Anticancer, NF-κB inhibitory and antioxidant properties of Thai traditional anti-inflammatory plants

A total of 27 petroleum ether, ethyl acetate, and methanol extracts from 9 plant species used traditionally in Thailand as anti-inflammatory remedies, and representing 7 different families, were screened for their pharmacological activities, with the aim of selecting the most active plant for further identification of the active principles. The chosen species included Basella alba L., Basella rubra L. (Basellaceae), Cayratia trifolia L.,Domin (Vitaceae), Gynura pseudochina L. var. hispida, Gynura pseudochina L. var. pseudochina (Compositae), Muehlenbeckia platyclada F. Muell.,Meisn (Polygonaceae), Oroxylum indicum L.,Kurz (Bignoniaceae), Pouzolzia indica L.,Gaudich (Urticaceae), and Rhinacanthus nasutus L.,Kurz (Acanthaceae). Cytotoxicity and anticancer activity were examined by in vitro MTT reduction using HeLa cells, and XTT reduction using human CCRF-CEM leukemia cells including a multidrug-resistant CCRF-ADR5000 subline. Anti-inflammatory; NF-κB inhibition were determined by IL-6/luciferase assay [1]. Methods for assessing antioxidant effects included DPPH [2], lipid-peroxidation [3], and Folin-Ciocalteau [4] analysis. Chromatographic analysis TLC and column chromatography were also used to establish the identities of compounds. Additionally, we also conducted different NMR experiments on the most interesting fractions. Overall, the petroleum extract of P. indica exhibited the strongest anti-leukemia effect on CCRF-CEM leukemia cells (90.25±0.29% cells dead) and multidrug-resistant CCRF-ADR5000 cells (89.52±0.12% cells dead) at a concentration of 10µg/ml. The methanol extract of C. trifolia and the methanol extract of G. pseudochina var. hispida showed prominent NF-kB inhibitory effects (64% and 59% respectively). The methanol extract of C. trifolia presented the greatest and widest range of antioxidant activities (TEAC-DPPH=1.92, TEAC-Lipid peroxidation=5.33, Phenol content equivalent to caffeic acid=28.14).

Acknowledgements: Dr. M. Mukhlesur Rahman

References: 1. Bremner, P. et al. (2004) Planta Med 70:1–5.

2. Acuna, UM. et al (2002) Phytother Res 16:63–65. 3. Houghton, PJ. et al. (1995) Planta Med 61:33–36. 4. Lowry, OH. et al. (1951)J Biol Chem 193:265.