Medicinal plant extracts are widely explored for their beneficial effects on human health. A number of previous reports highlight the protective effect of plant extracts against oxidative damage, including on erythrocytes (e.g. Luqman et al. Pharmaceutical Biology, 2009; 47(6): 483–490). The catmint Nepeta nuda L. (Lamiaceae) was reported to exhibit antioxidant effects due to its phenolic compounds and iridoids, however to the best of our knowledge, no studies have been performed so far on red blood cells (RBC).
In this work, we evaluate the effect of water extract from catmint flowers prepared at 60 °С on RBC resistance to hemolysis and oxidative stress-induced deformation. Control studies are performed with 0.1 M Trolox antioxidant that is a water-soluble analogue of the vitamin E. First we show that the utilized extract is not hemotoxic since RBC (1 mg haemoglobin/ml) treatment with 0.01 – 1 mg/ml extract for 1 h does not induce cell hemolysis and does not alter significantly the RBC shape. In vitro induced oxidative stress by 0.8 M H2O2 leads to significant increase in lipid peroxidation (evaluated by malondialdehyde level). This is accompanied by reduction in the number of biconcave RBC and increase in the amount of echinocytes. Pre-treatment of RBC with catmint extract and Trolox does not reduce the lipid peroxidation level, however it results in partial restoration of the relative abundance of biconcave cells and respective reduction in echinocytes number.
In conclusion, our data show that water catmint extract exhibits protective effect on RBC morphology in the conditions of H2O2-induced oxidative stress.
Acknowledgment: Financial supported was obtained by the Bulgarian National Science Fund (BNSF), Grant No. KP-06-N56/9/12.11.2021. Equipment of the Distributed Scientific Infrastructure INFRAMAT (National Roadmap of Bulgaria for Scientific Infrastructure), financially supported by the Ministry of Education and Science was utilized.
