Can Bullfrog Eggs Treat Mesothelioma?

What do bullfrog eggs and the chemo drug Alimta® (pemetrexed) have in common? Well, it appears that both may be able to extend the lives of those stricken with malignant mesothelioma.

A group of Japanese researchers recently published a study in the public-access journal PLOS, outlining their work spurred by the growing interest in naturally-derived molecules as potential treatments for cancer. In particular, this research involved the use of sialic acid-binding lectin (cSBL), a protein derived from the eggs of bullfrogs. This protein can bind itself to cell membranes and degrade RNA, hence triggering anti-humor activity, the study showed.

Tests were done both in vitro (in test tubes) and in vivo (using mice). Some of the mice were treated with cSBL while others received Alimta. Yet another group of mice was treated with both simultaneously.

“The administration of cSBL significantly inhibited tumor growth in two xenograft [mouse] models, without any adverse effects,” wrote lead study author, Takeo Tatsuta. He also added that when both the cSBL and Alimta were administered, they had a synergistic effect on the mesothelioma cells to the extent not even seen with the standard drug treatment, which generally includes pemetrexed combined with the platinum-based chemo drug, cisplatin.

“These results suggest that cSBL has potential as a novel drug for the treatment of malignant mesothelioma,” concludes Tatsuta and his colleagues, adding that the use of the bullfrog eggs might actually be able to reduce the use of pemetrexed in the treatment of mesothelioma patients, hence eliminating some of the most debilitating side effects of this type of chemo, which is quite aggressive.

Indeed, researchers are turning more often to unusual and unexpected sources for cancer treatments, including natural products. Dr. Tatsuta’s team has also reviewed the use of the polysulfur aromatic alkaloids of the Pacific Sea Squirt in the treatment of mesothelioma. The alkaloids have shown to trigger cell death in mice with this form of asbestos-caused cancer.

Other researchers are using plants and other natural items in their studies, hoping to find treatments that are less harsh than chemo. Often, patients describe the side effects of chemotherapy as worse than their disease, and many individuals with cancer die as a result of the rigors of their treatment.