Protective role of Ocimum sanctum infusion against norethynodrel-induced genotoxic damage in cultured human peripheral blood lymphocytes.

ABSTRACT

Synthetic progestins have wide spread use in medicine, but their side effects are often debatable. Norethynodrel is a synthetic progestin used either as single entity drug, or in combination with an estrogen such as ethinylestradiol in oral contraceptives. It induces chromosomal aberrations (CAs), sister chromatid exchanges (SCEs), and inhibits lymphocyte proliferation in the presence of metabolic activation (S9 mix) in cultured human peripheral blood lymphocytes. The genotoxic effects of steroids can be reduced by the use of various antioxidants and natural plant products. Aqueous extract of Ocimum sanctum L. (Sacred Basil) leaves have been used for the treatment of a variety of conditions since ancient times. Pharmacological evidence shows that Sacred Basil possesses immunomodulating, hepatoprotective, chemopreventive, anticancer, antioxidant, antimutagenic and antigenotoxic properties. Infusion concentrations of 1.075x10−4, 2.127x10−4 and 3.15x10−4 g/ml of culture medium were tested against 60 mg/ml of norethynodrel, separately in the presence of S9 mix. Aqueous plant infusion resulted in the reduction of the genotoxic damage by norethynodrel. Our study on other synthetic progestins such as ethynodioldiacetate, lynestrenol, and medroxy-progesterone acetate showed genotoxic effects only in the presence of S9 mix. Estrogens such as estradiol-17b and ethinylestradiol undergoes aromatic hydroxylation by cytochrome P450 and generates various forms of quinones. Quinones, via redox cycling in the presence of NADP generates reactive oxygen species (ROS). Pharmacologically active compounds of O. sanctum L. like eugenol, rosmarinic acid and epigenin are excellent antioxidants. Flavonoids, orientin and vicenin have shown a protective effect against radiation induced genotoxic damage in cultured human lymphocytes by scavenging free radicals. Infusion of medicinal plants can modulate DNA damage when combined with other substances.