The effects of Fe3O4 nanoparticles on the physiological traits in the sour tea plant (Hibiscus sabdariffa L.)

In order to compare the effects of iron oxide (Fe3O4) and iron oxide nanoparticles (Nano-Fe3O4) on physiological traits and antioxidant activity evaluation of sour tea ( Hibiscus sabdariffa L. ), an experiment was conducted. Typically, when iron oxide nanoparticles were applied to the leaves at a concentration of 1%, the following plant parameters were measured: chlorophyll index (40.7 mg/g fw), chlorophyll a and b content (43.16 mg QUE/mg − 34.23 mg QUE/mg), carotenoid content (27.1 mg QUE/mg), protein content (62.5 mg/g fw), and iron content (0.11%). Applying iron oxide nanoparticles at a concentration of 1% in methanol solvent resulted in the highest concentration of phenolic compounds (74.86 mg GAE/g fw) and flavonoids (58.15 mg QUE/mg fw). The highest antioxidant power by the FRAP method (211.63 mϻFe2+/mg sample) and DPPH method (19.12 mg/ml) was obtained by using iron oxide nanoparticles at a concentration of 1% with methanol solvent and the lowest antioxidant power in control plants with aqueous solvent. The results of the antibacterial effects of the extracts of the sour tea plant showed that the extracts had a significant inhibitory effect on both bacteria used, so that this effect was completely dependent on the concentration and increased with increasing the concentration of the extracts. In general, based on the results obtained, the application of iron nanoparticles at a concentration of 1% w/w in the sour tea plant can be used as a good candidate for the treatment of diseases caused by oxidative stress and diseases caused by pathogenic microbes, and given the high power of this plant in eliminating pathogenic agents, it can be a suitable alternative to antibiotics.