title: 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.
abstract: Mosquitoes act as vectors of devastating pathogens and parasites, representing a key threat for millions of humans and animals worldwide. The control of mosquito-borne diseases is facing a number of crucial challenges, including the emergence of artemisinin and chloroquine resistance in Plasmodium parasites, as well as the presence of mosquito vectors resistant to synthetic and microbial pesticides. Therefore, eco-friendly tools are urgently required. Here, a synergic approach relying to nanotechnologies and biological control strategies is proposed. The marine environment is an outstanding reservoir of bioactive natural products, which have many applications against pests, parasites, and pathogens. We proposed a novel method of seaweed-mediated synthesis of silver nanoparticles (AgNP) using the spongeweed Codium tomentosum, acting as a reducing and capping agent. AgNP were characterized by UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). In mosquitocidal assays, the 50 % lethal concentration (LC50) of C. tomentosum extract against Anopheles stephensi ranged from 255.1 (larva I) to 487.1 ppm (pupa). LC50 of C. tomentosum-synthesized AgNP ranged from 18.1 (larva I) to 40.7 ppm (pupa). In laboratory, the predation efficiency of Mesocyclops aspericornis copepods against A. stephensi larvae was 81, 65, 17, and 9 % (I, II, III, and IV instar, respectively). In AgNP contaminated environment, predation was not affected; 83, 66, 19, and 11 % (I, II, III, and IV). The anti-plasmodial activity of C. tomentosum extract and spongeweed-synthesized AgNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. Fifty percent inhibitory concentration (IC50) of C. tomentosum were 51.34 μg/ml (CQ-s) and 65.17 μg/ml (CQ-r); C. tomentosum-synthesized AgNP achieved IC50 of 72.45 μg/ml (CQ-s) and 76.08 μg/ml (CQ-r). Furthermore, low doses of the AgNP inhibited the growth of Bacillus subtilis, Klebsiella pneumoniae, and Salmonella typhi, using the agar disk diffusion and minimum inhibitory concentration protocol. Overall, C. tomentosum metabolites and spongeweed-synthesized AgNP may be potential candidates to develop novel and effective tools in the fight against Plasmodium parasites and their mosquito vectors. The employ of ultra-low doses of nanomosquitocides in synergy with cyclopoid crustaceans seems a promising green route for effective mosquito control programs.
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.|Department of Biotechnology, Thiruvalluvar University, Serkkadu, Vellore, Tamil Nadu, 632115, India.
authors.forename: Kadarkarai
authors.initials: K
authors.lastname: Murugan
authors.affiliation: Biology Department, Faculty of Science, University of Tabuk, Tabuk, Saudi Arabia.
authors.forename: Chellasamy
authors.initials: C
authors.lastname: Panneerselvam
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
authors.forename: Jayapal
authors.initials: J
authors.lastname: Subramaniam
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
authors.forename: Pari
authors.initials: P
authors.lastname: Madhiyazhagan
authors.affiliation: Institute of Marine Biology, National Taiwan Ocean University, Keelung, 20224, Taiwan.
authors.forename: Jiang-Shiou
authors.initials: JS
authors.lastname: Hwang
authors.affiliation: School of Life Science and Technology, Shanxi University, Taiyuan, 030006, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Wang
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
authors.forename: Devakumar
authors.initials: D
authors.lastname: Dinesh
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
authors.forename: Udaiyan
authors.initials: U
authors.lastname: Suresh
authors.affiliation: Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
authors.forename: Mathath
authors.initials: M
authors.lastname: Roni
authors.affiliation: Department of Chemical and Materials Engineering, National Central University, No. 300 Jhongli, Taoyuan, 32001, Taiwan.
authors.forename: Akon
authors.initials: A
authors.lastname: Higuchi
authors.affiliation: Department of Environmental Biology, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Nicoletti
authors.affiliation: Insect Behaviour Group, Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124, Pisa, Italy. g.benelli@sssup.it.|The BioRobotics Institute, Sant'Anna School of Advanced Studies, Viale Rinaldo Piaggio 34, 56025, Pontedera, Italy. g.benelli@sssup.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Benelli
mesh_terms: D000818:Animals; D000852:Anopheles / Q000187:drug effects*; D000460:Chlorophyta / Q000737:chemistry*; D033342:Copepoda / Q000187:drug effects; D006801:Humans; D007303:Insect Vectors / Q000187:drug effects; D007306:Insecticides / Q000737:chemistry; D007814:Larva / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry; D009032:Mosquito Control; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000378:metabolism; D010963:Plasmodium falciparum / Q000187:drug effects*; D011679:Pupa / Q000187:drug effects; D012624:Seaweed / Q000737:chemistry*; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D007306:Insecticides; D010936:Plant Extracts; D012834:Silver
keywords: Anopheles stephensi; Anti-bacterial activity; Codium tomentosum; Malaria; Mesocyclops aspericornis; Mosquito-borne diseases; Plasmodium falciparum