In vitro antiproliferative and anti-inflammatory activities of two phenolic compounds isolated from Pogostemon stellatus.

Pogostemon stellatus remains underexplored despite the recognised pharmacological potential of other members of the genus. This study investigated the aerial parts to characterise their constituents and assess in vitro anti-inflammatory and antiproliferative activities. Bioactivity-guided fractionation of the n-hexane extract afforded two phenolic compounds. Compound 1, (E)‑1‑(2,4,6‑trimethoxyphenyl)but‑2‑en‑1‑one, and compound 2, (3 R)-3‑hydroxy‑1‑(2‑hydroxy‑4,6‑dimethoxyphenyl)butan‑1‑one, were both reported for the first time from this species. Compound 1 exhibited antiproliferative activity against B16F10 melanoma cells (IC50 = 74.6 μM) and induced apoptotic nuclear changes as shown by DAPI staining. It also inhibited nitric oxide production in LPS‑stimulated RAW 264.7 macrophages, reducing NO levels by 64.64% at 2.12 μM. Although inactive in antiproliferative assays, compound 2 suppressed NO production by 48.3% at 2.08 μM without detectable cytotoxicity. These findings highlight compounds 1 and 2 as potential agents for drug discovery and warrant further studies to clarify their mechanisms of action and safety profiles.