Comprehensive phytochemical profiling and biological activities of Hodgsonia heteroclita subsp. indochinensis seed extracts

<i>Hodgsonia heteroclita</i> subsp. <i>indochinensis</i>, a member of the Cucurbitaceae family, is utilized in traditional medicinal remedies based on indigenous wisdom. This study aimed to comprehensively identify and analyze the bioactive phytoconstituents within <i>H. heteroclita</i> subsp. <i>indochinensis</i> seeds. Seeds were sequentially extracted with n-hexane, ethyl acetate, and methanol. Liquid chromatography-mass spectrometry analysis detected ferulic acid, salicylic acid, cucurbitacin E, stigmasterol glucoside, and β-sitosterol glucoside in all extracts. The total phenolic content in the HH(S)-EtOAc and HH(S)-MeOH was 14.22 ± 1.58 and 12.98 ± 1.03 mg gallic acid equivalent/g, respectively. Consequently, the HH(S)-EtOAc demonstrated antioxidant activity with an IC₅₀ of 1.10 ± 0.28 mg/mL, while the HH(S)-MeOH displayed strong antioxidant potential with an IC₅₀ of 0.04 ± 0.00 mg/mL according to an ABTS assay. Antibacterial evaluations of both the HH(S)-hexane and HH(S)-EtOAc revealed significant activity against <i>Staphylococcus aureus</i> (zone of inhibition (ZOI): 13.67 ± 2.31 and 11.67 ± 1.53 mm, respectively) but limited activity against <i>Escherichia coli</i> (ZOI: 7.33 ± 0.58 and 7.67 ± 0.58 mm, respectively). Additionally, the extracts exhibited low minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values, ranging from 62.50 to 250 mg/mL. The antiproliferative activity of seed extracts was assessed against two breast cancer cell lines (MCF-7 and MDA-MB-231), normal breast cells (MCF10A), and human embryonic kidney (HEK) 293T cells, through MTT and clonogenic assays. The results revealed IC₅₀ values exceeding 400 μg/mL, indicating that the extracts are safe. Furthermore, all seed extracts (50 μg/mL) exhibited potent anti-inflammatory activity, evident by their substantial inhibition of nitric oxide production (<i>p</i> < 0.001) and <i>inducible nitric oxide synthase</i> (<i>iNOS</i>) gene expression (<i>p</i> < 0.05) in LPS-induced RAW264.7. These findings demonstrate the potential for <i>H. heteroclita</i> subsp. <i>indochinensis</i> seed extracts in the development of functional foods, nutraceuticals, and dietary supplements due to their diverse bioactive compounds and substantial biological activities, particularly their anti-inflammatory effects.