Evaluation of antimicrobial activity of curcuminoids isolated from turmeric

In a search for plant extracts with potent antimicrobial activity, turmeric (Curcuma longa) was extracted to get volatile oil and total curcuminoids .Further total curcuminoids portion was isolated by column chromatography to get curcumin , bisdemethoxycurcumin and demethoxycurcumin. The isolated curcuminoids were identified and characterized by melting point, thin layer chromatography, infra red spectroscopy, nuclear magnetic resonance and mass spectrometry. All the three isolated curcuminoids were evaluated for antibacterial activity by Agar diffusion method against medically important bacteria viz. B. subtilis, K. pneumonia, E. coli, Enterobacter aerogenes, Pseudomonas aeruginosa, S. auresus and P. Mirabilis. Two fungi were selected viz. Aspergillus niger and Candida albicans for antifungal potential of three isolated curcuminoids by Agar well diffusion method. Out of three curcuminoids, curcumin showed better antibacterial as well as antifungal activity as compare to bisdemethoxycurcumin and demethoxycurcumin. Kanamycin was used as standard drug for antibacterial activity and Fluconazole as standard for antifungal activity. Key-Words: Curcuma longa, Total curcuminoids, Curcumin, Bisdemethoxycurcumin, Demethoxycurcumin, Antibacterial activity, Antifungal activity. Introduction Now a days multiple drug resistance has developed due to the indiscriminate use of commercial antimicrobial drugs commonly used in the treatment of infectious diseases [1, 2]. In addition to this problem, antibiotics are sometimes associated with adverse effects on the host including hypersensitivity, immune-suppression and allergic reactions [3].This situation forced scientists to search for new antimicrobial substances. Given the alarming incidence of antibiotic resistance in bacteria of medical importance [4], there is a constant need for new and effective therapeutic agents [5]. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases from medicinal plants [6, 7]. Several screening studies have been carried out in different parts of the world. There are several reports on the antimicrobial activity of different herbal extracts in different regions of the worlds [8, 9]. * Corresponding Author E-mail: [email protected] Mob.: +91-7417570832 Curcuma longa L. (turmeric) is a medicinal plant that botanically is related to Zingiberaceae family[10]. Turmeric powder, derived from the rhizome of Curcuma longa, is commonly used as a spice, food preservative, and food-coloring agent [11-13]. It also has a long history of therapeutic uses. Turmeric extract is an oleoresin consisting of a volatile oil (light) fraction and a yellow–brown colour (heavy) fraction. It contains a number of curcuminoids, monoterpenoids and sesquiterpenoids. The compounds showing yellow colour are three curcuminoid compounds; curcumin, demethoxycurcumin and bisdemethoxycurcumin. Curcumin , a yellow bioactive pigment, is the major component of turmeric[13-15]. It has been shown that curcumin have a wide spectrum of biological activities such as antifungal[10], antidiabetic[11], antioxidant[13,14], antiinflammatory[16,17], anticancer[18], antiallergic[19], antiprotozoal[20] and antibacterial activities[10,12,21]. The volatile oil of C. longa reported for anti-inflammatory [22], antibacterial [23, 24] and antifungal [24] activities. The present study has been focused to isolate curcuminoids from turmeric (C.longa) for their antimicrobial properties. Research Article [Singh & Jain, 3(1): Jan., 2012]