Radiation mitigating activities of Psidium guajava L. against whole-body X-ray-induced damages in albino Wistar rat model

In the present study, we investigated radiation mitigating activities of Psidium guajava L. (P. guajava) against whole-body X- ray induced damages in albino Wistar rat model. The animals were orally administered with 200 mg/kg bodyweight of hydroalcoholic leaf extract of P. guajava for five consecutive days and on the fifth day, after the last dose of extract administration, animals were exposed to 4 Gy of X-rays. Rats were sacrificed 24 h post X–ray irradiation. The radiomitigating activity of the herb extract was assessed by micronucleus assay, histopathology of the small intestine and hematological parameters. Hepatic cyclooxygenase–2 (COX-2), interleukin–6 (IL-6) and interleukin –10 (IL-10) levels were assayed to validate the anti-inflammatory property. Biochemical estimations were also performed in RBC lysates to corroborate antioxidant properties in the leaf extract. HPLC analysis of crude extract confirmed the presence of standard flavonoid quercetin. Our results indicated that radiation elevated COX-2, IL-6 and decreased IL-10 levels and also induced micronucleus formation in polychromatic erythrocytes, simultaneously impairing hematological parameters along with erythrocyte antioxidants. The animals pre-treated with P. guajava exhibited a significant decrease in the COX-2 (P ≤ 0.01), IL-6 levels (P ≤ 0.05) and also displayed significant increase in the hepatic IL-10 levels (P ≤ 0.01). Pre-treatment with plant extract improved antioxidant enzyme activities, hematological parameters and reduced the intestinal damage by recovering the architecture of the small intestine. Moreover, extract also rendered protection against radiation induced DNA damage, as evidenced by the significant (P ≤ 0.01) decrease in the percentage of radiation-induced micronucleus in polychromatic erythrocytes. Furthermore, the herb extract treatment increased radiation LD(50/30) from 6.6 Gy to 9.0 Gy, offering a dose reduction factor (DRF) of 1.36. Our findings for the first time propose the beneficial use of P. guajava as a radioprotector against X-ray induced damage.