44 research outputs found

    Pseudohypericin is necessary for the Light-Activated Inhibition of Prostaglandin E2 pathways by a 4 component system mimicking an Hypericum perforatum fraction

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    Hypericum perforatum (Hp) has been used medicinally to treat a variety of conditions including mild-to-moderate depression. Recently, several anti-inflammatory activities of Hp have been reported. An ethanol extract of Hp was fractionated with the guidance of an anti-inflammatory bioassay (lipopolysaccharide (LPS)-induced prostaglandin E2 production (PGE2)), and four constituents were identified. When combined together at concentrations detected in the Hp fraction to make a 4 component system, these constituents (0.1 μM chlorogenic acid, 0.08 μM amentoflavone, 0.07 μM quercetin, and 0.03 μM pseudohypericin) explained the majority of the activity of the fraction when activated by light, but only partially explained the activity of this Hp fraction in dark conditions. One of the constituents, light-activated pseudohypericin, was necessary, but not sufficient to explain the reduction in LPS-induced PGE2 of the 4 component system. The Hp fraction and the 4 component system inhibited lipoxygenase and cytosolic phospholipase A2, two enzymes in the PGE2-mediated inflammatory response. The 4 component system inhibited the production of the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α), and the Hp fraction inhibited the antiinflammatory cytokine interleukin-10 (IL-10). Thus, the Hp fraction and selected constituents from this fraction showed evidence of blocking pro-inflammatory mediators but not enhancing inflammation-suppressing mediators.

    Hypericum in infection: Identification of anti-viral and anti-inflammatory constituents

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    The Iowa Center for Research on Botanical Dietary Supplements seeks to optimize Echinacea, Hypericum, and Prunella botanical supplements for human-health benefit, emphasizing anti-viral, anti-inflammatory, and anti-pain activities. This mini-review reports on ongoing studies on Hypericum. The Center uses the genetically diverse, well-documented Hypericum populations collected and maintained at the USDA-ARS North Central Regional Plant Introduction Station (NCRPIS), and the strength of research in synthetic chemistry at Iowa State University to tap natural diversity, to help discover key constituents and interactions among constituents that impact bioactivity and toxicity. The NCRPIS has acquired more than 180 distinct populations of Hypericum, with a focus on Hypericum perforatum L. (Hypericaceae), representing about 13% of currently recognized taxa. Center chemists have developed novel synthetic pathways for key flavones, acyl phloroglucinols, hyperolactones, and a tetralin that have been found in Hypericum, and these compounds are used as standards and for bioactivity studies. Both light-dependent and light-independent anti-viral activities have been identified by using bioactivity-guided fractionation of H. perforatum and a HIV-1 infection test system. Our Center has focused on light-independent activity, potentially due to novel chemicals, and polar fractions are undergoing further fractionation. Anti-inflammatory activity has been found to be light-independent, and fractionation of a flavonoid-rich extract revealed four compounds (amentoflavone, chlorogenic acid, pseudohypericin, and quercetin) that interacted in the light to inhibit lipopolysaccharide-induced prostaglandin E2 activity. The Center continues to explore novel populations of H. perforatum and related species to identify constituents and interactions of constituents that contribute to potential health benefits related to infection

    Identification of light-independent inhibition of human immunodeficiency virus-1 infection through bioguided fractionation of Hypericum perforatum

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    <p>Abstract</p> <p>Background</p> <p>Light-dependent activities against enveloped viruses in St. John's Wort (<it>Hypericum perforatum</it>) extracts have been extensively studied. In contrast, light-independent antiviral activity from this species has not been investigated.</p> <p>Results</p> <p>Here, we identify the light-independent inhibition of human immunodeficiency virus-1 (HIV-1) by highly purified fractions of chloroform extracts of <it>H. perforatum</it>. Both cytotoxicity and antiviral activity were evident in initial chloroform extracts, but bioassay-guided fractionation produced fractions that inhibited HIV-1 with little to no cytotoxicity. Separation of these two biological activities has not been reported for constituents responsible for the light-dependent antiviral activities. Antiviral activity was associated with more polar subfractions. GC/MS analysis of the two most active subfractions identified 3-hydroxy lauric acid as predominant in one fraction and 3-hydroxy myristic acid as predominant in the other. Synthetic 3-hydroxy lauric acid inhibited HIV infectivity without cytotoxicity, suggesting that this modified fatty acid is likely responsible for observed antiviral activity present in that fraction. As production of 3-hydroxy fatty acids by plants remains controversial, <it>H. perforatum </it>seedlings were grown sterilely and evaluated for presence of 3-hydroxy fatty acids by GC/MS. Small quantities of some 3-hydroxy fatty acids were detected in sterile plants, whereas different 3-hydroxy fatty acids were detected in our chloroform extracts or field-grown material.</p> <p>Conclusion</p> <p>Through bioguided fractionation, we have identified that 3-hydroxy lauric acid found in field grown <it>Hypericum perforatum </it>has anti-HIV activity. This novel anti-HIV activity can be potentially developed into inexpensive therapies, expanding the current arsenal of anti-retroviral agents.</p

    beta-Hydroxy-beta-methylbutyrate free acid reduces markers of exercise-induced muscle damage and improves recovery in resistance-trained men

