Development of novel plant-based adjuvant formulation against rubella and hepatitis B vaccine antigen

Introduction: Numerous metabolites present in the aqueous extract from plants are responsible for inducing adjuvant activity against rubella and hepatitis B vaccine antigen (HBsAg). One of the medicinal plants, Adhatoda vasica has been pointed out with great potential of vaccine adjuvant property. Objective: The objective of our study is to evaluate the adjuvant potential of aqueous leaves extract of Adhatoda vasica against rubella and hepatitis B vaccine antigen (HBsAg). Methods: For these studies, our group evaluated the antibody (IgG) titre of HBsAg and rubella vaccine antigen using variable doses (0.625–5 mg) of aqueous leaves extract of Adhatoda vasica and also determined the lymphocyte (splenocyte) proliferation assay (0.625–5 mg; 50 μl) in mice model studies ex vivo (i.e. immunized with HBsAg subcutaneously). Results: The results showed that aqueous leaves extract showed anti-HBsAg and anti-rubella titre and also enhanced the lymphocyte proliferation assay at higher doses (5 mg) as compared to control. Conclusion: Aqueous leaves extract of Adhatoda vasica showed adjuvant activity against HBsAg and rubella vaccine antigen.