Immunomodulatory and Adaptogenic Activity Evaluation

Immunomodulatory evaluation assesses a candidate extract's capacity to enhance (immunostimulant), suppress (immunosuppressant), or normalise (adaptogenic) immune system function, reflecting the traditional use of numerous botanicals — most notably Withania somnifera, Tinospora cordifolia, and Panax ginseng — as immune and stress-adaptive tonics. The carbon clearance test assesses phagocytic function by measuring the rate of clearance of intravenously injected colloidal carbon particles from the bloodstream, expressed as a phagocytic index. The neutrophil adhesion test measures the change in circulating neutrophil count following passage through a standardised nylon fibre column, reflecting neutrophil activation state. Humoral immune response is assessed through the hemagglutination antibody titre against a test antigen such as sheep red blood cells, distinguishing early IgM from later IgG antibody responses, while cell-mediated immunity is assessed through the delayed-type hypersensitivity response, measured as footpad swelling following antigen re-challenge in a previously sensitised animal. Adaptogenic activity specifically is evaluated using chronic stress models, in which extract-treated animals are subjected to repeated unpredictable stressors and assessed for stress-hormone (corticosterone) levels, adrenal gland weight, gastric ulceration, and performance in behavioural despair tests such as the forced swim test, with reduced stress-induced pathology in extract-treated animals interpreted as evidence of adaptogenic activity.