Liposomes and phytosomes: Nanocarrier systems and their applications for the delivery of phytoconstituents

Phytochemicals, such as terpenes, polyphenols, and tannins, have been used in history, for the treatment of illnesses and fever. Phytochemicals are easily available in nature, can be isolated easily, and can be used against microbial infections, cancers, and for wound healing. However, due to poor pharmacokinetics, therapeutic applications of phytochemicals are heavily affected. Novel methods have been developed, for carrying and delivering phytochemicals to the target sites in a sustained manner. Liposomes and phytosomes are useful for encapsulating and delivering both lipophilic and hydrophilic therapeutic agents in higher quantity, without being identified by the reticuloendothelial system (RES). Surface modification of these nanocarriers, with polyethylene glycol (PEG), polyacrylic acid (PAA), or poly-L-lactic acid (PLA), has improved the bioavailability and stability. Development of immunoliposomes and immunophytosomes, by conjugating monoclonal antibodies, fragments, or targeting moieties, has improved the active targeting of cancer cells. If conjugated with the cancer specific antibodies, such as anti-HER2, transferrin, and folate, liposomes and phytosomes are capable for identifying and attaching cancer cells more efficiently. Targeted nanocarriers can carry phytochemicals and internalize them into the target cells. Liposomes and phytosomes have improved the wound healing actions of phytochemicals. Codelivery of phytochemicals and therapeutic agents can further eliminate the odds of drug resistance or failure. Such drug delivery systems are able to minimize the enzymatic degradation in gastrointestinal tract, avoid first pass metabolism, and diminish off-target toxicity. Continuous development in this area can further identify the untapped potentials of liposome and phytosome based delivery of natural products and phytochemicals, for therapeutic purpose.