The synergistic anti-asthmatic effects of glycyrrhizin and salbutamol.
Klíčová slova
Abstraktní
OBJECTIVE
To investigate the efficacy of glycyrrhizin (GL) combined with salbutamol (SA) as an anti-asthma therapy.
METHODS
Rat lung beta2-adrenergic receptor (beta(2)-AR) mRNA level was measured by real-time RT PCR. Intracellular cAMP accumulation was evaluated with a reporter gene assay. An in vitro acetylcholine-induced guinea pig tracheal strip contraction model was used to test the relaxing effects of GL and SA. The anti-inflammatory effects of GL and SA were tested using tumor necrosis factor-alpha-induced NF-kappaB transcriptional activation reporter assay, I-kappaB Western blotting and interleukin-8 ELISA. An in vivo guinea pig asthma model was used to prove further the synergistic effect of GL and SA.
RESULTS
GL (0.3 micromol/L) increased mRNA levels of beta(2)-AR in vivo and the accumulation of cAMP in vitro. The combination of GL and SA also resulted in significant complementary anti-inflammatory effects via inhibition of NF-kappaB activation, degradation of I-kappaB and production of interleukin-8. A significant synergistic effect of the combination was detected both in vitro and in vivo in a guinea pig mode.
CONCLUSIONS
The results demonstrate that GL and SA have synergistic anti-asthmatic effects and offer the possibility of a therapeutic application of GL in combination with beta(2)-AR agonists in the treatment of asthma.
