Extract of Azadirachta indica (neem) leaf induces apoptosis in rat oocytes cultured in vitro

Abstract

Objective: To determine whether aqueous neem leaf extract (NLE) could induce degeneration of rat oocytes and, if so, whether apoptosis is involved during NLE-induced degeneration of oocytes cultured in vitro.

Design: A controlled prospective study.

Setting: Laboratory research setting at Department of Reproductive Biomedicine of the Institute.

Animal(s): Fifty-four sexually immature female rats that were 24-25 days of age.

Intervention(s): The immature female rats were injected with 10 IU pregnant mare serum gonadotropin for 48 h followed by 10 IU human chorionic gonadotropin (hCG) for 16 h. After 16 h, the rats were killed and ovulated cumulus oocyte complexes were collected from the oviduct. Cumulus-enclosed as well as denuded oocytes were used in the present study.

Main outcome measure(s): Rates of shrinkage, membrane leakage, degeneration, assessment of morphological apoptotic changes, bax protein expression, and DNA fragmentation.

Result(s): The NLE induced morphologic apoptotic changes such as shrinkage, membrane leakage, and cytoplasmic fragmentation prior to degeneration of oocytes. The NLE-treated oocytes that had morphologic apoptotic features showed overexpression of bax protein and DNA fragmentation as evidenced by terminal deoxynucleotidyl transferase nick-end labeling-positive staining and DNA ladder pattern.

Conclusion(s): Neem leaf extract induced apoptosis in rat oocytes prior to degeneration in vitro.