No abstract

A method for the determination of acephate, methamidophos and monocrotophos in oil matrices is described. Pesticide residues in crude palm oil were extracted with acetonitrile, and a clean-up process was performed by cooling the entire extract below 10 7C, followed by a discolouring process using a Carbograph SPE cartridge. The extract was analysed using gas chromatography coupled with a pulsed flame photometry detector. The limit of detection for the method was calculated from regression data, and the recovery test results were in the range of 85-109%.

The vitamin E component of palm oil provides a rich source of tocotrienols which have been shown previously to be growth inhibitory to two human breast cancer cell lines: responsive MCF7 cells and unresponsive MDA-MB-231 cells. Data presented here shows that the tocotrienol-rich fraction (TRF) of palm oil and individual fractions (alpha, gamma and delta) can also inhibit the growth of another responsive human breast cancer cell line, ZR-75-1. At low concentrations in the absence of oestrogen tocotrienols stimulated growth of the ZR-75-1 cells, but at higher concentrations in the presence as well as in the absence of oestradiol, tocotrienols inhibited cell growth strongly. As for MCF7 cells, a-tocopherol had no effect on growth of the ZR-75-1 cells in either the absence or presence of oestradiol. In studying the effects of tocotrienols in combination with antioestrogens, it was found that TRF could further inhibit growth of ZR-75-1 cells in the presence of tamoxifen (10 -7 M and 10 -8 M). Individual tocotrienol fractions (alpha, gamma, delta) could inhibit growth of ZR-75-1 cells in the presence of 10 -8 M oestradiol and 10 -8 M pure antioestrogen ICI 164 384. The immature mouse uterine weight bioassay confirmed that TRF could not exert oestrogen antagonist action in vivo. These results provide evidence of wider growth-inhibitory effects of tocotrienols beyond MCF7 and MDA-MB-231 cells, and with an oestrogen-independent mechanism of action, suggest a possible clinical advantage in combining administration of tocotrienols with antioestrogen therapy. Int J Food Sci Nutr Downloaded from informahealthcare.com by University of Calgary on 02/02/15 For personal use only. S96 K. Nesaretnam et al.Figure 5. Effect of the tocotrienol-rich fraction (TRF) of palm oil on uterine weight in immature female CD1 mice. Mice were treated with subcutaneous injection of 0.5 ml of ethanol alone (control) (n = 6), of 10 -5 M estradiol in ethanol (+E) (n = 5), of 10 -3 M TRF in ethanol (+TRF) (n = 4) or of both 10 -5 M estradiol in ethanol and 10 -3 M TRF in ethanol (+E+TRF) (n = 3). Error bars indicate the standard error within each treatment group. Int J Food Sci Nutr Downloaded from informahealthcare.com by University of Calgary on 02/02/15 For personal use only.