doi:10.1038/nindia.2014.45 Published online 2 April 2014
Researchers have identified polysaccharides with anticancer activities in lemongrass (Cymbopogon citratus), a tropical herb widely used in traditional medicine . These polysaccharides were found to kill cultured cervical and prostate cancer cells.
Aqueous extracts of dried lemongrass leaves are used in traditional medicine for treating digestive disorders, diabetes, nervous disorders and cancer. However, previous studies had not investigated their anti-inflammatory and anticancer properties.
From lemongrass leaf extracts, the researchers purified the polysaccharides and made three fractions — an unbound fraction and two fractions containing acidic polysaccharides. The anticancer properties of these fractions were investigated by exposing cultured cervical and prostate cancer cells to them.
The two fractions containing acidic polysaccharides exhibited higher anticancer activities against both types of cancer cells than the unbound fraction. These two fractions induced apoptosis — a process that causes controlled death of cancer cells. Fluorescence images demonstrated that exposure to the acidic polysaccharides disrupted the activity of mitochondrial membranes, an initial step of apoptosis.
In addition to mitochondrial damage, the acidic polysaccharides turned on a gene that suppresses tumour growth. The activation of this tumour-suppressor gene enhanced the activity of death-triggering enzymes and turned off certain genes that prevent cell death. "These polysaccharides could be useful in developing novel anticancer drugs," says Ramar Thangam, a co-author of the study.