Phagocytosis inhibition

Depresses cell destruction by leukocytes via phagocytosis, inhibits proliferation of lymphocytes, depresses systemic tolerance of an organism, disturbs proper functions of macrophages, especially macrophage listericidal mechanisms. 

Thalidomide has significant teratogenic effects in humans, and it also affects the central and peripheral nervous systems through unknown mechanisms. Evidence of a toxic arene oxide metabolite is unsubstantiated. Thalidomide likely inhibits neutrophil chemotaxis and monocyte phagocytosis, inhibits free radical formation, and alters the ratio of helper and suppressor T-cells. Reduced formation of tissue necrosis factor-a may be at least partially responsible for the antiinflammatory effects of thalidomide. 

In other studies, intrapleural tetracycline was found to cause an acute and rapid rise in the level of interleukin-8, which correlated with the presence of neutrophils in pleural fluids of patients (50). In in vitro studies, we investigated whether talc stimulated pleural mesothelial cells to release C-X-C and/or C-C chemokines. We found that both IL-8 and MCP-1 release were induced in pleural mesothelial cells stimulated by talc (51). This release of chemokines is associated with several other phenomena including the expression of intracellular adhesion molecule-1 (ICAM-1). ICAM-1 is an adhesion molecule that binds with its natural ligand (CDl 1-CD18) receptors on leukocytes, which then transmigrate across the inflamed mesothelium into the pleural space in response to talc. Release of IL-8 and MCP-1 by talc-stimulated mesothelial cells required active phagocytosis of the talc particles by mesothelial cells. Inhibition of phagocytosis inhibited chemokine release. 

Cichoric acid Stimulation of phagocytosis Inhibition of hyaluronidase... 

Vinca alkaloids (vincristine, vinblastine, vindesine) are derived from the periwinkle plant (Vinca rosea), they bind to tubulin and inhibit its polymerization into microtubules and spindle formation, thus producing metaphase arrest. They are cell cycle specific and interfere also with other cellular activities that involve microtubules, such as leukocyte phagocytosis, chemotaxis, and axonal transport in neurons. Vincristine is mainly neurotoxic and mildly hematotoxic, vinblastine is myelosuppressive with veiy low neurotoxicity whereas vindesine has both, moderate myelotoxicity and neurotoxicity. 

Inhibition of inflammatory cytokines (Fig. 2) Humanized monoclonal anti-TNF antibodies (Infliximab (Remicade ), Adalimumab (Humira )) bind with high selectivity to human TNF-a and neutralize its activity. Thereby, infliximab decreases the effects of enhanced TNF levels during inflammatory disease such as production of proteases, chemokines, adhesion molecules, cyclooxygenase products (prostaglandins), and proinflammatory molecules such as interleukin-1 and -6. The antibodies may also recognize membrane-bound TNF-a on lymphocytes and other immune cells. These cells may subsequently become apoptotic or are eliminated via Fc-receptor-mediated phagocytosis. 

Vinca alkaloids are derived from the Madagascar periwinkle plant, Catharanthus roseus. The main alkaloids are vincristine, vinblastine and vindesine. Vinca alkaloids are cell-cycle-specific agents and block cells in mitosis. This cellular activity is due to their ability to bind specifically to tubulin and to block the ability of the protein to polymerize into microtubules. This prevents spindle formation in mitosing cells and causes arrest at metaphase. Vinca alkaloids also inhibit other cellular activities that involve microtubules, such as leukocyte phagocytosis and chemotaxis as well as axonal transport in neurons. Side effects of the vinca alkaloids such as their neurotoxicity may be due to disruption of these functions. 

The cytochalasins are a group of metabolites produced by certain fungi (e.g., Helminthosporium dermatoideum) that inhibit actin-dependent types of cell movement such as leukocyte locomotion, phagocytosis, cytokinesis, the retraction of... 

Tomassini N, Renaud F, Roy S, Loh HH (2004) Morphine inhibits Fc-mediated phagocytosis through mu and delta opioid receptors. J Neuroimmunol 147 131-133 Trillo-Pazos G, Kandanearatchi A, Eyeson J, King D, Vyakamam A, Everall IP (2004) Infection of stationary human brain aggregates with HIV-1 SF162 and IIIB results in transient neuronal damage and neurotoxicity. Neuropathol Appl Neurobiol 30 136-147... 

The objective of antibiotic treatments is to reduce the density of microbial pathogen in infected udder tissues and thereby improve the capacity of the animal s immune system to deal with the infection. The effect of a successful antibiotic treatment is therefore self-cure of mastitis (Hamann and Kromker, 1999). However, some antibiotics (e.g. tetracycline and gentamycine) may also have negative side effects on the animal s immune response to udder infection, as they have been shown to inhibit/reduce phagocytosis of the animal s own defence cells (Nickerson et al 1986). 

Champion JA, Mitragotri S (2009) Shape induced inhibition of phagocytosis of polymer particles. Pharm Res 26 244—249... 

No marked effect on phagocytosis at 25 mg/kg medium significant inhibition of proliferative response of splenocytes at 20-25 mg/kg PCB 138, but no inhibition at this concentration by other PCBs no measurable effect at 5 mg/kg medium for any PCB tested... 

Tetracyclines inhibit P. acnes, reduce the amount of keratin in sebaceous follicles, and have antiinflammatory properties (inhibiting chemotaxis, phagocytosis, complement activation, and cell-mediated immunity). Drawbacks to tetracyclines include hepatotoxicity and predisposition to infections (e.g., vaginal candidiasis). Other adverse effects include GI disturbances, photosensitivity, tooth discoloration in children, and inhibition of skeletal growth in the developing fetus. Tetracyclines must not be combined with systemic retinoids because of an increased risk of intracranial hypertension. / Tetracycline is the least expensive agent in this class and is often... 

---