Elicitation of licorice callus for improving anti-inflammatory agent production

Abstract

Ononin and formononetin are bioactive licorice flavonoids with known anti-inflammatory effects. This study used methyl jasmonate (MJ, dose 50 or 100 µM) or cellulase (CL, dose 33.6 and 168 mU/mL) to enhance their production in licorice callus, with samples pre-treated at harvest. Ononin levels peaked on day 3, increasing 3- and 5.93-fold with MJ and CL, respectively. Formononetin levels peaked on day 7, rising 3.22- and 5.46-fold. Anti-inflammation assay exhibited a dose-dependent reduction of nitric oxide (NO) level induced by LPS. MJ and CL (33.6 mU/mL) exhibited NO reduction lower than L-NAME (positive control). At 1000 µg/mL of MJ and CL elicited callus extract showed maximum inhibition of iNOS, COX-2 and IL-6 expression corresponding to 3.8, 6.5, and 14 times, respectively over the LPS treated group. Elicitation enhanced antioxidant defenses, gene expression, and flavonoid levels, improving anti-inflammatory activity. Combining pretreatment with elicitation can thus enhance medicinal yields from licorice.

Keywords

• Flavonoids
• cellulase enzyme
• methyl jasmonate
• antioxidant
• RAW 264.7 macrophage cells