Sint Jan’s kruid en kanker*
De stof hypercine uit Sint Jan’s kruid
blijkt volgens een Amerikaanse studie goed werkzaam te zijn tegen een glioom, een soort tumor die doorgaans ontstaat in de hersenen. Omdat
laboratoriumproeven goede resultaten te zien gaven in het aanpakken van tumoren met hypercine werd nu een studie gedaan onder 42 mensen uit de VS en Canada die allen reeds behandeld waren voor deze tumor en waarbij sprake was van terugkeer en groei van de tumor. De deelnemers kregen drie maanden lang telkens meer hypercine per dag, beginnend bij 0,05 mg tot 0,50 mg per kilo lichaamsgewicht. 17 deelnemers konden de 3 maanden vol maken en van hen hadden 9 deelnemers geen toename van de tumor of zelfs vermindering. Van de 12 deelnemers die nog eens 3 maanden hypercine kregen bleek de helft geen toename of zelf een vermindering te hebben.
De onderzoekers willen nu verder onderzoeken of hypercine aanvulling mogelijk al
veel eerder bij de behandeling van een glioom werkzaam zal zijn.
Incurable brain tumor breakthrough - St. John's wort compound discovered as promising treatment
In findings just published in the journal Cancer, scientists are reporting that synthetic hypericin strongly inhibits the growth of gliomas. The reason appears to be, at least in part, because hypericin inhibits protein kinase C, a family of enzymes that spur on the proliferation of these tumors.
"Because hypericin has shown dramatic results in stopping tumor growth in gliomas in the laboratory, we wanted to examine the safety and potential antitumor activity of synthetic hypericin in patients with recurrent malignant gliomas," said William T. Couldwell, MD, PhD, professor and chairman of neurosurgery at the University of Utah School of Medicine and lead author on the study, in a statement to the press.
Dr. Couldwell and a research team from across the US and Canada gave oral synthetic hypericin to patients with two types of gliomas (anaplastic astrocytoma and glioblastoma). Their tumors had recurred or progressed despite standard chemo and other mainstream medical treatment. The scientists gave the patients gradually increasing dosages of hypericin and checked them for any adverse side
effects.
Overall, 40 percent of the patients in the study finished a three-month treatment regimen, showing that hypericin is well-tolerated as an oral medication in glioma patients. Most importantly, the scientists found that 9 of the research participants experienced either no progression or a partial response during treatment with hypericin.
But when they looked at the 12 patients who took hypericin for at least 60 days, the results were even more incredible. Fifty percent of these people -- who, remember, suffered from a tumor considered almost universally fatal -- achieved either stable disease or a partial response.
Bottom line: the herb-derived substance did what no other medical treatment (typically a combination of surgery, radiation and chemotherapy) has been able to do. It kept these research subjects from getting worse (and probably dying) and some got
better.
"The patients enrolled in our study were all individuals whose tumors had recurred or progressed after extensive prior therapy," Dr. Couldwell emphasized in the media statement. "Finding evidence of potential antitumor activity among this very ill population of patients who had failed conventional treatment is a promising sign that hypericin could be useful as an adjunct to the current standard of care."
"Despite advances in care, the prognosis for patients with malignant glioma remains poor. The next step is to examine the effect of hypericin if given earlier in the course of therapy," Dr. Couldwell stated.
Abstract
BACKGROUND:
Hypericin is a potent inhibitor of glioma growth in vitro. To examine whether synthetic oral hypericin can be tolerated by patients with recurrent malignant gliomas (anaplastic astrocytoma and glioblastoma) and to investigate its efficacy against these tumors, the authors undertook an open-label, sequential dose escalation/de-escalation tolerance study.
METHODS:
Patients with documented recurrent or progressive malignant gliomas who had received standard radiation therapy with or without chemotherapy were included. Patients were excluded for previous treatment with agents known to contain hypericin or treatment within 30 days with medications known to cause photosensitivity. Enrolled patients were given gradually increasing dosages of oral synthetic hypericin (0.05-0.50 mg/kg) for up to 3 months if no toxicity was observed, and patient response to treatment was noted. The patients were examined each month and underwent magnetic resonance imaging to evaluate tumor status at 3 months.
RESULTS:
Synthetic hypericin administered orally appeared to provide stabilization or a slight (<50%) decrease in tumor volume (coded as stable disease) at 3 months for 7 of 42 patients (17%) and produced a tumor reduction >50% (partial response) in 2 patients (5%). Seventeen patients (40%) survived for 3 months on daily synthetic hypericin at dose levels of 0.33 ± 0.070 mg/kg daily. The mean maximum tolerated dose was 0.40 ± 0.098 mg/kg daily. Twelve patients continued on hypericin therapy beyond 3 months. The median survival was 26 weeks (Kaplan-Meier method).
CONCLUSIONS:
The results of this study indicated that synthetic, oral hypericin is well tolerated in this patient group. The response results were comparable to those reported from other studies of salvage therapies for recurrent malignant brain tumors. Cancer 2011;. © 2011 American Cancer Society.
Copyright © 2011 American Cancer Society.
(Augustus 2011)
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