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    The purpose of the present study was to determine the effects of short-term supplementation with the free acid form of beta-hydroxy-beta-methylbutyrate (HMB-FA) on indices of muscle damage, protein breakdown, recovery and hormone status following a high-volume resistance training session in trained athletes. A total of twenty resistance-trained males were recruited to participate in a high-volume resistance training session centred on full squats, bench presses and dead lifts. Subjects were randomly assigned to receive either 3 g/d of HMB-FA or a placebo. Immediately before the exercise session and 48 h post-exercise, serum creatine kinase (CK), urinary 3-methylhistadine (3-MH), testosterone, cortisol and perceived recovery status (PRS) scale measurements were taken. The results showed that CK increased to a greater extent in the placebo (329%) than in the HMB-FA group (104%) (P=0.004, d=1.6). There was also a significant change for PRS, which decreased to a greater extent in the placebo (9.1 (SEM 0.4) to 4.6 (SEM 0.5)) than in the HMB-FA group (9.1 (SEM 0.3) to 6.3 (SEM 0.3)) (P=0.005, d = -0.48). Muscle protein breakdown, measured by 3-MH analysis, numerically decreased with HMB-FA supplementation and approached significance (P=0.08, d = 0.12). There were no acute changes in plasma total or free testosterone, cortisol or C-reactive protein. In conclusion, these results suggest that an HMB-FA supplement given to trained athletes before exercise can blunt increases in muscle damage and prevent declines in perceived readiness to train following a high-volume, muscle-damaging resistance-training session

    Normative misperceptions of peer seatbelt use among high school students and their relationship to personal seatbelt use

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    Objectives: This research examined gender-specific perceptions of peer seat belt use norms among high school students and their relationship with one’s own seat belt use. We expected that students would underestimate the seat belt use of their peers and that these perceptions would be positively associated with their own seat belt use. Methods: High school students from 4 schools (N = 3348; 52% male) completed measures assessing perceived seat belt use and personal seat belt use. Results: Findings demonstrated that students perceived that others engaged in less seat belt use than they do and that perceived norms were positively associated with one’s own seat belt use. Conclusions: Peer influences are a strong predictor of behavior, especially among adolescents. Ironically, adolescents’ behaviors are often influenced by inaccurate perceptions of their peers. This research establishes the presence of a misperception related to seat belt use and suggests that misperception is associated with own behaviors. This research provides a foundation for social norms–based interventions designed to increase seat belt use by correcting normative misperceptions among adolescents

    Development of a marketing campaign to recruit non-adjudicated and untreated abusive men for a brief telephone intervention

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    Abstract Although voluntary enrollment by abusive men in domestic violence perpetrator treatment programs occurs, most men enter treatment only after they have injured a partner or family member and have been arrested, convicted and sentenced. This leaves a serious gap for those who engage in abusive behavior but who have not been served by the legal or social service systems. To address this gap, the researchers applied social marketing principles to recruit abusive men to a telephone-delivered pre-treatment intervention (the Men&apos;s Domestic Abuse Check-Up-MDACU), designed to motivate non-adjudicated and untreated abusive men who are concurrently using alcohol and drugs to enter treatment voluntarily. This article discusses recruitment efforts in reaching perpetrators of intimate partner violence, an underserved population. Informed by McGuire&apos;s communication and persuasion matrix, the researchers describe three phases of the MDACU&apos;s marketing campaign: (1) planning, (2) early implementation, and (3) revision of marketing strategies based on initial results. The researchers&apos; &quot;lessons learned&quot; conclude the paper

    Normative misperceptions of abuse among perpetrators of intimate partner violence

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    This research was designed to evaluate the applicability of social norms approaches to interventions with male perpetrators of intimate partner violence (IPV). Participants included 124 nonadjudicated IPV perpetrating men recruited from the general population who completed assessment of their own IPV behaviors via telephone interviews and estimated the prevalence of behaviors in other men. Results indicated that IPV perpetrators consistently overestimated the percentage of men who engaged in IPV and that their estimates were associated with violence toward their partner over the past 90 days. Findings provide preliminary support for incorporating social norms approaches into clinical applications
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