RETRACTED: Protective effects of Mentha piperita Linn on benzo[a]pyrene-induced lung carcinogenicity and mutagenicity in Swiss albino mice (Retracted Article. See vol 22, pg 303, 2007)

The chemopreventive and antimutagenic effects of an aqueous extract of Mentha piperita leaves were evaluated by using 9 week medium term model of benzo[a]pyrene (BP)-induced lung tumors. Lung tumors were induced by a single subcutaneous injection in the scapular region with BP in newborn Swiss albino mice (< 24 h old). The oral administration of Mentha extract (ME) showed a significant reduction in the number of lung tumors from an incidence of 67.92% in animals given only BP to 26.31%. The inhibition rate was 61.26% in ME treated group with respect to reference group (BP-alone). However, tumor multiplicity was reduced from 0.83 in the BP-alone group to 0.31 in the BP + ME group. Also, ME treatment reduced the frequency of BP-induced chromosomal aberrations and micronuclei in bone marrow cells and decreased the levels of lipoperoxides and increased sulfhydryl groups in liver as well as lung. In cell-free assays, ME showed strong scavenging activity for both the DPPH(.) and ABTS(.+) radicals. ME had an IC(50) value of 272 mu g/ml in the DPPH(.) assay. The chemopreventive action and antimutagenic effects observed in the present study is attributed to the antioxidative and radical scavenging properties of ME.