Antioxidant effect of lemon verbena extracts in lymphocytes of university students performing aerobic training program

Aerobic training is related to an increase in blood oxidation markers. The purpose of the present study was to investigate the antioxidant capacity of Lippia citriodora extracts (PLX (R)) on plasma and blood cell oxidative status of university students beginning a 21 days aerobic training routine (3 days/week). Using a double-blind design, 15 male athletes (21 +/- 2.1 years) were assigned to a group consuming 1.8 g/day of the plant extract (PLX (R)-group) or a placebo (PLB-group). Two blood extractions were performed at day 0 and 21, from which lymphocytes, erythrocytes and plasma were isolated. Several circulating parameters, antioxidant enzyme activities and oxidative stress markers were measured. The PLX (R)-group displayed an increased HDL-cholesterol, a modest decrease in erythrocyte number and an increased circulating urea. Activation of glutathione (GSH)-reductase was observed in erythrocytes and lymphocytes of PLX (R)-group, accompanied by lower levels of oxidative stress markers, such as malondialdehyde and protein carbonyls in plasma. The antioxidant action exerted by PLX (R) on GSH-reductase seems to be post-translational and mainly due to verbascoside, a phenylpropanoid that represents 10% (w/w) of extract content. In conclusion, PLX (R) shows antioxidant properties that could play an important role in modulating GSH-reductase activity in lymphocytes and erythrocytes and protecting plasma from exercise oxidative damage.