Chloroform extract of garlic (Allium sativum) stimulates production of superoxide anion and CXCL8 in human neutrophils

Abstract

Garlic has garnered attention as a useful material which contains many bioactive molecules for the prevention and/or treatment of various human ailments, including infectious diseases. In this study we tested several extracts of garlic on cellular activity in human neutrophils. Stimulation of human neutrophils with chloroform extract of garlic (GCE) elicited intracellular calcium ([Ca 2+ ]i) increases in a phospholipase C independent manner. GCE also stimulated superoxide anion production, which was completely blocked by a calcium (Ca 2+ ) chelator. We also observed that stimulation of human neutrophils with GCE caused production of the chemokine CXCL8 in a concentration-dependent manner. GCE also stimulated activity of two important mitogen activated protein kinases (MAPKs), extracellular signal-regulated kinase (ERK) and p38 MAPK. Moreover, GCE-induced CXCL8 production was inhibited by a p38 MAPK inhibitor (SB203580) but not by an ERK inhibitor (PD98059). Taken together, our results demonstrate that GCE contains bioactive natural compounds that stimulate [Ca 2+ ]i signaling, superoxide anion production, and CXCL8 production. Thus, GCE may be useful for the development of immune-modulating agents against infectious diseases.Additional key words: ERK, infectious disease, intracellular calcium, natural compound, p38 MAPK Hort. Environ. Biotechnol. 52(2):218-223. 2011.