added 3 research items
Objective: Lomatium dissectum is a plant native to the Western US traditionally used in the Native American culture to treat influenza, which remains a persistent threat to human health. Evidence suggests that dysregulation of cytokines and chemokines, including CXCL10, is the primary factor leading to poor prognosis in highly pathogenic influenza infection. This study was conducted to address the hypothesis that an aqueous extract of L. dissectum root inhibits CXCL10 secretion by human bronchial epithelial cells stimulated with polyinosinic:polycytidylic acid (poly i:c), a synthetic analog of viral dsRNA. Design: BEAS-2B cells treated with poly i:c were exposed to L. dissectum root aqueous extract simultaneously or at 2 h intervals up to 8 h post-stimulation. Supernatants were harvested at 24 h and enzyme-linked immunosorbent assay (ELISA) performed to determine CXCL10 concentrations. Results: L. dissectum root aqueous extract at 1 µg/mL significantly inhibited CXCL10 secretion (P=0.043, Anova, Tukey HSD) and demonstrated maximal inhibition 6 h post poly i:c exposure. MTT cytotoxicity assay results suggest that this inhibitory effect was not due to extract-induced cytotoxicity. Conclusion: The observation that L. dissectum extract inhibits CXCL10 secretion provides a plausible mechanism for the efficacy of L. dissectum in influenza treatment reported in ethnobotanical studies and case reports. L. dissectum may reduce morbidity and mortality associated with influenza and merits further research.
Objective: To determine if aqueous, polysaccharide-containing Echinacea purpurea extracts taken orally increase pro-inflammatory cytokine responses ex vivo. Design: In two separate studies, the levels of TNF-alpha (TNF), interleukins 2 and 6 (IL-2 and IL-6) and interferon gamma (IFN-γ) secreted by phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC) from healthy adults randomized to take one of three E. purpurea formulations or placebo orally for 10 consecutive days were measured. Blood was obtained from participants at baseline and on days 2, 3, 7, and 10 while on study medication. PBMC were isolated and stimulated with PHA for 24 h, and supernatants collected for measurement of pro-inflammatory cytokine levels. Outcome Measures: Primary outcomes were peak concentrations of PHA-induced TNF, IL-2, IL-6, and IFN-γ from PBMC isolates collected while on study medication. Cytokine responses of PBMC from participants randomized to one of the Echinacea formulations were compared with those of placebo recipients by regression analysis. Results: Cytokine levels were obtained from mitogen-activated PBMC from 86 participants, collected while on study medication. No significant differences in the peak levels of PBMC-secreted TNF, IL-2, IL-6 and IFN-γ were observed between PBMC from those taking active Echinacea preparation vs. a placebo. After adjusting for age, a trend toward increased IL-6 secreted by PHA-stimulated PBMC isolated on day 3 of oral administration was observed for the group taking one of the E. purpurea formulations compared with placebo (P=0.064). Conclusions: Oral administration of E. purpurea did not significantly enhance peak pro-inflammatory cytokine responses in mitogen-stimulated PBMC.