Anthocyanin Quantification and In Vitro Anticancer Activity of Alpinia purpurata Flower Extract Against Human Lung Adenocarcinoma (A549) Cells

Abstract

Anthocyanins are naturally occurring flavonoid pigments recognized for their strong antioxidant and anticancer properties. Alpinia purpurata, an important medicinal plant, is a rich source of bioactive phytochemicals with potential therapeutic applications. The present study investigates the total anthocyanin content of Alpinia purpurata extract and evaluates its in vitro anticancer activity against the human lung adenocarcinoma (A549) cell line using the MTT assay. Anthocyanin content was estimated by the pH differential spectrophotometric method, while cytotoxic activity was assessed at extract concentrations of 25, 50, and 100 µg/mL, with doxorubicin serving as the positive control. The results demonstrated a concentration-dependent increase in cytotoxicity, with values of 37.6 ± 0.75%, 54.3 ± 1.05%, and 65.6 ± 0.75% at 25, 50, and 100 µg/mL, respectively, accompanied by a corresponding decrease in cell viability to 62.3 ± 1.05%, 45.6 ± 0.75%, and 34.3 ± 1.05%. The extract exhibited an IC₅₀ value of 41.6 µg/mL, indicating significant antiproliferative activity against A549 cells. Microscopic examination further confirmed dose-dependent morphological alterations, including cell shrinkage, loss of normal morphology, and increased numbers of dead cells following treatment. At the highest concentration (100 µg/mL), the extract produced cytotoxicity comparable to that of doxorubicin (71.9 ± 0.57%). These findings demonstrate that Alpinia purpurata extract possesses appreciable anthocyanin content and significant cytotoxic potential against lung cancer cells, suggesting that it may serve as a promising natural source of anticancer compounds. Further phytochemical characterization and mechanistic studies are warranted to identify the active constituents and validate their therapeutic potential for lung cancer management.