Teratogenesis, Carcinogenesis, and Mutagenesis 14:175-181 (1994) zy Impact of Higher Doses of Vitamin C in Modulating Pesticide Genotoxicity Parimal Kumar Khan and S.P. Sinha zyxwv Department of Zoology, Bhagalpur University, Bhagalpur, India zyxw The modulatory effect of higher doses of vitamin C (ascorbic acid) on the genotoxicity of the three pesticides (endosulfan, phosphamidon, and mancozeb) was assessed in the in vivo micronucleus test in Swiss albino mice. Concurrent administration of the vitamin in a dose (20 m g k g bwt/day) equivalent to double the human therapeutic one, along with each of the three pesticides, was most effective as zyxwv an antimutagen. The therapeutic dose (10 mg/kg bwt/day) was comparatively less so, and the quadruple (40 mgkg bwt/day) of it did not show any further amelioration. zyxwvu o 1994 Wiley-Liss, Inc. Key words: pesticide genotoxicity, endosulfan, phosphamidon,mancozeb, vitamin C (ascorbic acid), micronucleus, polychromatic, normochromatic, Swiss albino mice INTRODUCTION Use of vitamin C (L-ascorbic acid) as an antimutagen has been shown to be a promising solution to circumvent the genotoxicity of pesticides in vivo [1-6]. The recommended dietary allowances (RDA) for this vitamin to prevent scurvy is 45-60 mg/day for a healthy person [7]. Nevertheless, the need for higher supplementation of vitamin C has been suggested by a number of clinical observations [8-101 because what is considered adequate during a healthy state may not be adequate during stress or perturbation of homeostasis. In continuation with our previous experiments [4,5], the present ones have been undertaken to explore the extent of amelioration provided by higher doses of vitamin C against the cytogenetic toxicity of pesticide formulations. Fortunately, vitamin C has practically no toxic effects of its own even when administered at comparatively higher doses [ 1 1,121. The mouse micronucleus assay [ 131 has been used in the present study as a screening test for assaying the extent of vitamin C-mediated in vivo modulation of pesticide genotoxicity. Address reprint requests and correspondenceto Dr. S.P. Sinha, Department of Zoology, BhagalpurUniversity, Bhagalpur 8 12 007, India. 0 1994 Wiley-Liss, Inc.