The effect of in vitro gastrointestinal digestion on the anti-inflammatory activity of Vitis vinifera L. leaves.

Botanicals are widely consumed all over the world for health purposes, with increased usage in the general population, in many different types of products, including foods and plant food supplements. Several reports support for the beneficial effects of botanicals against gastrointestinal inflammation. However, no studies regarding the anti-inflammatory activity in the gastrointestinal tract of red vine leaves have been reported so far. The present work investigates the biological activity of Vitis vinifera L. water extract (VVWE) from dried leaves in two in vitro models of gastric and intestinal inflammation. The extract was characterized by a validated HPLC-DAD method, and tested on human epithelial gastric (AGS) and intestinal (Caco-2) cells with the aim to investigate the inhibitory effect on IL-8 secretion and promoter activity, before and after in vitro gastric or gastrointestinal digestion. Our results show that the water extract from red vine leaves inhibits TNFα-induced IL-8 secretion and expression in human gastric epithelial cells; the effect should be maintained, although to a lesser extent, after gastric digestion. In contrast, the effect after intestinal digestion is dramatically decreased since degradation of the active components in the gut does not allow the extract to efficiently counteract TNFα or IL-1ß induced IL-8 expression and the NF-κB pathway. The main molecular target of VVWE at the gastric level includes TNFα-induced activation of NF-κB and occurs at concentrations easily reachable after PFS consumption based on red vine leaf water extract as the ingredient. Our findings suggest that PFS containing water extracts from Vitis vinifera L. leaves could be useful to inhibit/attenuate gastric inflammation inhibiting IL-8 secretion and expression through impairment of the NF-κB pathway.

Old and new targets for innovative antimalarial compounds: the different strategies of the Italian Malaria Network.

Clinical treatment-failures to affordable drugs encouraged new investigation for discovery and development of new prophylactic and therapeutic interventions against malaria. The Drug Discovery Cluster (DDcl) of the Italian Malaria Network gathers several highly integrated and complementary laboratories from different Italian Institutions to identify, synthesise, screen in vitro and in vivo new antimalarial molecules directed against the intraerythrocytic stage of P. falciparum parasites and/or with transmission blocking activity to select lead compounds for further development. Complementary research activities, both in vitro and in the clinics, aim at investigating the pathogenetic mechanisms of severe malaria anaemia and the different manifestations of the disease in malaria-HIV co-infected patients to identify new therapies and improve survival.

A structure-activity study for the inhibition of metalloproteinase-9 activity and gene expression by analogues of gallocatechin-3-gallate.

Catechins are able to modulate the gelatinolytic activity of matrix metalloproteinase-9 (MMP-9) by reducing its release from macrophages. Gallocatechins decrease MMP-9 secretion by lowering MMP-9 promoter activity and mRNA levels. The effect appears to be dependent on some structural and stereochemical requirements. In this study, the relationship between chemical structure and activity was studied by testing the effect of analogues of (+/-)-gallocatechin-3-gallate (+/-)-GCG, selectively deprived of hydroxyl groups, on MMP-9 activity, transcription, and secretion. Our results indicate that (+/-)-GCG and (+/-)-catechin-3-gallate are characterized by a substitution pattern compatible with direct inhibition of MMP-9 activity. Conversely, when transcription was the target, (+/-)-trans-3-flavanol-3-benzoate, lacking all the hydroxyl groups, was the most effective both in lowering MMP-9 promoter activity and consequently protein secretion, and in inhibiting nuclear-factor-kappaB-driven transcription. Our results suggest that the structural requirements for enzyme inhibition are different from those necessary for targeting gene expression.

Analysis by high-performance liquid chromatography of teucrin A in beverages flavoured with an extract of Teucrium chamaedrys L.

