The utilization of irrigation water contaminated with antibiotics can potentially affect the growth and production of metabolites in crops. Thus, the effect of Ciprofloxacin (CIP) in irrigation water on the morphological characteristics and polyphenol content in the Pasakalla variety of quinoa was evaluated. Quinoa seeds were sown and irrigated twice weekly with different CIP doses (1, 10, and 100 µg/L). The plant was divided into roots, leaves, panicles, and grain to measure their morphological characteristics and antioxidant properties (the content of total polyphenols, antioxidant capacity, and polyphenolic profile). Root length and biomass of the plant were not affected by the dosage of CIP during physiological maturity. On the contrary, plant growth was reduced (16%) when 10 ug/L of CIP was used. On the other hand, the presence of high CIP concentrations (100 ug/L) improved the biosynthesis of polyphenols and antioxidant capacity by 52 and 59% compared to the control. Profile polyphenols show that vanillic acid and procyanidins A2 and B2 were significantly increased. Thus, the use of CIP could promote a higher enzymatic activity to produce specific polyphenols in order to inhibit the presence of ROS. Finally, under CIP-controlled conditions, the production of polyphenols could be improved without altering the plant’s expected growth.

The present study assessed the impact of using irrigation water contaminated with Azithromycin (AZM) residues on the biomass and antioxidant compounds of purple corn; for this purpose, the plants were cultivated under ambient conditions, and the substrate used consisted of soil free from AZM residues, mixed with compost in a ratio of 1:1 (v/v). The experiment was completely randomized with four replications, with treatments of 0, 1, 10, and 100 μg/L of AZM. The results indicate that the presence of AZM in irrigation water at doses of 1 and 10 μg/L increases the weight of dry aboveground biomass, while at an amount of 100 μg/L, it decreases. Likewise, this study reveals that by increasing the concentration of AZM from 1 to 10 μg/L, total polyphenols and monomeric anthocyanins double, in contrast, with an increase to 100 μg/L, these decrease by 44 and 53%, respectively. It has been demonstrated that purple corn exposed to the antibiotic AZM at low doses has a notable antioxidant function in terms of DPPH and ORAC. The content of flavonols, phenolic acids, and flavanols increases by 57, 28, and 83%, respectively, when the AZM concentration is from 1 to 10 μg/L. However, with an increase to 100 μg/L, these compounds decrease by 17, 40, and 42%, respectively. On the other hand, stem length, root length, and dry weight of root biomass are not significantly affected by the presence of AZM in irrigation water.

Pharmaceutical contamination of irrigation water is an increasing concern for food safety, especially in hydroponic systems where dissolved contaminants remain highly bioavailable. This study evaluated low-dose ciprofloxacin (CIP; 0, 1, 5, and 10 µg L⁻¹) effects on fresh shoot biomass, total phenolic content, in vitro antioxidant capacity (ORAC and DPPH), and CIP residues in edible tissue of hydroponically grown lettuce (Lactuca sativa L.). Shoot biomass increased by 13%, 20%, and 30% with increasing CIP, without visible phytotoxicity, while total phenolic content and ORAC increased by up to 97% and 12.4%, respectively, and DPPH IC₅₀ decreased by 38–44%. In contrast, apparent CIP residues in shoot tissue tended to be lower at 5 and 10 µg L⁻¹ than at 1 µg L⁻¹; given these values were below the method limit of quantification (LOQ), this pattern is reported only as an indicative trend, and possible explanations such as uptake saturation and/or detoxification remain hypotheses that were not tested here. These results suggest that low-dose CIP exposure can be associated with higher biomass and phenolic/antioxidant indicators without evidence of a proportional rise in quantifiable residues, offering preliminary insight for food safety assessment in antibiotic-contaminated hydroponic systems. As this remains a preliminary assessment based mainly on biomass, total phenolics, in vitro antioxidant capacity, and CIP residues, further physiological and molecular analyses are needed to confirm the underlying mechanisms, together with longer-term validation under real production conditions.