Modulatory influence of oral contraceptives on mammary growth pattern of normal and ovariectomised mice.

The present study reports the modulatory influence of oral contraceptive formulations, Ovral (0.05 mg ethinylestradiol plus 0.5 mg norgestrel per pill), Noracycline (0.05 mg ethinylestradiol plus 0.1 mg lynestrenol per pill), Pearl (0.03 mg ethinylestradiol plus 0.30 mg norgestrel) and Centchroman (30 mg), on the growth and developmental pattern of murine mammary epithelium in normal as well as ovariectomised mice. Oral treatments of ovariectomised mice for 15 days with doses D1 (1/5th of a pill) and D2 (1/10th of a pill) of Ovral, Noracycline and Pearl enhanced the diameter of the terminal end buds (TEBS) and lateral buds (LBS) significantly. The increase in the diameters of TEBS and LBS on treatment with similar doses of Centchroman were not much significant. Hence, it may be concluded from the present study that the growth and development pattern of mammary epithelium can be modulated by treatment with oral contraceptives Oral, Noracycline, Pearl and Centchroman which is indicated by the increase in the diameters of TEBS and LBS.

PIP: In India, researchers at Jawahar Lal Nehru University in New Delhi compared data on 80 bilaterally ovariectomized 4-5 week old virgin mice with data on 10 nonovariectomized age- and sex-matched controls to examine the modulatory influence of various combined oral contraceptives (OCs) on the growth and developmental pattern of mammary epithelium. The experimental groups of 10 mice each received either 20% or 10% of an OC pill administered orally for 15 days. The OC formulations included Ovral (.05 mg ethinyl estradiol [EE2]+ .5 mg norgestrel), Noracycline (.05 mg EE2 + .1 lynestrenol), Pearl (.03 EE2 + .3 norgestrel), and Centchroman (a nonsteroidal contraceptive, 30 mg). Ovral, Noracycline, and Pearl at both doses increased the diameter of the terminal end buds and lateral buds of ovariectomized and nonovariectomized mice (p .0000001). Even though Centchroman also enhanced the diameter of the terminal end buds and lateral buds, the increase was not significant. These findings show that combined OCs do modulate the growth and developmental pattern of mammary epithelium. They lead us to question whether OCs might also increase the risk of breast cancer. In fact, many epidemiological studies demonstrate an increase in the risk of breast cancer among OC users.

Modulatory influence of sandalwood oil on mouse hepatic glutathione S-transferase activity and acid soluble sulphydryl level.

The effect of the oil from the wood of Santalum album on glutathione S-transferase (GST) activity and acid soluble sulphydryl (SH) levels in the liver of adult male Swiss albino mice was investigated. Oral feeding by gavage to mice each day with 5 and 15 microliters sandalwood oil for 10 and 20 days exhibited an increase in GST activity in time- and dose-responsive manners. Feeding a dose of 5 microliters sandalwood oil for 10 and 20 days caused, respectively, a 1.80-fold (P < 0.001) and 1.93-fold (P < 0.001) increase in GST enzyme activity, while feeding a dose of 15 microliters of the oil per day for 10 and 20 days induced, respectively, 4.73-fold (P < 0.001) and 6.10-fold (P < 0.001) increases in the enzyme's activity. In addition, there were 1.59-fold (P < 0.001) and 1.57 (P < 0.001) increases in acid-soluble SH levels in the hepatic tissue of the mice following feeding of the oil at the dose levels of 5 and 15 microliters for 10 days. Furthermore, mice fed on a diet containing 1% 2(3)-butyl-4-hydroxyanisole (positive control) also showed an increase in hepatic GST activity and SH levels. Enhancement of GST activity and acid-soluble SH levels are suggestive of a possible chemopreventive action of sandalwood oil on carcinogenesis through a blocking mechanism.