Enhancing docetaxel efficacy in prostate cancer: the synergistic role of thymus vulgaris extract in inducing apoptosis and autophagy

Abstract Prostate cancer (PC) is a common malignancy in men, and resistance to treatment in advanced stages remains a significant clinical problem. Docetaxel (DTX) is widely used in advanced PC therapy; however, its efficacy can be limited by toxicity and acquired resistance. Therefore, plant-derived compounds are being explored as supportive therapeutic agents. This study investigated the cytotoxic and antiproliferative effects of Thymus vulgaris (T. vulgaris) extract on PC-3 prostate cancer cells, both alone and in combination with DTX. PC-3 cells were treated with varying concentrations of T. vulgaris and DTX individually and in combination. Cell viability was measured using the MTT assay, and proliferative activity was assessed by AgNOR staining. Cell cycle distribution was analyzed using a Muse cell analyzer, apoptosis was detected via the TUNEL assay, and autophagy-associated protein expression (LC3 and p62) was examined immunohistochemically. T. vulgaris extract exhibited dose-dependent cytotoxicity with an IC50 of 8 μg/mL. The combined treatment with T. vulgaris and DTX resulted in greater inhibition of cell viability, significant G0/G1 cell cycle arrest, increased apoptosis, and enhanced autophagy. Additionally, AgNOR analysis indicated reduced proliferative capacity. These findings suggest that T. vulgaris may enhance DTX efficacy and serve as a promising natural adjuvant in PC therapy.