Methanolic extract (ME) of both C. reflexa stem and C. olitorius seed arrested the normal oestrus cycle of adult female mouse and significantly decreased the weight of ovaries and uterus. The cholesterol and ascorbic acid contents in ovaries were significantly increased in the treated mice. Two key enzymes, delta5-3beta-hydroxysteroid dehydrogenase and glucose-6-phosphate dehydrogenase, were decreased significantly in ME of both C. reflexa stem and C. olitorius seed after 17 days of treatment. High level of substrates and low level of enzymes indicate the inhibition of steroidogenesis in treated mice and may be due to the presence of flavonoids.