be used as an effective larvicide against mosquitoes. The non-toxicity of the extracts towards P. reticulata further suggests that these plant extracts could be used along with predatory fishes in integrated vector control approaches.