Immunity and the role of selected plants as immunomodulators: a review

The immune system is an incredible constellation of cells, tissues, organs and molecules that provides protection against a wide spectrum of pathogens and particles keeping us healthy within the challenging microbial environment. Immune system is capable of neutralizing most of the pathogenic attacks without leaving any trace of disease or abnormality in normal functionality of the body. However, some pathogens are strong enough to cause infectious diseases. In the battle against pathogens the immune system adopts two distinct pathways namely, innate immunity and adaptive immunity. Nonspecific innate immunity elicits the same generic response regardless of the pathogen and it mediated by key phagocytic cells. Adaptive immunity elicits pathogen specific immune responses carrying immunological memory. In therapeutic approaches the immune system is fine-tuned with the aid of external agents called immunomodulators. Immunomodulation refers to any alterations in the immune system involving induction, expression, amplification or inhibition of any part or phase in the immune response in order to achieve a better immune response. In clinical perspective immunomodulators appear in three categories including Immuno adjuvants, immune stimulants, and immune suppressants. A diverse array of synthetic and natural agents is applied in therapies. Plants are a rich source of bioactive substance exerting their effects on almost all the systems of the body while playing as immunomodulators. Thus the present review is focused on the immunemodulating activity of various plants in experimental perspective.