The Effect of Green-synthesized Silver Nanoparticles from Extract of Hyssopus Officinalis on Secondary Metabolites in Callus of Two Plants: Hyoscyamus muticus and Datura innoxia

Abstract

Silver nanoparticles (AgNPs) synthesised using the valued medicinal plant Hyssopus officinalis were applied as elicitors to callus cultures of two medicinal species, Hyoscyamus muticus and Datura innoxia, to investigate their effects on callus proliferation and secondary metabolite accumulation. AgNPs were biosynthesised using an aqueous extract of hyssop in the laboratories of the Department of Applied Life Sciences-College of Biotechnology. Characterisation of these NPs (UV-Vis spectrometry, Fourier Transform Infrared FTIR, Atomic force microscopy AFM, and Transmission electron microscopy TEM) was conducted in the Chemistry Department of the Science College, while tissue culture studies and evaluation of the effects of AgNPs on callus proliferation and secondary metabolite accumulation in hyssop and datura plants were conducted at the Biotechnology Research Center, Al-Nahrain University. The results showed that callus fresh weights were significantly lower in elicited treatments than in the control group in both species at 5, 10, and 15 mg/L AgNPs. HPLC analysis demonstrated that a high concentration of AgNPs (15 mg/L) caused a significant increase in tropane alkaloid content. In H. muticus, scopolamine showed the largest increase (190%) compared with the control, while the largest increase (141%) in D. innoxia was observed for hyoscyamine. Overall, 15 mg/L AgNPs was considered optimal under the conditions of this study because it produced the greatest response in tropane alkaloid formation. In conclusion, this approach may provide an effective method for enhancing the yield of high-value pharmaceutical compounds in callus culture systems using a low-cost and eco-friendly method for producing metallic NPs.