Effect of Silymarin as Natural Antioxidants and Antimicrobial Activity

Silymarin is a lipophilic extract from the seeds of milk thistle and is composed of three isomer flavonolignans, silybin, silydianin and silychristin. Silymarin content of milk thistle seed ranged from 4 to 6% based on dry weight. Silybin is the component with the greatest degree of biological activity and comprises 50–70% of silymarin [1] Silymarin has free radical scavenging properties and its ability to enhance endogenous anti-oxidant defense systems in vivo Silymarin has been shown to inhibit the growth of human prostate, breast, and cervical cancer cells in test tubes. Silymarin can protect liver, brain, heart and other vital intra organs from oxidative damage for its ability to prevent lipid peroxidation and replenishing the reduced glutathione levels [2]. Silymarin have anti-inflammatory and anti-arthritic effects due to excellent antioxidant property, scavenging free radicals which act as pro-inflammatory agents. Silymarin was found to be more effective in cases of developing arthritis compared to developed arthritis. Silymarin and silibinin hinder inflammatory process by inhibiting neutrophil migration and kuppfer cell inhibition. They also inhibit the formation of inflammatory mediators viz. prostaglandins and leukotriens and release of histamine from basophils [3]. Silymarin is a strong antioxidant that has been proven to promote liver cell regeneration, to reduce blood cholesterol and to help prevent cancer [4]


INDTRODCTION
Silymarin is a lipophilic extract from the seeds of milk thistle and is composed of three isomer flavonolignans, silybin, silydianin and silychristin. Silymarin content of milk thistle seed ranged from 4 to 6% based on dry weight. Silybin is the component with the greatest degree of biological activity and comprises 50-70% of silymarin (Ramasamy and Agarwal, 2008). Silymarin has free radical scavenging properties and its ability to enhance endogenous anti-oxidant defense systems in vivo .
Silymarin has been shown to inhibit the growth of human prostate, breast ، and cervical cancer cells in test tubes. Silymarin can protect liver, brain, heart and other vital intra organs from oxidative damage for its ability to prevent lipid peroxidation and replenishing the reduced glutathione levels. (Das et al., 2008).
silymarin have anti-inflammatory and anti-arthritic effects due to excellent antioxidant property, scavenging free radicals which act as pro-inflammatory agents. Silymarin was found to be more effective in cases of developing arthritis compared to developed arthritis. Silymarin and silibinin hinder inflammatory process by inhibiting neutrophil migration and kuppfer cell inhibition.
They also inhibit the formation of inflammatory mediators viz.
prostaglandins and leukotriens and release of histamine from basophils (Dixit et al., 2009). Silymarin is a strong antioxidant that has been proven to promote liver cell regeneration, to reduce blood cholesterol and to help prevent cancer (Vaknin et al., 2008).
The hepatoprotective action of silymarin is mainly through its anti-free radical and anticarcinogenic roles (Shaker et al., 2010), but it has also been ascribed other actions includes antioxidant, anti-lipid peroxidative, antifibrotic, anti-inflammatory immunomodulatory and liver regenerating activity. Silymarin has clinical applications in alcoholic liver diseases, liver cirrhosis, Amanita mushroom poisoning, viral hepatitis, toxic and drug diseases of the liver, psoriasis and in neuroprotective and neurotropic activity (Ghosh et al., 2010).Silymarin acts as a toxin blockade agent by inhibiting binding of toxins to hepatocyte cell membrane receptors .The toxicity of silymarin is very low, the oral 50% lethal dose being 10,000 mg kg −1 in rats and the maximum tolerated dose being 300 mg kg −1 in dogs (Abenavoli et al., 2010).Silymarin is not soluble in water and is usually administered in capsules as a standard extract (70-80% silymarin). Formulation of the phytotherapic extract (silymarin) in selfemulsifying pellets gave rise to a simultaneous improvement of the oral biodiversity of its main active compounds (Iosio et al., 2010). Silymarin has been shown to reduce liver fibrosis up to 30-35%, and in few cases it has reversed the liver fibrosis (Haddad  The main objective of the present study was to investigate effect of silymarin as natural antioxidants and antimicrobial activity substance.

Determination of fatty acids profile
Fatty acid profile of sunflower oil were esterified into their corresponding FAMEs using methanoleic NaOH and BF3 with methanolic (Boron triflouride) as

Physical and chemical properties of sunflower oil
The physical and chemical properties of sunflower oil used in the present study were determined to define the identity of the oil, and insure that oxidative reaction has not begun. The obtained results are shown in Table (

Fatty acids composition of sunflower oils
The fatty acids composition of sunflower oil show in Table ( In sunflower oil, the main fatty acid is Linoleic acid, followed by oleic, Palmitic and Stearic acids. Also, these results were confirmed by the ratio between ∑ PUFA / ∑SFA, MUFA / ∑PUFA and ∑USFA / ∑SFA ,( 4.234 , 0.485 and 6.289 ) respectively which showed that the oil had a high TU/ TS ratio (6.289 ). This means that sunflower oil is distinguished by containing fatty acids profile with high degree of unsaturation such as C18:2 (essential fatty acid) Moreover, the obtained data was in harmony with the findings

Effect of different concentrations of the silymarin on oxidative stability of sunflower oil
The antioxidant properties of the silymarin on refined sunflower oil were determined by Rancimat test at 100 ºC and calculated at 25ºC using the temperature coefficient of 2.2 .The obtained results are recorded in Tables ( 3 ) .
From these results, it could be found that addition of silymarin exhibited antioxidant activities of fresh sunflower oil compared with control sample.
The data in Table (3) showed that silymarin at level 100 to500 ppm had highly antioxidant activity more than that of BHT at 200 ppm or control sample.  It could be concluded that the silymarin considered as good natural antioxidant which prolongs stability of sunflower oil and it may be a potent antioxidant activity for its stabilization