S-allylcysteine (SAC) among Many Compounds Found in Garlic Shown Anti-Cancer Effects Especially on Hepatocellular (Liver) Carcinoma

Garlic, a member of Allium vegetables, has long known medicinal properties. It is known for its anti-hypertensive and anti-tumor effects. Organosulfur compounds (OSCs) found in these vegetables have the potential to prevent and treat different cancers.
Garlic

There are two major types of OSCs found in garlic;

Lipid soluble:

Diallyl sulfide (DAS),
Diallyl disulfide (DADS),
Diallyl trisulfide (DATS) and
Dithiins.

2. Water soluble:

S-allylcysteine (SAC) and
S-allylmercaptocysteine (SAMC).

Several works show that SAC has anti-tumor effect against different human cancers such as prostate cancer, breast cancer, oral cancer, neuroblastoma and non-small-cell lung carcinoma.

Now, it has been found to inhibit liver cancer metastasis.
HCC

Surgical treatments such as liver resection and liver transplantation are better options for patients of early stage Hepatocellular Carcinoma (HCC) having good prognosis.
Nearly 70% of HCC patients have limited treatment options due to late diagnosis and/or advanced stage of the disease when however, surgical treatments as well as regional therapy are not feasible.
In this context, the researchers tried SAC, a garlic derived water soluble organosulfur compound (OSC), to see if that can have anti-tumor effects against HCC cell line.
They demonstrated that SAC could inhibit the proliferation rate of MHCC97L cells in dose- and time-dependent manners. Its effect is marked after more than 3 days of treatment.
These phenomena were also seen in other cancers like breast, prostate and lungs; suggesting a common mode of action of SAC on cancers.
SAC acts by;

The anti-proliferative effect. Inhibiting the colony-forming ability of HCC97L cells from single cell, indicating its suppressive effect on initiation of HCC; explained to be its suppressive effect on the expressions of proliferative markers including Ki-67 and PCNA.
Induction of apoptosis of tumor cells. The suppressive effect of SAC of HCC cells might be attributed to the induction of caspase-mediated apoptosis through down-regulation of anti-apoptotic proteins.

Several lines of evidences suggest that cancer cells treated with OSCs can lead to the arrest in G2/M phase of the cell cycle through modulating the expressions or activities of cyclins, cyclin-dependent kinases (Cdks) , signaling molecules and histones.

The expressions of cdc25c, cdc2 and cyclin B1 in HCC cells were down-regulated by SAC treatment in a dose-dependent manner, indicating SAC may delay S phase progression to G2/M phase of HCC cells through suppression of cell cycle regulators.

Apart from anti-proliferative effect on cancers, SAC has been found to inhibit the invasion of cancer cells such as breast and prostate cancer cells by modulating the expression of E-cadherin.

SAC could reduce the metastatic potential of MHCC97L-Luc cells from 87.5% to 37.5%, suggesting an anti-metastatic effect of SAC on HCC metastasis.
Moreover, combination of SAC and cisplatin could significantly inhibit lung metastasis of MHCC97L-luc cells, indicating its synergetic implication on HCC treatment.

VEGF is a critical factor of angiogenesis whose up-regulation in HCC patients is significantly associated with high proliferative index, angiogenesis, tumor invasion and poor prognosis after liver resection.

Targeted inhibition of VEGF has been proved to improve clinical outcome of advanced HCC patients.
SAC could suppress the proliferation and metastatic potential of HCC by modulating important regulators involved in proliferation, invasion, apoptosis, cell cycle and angiogenesis, suggesting that SAC may be a potential therapeutic agent for the treatment of HCC patients.

The article was first published in PLoS ONE

Article Source: http://www.articlesbase.com/cancer-articles/s-allylcysteine-sac-among-many-compounds-found-in-garlic-shown-anti-cancer-effects-especially-on-hepatocellular-liver-carcinoma-5711644.html