Liquorice exaggerates protective action of Solanum xanthocarpum against cigarette smoke induced pulmonary inflammation

Liquorice and Solanum xanthocarpum (Kantakari) are known to possess protective efficacy against inflammation as well as asthma but their effect on pulmonary inflammation caused by cigarette smoke is unknown. Therefore, the present study was carried to evaluate the effect of both plants individually as well as in combination on a rat model of cigarette smoke (CS) induced acute lung inflammation. The albino rat groups orally received Solanum xanthocarpum extract- SXE, Glycyrrhiza glabra extract-LE, and their combination- LE+SXE one hour before exposure to 20 commercial nonfiltered cigarettes per day for 11 days. Treatment with SXE, LE, and their combination- LE+SXE caused reduction in percentage of neutrophils and Cytokine-induced neutrophil chemoattractant 1 (CINC-1) levels in bronchio alveolar lavage fluid (BALF). Lung tissue TNF-α level was attenuated in LE, SXE and LE+SXE treated rats. Lung tissue histology of LE, SXE and LE+SXE treated groups exhibited significant reduction in cellular infiltration, edema and showed intact alveolar architecture. Treatment with LE, SXE and LE+SXE restored the levels of redox cycle components melonaldehyde, reduced glutathione, super oxide dismutase and catalase activity in lung tissue of rat experimental model. Thus, LE+SXE effectively attenuated CS-induced pulmonary inflammation through inhibition of inflammatory cells infiltration, reduction of oxidative stress markers and reduction of pro-inflammatory mediator expression in lung, providing with the potential rationale for development of anti-inflammatory combination.