Yellow Gentian infusion mitigates ɤ-rays induced genotoxic effects by altering levels of DNA repair enzymes

Abstract

Ionizing radiation from natural and artificial sources causes DNA damage, directly and indirectly, inducing strand breaks and generating reactive oxygen species, leading to oxidative stress and biomolecular alterations. Yellow gentian (Gentiana lutea) root infusion has shown genoprotective potential by activating antioxidative defense and promoting DNA repair of radiation-induced cellular damage. This study aimed to elucidate the pre-treatment effect of 0.25, 0.5, 1, and 2 mg/mL of yellow gentian root infusion on genomic damage in peripheral blood mononuclear cells exposed to 0.5 and 2 Gy of gamma radiation (source 60Co). Micronucleus frequency, proliferation index, and DNA fragmentation were assessed, along with expression of DNA repair genes 8-oxoguanine glycosylase-1 (OGG1), Poly(ADP-ribose) polymerase1 (PARP1), and X-ray repair cross-complementing-1 (XRCC1), via real- time PCR. Pretreatment with 0.25 and 0.5 mg/mL infusion significantly reduced micronucleus formation and DNA fragmentation in irradiated cells at 2 Gy, indicating protection against radiation-induced genetic damage. The results showed a decrease in proliferation index at 0.5 Gy, suggesting that treatments inhibited cell proliferation after exposure to the lower radiation doses. XRCC1 expression was significantly upregulated with 2 Gy at all treatment concentrations, indicating enhanced base excision repair activity. PARP expression increased significantly at all treatments’ concentrations following 0.5 Gy irradiation, and at 2 Gy, induction occurred only at 0.5 and 1 mg/mL, reflecting dose-dependent modulation of PARP-mediated repair. OGG1 expression remained unchanged under all tested conditions. The results demonstrate that yellow gentian root infusion activates the base excision DNA repair pathway and may serve as a promising agent for mitigating radiation-induced damage in developing effective radiation protection strategies.