Naturally Occurring Organic Sulfur Compounds: An Example of a Multitasking Class of Phytochemicals in Anti-Cancer Research

Abstract

Allium plants, especially garlic (Allium sativum), have been cultivated since thousands of years all over the world not only as spicy food but also as medicinal plant. According to Block, the garlic plant was for the first time referred to in an Egyptian medical papyrus 1550 BC. In this Codex Ebers, 22 formulas of garlic were specified for the treatment of various disorders including heart problems, headache, bites, parasites and even tumors (Block, 1985). Today, the therapeutic value of garlic and other Allium vegetables is confirmed by multiple epidemiological and experimental studies. Especially prevention of cardiovascular diseases has been attributed to regular garlic consumption (Galeone et al., 2009; KrisEtherton et al., 2002; Rahman & Lowe, 2006). Moreover, cholesterol lowering, hypoglycemic, immune-stimulatory, anti-microbial and even anti-cancer properties have been reported for garlic compounds (Agarwal, 1996; Amagase et al., 2001; Balkwill & Mantovani, 2001; Borrelli et al., 2007; Goncagul & Ayaz, 2010; Kalra et al., 2006). Epidemiological studies clearly show the correlation between moderate garlic intake and a low cancer incidence (Galeone et al., 2006; Kim, J.Y. & Kwon, 2009; Salem et al., 2011). A case-control study conducted in the 1980s in Italy revealed for example that people living in high-risk areas for gastric cancer consumed less garlic compared to people in low-risk regions where stomach and colon cancers were three times less frequent (Buiatti et al., 1989). The health beneficial effects of garlic and other Allium species make this plant family an extremely interesting research topic.