Methanol Extract of the Seaweed Gloiopeltis furcata Induces G2/M Arrest and Inhibits Cyclooxygenase-2 Activity in Human Hepatocarcinoma HepG2 Cells
Song Ja Bae1 and Yung Hyun Choi2,3*
1.Department of Food Science and Nutrition, Silla University and Marine Biotechnology center for Bio-Functional Material Industries, Busan 617-736, Korea 2Department of Biochemistry, Dongeui University College of Oriental Medicine, Busan 614-052, South Korea 3Department of Biomaterial Control, Dongeui University Graduate School, Busan 614-052, South Korea
It was previously reported that a methanol extract of Gloiopeltis furcata (MEGF), a kind of edible seaweed, inhibited the growth of several human cancer cell lines. In the present study, the effect of MEGF on the growth of human hepatocarcinoma HepG2 cells and its effect on the cyclooxygenases (COXs) expression were investigated. MEGF markedly reduced the viability of HepG2 cells and induced the G2/M arrest of the cell cycle in a concentration dependent manner. These effects were associated with the down-regulation of cyclin A, up-regulation of cyclin-dependent kinase (Cdk) inhibitor p21 (WAF1/CIP1) and dephosphorylation of Cdc25C. Furthermore, it was found that MEGF decreased the levels of COX-2 mRNA and protein expression without significant changes in the levels of COX-1, which was correlated with a decrease in prostaglandin E2 (PGE2) synthesis. These findings indicate that MEGF may have a possible therapeutic potential in hepatoma cancer patients.
Seaweed extract may hold promise for non-Hodgkin's lymphoma treatment
DEAD SEA, Jordan — Seaweed extract may eventually emerge as a lymphoma treatment, according to laboratory research presented at the second AACR Dead Sea International Conference on Advances in Cancer Research: From the Laboratory to the Clinic, held here March 7-10, 2010.
Lymphoma is a cancer of the immune system and is classified into Hodgkin's and non-Hodgkin's types, which are then further classified into B-cell and T-cell groups.
"Some forms of B-cell lymphoma are especially resistant to standard treatment and thus new therapies are needed," said Mohammad Irhimeh, Ph.D., assistant professor of hematoncology and stem cells at the Hashemite University in Jordan. "In this study, we looked at a new treatment strategy using novel active compounds derived from a natural source ¬¬— seaweed."
Seaweeds containing fucoidan, a sulfated polysaccharide similar to heparin in chemical structure, have been reported to have anti-tumor activity in mice and some cell lines.
For the current study, Irhimeh and colleagues at the University of California, Berkeley, and Royal Hobart Hospital in Australia treated lymphoma cell lines with a commercially available seaweed extract.
They found that the extract had an inhibitory effect on the growth of lymphoma cell lines, while leaving the control healthy cells intact. The researchers also noted a significant pattern of activity in the genes known to be linked with apoptosis, or cell death, in lymphoma.
Irhimeh said they would continue to study the mechanism of action for these biological effects and had a goal of conducting phase II or III clinical trials.