Physiological and biochemical responses of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) to combined exposure of Pharmaceuticals, personal care products (PPCPs), and artificial sweeteners (ASs)

In this study, pharmaceutical active ingredients (gemfibrozil, acetaminophen and ciprofloxacin) and artificial sweeteners (aspartame and sucralose) were combined and applied to wheat and barley plants. After 15 days of cultivation, a series of biochemical and physiological parameters were evaluated. These included electrolyte leakage, antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), chlorophyll levels, total phenolic content (TPC), Ferric Reducing Antioxidant Power (FRAP), total flavonoid content (TFC) and concentrations. The relationship between the control samples and the samples treated with pharmaceutical active ingredients and artificial sweeteners was statistically evaluated at the 95% confidence interval, and significant differences were found. The treatments markedly influenced plant physiology and antioxidant defense mechanisms. Electrolyte leakage increased to 795.71 ± 50.14 µS cm-1 in wheat, while catalase (CAT), peroxidase (POX), and superoxide dismutase (SOD) activities showed significant elevations, reaching 5797.5 ± 115.14, 95176.00 ± 3675.42, and 1766.11 ± 13.97 EU g−1, respectively. In contrast, chlorophyll a + b, carotenoids, total phenolic content (TPC), total flavonoid content (TFC), and FRAP values decreased substantially compared with controls. These findings demonstrate that mixtures of pharmaceuticals and artificial sweeteners can disrupt photosynthetic pigment stability, and impair antioxidant defense in wheat and barley, highlighting potential ecological and agricultural risks associated with emerging contaminant mixtures.