**4. Nanoparticle based drug delivery of phytoconstituents**

Novel nano drug delivery systems can improve the solubility, permeability, physicochemical stability and reduce toxicity of drugs [52]. Previous studies showed that the phospholipid based nano drug delivery systems can improve the oral delivery of thymoquinone [56, 57], and effective against breast cancer cell line. Mesoporous silica and chitosan nanoparticles are developed for delivery of thymoquinone to the brain [58]. In other study self nanoemulsifying and alginate beads delivery system were developed to improve the bioavailability, stability and targeted delivery of black seed oil [59].

Nanoparticulate based drug delivery system of phytol was used for Alzheimer's disease [60]. Previous research also showed strong cytotoxic, anti-phytopathogenic and hepatoprotective effect of phytol loaded nano drug delivery systems [61, 62]. Phospholipid based nano formulation of EGCG are developed to enhance the release characteristics, bioavailability, and stability [63–66]. Previous study data suggest that nanoparticulate based delivery of EGCG showed better cytotoxic and *in-vivo* performance compared to pure EGCG [67–69].
