PHARMACOLOGY OF PLANT IMMUNOMODULATORS
Overview
The immunomodulators or Rasayana’s (in Ayurveda) are agents used to modulate the immune system and can be obtained from both natural as well as synthetic origin from plants and chemicals respectively. The aim of this review is to highlight the work on pharmacological aspects of plant immunomodulators and also provides the knowledge on the recent pharmacological research update in current year (2011). Plants explained in this review having potential of immunomodulating activity are identified from various sources in the literature. Among these many plants have undergone in vitro as well as in vivo evaluations which are explained in this review including the dose administered of particular plant extract and the mechanism involved in immunomodulation.
Immunity
From this discussion it is evident that there are many medicinal plants which exert immunomodulatory effect in experimental models at a particular dose. Different types of in vivo and in vitro screening methods have been employed in determining their pharmacological activity. Some medicinal plants may stimulate the immune system like Ocimum sanctum, Tinospora cordifolia and some of them may suppress the immune responses example Alternanthera tenella. The review also reveals an update of the current immunomodulator plants and their pharmacological aspects in the year 2011. Thus successful results have been achieved by following an appropriate screening approach
It refers to the ability of the body to identify and resist microorganisms that are potentially harmful. This ability enables the body to fight or prevent infectious disease and inhibit tissue and organ damage. The immune system is not confined to any one part of the body. Immune stem cells, formed in the bone marrow, may remain in the bone marrow until maturation or migrate to different body sites for maturation. After maturation, most immune cells circulate into the body and exert specific effects. The immune system has two distinct, but overlapping, mechanisms which help to fight invading organisms: • Cell-mediated defences (cellular immunity) • Antibody-mediated defences (humoral immunity)