Introduction: Corallocarpus epigaeus (Rottler) C.B. Clarke is a medicinal plant traditionally used for the treatment of various ailments. However, scientific evidence regarding its phytochemical composition and biological activities remains limited. The present study aimed to investigate the phytochemical constituents, antioxidant, anticancer, and antibacterial activities of methanol, acetone, and aqueous extracts of C. epigaeus rhizomes.

Methods: Rhizome extracts were prepared using methanol, acetone, and water. Total phenolic content (TPC) and total flavonoid content (TFC) were determined spectrophotometrically. The phytochemical profile of the methanol extract was analysed using gas chromatography–mass spectrometry (GC–MS). Antioxidant activity was evaluated by DPPH, hydrogen peroxide (H₂O₂), nitric oxide (NO) scavenging, and reducing power assays. Anticancer activity was assessed against LoVo and HCT-116 human colon cancer cell lines using MTT, Hoechst 33342 staining, lactate dehydrogenase (LDH) cytotoxicity, and wound healing assays. Antibacterial activity was determined by the agar well diffusion method against selected Gram-positive and Gram-negative bacterial strains.

Results: The aqueous extract yielded the highest extraction efficiency (13.07 ± 0.24%), whereas the methanol extract contained the highest total phenolic content (282.1 ± 11.2 mg GAE/g) and the acetone extract exhibited the highest flavonoid content (7.1 ± 0.9 mg QE/g). GC–MS analysis identified thirteen major compounds, with germacrene-D (22.01%), palmitone (16.92%), and trans-caryophyllene (12.12%) as the predominant constituents. The acetone extract showed the strongest DPPH radical scavenging activity (IC₅₀ = 33.9 ± 4.8 μg/mL), while the methanol extract demonstrated superior nitric oxide scavenging activity (IC₅₀ = 12 ± 4.2 μg/mL). All extracts exhibited significant reducing power and concentration-dependent antioxidant activity. In -vitro anticancer assays revealed marked inhibition of LoVo and HCT-116 cell proliferation, induction of apoptotic nuclear changes, increased LDH-mediated cytotoxicity, and suppression of cell migration. Furthermore, the methanol and acetone extracts displayed broad-spectrum antibacterial activity, particularly against Staphylococcus aureus and Pseudomonas aeruginosa.