Due to its liver toxicity, the medicinal use of germander (Teucrium chamaedrys L.) was banned in some countries. Nevertheless, alcoholic extracts are still permitted as flavour ingredients since they are fundamental in providing a bitter aromatic taste. Teucrin A represents the substance of major concern regarding the potential toxicity of germander. Hence, teucrin A represents the best analytical and toxicological marker of alcoholic extracts of T. chamaedrys. A sensitive high-performance liquid chromatography method to detect teucrin A in beverages is reported. Teucrin A was prepared by isolation from the plant extract using column chromatography and crystallization. The identity and purity (99%) were established by melting point, nuclear magnetic resonance and liquid chromatography-mass spectrometry. The high-performance liquid chromatography procedure was validated and its intra- and interday performance was established (relative standard deviation < or = 13% and error < or = 10%). In-house validation was carried out by analysing samples of beverages not containing T. chamaedrys spiked with a range of concentrations of teucrin A. The limit of detection was 0.1 ppm and the limit of quantification was 0.3 ppm. Teucrin A accounted for about 70% of the neo-clerodane diterpenoids found in the total extract of a specimen of T. chamaedrys. The content (+/- standard deviation) in 18 batches of different geographical origin was 2338 +/- 740 ppm, per cent coefficient of variation = 32, minimum-maximum = 999 - 3445 ppm. The mean level of teucrin A in 10 bottles of the same brand was 6.1 +/- 0.8 ppm, per cent coefficient of variation = 12. In 10 different brands found on the Italian market, the content of teucrin A ranged from not detectable to 10 ppm.

Inhibition of metalloproteinase-9 activity and gene expression by polyphenolic compounds isolated from the bark of Tristaniopsis calobuxus (Myrtaceae).

Excessive breakdown of extracellular matrix by metalloproteinases (MMPs) occurs in many pathological conditions, and thus inhibition of MMP activity might have therapeutic potential. The methanolic extract and the identified compounds from the bark of Tristaniopsis calobuxus Brongniart & Gris (Myrtaceae) were tested on the activity, production, and gene expression of MMP-9. The extract produced a concentration-dependent inhibition (50-95% at 10-50 microg/ml) of MMP-9 activity. The inhibitory activity was retained in the ethyl acetate-soluble fraction (50-95% inhibition at 10-50 microg/ml) which also reduced the release of MMP-9 by mouse peritoneal macrophages up to 80%. In the ethyl acetate-soluble fraction, two active fractions, 5A and 5B were identified. HPLC-MS and NMR analyses of these fractions indicated the presence of gallocatechin, ellagic acid, and its glycoside derivatives. Since the absolute configuration of gallocatechin was not determined, in the next experiments both (+)-gallocatechin (2R,3S) and (-)-gallocatechin (2S,3R) were tested, and (-)-epigallocatechin (2R,3R) was included for comparison. 5A and 5B inhibited MMP-9 secretion, an observation which correlated with the decrease of MMP-9 promoter activity and the downregulation of mRNA levels. All compounds decreased MMP-9 mRNA levels and secretion. Ellagic acid, (+)-gallocatechin and (-)-epigallocatechin, but not (-)gallocatechin inhibited promoter-driven transcription. Thus configuration at C2 (R) of the flavanol seem to be critical for the interaction with the promoter.

In vitro antiplasmodial activity of extracts of Tristaniopsis species and identification of the active constituents: ellagic acid and 3,4,5-trimethoxyphenyl-(6'-O-galloyl)-O-beta-D-glucopyranoside.

Screening of plants from New Caledonia for antiplasmodial activity against Plasmodium falciparum revealed that methanolic extracts of the leaves and bark of Tristaniopsis calobuxus, T. yateensis, and T.glauca inhibited the growth of chloroquine-sensitive and -resistant clones. Ellagic acid and the new compound 3,4,5-trimethoxyphenyl-(6'-O-galloyl)-O-beta-D-glucopyranoside were identified as the active constituents (IC50 0.5 and 3.2 microM, respectively). The growth inhibition of both clones was comparable. The compounds showed negligible or very low cytotoxicity to human skin fibroblasts and Hep G2 cells when tested at concentrations ranging from 0.5 to 100 microM.