Biological activity of three curcuminoids from Curcuma longa L. (turmeric) grown in Quindío, Colombia

Introduction: Curcuma longa L. is a plant from the family Zingiberaceae distributed in tropical and subtropical regions and used in the food industry, in medicine and in cosmetics. Its main coloring substance is curcumin, a polyphenol with many medicinal properties. Objectives: Obtain, characterize chemically and evaluate the biological activity of three curcuminoids from C. longa grown in Quindío, Colombia. Methods: Three curcuminoids (curcumin (C), demethoxycurcumin (DMC) and bisdemethoxycurcumin BDMC) from the rhizome of the plant were purified in a dry state by column chromatography and characterized by fusion point, infrared (IR) spectroscopy, UV-vis spectroscopy and mass spectrometry. Antimicrobial activity against bacteria and fungi was evaluated by the modified agar well method, cytotoxicity to BHK-21 cells by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method, and toxicity against Artemia salina. Finally, determination was made of the effect of the curcuminoids in BHK-21 cells infected with dengue virus 2. Results: Curcumin had the highest fusion point (177.3 ºC-183.2 ºC). IR spectroscopy revealed the characteristic functional groups and UV-vis spectroscopy showed maximum absorption values for curcumin, demethoxycurcumin and bisdemethoxycurcumin of 419, 418 and 414 nm in chloroform, respectively. Mass spectrometry found that m/z values were C: 368, DMC: 338 and BDMC: 308. Antimicrobial activity was observed against Staphylococcus aureus and Staphylococcus epidermidis. BDMC was found to have lower toxicity. A greater inhibitory effect against infective dengue virions was observed with curcumin at 20 y 30 µM. Conclusions: Characterization of the compounds confirms their polyphenolic composition, which manifests in their biological activity, mainly the capacity of curcumin to alter infection by dengue virus in cell cultures. The study corroborated the importance of the active principles of plants with a wide pharmacological spectrum, such as C. longa(AU)