Seaweed-synthesized silver nanoparticles: an eco-friendly tool in the fight against Plasmodium falciparum and its vector Anopheles stephensi?

Abstract

Malaria, the most widespread mosquito-borne disease, affects 350-500 million people each year. Eco-friendly control tools against malaria vectors are urgently needed. This research proposed a novel method of plant-mediated synthesis of silver nanoparticles (AgNP) using a cheap seaweed extract of Ulva lactuca, acting as a reducing and capping agent. AgNP were characterized by UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The U. lactuca extract and the green-synthesized AgNP were tested against larvae and pupae of the malaria vector Anopheles stephensi. In mosquitocidal assays, LC50 values of U. lactuca extract against A. stephensi larvae and pupae were 18.365 ppm (I instar), 23.948 ppm (II), 29.701 ppm (III), 37.517 ppm (IV), and 43.012 ppm (pupae). LC50 values of AgNP against A. stephensi were 2.111 ppm (I), 3.090 ppm (II), 4.629 ppm (III), 5.261 ppm (IV), and 6.860 ppm (pupae). Smoke toxicity experiments conducted against mosquito adults showed that U. lactuca coils evoked mortality rates comparable to the permethrin-based positive control (66, 51, and 41%, respectively). Furthermore, the antiplasmodial activity of U. lactuca extract and U. lactuca-synthesized AgNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. Fifty percent inhibitory concentration (IC50) values of U. lactuca were 57.26 μg/ml (CQ-s) and 66.36 μg/ml (CQ-r); U. lactuca-synthesized AgNP IC50 values were 76.33 μg/ml (CQ-s) and 79.13 μg/ml (CQ-r). Overall, our results highlighted out that U. lactuca-synthesized AgNP may be employed to develop newer and safer agents for malaria control.

Eco-friendly drugs from the marine environment: spongeweed-synthesized silver nanoparticles are highly effective on Plasmodium falciparum and its vector Anopheles stephensi, with little non-target effects on predatory copepods

“…The fluorescence counts were plotted against the drug concentration and the 50 % inhibitory concentration (IC 50 ) was determined by an analysis of dose-response curves. Results were validated microscopically by the examination of Giemsa-stained smears of extract-treated parasite cultures (Bagavan et al 2011;Murugan et al 2015h). …”

“…Furthermore, to the best of our knowledge, the anti-plasmodial activity of green-synthesized metal nanoparticles has been scarcely studied (Benelli 2016a, b;. For example, Murugan et al (2015h) reported that anti-plasmodial activity of seaweedsynthesized AgNP against CQ-resistant (CQ-r) and CQsensitive (CQ-s) strains of P. falciparum, IC 50 of U. lactuca extract were 57.26 μg/ml (CQ-s) and 66.36 μg/ml (CQ-r), while U. lactuca-synthesized AgNP IC 50 were 76.33 μg/ml (CQ-s) and 79.13 μg/ml (CQ-r). In addition, AgNP synthesized using Catharanthus roseus, and Couroupita guianensis are active against blood stages of P. falciparum (Ponarulselvam et al 2012(Ponarulselvam et al , 2015Subramaniam et al 2016b).…”

“…The marine environment is an outstanding reservoir of bioactive natural products, which have many applications against pests, parasites, and pathogens (Kalimuthu et al 2014;Murugan et al 2016). Concerning the seaweed-mediated synthesis of nanomosquitocides and anti-plasmodial drugs, good examples included seaweed extracts of Sargassum muticum , Hypnea musciformis , Ulva lactuca (Murugan et al 2015h), and Centroceras clavulatum .…”

Nanofabrication of Graphene Quantum Dots with High Toxicity Against Malaria Mosquitoes, Plasmodium falciparum and MCF-7 Cancer Cells: Impact on Predation of Non-target Tadpoles, Odonate Nymphs and Mosquito Fishes

“…Following the method by Murugan et al [35], here a CQ-sensitive strain 3D7 and CQ-resistant strain INDO of P. falciparum were used in in vitro blood stage culture to test the anti-malarial efficacy of GQDs. The culture was carried out at G. Kuppusamy Naidu Memorial Hospital (Coimbatore, India).…”

“…Recently, a number of plant extracts and related metabolites have been exploited for efficient and rapid extracellular synthesis of mosquitocidal nanocomposites with high effectiveness, even if field conditions (e.g. [11,15,[32][33][34][35][36][37]). …”