Cathy Hauck

Effect of Processing on Fumonisin Content of Corn

Fumonisins (FBs) are a family of mycotoxins produced by Fusarium moniliforme and F. proliferatum, predominant corn pathogens, and are found in most corn-containing foods. The FBs are heat stable, resistant to ammoniation, and unlike most mycotoxins, are water-soluble. The levels in corn and corn-containing foods will be presented ranging from < 20 ppb to > 2 ppm. Washing of contaminated FB-corn with water did not reduce the measured FB levels of significantly. The traditional processing step to make tortilla flour, nixtamalization [Ca(OH)2 cooking] to produce masa, reduced FB levels but produced hydrolyzed FB which was almost as toxic as FB. Retorting sweet corn in brine apparently produced hydrolyzed FB. Fermentation of corn to ethanol did not alter FB levels but distillation yielded FB-free ethanol. Attempts to enzymatically modify FB with several enzymes were unsuccessful. Reactions between FB and reducing sugars (glucose or fructose) to produce Schiffs bases yielded products that were not toxic. The effects of these processing treatments must be evaluated both chemically and biologically.

Rosmarinic Acid in Prunella vulgaris Ethanol Extract Inhibits Lipopolysaccharide-Induced Prostaglandin E2 and Nitric Oxide in RAW 264.7 Mouse Macrophages

Prunella vulgaris has been used therapeutically for inflammation-related conditions for centuries, but systematic studies of its anti-inflammatory activity are lacking and no specific active components have been identified. In this study, water and ethanol extracts of four P. vulgaris accessions were applied to RAW 264.7 mouse macrophages, and the ethanol extracts significantly inhibited lipopolysaccharide (LPS)-stimulated prostaglandin E2 (PGE2) and nitric oxide (NO) production at 30 microg/mL without affecting cell viability. Extracts from different accessions of P. vulgaris were screened for anti-inflammatory activity to identify accessions with the greatest activity. The inhibition of PGE2 and NO production by selected extracts was dose-dependent, with significant effects seen at concentrations as low as 10 microg/mL. Fractionation of ethanol extracts from the active accession, Ames 27664, suggested fractions 3 and 5 as possible major contributors to the overall activity. Rosmarinic acid (RA) content in P. vulgaris was found to independently inhibit inflammatory response, but it only partially explained the extracts activity. LPS-induced cyclooxygenase-2 (COX-2) and nitric oxide synthase (iNOS) protein expression were both attenuated by P. vulgaris ethanol extracts, whereas RA inhibited only COX-2 expression.

IDENTIFICATION OF ANTI-INFLAMMATORY CONSTITUENTS IN HYPERICUM PERFORATUM AND HYPERICUM GENTIANOIDES EXTRACTS USING RAW 264.7 MOUSE MACROPHAGES

Hypericum perforatum (St. Johns wort) is an herb widely used as supplement for mild to moderate depression. Our prior studies established synergistic anti-inflammatory activity associated with 4 bioactive compounds in a fraction of a H. perforatum ethanol extract. Whether these 4 compounds also contributed to the ethanol extract activity was addressed in the research reported here. Despite the popularity of H. perforatum, other Hypericum species with different phytochemical profiles could have their anti-inflammatory potentials attributed to these or other compounds. In the current study, ethanol extracts of different Hypericum species were compared for their inhibitory effect on LPS-induced prostaglandin E2 (PGE2) and nitric oxide (NO) production in RAW 264.7 mouse macrophages. Among these extracts, those made from H. perforatum and H. gentianoides demonstrated stronger overall efficacy. LC-MS analysis established the 4 compounds were present in the H. perforatum extract and pseudohypericin in all active fractions. The 4 compounds accounted for a significant part of the extracts inhibitory activity on PGE2, NO, tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in RAW 264.7 as well as peritoneal macrophages. Pseudohypericin was the most important contributor of the anti-inflammatory potential among the 4 compounds. The lipophilic fractions of H. gentianoides extract, which did not contain the previously identified active constituents, decreased PGE2 and NO potently. These fractions were rich in acylphloroglucinols, including uliginosin A that accounted for a proportion of the anti-inflammatory activity observed with the active fractions. Overall, the current study established that a different group of major anti-inflammatory constituents were present in H. gentianoides, while showing that the previously identified 4 compound combination was important for H. perforatums anti-inflammatory potential.

