St. John's Wort Compound May Help Brain Tumor Patients
St. John’s wort is often viewed as a remedy for depression, but a new study finds that a synthetic version of a compound in the herb may help patients who have a type of brain tumor. The compound, hypericin, was studied in patients with recurrent malignant brain tumors.
St. John’s wort ingredient may fight cancer
A largely incurable type of cancer known as malignant glioma is characterized by tumors that develop in the brain or spine. Each year, about 10,000 Americans are diagnosed with malignant glioma, a tumor that tends to grow or infiltrate normal brain tissue, making surgical extraction difficult or impossible.
Previous research has shown that synthetic hypericin can inhibit the growth of gliomas in a laboratory setting. Hypericin appears to inhibit the activity of protein kinase C, enzymes that are known to promote the rapid growth of tumors.
In a new study conducted by a team composed of both American and Canadian scientists, oral doses of synthetic hypericin were given to 42 patients who had either recurrent or progressive malignant gliomas (anaplastic astrocytoma or glioblastoma) that had failed extensive treatment. The doses were gradually increased (range, 0.05 to 0.50 mg/kg) for up to three months if the patients did not experience toxicity.
The patients were examined each month and underwent magnetic resonance imaging at three months to determine the status of their tumor. At three months, 7 patients (17%) showed stabilization or a slight decrease (less than 50%) in tumor volume, while 2 patients (5%) had a greater than 50 percent reduction in tumor volume.
The average one-year survival is about 50 percent for all patients who have malignant glioma. In this study, 17 (40%) of the patients survived for 3 months while taking an average dose of 0.33 mg/kg of synthetic hypericin. Twelve patients continued taking hypericin for more than 3 months, and the median survival for the entire treatment group was 26 weeks.
According to William T. Couldwell, MD, PhD, professor and chairman of neurosurgery at the University of Utah School of Medicine and the study’s lead author, “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.”
Currently, gliomas are treated using a combination of chemotherapy, radiation, and surgery. Couldwell noted that adding a component of St. John’s wort to existing treatments for malignant glioma might have “an additive or synergistic effect” and offer another option for these brain tumor patients.
Couldwell WT et al. Cancer 2011; doi: 10.1002/cncr.26123