Phagocytosis

Immune activation is an effective as well as protective approach against emerging infectious diseases. The immunomodulatory activities of Triphala (Terminalia chebula, Terminalia belerica and Emblica officinalis) were assessed by testing the various neutrophil functions like adherence, phagocytosis (phagocytic index (P.I) and avidity index (A.I)) and nitro blue tetrazolium (NBT) reduction in albino rats. In recent years much attention is being focused on the immunological changes occur during stress. Noise (100 dB) stress for 4 h/d for 15 d, was employed to alter the neutrophil functions.

AIM: To study the effects of artesunate (dihydroartemisinine-12-alpha-succinate, Art) on immune function in mice. METHODS: Hemolysin concentration was determined by colorimetric method. Serum IgG and C3 contents were measured by single immunodiffusion method. Percentage of lymphocyte transformation, phagocytosis percentage and phagocytic index were counted under microscope. RESULTS: Art im 75 mg kg-1 bid x 7 d decreased the humolysin-forming capacity and levels of serum IgG of mice sensitized with sheep red blood cell.

The effect of dihydroartemisinin, artemisinin and artesunate (0.1, 0.5, 5 and 50 mg/L) on phagocytic function and release of reactive oxygen products by neutrophils was studied by flow cytometry. Incubation with dihydroartemisinin, artemisinin and artemether resulted in a decreased capacity to phagocytose Escherichia coli (0.1-50 mg/L: 62-40%, 66-32% and 59-47% of the control values, respectively; P < 0.001 for all).

The spleen plays a central role in the pathophysiology of several potentially severe diseases such as inherited red cell membrane disorders, hemolytic anemias, and malaria. Research on these diseases is hampered by ethical constraints that limit human spleen tissue explorations. We identified a surgical situation--left splenopancreatectomy for benign pancreas tumors--allowing spleen retrieval at no risk for patients. Ex vivo perfusion of retrieved intact spleens for 4 to 6 hours maintained a preserved parenchymal structure, vascular flow, and metabolic activity.

In Plasmodium falciparum-infected red blood cells (RBCs), the flavoenzyme glutathione reductase (GR) regenerates reduced glutathione, which is essential for antioxidant defense. GR utilizes NADPH produced in the pentose phosphate shunt by glucose-6-phosphate dehydrogenase (G6PD). Thus, conditions affecting host G6PD or GR induce increased sensitivity to oxidants. Hereditary G6PD deficiency is frequent in malaria endemic areas and provides protection against severe malaria.

BACKGROUND: The leaves of Stachytarpheta cayennensis C. Rich. (Verbenaceae) have been reported to possess potent anti-inflammatory and anti-malarial activities. Due to close association between inflammatory and immune responses, we evaluated the immunomodulatory activity of leaves extract of S. cayennensis. The combined effects of the leaves extract and artesunate, a standard antimalarial agent with immunomodulatory effects, were also evaluated. METHODS: The immunomodulatory activity of the methanol extract of the leaves of S.

The immunobiological activity was investigated of certain medicinal plants widely used in the Ayurvedic and Unani systems of medicine for treatment of chronic infections and immunological disorders. The effect of an ethanolic extract of each drug was studied on delayed type hypersensitivity, humoral responses to sheep red blood cells, skin allograft rejection, and phagocytic activity of the reticuloendothelial system in mice. Picrorhiza kurroa was found to be a potent immunostimulant, stimulating both cell-mediated and humoral immunity.