EFFECTS OF THE APPLICATION OF DIFFERENT NANOPARTICLE CONCENTRATIONS ON THE ANTIOXIDANT AND ANTIDIABETIC PROPERTIES OF GERMINATED MUSTARD SEEDS (Sinapis alba L.)

Germinated seeds have emerged as promising alternatives to meet consumer demands for healthier foods, as they are important sources of bioactive compounds. Nanotechnology has been used to improve seed germination and plant development in the agricultural sector. This study aimed to evaluate the effects of nanoparticle application on the antioxidant and antidiabetic properties of germinated mustard seeds. White mustard seeds (Sinapis alba L.) were pre-treated with nanoparticles (carbon quantum dots) at concentrations of 1 and 5 μg/mL, with elemental composition of 69.37% (C1s), 23.07% (O1s), and 5.29% (N1s), during the imbibition phase (12 hours). Germination was conducted under dark conditions for 72 hours at 25 °C in a germination chamber. Germinated seeds without nanoparticle treatment were used as the control. Germination rate was determined as the ratio between the number of germinated seeds and the total number of seeds subjected to germination. Antioxidant properties were assessed using the ABTS and DPPH radical scavenging assays and the ferric reducing antioxidant power (FRAP) method. Total phenolic content was quantified and expressed as mg of gallic acid equivalents per gram of sample (mg GAE/g). The antidiabetic potential was determined through the inhibition of α-glucosidase and α-amylase enzymes for the samples that presented highest antioxidant properties. The germination rate of germinated mustard seeds treated with a nanoparticle concentration of 1 μg/mL was 97%, the treatment with 5 μg/mL was 80%, while the control group reached 90%. Samples pre-treated with 1 μg/mL of nanoparticles showed increases of 9%, 6%, and 19% in ABTS (288.15 µmol TE/g), DPPH (51.44 µmol TE/g), and FRAP (79.06 µmol TE/g), respectively, compared to the control. Conversely, samples treated with 5 μg/mL exhibited reductions of 5%, 4%, and 10% in ABTS (252.00 µmol TE/g), DPPH (46.45 µmol TE/g), and FRAP (59.71 µmol TE/g), respectively. The total phenolic content increased by 14% and decreased by 12% for treatments with 1 and 5 μg/mL, respectively. Regarding antidiabetic activity, the control and the samples treated with 1 μg/mL of nanoparticles inhibited α-glucosidase by 28% and 45%, respectively, representing a 30% increase in inhibition compared to untreated seeds (control). For α-amylase, inhibition rates were 38% (control) and 39% (1 μg/mL), there is no statistically significant difference (p > 0.05) between the results. Considering the evaluated parameters, higher nanoparticle concentrations appeared detrimental to seed performance. Nonetheless, when applied at appropriate concentrations, nanoparticles may mitigate abiotic stress, enhance plant yield, and induce the synthesis of antioxidant compounds.