In vitro bio activity of allium species extracts on cancer cells

Abstract

Consisting of about 1250 species, Allium is one of the largest genera within the Liliaceae family. Member of the genus differ in their appearance, colour and taste but share close similarity in their phytochemical contents. Garlic (Allium sativum) and onion (Allium cepa) are among the oldest of all cultivated plants and both plants have been used for culinary and medicinal purposes for thousands of years. In recent years, extensive research has focused on the beneficial and medicinal properties of garlic and onions. Essential oils (EO) have been shown to exhibit a wide range ofbioactive properties including amongst others antimicrobial, antithrombotic, antiplatelet, antiasthmatic, antitumor, antiarthritic, hypoglycemic and antioxidant activity. A number of studies have demonstrated a chemopreventive and anticarcinogenic effect of onion and garlic by using different garlic preparations including fresh garlic extract, aged garlic extract and garlic oil which activity is attributed to organo-sulfur compounds and isothiocyanates generated upon processing of these vegetables. Preclinical studies have provided convincing evidence to indicate that Allium compounds including diallyl sulfides, allyl isothiocyanate, quercetin, ajoene, allicin were highly effective in affording protection against cancer in laboratory animals induced by a variety of chemical carcinogens. Experiments have also shown that garlic and its chemical compounds were able to influence cell proliferation and programmed cell death and mediate their activity via apoptosis inducing bioactivity. Despite these reports there is very little basic data published in the literature on the extent of the growth inhibitory and apoptosis-inducing bioactivity of different Allium extracts on cancer cells. Thus, the present study was undertaken to screen and evaluate the growth inhibitory effect and possible cytotoxicity of EO and solvent extracts (SE) of selected Allium species, namely Allium cepa L. (Granex and White Globe Onion cultivars), Allium sativum L. (Aglio Bianco Polesano cultivar) and the related garlic weed, Nothoscordum inodorum (Aiton) Nicholson.