Biogenic Silver nanoparticles from Thottea siliquosa: Synthesis, characterization, and evaluation of antioxidant, anti-inflammatory, anticancer, and antibacterial activities

Traditional herbal medicines are important sources of drug candidates against various diseases. Though the plant-derived molecules are active secondary metabolites with potential pharmacological efficacy, their utility is largely limited due to reduced bioavailability and half-life. Conversion to nano-formulation and biogenic nanoparticles is considered to be an alternative for overcoming the issues associated with herbal medicines. In the present study, green synthesized nanoparticles from the methanolic leaf extract of Thottea siliquosa, a traditionally used ayurvedic plant belonging to the family Aristolochiaceae, were assessed for their biological efficacy. The characterization of silver nanoparticles from Thottea siliquosa (TNP) was carried out using X-ray Diffraction and Transmission Electron Microscopy, where the size of the particle was estimated to be between 15 and 34 nm (29.95 nm as per XRD). TNP showed significant radical scavenging capabilities as indicated by DPPH (132.7 ± 3.7 μg/mL), ABTS (106.0 ± 16.33 μg/mL), and peroxide radical scavenging (116.27 ± 4.1 μg/mL). In addition, the TNP also showed significant anti-inflammatory activity in Raw 264.7 macrophages triggered by Lipopolysaccharide (LPS) by inhibiting the release of inflammatory cytokines. The anticancer activity of TNP was also assessed against MCF7 (3.02 ± 0.19 μg/mL), MDA-MB-231 (5.41 ± 0.22 μg/mL), and HCT15 cells (6.07 ± 0.11 μg/mL). Overall, the study revealed that the TNP exhibits significant antioxidant, anti-inflammatory, anticancer, and antibacterial activities.