Biosynthesized sulfur nanoparticles: a novel strategy to enhance antioxidant secondary metabolites in Lotus arabicus L. callus cultures.

BACKGROUND

Secondary metabolites are distinct compounds with significant medicinal value, yet their production and chemical synthesis present considerable challenges. This necessitates the development of innovative strategies to improve their yield. This study investigated the potential of biosynthesized sulfur nanoparticles (SNPs) as an eco-friendly elicitor to enhance the synthesis of antioxidant secondary metabolites in Lotus arabicus L. callus cultures.

RESULTS

After seven weeks, induced calli of L. arabicus L were transferred to MS media supplemented with SNPs at different concentrations (0, 25, 50, 100, and 200 mg/l). The results indicated that SNPs (100 mg/l) induced significantly higher profiles for biomass and secondary metabolite compared to the control treatments. Enzyme activities related to secondary metabolite biosynthesis, specifically phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) were enhanced in a dose-dependent manner, with the greatest increases observed at 100 mg/l SNPs. The SNPs also modulated oxidative stress markers (MDA and HO), generally improving callus growth conditions by reducing oxidative stress, except at the highest concentration of 200 mg/l. Additionally, the application of SNPs at 100 mg/l markedly upregulated the expression levels of six crucial genes in the biosynthesis pathway of secondary metabolites (chalcone synthase (CHS), phenylalanine ammonia lyase (PAL), flavonol synthase (FLS), chalcone isomerase (CHI), hydroxycinnamoyl CoA quinate hydroxycinnamoyl transferase (HQT), and deoxyxylulose phosphate reductoisomerase (DXR)). Quantitative HPLC profiling of 16 phenolic and flavonoid compounds revealed that supplementation with SNPs resulted in noticeable boots in the majority of the measured compounds with SNP supplementation.

CONCLUSION

Overall, the supplementation of SNPs in the culture media of L. arabicus L callus positively influenced secondary metabolite production at the molecular and physiological levels, increasing its potential for medicinal use.