Group B Saponins in Soy Products in the U.S. Department of Agriculture—Iowa State University Isoflavone Database and Their Comparison with Isoflavone Contents

Isoflavones in soy protein foods are thought to contribute to the cholesterol-lowering effect observed when these products are fed to humans. The group B saponins are another ethanol-soluble phytochemical fraction associated with soy proteins and isoflavones and have also been associated with cholesterol-lowering abilities. We measured the group B soyasaponin concentrations in a variety of soy foods and ingredients in the U.S. Department of AgricultureIowa State University Isoflavone Database. We compared the isoflavone and soy saponin concentrations and distributions in intact soybeans, soy ingredients, and retail soy foods. Group B saponins occur in six predominant forms. There appears to be no correlation between saponin and isoflavone concentrations in intact soybeans ranging from 5 to 11 mumol isoflavones/g soybean and from 2 to 6 mumol saponin/g soybean. Depending upon the type of processing, soy ingredients have quite different saponins/isoflavones as compared to mature soybeans. In soy foods, the saponin:isoflavone ration ranges from 1:1 to 2:5, whereas in soy protein isolates, the ratio is approximately 5:3. Ethanol-washed ingredients have very low saponins and isoflavones. These very different distributions of saponins and isoflavones in soy products may affect how we view the outcome of feeding trials examining a variety of protective effects associated with soy consumption.

Enrichment of Echinacea angustifolia with Bauer Alkylamide 11 and Bauer Ketone 23 Increased Anti-inflammatory Potential through Interference with COX-2 Enzyme Activity

Bauer alkylamide 11 and Bauer ketone 23 were previously found to be partially responsible for Echinacea angustifolia anti-inflammatory properties. This study further tested their importance using the inhibition of prostaglandin E(2) (PGE(2)) and nitric oxide (NO) production by RAW264.7 mouse macrophages in the absence and presence of lipopolysaccharide (LPS) and E. angustifolia extracts, phytochemical enriched fractions, or pure synthesized standards. Molecular targets were probed using microarray, qRT-PCR, Western blot, and enzyme assays. Fractions with these phytochemicals were more potent inhibitors of LPS-induced PGE(2) production than E. angustifolia extracts. Microarray did not detect changes in transcripts with phytochemical treatments; however, qRT-PCR showed a decrease in TNF-alpha and an increase of iNOS transcripts. LPS-induced COX-2 protein was increased by an E. angustifolia fraction containing Bauer ketone 23 and by pure phytochemical. COX-2 activity was decreased with all treatments. The phytochemical inhibition of PGE(2) production by Echinacea may be due to the direct targeting of COX-2 enzyme.

Abstract A46: Pseudohypericin in Hypericum perforatum inhibited LPS-stimulated PGE2 and NO in mouse macrophages by potentiating SOCS3 expression

Introduction: Hypericum perforatum, also known as ‘St. John9s wort’, is one of the most studied medicinal plants. Despite its primary use as an anti-depression agent, certain compounds such as hypericin and hyperforin in H. perforatum extract have been shown to inhibit tumor growth by inducing apoptosis/necrosis and inhibiting angiogenesis. Using hypericin in photodynamic cancer therapy is also being studied. Our previous studies have demonstrated that H. perforatum extract and a group of 4 compounds in it, namely pseudohypericin, amentoflavone, quercetin, and chlorogenic acid, decreased lipopolysaccharide (LPS)-stimulated macrophage inflammatory response, and identified the activation of suppressor of cytokine signaling 3 (SOCS3) as a candidate mechanism for this activity. Given that both inflammation and SOCS3 suppression are associated with tumor progression, we studied the role of SOCS3 activation in the anti-inflammatory activity of H. perforatum extract and its components. Methods: Specific siRNA was used to knockdown the expression of SOCS3 in RAW 264.7 mouse macrophages. Activation of SOCS3 in macrophages was measured at mRNA and protein levels using qRT-PCR and Western blot. H. perforatum extract at 30 µg/mL, the 4 compounds at the same concentrations as in the extract, and the combinations of individual compounds were applied to macrophages with and without SOCS3 knockdown to reveal whether their inhibition of LPS-stimulated prostaglandin E2 (PGE2) and nitric oxide (NO) was dependent on SOCS3. Results: SOCS3 expression in the mouse macrophages was activated upon LPS stimulation and further potentiated by H. perforatum extract and the 4 compounds studied. SOCS3 siRNA transfection significantly compromised the activation of SOCS3. H. perforatum extract and the 4 compounds reduced LPS-stimulated PGE2 and NO production, but only the inhibitory effect of the 4 compounds was negated by SOCS3 knockdown. Combinations of two or three of the 4 compounds that include pseudohypericin, the most essential component among the four that act synergistically in reducing macrophage inflammatory response, lost their inhibitory effect on PGE2 and NO production in SOCS3 knockdown cells. Conclusions: SOCS3 activation was critical for pseudohypericin9s independent and interactive anti-inflammatory activity with amentoflavone, quercetin, and chlorogenic acid. H. perforatum extract utilized alternative mechanisms that are SOCS3 independent to inhibit macrophage inflammation. In addition to light-activated cytotoxicity and inhibition of angiogenesis, magnification of SOCS3 activation by H. perforatum extract might contribute to its anti-tumor potential. Citation Information: Cancer Prev Res 2010;3(12 Suppl):A46.