RESUMO
KEY MESSAGE: Atropa acuminata aqueous leaf extract biosynthesized silver nanoparticles showed strong antioxidant, anticancerous (HeLa cells) and anti-inflammatory activities. Besides, this bio syn-AgNP also proved effective against mosquito vectors causing malaria, dengue and filariasis. Present study highlights eco-friendly and sustainable approach for the synthesis of silver nanoparticles (AgNP) using aqueous leaf extract of A. acuminata, a critically endangered medicinal herb. The addition of 1 mM silver nitrate to aqueous leaf extract resulted in the synthesis of AgNP when solution was heated at 60 °C for 30 min at pH 7. Absorption band at 428 nm, as shown by UV-Vis spectroscopy confirmed the synthesis of AgNP. XRD patterns revealed the crystalline nature of AgNP and TEM analysis showed that most of the nanoparticles were spherical in shape. Zeta potential of AgNP was found to be - 33.5 mV which confirmed their high stability. FT-IR investigations confirmed the presence of different functional groups involved in the reduction and capping of AgNP. The synthesized AgNP showed effective DPPH (IC50-16.08 µg/mL), H2O2 (IC50-25.40 µg/mL), and superoxide (IC50-21.12 µg/mL) radical scavenging activities. These plant-AgNP showed significant inhibition of albumin denaturation (IC50-12.98 µg/mL) and antiproteinase activity (IC50-18.401 µg/mL). Besides, biosynthesized AgNP were found to have strong inhibitory effect against a cervical cancer (HeLa) cell line (IC50-5.418 µg/mL) as well as larvicidal activity against 3rd instar larvae of Anopheles stephensi (LC50-18.9 ppm, LC90-40.18 ppm), Aedes aegypti (LC50-12.395 ppm, LC90-36.34 ppm) and Culex quinquefasciatus (LC50-17.76 ppm, LC90-30.82 ppm) and were found to be non-toxic against normal cell line (HEK 293), and a non-target organism (Mesocyclops thermocyclopoides). This is the first report on the synthesis of AgNP using aqueous leaf extract of A. acuminata, validating their strong therapeutic potential.