Abstract
This manuscript aimed to study the effect of co-exposure of both lead acetate and titanium dioxide nanoparticles (TiO2 NPs) on the major histocompatibility complex (Mhc) region and 16S rRNA sequence in vivo. Twenty-four male albino Swiss mice have randomly separated into four groups; Group 1 (control): was received only distilled water. Groups 2-4 received lead acetate (400 mg/kg body weight, orally by gavage for 15 consecutive days) + either distilled water (orally), or ZnCl2 (4 mg/kg body weight, intraperitoneal injection), or titanium deoxidize nanoparticles TiO2 (200 mg/kg body weight, intraperitoneal injection) for additional 15 consecutive days, respectively. According to the results of 16S rRNA sequence that the highest P-distance value (0.002) found between control group and both (lead acetate and lead acetate+TiO2)-treated groups which reflected the genetic effects of both lead acetate and TiO2 NPs. The results of microsatellites revealed that the exposure to lead acetate affected the genetic structure, where the genetic similarity between control group and lead acetate-treated group was 0.83, while zinc chloride decrease lead acetate-induced genotoxicity where the genetic similarity was 0.88 comparing to the control group. Moreover, the co-exposure to lead acetate and TiO2 NPs led to more genotoxicity and DNA damage, that is clear in the genetic similarity between control group and lead acetate+TiO2-treated group which was 0.74.