TIME-DEPENDENT EFFECT OF TOCOTRIENOL SUPPLEMENTATION ON THE QUALITY OF AGING MOUSE EMBRYO

Saidatul AK, Nasibah A, Esa NY, and Nuraliza AS*

Abstract

TIME-DEPENDENT EFFECT OF TOCOTRIENOL SUPPLEMENTATION ON THE QUALITY OF AGING MOUSE EMBRYO Saidatul AK1, Nasibah A2, Esa NY2, and Nuraliza AS2*

1 Institute of Medical Molecular Biotechnology, 2Faculty of Medicine, Universiti Teknologi MARA, Jalan Hospital, 47000 Sg. Buloh, Selangor.

2Faculty of Medicine, Universiti Teknologi MARA, Jalan Hospital, 47000 Sg. Buloh, Selangor.

Tocotrienol, an antioxidant is believed to play a great role in suppressing reactive oxygen species (ROS) levels in female reproductive system. Exposure to high level of ROS overwhelms the cellular antioxidant capacities in female body system, leading to oxidative stress. This situation resulted in DNA damage which lead to fertilization failure and reduced embryo quality, thus influence reproductive outcome. A consequence of cellular DNA damage caused by ROS is a major contributor in aging process. Therefore, this study is focused to determine the effect of tocotrienol (TCT) supplementation at different durations on the quality of embryo retrieved from aging mice. Our study showed that aging (mice at seven, eight, ten and twelve month’s old groups) caused a significant decline in the quality of embryos as compared to young mice at 6 weeks old. Thus, tocotrienol which is proposed to exhibit antioxidant properties is suggested to delay the effect of aging. Subsequently, six-month-old female mice (Mus musculus) were supplemented with tocotrienol (TCT) at the dose of 150 mg/kg body weight (BW) orally per day for one month or two months duration. Young mice at 6 weeks old were used as negative control while aging mice at the age of 6 months old were used as age-matched control group (positive control). At the end of the duration of respective TCT supplementation, embryos at 2-cell stage were harvested after superovulation and cultured in vitro. Results confirmed that aging caused a significant decline on the percentage of normal embryos (p<0.05) as compared to young group. Tocotrienol supplementation for one month significantly increased the percentage of normal embryo as compared to age-matched control group. On the other hand, the percentage of normal embryo was significantly lower (p<0.01) following two months of TCT supplementation as compared to age- matched control group. This finding indicate that aging may interfere with the quality of embryo, where the quality tended to decline with time and unable to improve with increase duration of tocotrienol supplementation.

Keywords: oxidative stress, embryo, tocotrienol, aging