Anticancer and toxic effects of curry leaf (Murraya koenigii) extracts

Abstract

Curry leaves (Murraya koenigii), native to South Asian countries are commonly used as a food flavoring agent and known to have antioxidant, anti-inflammatory and antidiabetic activities. The objectives of this study were to investigate the anticancer and toxic effects of Curry Leaf Extracts (CLE) in Caco-2 and HepG2 cells and to assess the phytochemical content and antioxidant activities of CLE. The Caco-2 human colon adenocarcinoma (ATCC HTB-37) cells and Hep2G human liver cells (ATCC HB-8065) and were obtained from the American Type Culture Collection (ATCC, Manassas, VA). For assay, 5×104cells/well were seeded in a 24 well culture plate and incubated at 37°C and 5% CO2 until development of a monolayer. Cells were incubated with aqueous CLE at selected concentrations (0.2-0.8 μg mL-1) for 12 and 24 h. Lactate dehydrogenase (LDH) release, histone-related DNA fragmentation and detoxification enzymes were determined. Phytochemical content and antioxidative activities of the extract were determined using in vitro methods. After 24 h, LDH release was highest in Caco-2 cells treated at 0.8 μg mL-1 (45.83 μg mL-1). The LDH of HepG2 cells peaked at 15.74% (12 h-0.8 μg mL-1), inferring low acute cytotoxicity. The GST activity in Caco-2 cells increased with increasing concentration of CLE, however, SOD activity decreased. Histone-related DNA fragmentation was highest in cells treated with 0.4 μg mL-1 for both cell lines. Total phenolics and flavonoids of methanolic CLE were 541.11±12.41 GAE/100 g CLE and 192.22±2.75 CE/100 g CLE. The results from this study indicate that curry leaf may be effective in colon cancer prevention while causing minimal toxic effects to liver cells.