Facile-one pot-green synthesis, antibacterial, antifungal, antioxidant and antiplatelet activities of lignin capped silver nanoparticles: A promising therapeutic agent

The current work portrays the green synthesis of Lignin Capped Silver Nanoparticles (LCSN) and their antibacterial, antifungal, antioxidant and antiplatelet potential. The LCSN was synthesized in water using a carbohydrate based polymer 'lignin' as the reducing and capping agents. The peak at 406 nm (lambda(max)) in the UV-Vis., spectrum and EDX analysis confirmed 1.68% (w/w) of silver was found to be loaded on lignin. The characteristic sharp peaks appeared in the PXRD spectrum showed fcc crystalline structure LCSN. SEM and TEM images indicated that the spherical Ag-NPs were well dispersed on lignin with an average particle size of similar to 10-15 nm. LCSN showed antibacterial and antifungal activity against human pathogens S. aureus, E. coil and A. niger and the percentage of zone of inhibition was found to be 10%, 12% and 80% respectively. Further, LCSN was evaluated for antioxidant potential using DPPH scavenging assay, interestingly it showed antioxidant activity and the percentage against positive control vitamin C was found to be 70%. Furthermore, LCSN did not interfere in plasma coagulation; however, it found to inhibit agonist ADP induced platelet aggregation of human platelet rich plasma. The observed inhibition was found to be 37% and the calculated IC50 value was found to be 9 mg/mL. LCSN did not lyses ABC membrane when assayed hemolytic activity suggesting its non-toxic nature.