CAT and polycystic ovary syndrome: Data are indicated as Mean ± SEM. Statistical evaluation was done by analysis of variance (one-way ANOVA), followed by Tukey's test. A value of *p < 0.05, **p < 0.01, and ***p < 0.001 was considered as significant versus the PCOS control group; A value of #p < 0.05, ##p < 0.01, and ###p < 0.001 was considered as significant versus the intact control group, PCOS: Polycystic ovarian syndrome, Met: Metformin, NS: Nigella sativa seed, MDA: Malondialdehyde, SOD: Superoxide dismutase, GPX: Glutathione peroxidase, CAT: Catalase