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BACKGROUND AND PURPOSEBrassica rapa species constitute one of the major sources of food. In the present study, we investigated the anti-inflammatory effects and the underlying molecular mechanism of arvelexin, isolated from B. rapa, on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and on a model of septic shock induced by LPS. EXPERIMENTAL APPROACHThe expression of Inducible nitric oxide synthase (iNOS) and COX-2, TNF-a, IL-6 and IL-1b were determined by Western blot and/or RT-PCR respectively. To elucidate the underlying mechanism(s), activation of NF-kB activation and its pathways were investigated by electrophoretic mobility shift assay, reporter gene and Western blot assays. In addition, the in vivo anti-inflammatory effects of arvelexin were evaluated in endotoxaemia induced with LPS. KEY RESULTSPromoter assays for iNOS and COX-2 revealed that arvelexin inhibited LPS-induced NO and prostaglandin E2 production through the suppression of iNOS and COX-2 at the level of gene transcription. In addition, arvelexin inhibited NF-kBdependent inflammatory responses by modulating a series of intracellular events of IkB kinase (IKK)-inhibitor kBa (IkBa)-NF-kB signalling. Moreover, arvelexin inhibited IKKb-elicited NF-kB activation as well as iNOS and COX-2 expression. Serum levels of NO and inflammatory cytokines and mortality in mice challenged injected with LPS were significantly reduced by arvelexin. CONCLUSION AND IMPLICATIONSArvelexin down-regulated inflammatory iNOS, COX-2, TNF-a, IL-6 and IL-1b gene expression in macrophages interfering with the activation of IKKb and p38 mitogen-activated protein kinase, and thus, preventing NF-kB activation. AbbreviationsIkBa, inhibitor of NF-kB-a; IKKs, IkB kinases; iNOS, inducible nitric oxide synthase; LPS, lipopolysaccharide; MAPK, mitogen-activated protein kinase; PBS, phosphate-buffered saline; PGE2, prostaglandin E2

Cisplatin (cis-diaminedichloroplatinum II) is one of the most effective chemotherapeutic agents and plays a major role in the treatment of a variety of human solid tumors including those of the head, neck, testis, ovary, and breast. 1)However, the nephrotoxicity of cisplatin limits the efficacy of this important anticancer drug.2) Although the pathogenesis of cisplatin-induced acute renal failure (ARF) has been the subject of many studies, the molecular mechanisms that underlie its toxicity are poorly understood. Some investigators have suggested that free radicals play an important role in cisplatin-induced nephrotoxicity, 3,4) and another proposed that reactive oxygen species (ROS), particularly the superoxide radical, play an important role in cisplatin-induced renal injury.5) It has also been reported that cisplatin-induced nephrotoxicity is closely associated with an increase in lipid peroxidation in the kidney. 6,7) In addition, cisplatin has been found to inhibit antioxidant activity 8) and to induce GSH depletion, which has been proposed to be involved in nephrotoxicity.9,10) Some evidence suggests that free radical scavengers and antioxidants ameliorate cisplatin-induced nephrotoxicity.11) The antioxidant DPPD (N,NЈ-diphenyl-pphenylenediamine) reduced nephrotoxicity in cisplatintreated rats, inhibited an increase in lipid peroxide level, and reduced the inhibition of p-aminohippurate transport in vitro.12,13) Actually, amifostine has been clinically approved as a cytoprotective agent during cisplatin therapy. It is known to act via a mechanism that involves the scavenging of free radicals, the donation of hydrogen ions to free radicals, the depletion of oxygen, and the binding to active derivatives of antineoplastic agents.14,15) Thus, as a part of our on-going screening program to evaluate the protective potentials of natural compounds, we investigated the nephroprotective activity of the ethanol extract of the roots of Brassica rapa in vitro and in vivo. The group Brassica rapa includes many significant crops such as the Chinese cabbage; in Italy this group is mainly represented by turnip tops [B. rapa L. subsp. sylVestris (L.) JANCH var. esculenta HORT.], which are used as a cooked vegetable and are known as "cime di rapa." In Korea, Brassica rapa is cultivated commercially in GangHwa County, Kyunggi Province. In previous studies on Brassica rapa, flavonoids (isorhamnetin, kaempferol, and quercetin glycosides), 16) phenylpropanoid derivatives, 16) indole alkaloids, 17) and sterol glucosides 17) were identified. The only report on the minor components of B. rapa involved the determination of glucosinolates, a group of secondary metabolites of b-thioglucose, which is characteristics of the genus of Brassica.17) It is generally assumed that flavonoid components are of great importance in view of their biological effects of the human metabolism, 18) but no report has been issued on the protective effect of B. rapa on cisplatin-induced nephrotoxicity. Therefore, we investigated whether the ethanol extract...

Although eupafolin, a flavone found in Artemisia princeps Pampanini, has been shown to inhibit the growth of several human cancer cells, its mode of action is poorly understood. In this study, we investigated the pro-apoptotic activities of eupafolin in human cervical carcinoma HeLa cells. It was found that eupafolin induced apoptosis in a dose-dependent manner, as evidenced by DNA fragmentation and the accumulation of positive cells for annexin V. In addition, eupafolin triggered the activations of caspases-3, -6, -7, -8, and -9 and the cleavages of their substrates, such as, poly (ADP-ribose) polymerase and lamin A/C. Furthermore, treatment with eupafolin resulted in a loss of mitochondrial membrane potential (DeltaPsi(m)), increased the release of cytochrome c to the cytosol, and altered the expression levels of B-cell lymphoma 2 (Bcl-2) family proteins. Interestingly, caspase-8, an initiator caspase, was activated after the loss of DeltaPsi(m) and the activations of caspases-3 and -9. Moreover, treatment with z-DEVD-fmk (a specific caspase-3 inhibitor) and the overexpression of Bcl-2 prevented eupafolin-stimulated caspase-8 activation. Altogether, these results suggest that the eupafolin-induced apoptosis in HeLa cells is mediated by caspase-dependent pathways, involving caspases-3, -9, and -8, which are initiated by the Bcl-2-dependent loss of DeltaPsi(m).