Impact of temperature and humidity conditions as abiotic stressors on the phytochemical fingerprint of oat (Avena sativa L.) sprouts.

This study aimed to evaluate the effect of temperature (20, 25, and 30 °C) and relative humidity (RH, 50, 55, and 60 %) as abiotic stressors during oat (Avena sativa L.) germination using a 2-level factorial design with central point. UPLC-QToF-MSE identified eighty polyphenols, nine avenanthramides, twelve lignans, and five phytosterols Notably, 100 % germination was achieved at 25 °C/60 % RH from day 3, yielding the longest radicle size. The highest content of most phenolic acids, avenanthramides, and lignans occurred at 30 °C/65 % RH, where 100 % germination was attained by day 5, but with a shorter radicle size. The best flavonoid and phytosterol profle was obtained at 20 °C/55 % RH, achieving only a 67 % germination rate. Therefore, while these conditions enhance the bioactive compound profile, the associate decrease in germination metrics suggests potential distress effects. Consideration of both photochemical outcomes and germination yield is crucial for comprehensive assessments in future applications.

Effect of saline stress on the metabolic profile and antidiabetic potential of Physalis peruviana.

Goldenberry is a fruit widely utilised for treating diabetes. Its nutraceutical properties can be enhanced by subjecting it to saline stress during cultivation. This study aimed to evaluate the effects of applying NaCl (0, 10, 20, 30, and 40 mM) to goldenberry plants on the metabolite profile and hypoglycaemic potential of both fruit and leaf decoctions. The findings demonstrated that NaCl increases the phenolic content, flavonoids, and hydrolysable polyphenols in leaf decoctions. Additionally, four alkaloids previously unreported in Physalis peruviana were identified. Saline stress improved the profile of extractable and non-extractable phenolic compounds in both leaves and fruits. Furthermore, incubation with decoctions of stressed leaves at a concentration of 0.50 mg/mL reduced extracellular glucose levels in 3T3-L1 adipocytes. Moreover, extracts of leaves subjected to 40 mM NaCl stress slightly diminished the postprandial hyperglycaemic peak in healthy rats, potentially attributable to increased glucose uptake in 3T3-L1 adipocytes.

Salicylic acid elicitation during cultivation of the peppermint plant improves anti-diabetic effects of its infusions.

Peppermint (Mentha piperita) infusions represent an important source of bioactive compounds with health benefits, which can be enhanced by applying salicylic acid (SA) during plant cultivation. The aim of this study was to evaluate the effect of SA (0, 0.5 and 2 mM) during peppermint cultivation on the chemical profile of saponins and alkaloids, as well as the anti-diabetic properties of the resulting infusions. The results showed that a 2 mM SA treatment significantly improved the chemical profiles of the infusions. Furthermore, the administration of 2 mM SA-treated peppermint infusions for 4 weeks to a high-fat diet/streptozotocin-induced diabetic rats decreased serum glucose levels (up to 25%) and increased serum insulin levels (up to 75%) as compared with the diabetic control. This can be related to the observed protection on pancreatic ß-cells. Furthermore, 0.5 and 2 mM SA-treated peppermint infusions decreased LDL (24 and 47%, respectively) and increased HDL levels (18 and 37%, respectively). In addition, all groups treated with peppermint infusions had lower serum and liver triglyceride contents, where 2 mM SA peppermint infusion showed the highest effect (44% and 56%, respectively). This is probably caused by its higher capacity to inhibit pancreatic lipase activity and lipid absorption. Moreover, SA-treated peppermint infusions improved the steatosis score in diabetic rat liver and decreased serum transaminase levels, probably as a result of the increase in steroidal saponins and alkaloids, such as trigonellin. Therefore, the application of 2 mM SA during cultivation of peppermint could be used to improve the anti-diabetic properties of peppermint infusions.

Metabolite profile, antioxidant capacity, and inhibition of digestive enzymes in infusions of peppermint (Mentha piperita) grown under drought stress.

Peppermint (Mentha piperita) infusions represent an important source of antioxidants, which can be enhanced by inducing abiotic stress in plants. The aim of this study was to evaluate the effect of drought stress on peppermint cultivation as well as the metabolite profile, antioxidant capacity, and inhibition of digestive enzymes of resulting infusions. At 45 days after planting, irrigation was suppressed until 85 (control), 65, 35, 24, and 12% soil moisture (SM) was reached. The results showed that 35, 24, and 12% SM decreased fresh (20%) and dry (5%) weight. The 35 and 24% SM treatments significantly increased total phenolic and flavonoid contents as well as antioxidant capacity. Coumaric acid, quercetin, luteolin, and naringenin were detected only in some drought treatments; however, in these infusions, fewer amino acids and unsaturated fatty acids were identified. The 24 and 12% SM treatments slightly improved inhibition of pancreatic lipase and α-amylase activity. Therefore, induction of moderate water stress in peppermint is recommended to enhance its biological properties.

Effect of chemical elicitors on peppermint (Mentha piperita) plants and their impact on the metabolite profile and antioxidant capacity of resulting infusions.

Infusions are widely consumed all over the world and are a source of dietary antioxidants, which can be improved in plants using elicitors. The aim of this study was to evaluate the foliar application of salicylic acid (SA) (0.5, 1 and 2mM) or hydrogen peroxide (H2O2) (0.05, 0.1 and 0.5mM) on peppermint (Mentha piperita) plants and its effect on the metabolite profile and antioxidant capacity of resulting infusions. Whereas 2mM SA treatment improved plant growth parameters and metabolite profile (carbohydrates and amino acids), 0.5 and 1mM SA treatments increased phenolic compound concentration. Sinapic acid, rutin and naringin were detected only in SA treatments; antioxidant capacity was also improved. Regarding H2O2 treatments, no differences in plant growth parameters, metabolite profile or antioxidant capacity were found. Therefore, the application of SA to peppermint is recommended in order to improve bioactive compounds and the antioxidant capacity of infusions.