Antibacterial, biofilm dispersal and antibiofilm potential of alkaloids and flavonoids of Curcuma

The aim of the present study is to determine the antibacterial and antibiofilm activity of alkaloids and flavonoids isolated from Curcuma species. To compare the potential of different constituents isolated from Curcuma species, the rhizomes of three species of Curcuma i.e. C. longa (Turmeric), C. caesia (Black turmeric) and C. aromatica (Wild turmeric) were processed and analyzed. Flavonoids and alkaloids were extracted using methanol and acetic acid, respectively. Antibiofilm activity of alkaloids and flavonoids was determined using Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis, which have unique properties to made biofilm very fast in solid surface as well as resist too many antibiotics. Results showed positive correlation with the concentration of alkaloids and flavonoids in both bacteria. The dispersal activity was further confirmed by the microscopic examination. In all the tests standard curcumin and camphor were used as a positive control. The flavonoid extract of C. aromatica showed pronounced zone of inhibition and antibiofilm activity against S. aureus in comparison to other two Curcuma species. In addition, alkaloid extract of C. aromatica exhibited maximum biofilm dispersal 89.22 +/- 3.42% and antibiofilm activity 92.16 +/- 0.76% against B. subtilis. C. aromatica which have a unique mechanism to inhibit the growth of bacteria in comparison to well explored C. longa.