This critical review passes the direct and indirect substantial for the immunomodulatory activity of T. procumbens using classic humoral and cell-mediated assays, bioactivity-directed fractionation, isolated constituents, inflammatory signal transduction (cyclooxygenase-2, inducible nitric oxide synthase, nuclear factor-κB), oxidative stress, toxicological profiling, and contemporary preparations. 

In vivo immunostimulation studies are rodents are an ethanol-insoluble fraction of aqueous extracts provided significant increases in peritoneal phagocytosis, total leucocyte counts, primary haemagglutination antibody titre, and plaque-forming splenic cells, with enhanced delayed-type hypersensitivity (DTH) responses. Bioactivity-directed fractionation showcase the immunological activity in medium-to-high polarity ethyl acetate and n-butanol fractions. In contrast, ex vivo assays using human peripheral blood mononuclear lymphocytes from systemic lupus erythematosus patients showed disease-state dependent immunosuppression with IgG secretion inhibited in healthy volunteers and quiescent SLE at concentrations above 62.5 μg/mL, but increased in active SLE patients. Characterized flavonoids, coumarins, polyacetylenes, and phenolic acids modulate inflammatory cyclooxygenases, cytokine production, and macrophage redox status.