Abstract
All therapeutic interventions aimed at modulating the immune response to pathogens, self-antigens, carcinogens, or xenogeneic antigens are referred to as immunomodulation, which either prevents hyperactivation or restores the appropriate response of the immune system. Since antiquity, medicinal plants have been used as a source of immune-boosting medicines with fewer side effects. These medicinal plants, for example, Curcuma longa, Camellia sinensis, Artemisia annua, and Andrographis paniculata, have been used to treat immune system disorders such as multiple sclerosis, psoriasis, lupus, and organ transplantation. Herein, we review the currently accessible medicinal plants, their phytoconstituents, and underlying mechanisms of immunomodulation.