Oral Supplementation with a Kudzu Root–Black Soybean Blend Attenuates Ovarian Dysfunction in Mice: Implications for Its Potential Use as a Dietary Supplement in Animal Nutrition

Kudzu (Pueraria lobata) root and black soybean (Glycine max) are plant-derived feed ingredients rich in bioactive phytochemicals, including puerarin, isoflavones, and anthocyanins. These compounds are recognized for their antioxidant and physiological regulatory properties, supporting their potential as dietary components in livestock nutrition. In this study, we evaluated the effects of the Pueraria–black soybean compound powder (KRBS) as a dietary additive on female reproductive performance using a cyclophosphamide (CTX)-induced ovarian dysfunction mouse model. The results showed that the high-dose KRBS group (CTX+H-KRBS) had a significantly increased ovarian index (p < 0.05), and all KRBS-treated groups recovered estrous cycle regularity (p < 0.01). Molecular analysis showed that KRBS significantly upregulated Amh expression (p < 0.05), decreased Bax expression, and increased Bcl2 expression, while reducing Esr1 and Vegfa expression in uterine tissues to levels comparable to those in the control group (p < 0.05). These molecular changes suggest that KRBS may alleviate CTX-induced ovarian dysfunction through the regulation of apoptosis-related gene expression, including Bax and Bcl2. These findings indicate that KRBS supplementation alleviates CTX-induced ovarian dysfunction through improvements in follicular development, reduction in serum FSH toward control levels, and apoptosis-related gene expression. These effects support the potential application of KRBS as a plant-based dietary supplement for preserving ovarian function.