immunomodulatory effects of medicinal herbs in veterinary medicine

The immune system has a key role in keeping health and well-being. any disruption in the function of immune system may lead to multiple lethal diseases like, autoimmune disease, cancer, and other inflammatory conditions. there are three types of immunomodulators including immunosuppressants (inhibit immune cell activation in autoimmune diseases and organ transplantation), immunostimulants (enhance immune responses during microbial infections or tumors), and immunoadjuvants (improve immune system responses to antigens). artificial immunomodulator agents with a clear mode of action have been produced, but they clinically failed to deliver good therapeutic activity due to their bioavailability and severe adverse effects. thus, there is a need to develop natural immunomodulators in order to control immune-related diseases with low side effects (1). medicinal herbs have been used for their several therapeutic properties throughout human history. several studies have shown that plant-derived compounds have beneficial immunomodulatory effects. but, immunomodulatory role of them has not been widely investigated in veterinary medicine like in human medicine (2). in experimental studies, therapeutic effects of some of these herbs like cardamom, cumin, licorice, turmeric, ginger, marjoram, rosemary, sage, and thyme have been proven in animal diseases. however, the mechanisms of how these herbs work are not clear. their mode of action, the ability to potentiate the immune system, and their role as growth promoters in animals have attracted research interests in recent decades. it can be considered that plant-based therapeutics represent a promising area, which may prove to be effective, both in terms of animals therapeutics and industry profits (3).