You may associate lemon grass with a refreshing glass of flavored tea or a delicious South Asian meal. But this herb has some surprising properties that may one day be harnessed for therapeutic purposes. Although lemon grass is not currently used as a treatment in humans, early laboratory studies indicate that it may be able to kill cancer cells by activating a process called apoptosis.
Definition of Apoptosis
In multicellular organisms, the number and type of cells in a tissue or organ is tightly regulated. Slowing or halting cell replication is one way to limit the number of cells. Another way is through regulated "suicide" of existing cells. This process is called programmed cell death or apoptosis. It is distinct from necrosis, in which cells die due to an acute injury. Instead, cells activate specific molecular signals that result in collapse of the cell structure, fragmentation of the nuclear DNA and cell membrane breakdown. The dying cell is rapidly engulfed by macrophage cells of the immune system.
Apoptosis and Cancer
Apoptosis is a key process that maintains healthy tissue function. Throughout our lifetime, normal metabolic processes or environmental exposures cause some cells to become damaged or mutated. These are typically removed through programmed cell death or apoptosis, a process that causes no local inflammation and leaves neighboring cells unaffected. When this regulatory system is altered, such as by a mutation, cells accumulate inappropriately in the tissue. Defective apoptosis is therefore one cause of tumor growth and progression.
Cymbopogon citratus is the scientific name for the lemon grass plant. This aromatic tropical grass is used as an herb for flavoring food and drinks in Asian cuisine. When crushed, both the grass and the fragrant yellow flowers produce a lemony scent. Other common names for the plant include fever grass, sereh, citroengras, te limon and zacate limon. The plant has also been applied in traditional medicine as an antiseptic and is now used in the cosmetic industry.
Anticancer Activity of Lemon Grass
In 2009, researchers at the Indian Institute of Integrative Medicine reported that an essential oil from the lemon grass variety Cymbopogon flexuosus was able to induce apoptosis in cancer cells. The lemon grass oil was effective in killing colon cancer cells, neuroblastoma cells and promyelocytic leukemia cells. In addition, the oil caused apoptosis in two types of solid tumors in animal studies. Earlier studies at the Ben Gurion University of the Negev in Israel indicated that citral, an ingredient in lemon-scented essential oils including those from lemon grass Cymbopogon citratus, causes apoptosis in tumor cells grown in the laboratory.