An In Vitro and In Vivo Study of the Efficacy and Toxicity of Plant-Extract-Derived Silver Nanoparticles.

Silver nanoparticles (AgNPs) display unique plasmonic and antimicrobial properties, enabling them to be helpful in various industrial and consumer products. However, previous studies showed that the commercially acquired silver nanoparticles exhibit toxicity even in small doses. Hence, it was imperative to determine suitable synthesis techniques that are the most economical and least toxic to the environment and biological entities. Silver nanoparticles were synthesized using plant extracts and their physico-chemical properties were studied. A time-dependent in vitro study using HEK-293 cells and a dose-dependent in vivo study using a Drosophila model helped us to determine the correct synthesis routes. Through biological analyses, we found that silver nanoparticles' cytotoxicity and wound-healing capacity depended on size, shape, and colloidal stability. Interestingly, we observed that out of all the synthesized AgNPs, the ones derived from the turmeric extract displayed excellent wound-healing capacity in the in vitro study. Furthermore, the same NPs exhibited the least toxic effects in an in vivo study of ingestion of these NPs enriched food in Drosophila, which showed no climbing disability in flies, even at a very high dose (250 mg/L) for 10 days. We propose that stabilizing agents played a superior role in establishing the bio-interaction of nanoparticles. Our study reported here verified that turmeric-extract-derived AgNPs displayed biocompatibility while exhibiting the least cytotoxicity.

Combating silver nanoparticle-mediated toxicity in Drosophila melanogaster with curcumin.

Nanoscale materials display unique physical and chemical properties that enable their assimilation into a variety of industrial and consumer products. Amongst the widely used nanomaterials, silver nanoparticles (AgNPs) have gained tremendous recognition for various applications, owing to their extraordinary plasmonic and bactericidal properties. Despite of the extensive usage of AgNPs in various sectors, its impact on human health remains ambiguous. Several studies have established that higher doses of AgNPs are detrimental to organismal health. In order to attain the best from these versatile nanoparticles, a recent advent of green nanotechnology, that is, employment of metal nanoparticles synthesized using plant extracts, has emerged. Here, using Drosophila as a model system, we tested if adding curcumin, a biologically active polyphenolic compound present in turmeric, having multitudes of therapeutic properties, could mitigate AgNP-mediated biotoxicity. We found that co-administration of AgNPs with curcumin in the fly food could alleviate several harmful effects evoked by AgNPs ingestion in Drosophila model. Addition of curcumin superseded reduction in feeding, pupation, eclosion, pigmentation, and fertility caused by AgNPs ingestion. Interestingly, impairment in ovary development observed in flies reared on AgNPs-supplemented food was also partially restored by co-administration of AgNPs with curcumin. Furthermore, substantial alleviation of reactive oxygen species level and cell death was observed in larval tissues upon co-supplementation of AgNPs with curcumin. We therefore propose that curcumin, when administered with AgNPs, can abrogate the toxic manifestations of AgNPs ingestion and hence can be incorporated in various consumer products encompassing it.

Discriminatory alteration of carbohydrate homeostasis by gold nanoparticles ingestion in Drosophila.

With the extensive usage of gold nanoparticles (AuNPs) in various industrial sectors and biomedical applications, evaluation of their possible effects on human health becomes imperative. Therefore, the present study was aimed toward assessing the dose-dependent impact of AuNPs ingestion on metabolic homeostasis using Drosophila melanogaster as a model system. We found that larval ingestion of higher dose of AuNPs significantly reduced body weight. Further analysis of the crucial energy reservoir showed selective alteration in carbohydrate levels without any change in the lipid and protein levels. Transcriptional downregulation of glycogen synthase further supported impaired glycogen metabolism in flies supplemented with higher dose of AuNPs. Additionally, ingestion of higher dose of AuNPs in larvae results in significantly increased levels of reactive oxygen species (ROS) in the peripheral tissues, suggestive of stress condition. Our findings clearly imply that supplementing higher doses of AuNPs at an early developmental stage can potentially cause weight loss, impair glycogen metabolism, and elevate ROS production. Therefore, determination of a biologically effective dose is critical for the safety of mankind and vulnerable populations at the workplace.