Impact of Cellulose and Nanocrystalline Cellulose on In Vitro Shoot Regeneration and Biochemical Composition of Echinacea purpurea

This study aimed to investigate the effects of cellulose (C) and nanocrystalline cellulose (CNC) on in vitro shoot regeneration and biochemical composition of Echinacea purpurea, a medicinally valuable species. For this purpose, different concentrations (1.5, 3.0, and 6.0 g/L) of C and CNC were supplemented into Murashige and Skoog (MS) medium, and their effects on shoot and root development as well as total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant capacity (TAC) were evaluated. The results revealed that cellulose-based treatments exerted dose-dependent effects on both growth and secondary metabolite production. The highest shoot formation efficiency was obtained with 6 g/L C (95.0%), whereas the greatest number of shoots per explant was recorded at 3 g/L C (2.85 shoots/explant). In terms of biochemical parameters, the highest TPC and TFC levels were observed in both shoot (40.27 mg GAE/g DW and 9.06 mg QE/g DW, respectively) and root tissues (48.11 mg GAE/g DW and 12.01 mg QE/g DW, respectively) treated with 6 g/L CNC. Regarding TAC, the highest antioxidant activity was found only in shoot tissues treated with 6 g/L CNC (55.56%). These findings suggest that C and CNC have considerable potential as both structural support materials and biochemical elicitors in the in vitro propagation of Echinacea purpurea. The results offer new insights into the development of integrated strategies aimed at simultaneously optimizing biomass yield and phytochemical content in medicinal plant biotechnology