Evaluation of immunomodulatory activity of Glycyrhiza glabra L roots in combination with zing

Abstract

ObjectiveTo determine the immunomodulatory properties of roots of Glycyrrhiza glabra (G. glabra) L. (Liquorice), and also to check whether significant potentiation in immunomodulation occurs or not with the combination of zinc. MethodsImmunomodulatory potential of aqueous liquorice extract (ALE) 0.75 and 1.5 g/kg BW and its combination with zinc (45 mg/kg BW) were determined by the effect on leukocyte count and spleen weight, In vivo phagocytosis (carbon clearance method), determination of cellular immune response, haemagglutination antibody titre and plaque forming cell (PFC) assay using sheep red blood cells (SRBC). In addition, the effect of the extract on Systemic Anaphylactic reaction was also measured. ResultsLeukocyte count and phagocytic index (carbon clearance) was increased significantly with the treatment of ALE (1.5 g/kg) compared to control (P <0.05). Zinc (45 mg/kg) in combination with ALE (0.75 g/kg) showed highly significant increase of leukocyte count and phagocytic index compared to control (P <0.01). Same groups also showed positive significant action on spleen weight. In cellular immune response study, an enhancement in foot pad thickness was observed when compared to control group. Neither of the two doses of ALE showed significant increase in HA titre value and antibody secreting cells of mouse spleen. However, combination of zinc (45 mg/kg) and ALE (0.750 g/kg) showed significant increase (P <0.05) in HA titre and antibody secreting cells of mouse spleen value compared to vehicle control. In systemic anaphylaxis reaction test, results indicate a positive effect on anaphylaxis with the treatment of ALE in both doses and in combination with zinc. ConclusionsThe present study has shown the immunomodulatory activity of aqueous root extract of G. glabra L. at the dose 1.5 g/kg BW. G. glabra L. in combination with zinc has shown potentiation of immunomodulatory activity in all aspects of the study.