Ethyl acetate extracts of alfalfa (Medicago sativa L.) sprouts inhibit lipopolysaccharide-induced inflammation in vitro and in vivo

Effects of sargentgloryvine stem extracts on HepG-2 cells in vitro and in vivo

AIM: To observe the effects of sargentgloryvine stem extracts (SSE) on the hepatoma cell line HepG-2 in vitro and in vivo and determine its mechanisms of action.

METHODS: Cultured HepG-2 cells treated with SSE were analysed by 3-(4,5-Dimethyl-thiazol-2-yl)-2,5-Diphenyltetrazolium bromide and clone formation assay. The cell cycle and apoptosis analysis were conducted by flow cytometric, TdT-Mediated dUTP Nick End Labeling and acridine orange/ethidium bromide staining methods, and protein expression was examined by both reverse transcriptase-polymerase chain reaction and Western blotting. The pathological changes of the tumor cells were observed by haematoxylin and eosin staining. Tumor growth inhibition and side effects were determined in a xenograft mouse model.

RESULTS: SSE treatment could not only inhibit HepG-2 cell proliferation in a dose- and time-dependent manner but also induce apoptosis and cell cycle arrest at the S phase. The number of colonies formed by SSE-treated tumor cells was fewer than that of the controls (P < 0.05). SSE induced caspase-dependent apoptosis accompanied by a significant decrease in Bcl-xl and Mcl-1 and elevation of Bak expression (P < 0.05). Tumor necrosis factor α in the xenograft tumor tissue and the liver functions of SSE-treated mice showed no significant changes at week 8 compared with the control group (P > 0.05). Systemic administration of SSE could inhibit the HepG-2 xenograft tumor growth with no obvious toxic side effects on normal tissues.

CONCLUSION: SSE can induce apoptosis of HepG-2 cells in vitro and in vivo through decreasing expression of Bcl-xl and Mcl-1 and increasing expression of Bax.

Tissue distribution and elimination of estrogenic and anti-inflammatory catechol metabolites from sesaminol triglucoside in rats

Sesaminol triglucoside (STG) is the main sesame (Sesamum indicum L.) lignan. Like many other plant lignans, STG can be converted to the mammalian lignans by intestinal microbiota. The objectives of the present study were to investigate the distribution of STG metabolite in rats, and the effects of STG and its metabolite on in vitro inflammation and estrogenic activities. STG was metabolized via intestinal microflora to a biologically active catechol moiety which would then be absorbed into the body in rats. After oral administration of STG to Sprague-Dawley rats, the concentrations of major STG metabolites in rectum, cecum, colon, and small intestines are higher than those in liver, lung, kidney, and heart. Its concentration in brain is low but detectable. The present study demonstrates that STG may be metabolized to form the catechol metabolites first by intestinal microflora and then incorporated via intestine absorption into the cardiovascular system and transported to other tissues. Results showed that the catechol metabolites were found to be able to penetrate the tail end of intestines (large intestine) and go through urinary excretion. STG metabolites significantly reduced the production of IL-6 and TNF-alpha in RAW264.7 murine macrophages stimulated with lipopolysaccharide. The estrogenic activities of STG metabolites were also established by ligand-dependent transcriptional activation through estrogen receptors. This study clearly shows that STG has anti-inflammatory and estrogenic activities via metabolism of intestinal microflora.

Inhibitory effects of Angelica sinensis ethyl acetate extract and major compounds on NF-kappaB trans-activation activity and LPS-induced inflammation

AIM OF THE STUDY

Previous study showed that the ethyl acetate (EtOAc) fraction from Angelica sinensis (Oliv.) Diels (Apiaceae) (AS) inhibited nitric oxide (NO) and prostaglandin E(2) secretions in vitro. This study was to evaluate anti-inflammatory activity of AS EtOAc extract and its major compounds in vivo and in vitro.

