A novel approach to silver nanoparticle biosynthesis using ursolic acid from Catharanthus roseus for therapeutic effects Krishnan Raguvaran, Parthasarathy Arunachalam Chettiyar Kamatchi, Murni Handayani, Manickam Kalpana, Kasim Sakran Abass, Malarkodi Velraj, Anbu Megala Murugesan, Akhtar Rasool, Rajan Maheswaran, Maryam Abbasi Tarighat, Gholamreza Abdi Scientific Reports, 2026 The present study attentive on the bio synthesis of silver nanoparticles (AgNPs) using ursolic acid (UA-AgNPs) isolated from Catharanthus roseus and investigated their antibacterial, antibiofilm, antioxidant, anti-inflammatory, and anticancer activities. The biosynthesized UA-AgNPs were characterized using techniques like UV-Vis, XRD, FT-IR, EDX, TEM, zeta potential, and DLS. The UA-AgNPs exhibited stronger antibacterial activity than ursolic acid and AgNO3, producing inhibition zones of 18.00 mm and 16 ± 0.3 mm against B. cereus and P. aeruginosa, respectively, which were comparable to the activity of standard antibiotics and MIC (Minimum inhibitory concentration) values of 6.95 and 12.39 µg/mL, respectively. The anti-biofilm activity inhibited 64.43% and 60.89% of biofilm production. UA-AgNPs also impaired bacterial motility and caused higher protein and (Deoxyribonucleic acid) DNA leakage in membrane integrity assays compared to the control. Antioxidant activity was confirmed by DPPH and FRAP assays, and in vivo experiments in Saccharomyces cerevisiae highlighted significant antioxidant effects. Furthermore, UA-AgNPs exhibited potential anticancer activity against the HeLa cell line (IC50 29.20 µg/mL) with minimal cytotoxicity on Vero cells (IC50 5.59 µg/mL). Moreover, UA-AgNPs reduced LPS-induced Nitric oxide (NO) production in RAW264.7 cells. Through molecular docking studies, they demonstrated interactions with breast cancer proteins BRCA1 and C-erbB2 and bacterial virulence proteins Hbl and aglD. These findings highlight the bio efficacy of UA-AgNPs as a dual-action therapeutic agent with potent antibacterial and anticancer activity, combined with low toxicity toward normal cells, making them promising candidates for biomedical applications.
Eco-Friendly Synthesis of Silver Nanoparticles and Its Larvicidal Property Against Malaria, Filariasis, and Dengue Vectors Krishnan Raguvaran, Manickam Kalpana, Palanisamy Devapriya, Suresh Kalaivani, Marissa Angelina, Fransiska Sri Herwahyu Krismastuti, Akhtar Rasool, Rajan Maheswaran Luminescence, 2025 The increasing resistance of mosquitoes to synthetic pesticides necessitates eco‐friendly alternatives for vector control. This study presents the green synthesis of silver nanoparticles (Ag‐NPs) using Aerva lanata flower extract and evaluates their larvicidal efficacy against Cx. quinquefasciatus, An. stephensi, and Ae. aegypti. The biosynthesized Ag‐NPs, characterized by UV–Vis, FT‐IR, XRD, SEM–EDX, TEM, Zeta potential, and DLS analyses, exhibited potent larvicidal and pupicidal activities, with LC50 values of 6.501, 20.875, and 22.649 ppm, respectively. The morphological and histopathological alterations in treated larvae, alongside significant modulation of antioxidant (SOD, GPx) and detoxification (GST, AChE) enzymes, indicate oxidative stress as a key mode of action. Importantly, biosafety tests revealed minimal toxicity to Artemia salina, highlighting the eco‐compatibility of these Ag‐NPs. This study demonstrates an innovative, plant‐based nanobiopesticide with strong potential for sustainable mosquito control, addressing the challenges of insecticide resistance and environmental toxicity.
Actinobacteria mediated synthesis of silver nanoparticles using Streptomyces diastaticus and their biological efficacy against human vector mosquitoes and agricultural insect pests Manickam Kalpana, Krishnan Raguvaran, Thulasiraman Manimegalai, Suresh Kalaivani, Palanisamy Devapriya, Rajan Maheswaran Journal of Natural Pesticide Research, 2024 Mosquitoes and agricultural insects were harmful to both public health and crops. Prolonged use of synthetic chemical pesticides for insect pest control was associated with resistance development and negative human and ecological effects. This study investigates the larvicidal activity of Ag-NPs produced using Streptomyces diastaticus against Culex quinquefasciatus, Anopheles stephensi, Aedes aegypti, Spodoptera litura, and Plutella xylostella. UV-Vis spectroscopy, XRD, SEM-EDX, FT-IR, TEM, DLS, and Zeta potential analysis were used to characterize the biosynthesized Ag-NPs. The results showed that biosynthesized Ag-NPs were more toxic to, A. stephensi, C. quinquefasciatus, and A. aegypti with LC50 values of 15.70, 11.10, and 17.53 µg/mL, respectively. Biosynthesized Ag-NPs exhibited the highest antifeedant effects against S. litura (88.73 %) and P. xylostella (92.36 %) at 50 µg/mL concentration. The mortality bioassay revealed considerable larvicidal activity against S. litura and P. xylostella larvae at greater doses of 50 µg/mL, 80.67 and 84.05 %, respectively. Morphogenetic variations were observed on treated larvae of C. quinquefasciatus, A. aegypti, and A. stephensi, S. litura, and P. xylostella with Ag-NPs. In the present investigation the impact of Ag-NPs on the antioxidant enzymes (SOD, CAT, and GPx), the activity of each enzyme were dramatically increased with higher concentrations resulting in significant differences. The study also found that Ag-NPs inhibited the detoxifying enzyme (GST and AChE) activity of target organisms. The histological structure of the treated and untreated larvae revealed structural changes between the midgut epithelial cells. As a consequence of these findings, the S. diastaticus-mediated Ag-NPs serve as a possible, eco-friendly biopesticide and alternative to synthetic chemicals for the control of human vector mosquitoes and destructive arthropod insect pests.
Bioefficacy of essential oil from Toddalia asiatica (L.) Lam. against dengue vector mosquitoes Aedes aegypti L. and aedes albopictus Skuse Indian Journal of Natural Products and Resources, 2016
Larvicidal activity of leucas aspera (Willd.) Against the larvae of culex quinquefasciatus say. And aedes aegypti L International Journal of Integrative Biology, 2008
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