Abstract

RADIATION DOSE RESPONSE AND DOSE MODIFICATION FACTOR OF PHYLLANTHUS NIRURI ON MICE: STANDARDIZATION OF RADIOPROTECTOR EFFECT

Indu Thakur*, P. Uma Devi and Papiya Bigoniya

Abstract

This study was aimed to assess the optimum route of administration for Phyllanthus niruri (family - Euphorbiaceae) alcoholic extract with maximum radioprotection by evaluating dose modification factor (DMF) and dose response on mice against different strengths of irradiation to establish the dosage profile. To optimize route of administration P. niruri alcoholic extract was administered via intraperitoneal (i.p), intramuscular (i.m), intravenous (i.v) and oral route 1 hr before 4 Gy irradiation and after 24 hr the percentage of aberrant cells were calculated. DMF was calculated by observing survival rate following whole body irradiation with 8, 9, 10 and 11 Gy radiation exposure with and without 200 mg/kg, i.p, P. niruri alcoholic extract before 1 hr of exposure. Radiation dose response effect of 200 mg/kg of P. niruri alcoholic extract was observed against 1, 2, 3 and 4 Gy gamma ray exposure by scoring different types of chromosomal aberrations from bone marrow metaphase plates. The i.p administered group showed significantly reduced aberrant cell percentage compared to i.m, oral, i.v and sham control groups. DMF was calculated to be 1.12 as evaluated by radiation LD50 determination with and without P. niruri alcoholic extract at 200 mg/kg dose. P. niruri alcoholic extract significantly (P<0.05-0.001) reduced percent aberrant cell and major aberrations like breaks, rings and polyploidy against 4 Gy radiation. The dose of 200 mg/kg was found to have maximum radioprotective potential in i.p route. It showed DMF of 1.12 with improved survival rate, delayed occurrence of lethality and radiation sickness. Alcoholic extract of P. niruri decrease the complex aberrations like rings, dicentrics and SDC indicating significant protection of bone marrow against double strand breaks and multiple chromosomal lesions. The optimum dose of P. niruri alcoholic extract is established to be 200 mg/kg, i.p., having safe and effective radioprotector efficiency.

Keywords: Phyllanthus niruri, radioprotection, chromosomal aberration, dose modification factor, dose response, lethality.