MATERIALS AND METHODS

NF-kappaB luciferase activity and pro-inflammatory cytokine secretions from lipopolysaccharide (LPS) plus interferon (IFN)-gamma-stimulated RAW 264.7 cells pre-treated with EtOAc extract or compounds were analyzed. For further in vivo study, BALB/c mice were tube-fed with 1.56 (AS1 group), 6.25 (AS2 group) mg/kg body weight/day in 100 microl soybean oil, while the control and PDTC (pyrrolidine dithiocarbamate, an anti-inflammatory agent) groups were tube-fed with 100 microl soybean oil/day only. After 1 week of tube-feeding, the PDTC group was injected with 50 mg/kg BW PDTC and 1 h later, all of the mice were injected with 15 mg/kg BW LPS. The pro-inflammatory cytokine levels and lifespan of LPS-challenged mice were determined.

RESULTS

The results showed that AS EtOAc extract significantly inhibited NF-kappaB luciferase activity and TNF-alpha, IL-6, macrophage inflammatory protein-2 (MIP-2) and NO secretions from LPS/IFN-gamma-stimulated RAW 264.7 cells. The AS1 and PDTC groups, but not AS2, had significantly higher survival rate than the control group. This was characterized by the inhibition of the serum TNF-alpha and IL-12p40 levels after LPS injection (p<0.05). The major compounds of AS, ferulic acid and Z-ligustilide, also significantly decreased NF-kappaB luciferase activity, which may contribute to the anti-inflammatory activity of AS.

CONCLUSIONS

Low dose of AS EtOAc extract that inhibits the production of inflammatory mediators alleviates acute inflammatory hazards and protect mice from endotoxic shock.

Isolation and identification of bioactive compounds in Andrographis paniculata (Chuanxinlian)

Andrographis paniculata (Burm. f.) Nees (Acanthaceae) is a medicinal plant used in many countries. Its major constituents are diterpenoids, flavonoids and polyphenols. Among the single compounds extracted from A. paniculata, andrographolide is the major one in terms of bioactive properties and abundance. Among the andrographolide analogues, 14-deoxy-11,12-didehydroandrographolide is immunostimulatory, anti-infective and anti-atherosclerotic; neoandrographolide is anti-inflammatory, anti-infective and anti-hepatotoxic; 14-deoxyandrographolide is immunomodulatory and anti-atherosclerotic. Among the less abundant compounds from A. paniculata, andrograpanin is both anti-inflammatory and anti-infective; 14-deoxy-14,15-dehydroandrographolide is anti-inflammatory; isoandrographolide, 3,19-isopropylideneandrographolide and 14-acetylandrographolide are tumor suppressive; arabinogalactan proteins are anti-hepatotoxic. The four flavonoids from A. paniculata, namely 7-O-methylwogonin, apigenin, onysilin and 3,4-dicaffeoylquinic acid are anti-atherosclerotic.

Anti-inflammatory activity of new compounds from Andrographis paniculata by NF-kappaB transactivation inhibition

Previous studies showed that the ethyl acetate (EtOAc) fraction of Andrographis paniculata (AP) possessed anti-inflammatory activity. This study further isolated these active compounds from bioactivity-guided chromatographic fractionation and identified eight pure compounds. Reporter gene assay indicated that 5-hydroxy-7,8-dimethoxyflavone (1), 5-hydroxy-7,8-dimethoxyflavanone (2), a mix of beta-sitosterol (3a) and stigmasterol (3b), ergosterol peroxide (4), 14-deoxy-14,15-dehydroandrographolide (5), and a new compound, 19-O-acetyl-14-deoxy-11,12-didehydroandrographolide (6a), significantly inhibited the transcriptional activity of NF-kappaB in LPS/IFN-gamma stimulated RAW 264.7 macrophages (P < 0.05). The two most abundant compounds, 14-deoxy-11,12-didehydroandrographolide (7) and andrographolide (8), had less inhibitory activity but exerted greater inhibitory activity by hydrogenation, oxidation, or acetylation to become four derived compounds, 9, 10, 11, and 12. All of the compounds significantly decreased TNF-alpha, IL-6, macrophage inflammatory protein-2 (MIP-2), and nitric oxide (NO) secretions from LPS/IFN-gamma stimulated RAW 264.7 cells. Compounds 5, 11, and 12 exerted the strongest inhibitory effect on NF-kappaB-dependent transactivation in the RAW 264.7 cell, with IC(50) values of 2, 2.2, and 2.4 microg/mL, respectively, providing encouraging results for bioactive compound development.