Rode zonnehoed

Rode zonnehoed / Echinacea purpurea. Mag ik wat wetenschappelijk doen? Rode en andere zonnehoeden zijn nu volledig uitgebloeid, maar de stengels met hun stekelige zaaddozen staan nog stevig rechtop. Ze worden niet voor niks in de Duitse taal 'Egelskopf' genoemd. Mooie planten voor de klassieke border, geneeskrachtig van bloem tot wortel en ook wetenschappelijk onderzocht van boven tot onder. Bij deze dan ook een nuchtere opsomming van enige recente literatuur, voor de curieusneuzen onder ons.

De foto is Echinacea pallida, uit mijn Franse kruidentuin in Bellegarde en Diois.

New Novel Uses For Isobutylamide-Rich Preparations of Echinacea
Two significant novel discoveries have been made through our federally-sponsored Echinacea research. First, we have characterized that the class of compounds in Echinacea known as alkamides specifically isobutyl amides are not immuno-stimulatory but are immno-inhibitory and anti-inflammatory. This discovery may further and more effectively explain why Echinacea is effective during the onset stage of rhinovirus (cold and flu virus) infections. High concentrations of this class of compounds are now being studied through pharmacokinetic, in-vitro, and in-vivo studies to determine more specifically the mechanism through which isobutylamide-rich Echinacea preparations are effective.

Title: Echinacea in infection.
Author: Birt,-D-F; Widrlechner,-M-P; Lalone,-C-A; Wu,-L; Bae,-J; Solco,-A-K; Kraus,-G-A; Murphy,-P-A; Wurtele,-E-S; Leng,-Q; Hebert,-S-C; Maury,-W-J; Price,-J-P
Citation: Am-J-Clin-Nutr. 2008 Feb; 87(2): 488S-92S
Abstract: Ongoing studies have developed strategies for identifying key bioactive compounds and chemical profiles in Echinacea with the goal of improving its human health benefits. Antiviral and antiinflammatory-antipain assays have targeted various classes of chemicals responsible for these activities. Analysis of polar fractions of E. purpurea extracts showed the presence of antiviral activity, with evidence suggesting that polyphenolic compounds other than the known HIV inhibitor, cichoric acid, may be involved. Antiinflammatory activity differed by species, with E. sanguinea having the greatest activity and E. angustifolia, E. pallida, and E. simulata having somewhat less. Fractionation and studies with pure compounds indicate that this activity is explained, at least in part, by the alkamide constituents. Ethanol extracts from Echinacea roots had potent activity as novel agonists of TRPV1, a mammalian pain receptor reported as an integrator of inflammatory pain and hyperalgesia and a prime therapeutic target for analgesic and antiinflammatory drugs. One fraction from E. purpurea ethanol extract was bioactive in this system. Interestingly, the antiinflammatory compounds identified to inhibit prostaglandin E(2) production differed from those involved in TRPV1 receptor activation.

Title: Cytotoxic activity of polyacetylenes and polyenes isolated from roots of Echinacea pallida.
Author: Chicca,-A; Pellati,-F; Adinolfi,-B; Matthias,-A; Massarelli,-I; Benvenuti,-S; Martinotti,-E; Bianucci,-A-M; Bone,-K; Lehmann,-R; Nieri,-P
Citation: Br-J-Pharmacol. 2008 Mar; 153(5): 879-85
Abstract: BACKGROUND AND PURPOSE: The n-hexane extracts of the roots of three medicinally used Echinacea species exhibited cytotoxic activity on human cancer cell lines, with Echinacea pallida found to be the most cytotoxic. Acetylenes are present in E. pallida lipophilic extracts but essentially absent in extracts from the other two species. In the present study, the cytotoxic effects of five compounds, two polyacetylenes (namely, 8-hydroxy-pentadeca-(9E)-ene-11,13-diyn-2-one (1) and pentadeca-(9E)-ene-11,13-diyne-2,8-dione (3)) and three polyenes (namely, 8-hydroxy-pentadeca-(9E,13Z)-dien-11-yn-2-one (2), pentadeca-(9E,13Z)-dien-11-yne-2,8-dione (4) and pentadeca-(8Z,13Z)-dien-11-yn-2-one (5)), isolated from the n-hexane extract of E. pallida roots by bioassay-guided fractionation, were investigated and the potential bioavailability of these compounds in the extract was studied. EXPERIMENTAL APPROACH: Cytotoxic effects were assessed on human pancreatic MIA PaCa-2 and colonic COLO320 cancer cell lines. Cell viability was evaluated by the WST-1 assay and apoptotic cell death by the cytosolic internucleosomal DNA enrichment and the caspase 3/7 activity tests. Caco-2 cell monolayers were used to assess the potential bioavailability of the acetylenes. KEY RESULTS: The five compounds exhibited concentration-dependent cytotoxicity in both cell types, with a greater potency in the colonic cancer cells. Apoptotic cell death was found to be involved in the cytotoxic effect of the most active, compound 5. Compounds 2 and 5 were found to cross the Caco-2 monolayer with apparent permeabilities above 10 x 10(-6) cm s(-1). CONCLUSIONS AND IMPLICATIONS: Compounds isolated from n-hexane extracts of E. pallida roots have a direct cytotoxicity on cancer cells and good potential for absorption in humans when taken orally.

Title: Effects of echinacea on the frequency of upper respiratory tract symptoms: a randomized, double-blind, placebo-controlled trial.
Author: O'Neil,-J; Hughes,-S; Lourie,-A; Zweifler,-J
Citation: Ann-Allergy-Asthma-Immunol. 2008 Apr; 100(4): 384-8
Abstract: BACKGROUND: Upper respiratory tract infection symptoms are a common cause of morbidity. Herbal preparations of the plant Echinacea purpurea have immune-enhancing properties. OBJECTIVE: To compare the frequency of upper respiratory tract symptoms in individuals receiving E. purpurea capsules and those receiving placebo to evaluate the preventive efficacy of echinacea. METHODS: In a randomized, double-blind clinical trial, 90 volunteers recruited from hospital personnel were randomly assigned to receive 3 capsules twice daily of either placebo (parsley) or E. purpurea for 8 weeks during the winter months. Upper respiratory tract symptoms were reported weekly during this period. RESULTS: Fifty-eight individuals were included in the final data analysis: 28 in the echinacea group and 30 in the placebo group. Individuals in the echinacea group reported 9 sick days per person during the 8-week period, whereas the placebo group reported 14 sick days (z = -0.42; P = .67). Mild adverse effects were noted by 8% of the echinacea group and 7% of the placebo group (P = .24). CONCLUSION: Prophylactic treatment with commercially available E. purpurea capsules did not significantly alter the frequency of upper respiratory tract symptoms compared with placebo use.

En natuurlijk zijn ook eigen ervaringen een vorm van wetenschappelijk onderzoek. Als het knabbelen op een stukje verse bloem mij binnen enkele minuten verlost van tandpijn, dan heb ik natuurlijk geen wetenschappelijk onderzoek meer nodig om te weten dat het werkt. Maar wel nieuwsgierig blijven onderzoeken, wetenschappers!