1 We have reported that andrographolide (ANDRO), an active component of Andrographis paniculata, inhibits in¯ammatory responses by rat neutrophils. To further elucidate the possible mechanism(s) underlying the ANDRO's e ect, N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced adhesion and transmigration of isolated peripheral human neutrophils were studied. 2 Pretreatment with ANDRO (0.1 ± 10 mM) concentration-dependently prevented fMLP-induced neutrophil adhesion and transmigration. We further examined the up-expression of surface Mac-1 (CD11b/CD18), an essential integrin mediated in neutrophil adhesion and transmigration. ANDRO pretreatment signi®cantly decreased fMLP-induced up-expression of both CD11b and CD18. 4 To clarify whether ROS production impeded by ANDRO could be an antagonism of fMLP binding, phorbol-12-myristate-13-acetate (PMA), a direct protein kinase C (PKC) activator, was introduced to activate ROS production. PMA triggered remarkable ROS production and adhesion, and were partially reversed by ANDRO. This indicated that a PKC-dependent mechanism might be interfered by ANDRO. 5 We conclude that the prevention of ROS production through, at least in part, modulation of PKC-dependent pathway could confer ANDRO the ability to down-regulate Mac-1 up-expression that is essential for neutrophil adhesion and transmigration.
Medical application of Panax ginseng was first found in "Shen-Nong Herbal Classic" around 200 AD Panax quinquefolium was first introduced in "Essential of Materia Medica" in 1694 in China. The most important bioactive components contained in P ginseng and P quinquefolium are ginseng saponins (GS). The contents of ginsenoside Rb1, Re, and Rd in P quinquefolium are higher than they are in P ginseng. In P ginseng, the contents of Rg1,Rb2, and Rc are higher than they are in P quinquefolium. P ginseng had a higher ratio of Rg1: Rb1, and which was lower in P quinquefolium. After steaming for several hours, the total GS will decrease. However, some ginsenosides (Rg2, 20R-Rg2, Rg3, Rh1 and Rh2) increase, while others (Rb1, Rb2, Rb3, Rc, Rd, Re, and Rg1) decrease. However, variation, especially in P quinquefolium, is high. P ginseng and P quinquefolium are general tonics and adaptogens. Rg1 and Rb1 enhance central nervous system (CNS) activities, but the effect of the latter is weaker. Thus, for the higher contents of Rg1, P ginseng is a stimulant, whereas the Rb1 contents of P quinquefolium are mainly calming to the CNS. Re, Rg1, panaxan A and B from P ginseng are good for diabetes. Re and Rg1 enhance angiogenesis, whereas Rb1, Rg3 and Rh2 inhibit it. Rh2, an antitumor agent, can be obtained from Rb1 by steaming. The content of Re in P quinquefolium are higher than in P ginseng by 3-4 times. The vasorelax, antioxidant, antihyperlipidemic, and angiogenic effects of Re are reported. Thus, for the CNS "hot," wound healing and hypoglycemic effects, P ginseng is better than P quinquefolium. For anticancer effects, P quinquefolium is better.
1 Andrographolide, an active component found in leaves of Andrographis paniculata, has been reported to exhibit nitric oxide (NO) inhibitory property in endotoxin-stimulated macrophages, however, the detailed mechanisms remain unclear. In the present study we investigated the e ect of andrographolide on the expression of inducible NO synthase (iNOS) mRNA, protein, and enzyme activity in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS) plus interferon-g (IFN-g). 2 RAW 264.7 cells stimulated with LPS/IFN-g activated NO production; in this condition andrographolide (1 ± 100 mM) inhibited NO production in a dose-dependent manner with an IC 50 value of 17.4+1.1 mM. Andrographolide also reduces the expression of iNOS protein level but without a signi®cant e ect on iNOS mRNA. The reduction of iNOS activity is thought to be caused by decreased expression of iNOS protein.3 In a protein stability assay, andrographolide moderately but signi®cantly reduced the amount of iNOS protein as suggested by accelerating degradation. Furthermore, andrographolide also inhibited total protein de novo synthesis as demonstrated by [ 35 S]-methionine incorporation. 4 As a whole, these data suggest that andrographolide inhibits NO synthesis in RAW 264.7 cells by reducing the expression of iNOS protein and the reduction could occur through two additional mechanisms: prevention of the de novo protein synthesis and decreasing the protein stability via a post-transcriptional mechanism. It is also possible that inhibition of iNOS protein expression and NO production under immune stimulation and/or bacteria infection may explain, in part, the bene®cial e ects of andrographolide as an anti-in¯ammatory agent.
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