Biochemical and phytochemical responses of Ammi visnaga L. (Apiaceae) callus culture elicited by SiO2 and graphene Oxide-SiO2 nanoparticles

Abstract

Ammi visnaga L. is an enriched medicinal plant with medicinally important compounds. Two types of nanoparticles (NPs) including silica (SiO₂) and graphene oxide bound with SiO₂ (GO-SiO₂) NPs at different concentrations (0, 15, 25 mg L^-1) were used as elicitors to investigate their effects on callus morphology, H₂O₂ content, total phenolic content (TPC), total flavonoids content (TFC), ferric reducing/antioxidant power (FRAP), and few antioxidant enzymes such as catalase (CAT), guaiacol peroxidase (GPX), superoxide dismutase (SOD), ascorbate peroxidase (APX), and polyphenol oxidase (PPO) in the callus cultures of A. visnaga. The effects of elicitation of both NPs on calli were observed using a scanning electron microscope (SEM). The 15 mg L^-1 concentration of GO-SiO₂ NPs produced the highest TPC (193.3 mg GAE g^-1 FW), CAT (13.1 U mg^-1 Protein), GPX (0.0089 U mg^-1 Protein), and APX (0.079 U mg^-1 Protein). Whereas, the maximum content of H₂O₂ (0.68 μmol g^-1 FW), FRAP (0.0092 μmol mg^-1), and TFC (62.27 mg QE g^-1 FW) was observed at 25 mg L^-1 and 15 mg L^-1 of SiO₂ NPs, respectively. Conclusively, in the callus culture of A. visnaga, the 15 mg L^-1 concentration of GO-SiO₂ NPs was the most suitable dosage for enhancing the enzymatic antioxidant activities (CAT, GPX, APX) and TPC, rather than SiO₂ NPs.

Keywords: Antioxidant activity; Catalase; Scanning electron microscopy; Total phenolic content.