Comparative Evaluation of Cytotoxic Activity of Ethanolic Leaf Extracts of Pink and White Catharanthus Roseus Using Brine Shrimp Lethality Assay

Abstract

Catharanthus roseus (L.) G. Don (Apocynaceae), commonly known as Madagascar periwinkle, is a well-known medicinal plant rich in bioactive phytochemicals, particularly indole alkaloids, flavonoids, and phenolic compounds, which possess diverse pharmacological activities, including cytotoxic effects. The present in vitro study was undertaken to comparatively evaluate the cytotoxic activity of ethanolic leaf extracts of the pink- and white-flowered varieties of Catharanthus roseus using the Brine Shrimp Lethality Assay (Artemia salina). Fresh leaves of both varieties were collected, authenticated, shade-dried, powdered, and extracted with ethanol using a suitable extraction method. The cytotoxic potential of the extracts was assessed by exposing brine shrimp nauplii to different concentrations of each extract, and mortality was recorded after 24 hours. Percentage mortality and LC₅₀ values were determined to compare the cytotoxic potency of the two varieties. The assay served as a simple, rapid, economical, and reliable preliminary in vitro screening method for identifying biologically active compounds with potential anticancer properties. Both ethanolic leaf extracts exhibited concentration-dependent cytotoxic activity, indicating the presence of potent bioactive constituents. Comparative evaluation revealed differences in the cytotoxic effects of the pink and white varieties, which may be attributed to variations in their phytochemical composition, particularly alkaloid content. The findings demonstrate that Catharanthus roseus is a valuable source of cytotoxic phytoconstituents and support its potential for further pharmacological investigations. This in vitro comparative study provides a scientific basis for future phytochemical isolation, mechanistic studies, and advanced anticancer research to identify and characterize the active compounds responsible for the observed cytotoxic activity.