Cytotoxic and anti-inflammatory activities of extracts of Pra-Sa-Ka-Phrao remedy and its plant components

Background: Pra-Sa-Ka-Phrao (PSKP) is a traditional Thai remedy recognized in the National List of Essential Herbal Medicines of Thailand. It is traditionally used for treating flatulence and colic pain. It consists of eight components derived from plants with Ocimum tenuiflorum leaves as a main ingredient. However, there are no reports regarding the biological activities and chemical composition of PSKP. Objectives: This study aimed to investigate cytotoxic activities, using cell lines related to the gastrointestinal (GI) system, and anti-inflammatory activities, along with chemical composition, of the PSKP complete formula (PSKPC) and a modified incomplete formula (PSKPIC). Materials and Methods: Two extraction processes were used: maceration in 95% ethanol and decoction. The anti-inflammatory effect was determined by an assay for inhibitory effect on nitric oxide production in RAW 264.7 cells, and the cytotoxic activity was evaluated, using the sulforhodamine B assay, against five types of GI cancer cell lines, including gastric carcinoma (KATO III), hepatocellular carcinoma (Hep G2), colorectal adenocarcinoma (SW480 and LS 174T), cholangiocarcinoma (KKU-M156). The chemical composition was analyzed by gas chromatography–mass spectrometry. Results: The ethanolic extract of PSKPC (PSKPCE) demonstrated cytotoxic activities against all tested cancer cell lines, and had no effect against the normal cell line. In addition, it also demonstrated an anti-inflammatory effect. The ethanolic extract of PSKPIC (PSKPICE) showed lower cytotoxic and anti-inflammatory activities than PSKPCE. Caryophyllene and trans-geranylgeraniol were determined as the main active ingredients of PSKPCE, whereas PSKPICE exhibited higher concentrations of linolenic acid and methyl eugenol. Conclusion: The results demonstrated that PSKPCE, which includes Citrus hystrix DC. and Piper retrofractum Vahl, exhibited higher activity compared to PSKPICE. These findings support the traditional use of PSKP and highlight its potential as a natural source of cytotoxic and anti-inflammatory agents, particularly for GI conditions.