Abstract

This study evaluated the effect of ginger rhizome and its callus as well as callus elicited by yeast extract, glycine and salicylic acid on the production of pro-inflammatory (TNF-α, IL-1 and IL-6) and anti-inflammatory (IL-10 and TGF-β) cytokines in vitro. Petroleum ether (PE) and chloroform; methanol (1:1) (CM) extracts of rhizome and callus were shown to significantly (P < 0.05) suppress in a dose-dependent manner the LPS-induced production of TNF-α, IL-1 and IL-6. Both callus extracts showed significantly (P < 0.05) higher ability than the rhizome extracts. CM extract of ginger callus treated with elicitors showed significant (p < 0.05) capacity to inhibit IL-1, IL-6 and TNF-α secretion at highest concentration used (100 μg/mL) when compared to control (untreated callus). Elicitors improved significantly (P < 0.05) the callus capacity to produce the IL-10 and TGF-β anti-inflammatory cytokines. HPLC analysis showed that 6-gingerol and 6-shogaol were found in both extracts of rhizome, but were not detected in the callus extracts. Furthermore, gallic acid was found only in CM extracts of rhizome (34.05 ± 0.39 μg/mg) and callus (17.88 ± 0.01 μg/mg). Yeast extract, salicylic acid and glycine elicitors enhanced significantly (p < 0.05) the production of gallic acid in callus CM extract where the highest content was obtained from callus elicited with 100 mg/L of yeast extract followed by callus elicited with 50 mg/L of salicylic acid and 200 mg/L of glycine, respectively. Therefore, ginger callus could be included in nutraceutical formulations where it could provide valuable protection against inflammatory diseases.

Key words: Anti-inflammatory, ginger, callus, elicitors.