• Toxicological Research
• /
• v.17
• /
• pp.271-280
• /
• 2001

We report on the applicability oj a method recently developed in our laboratory for measuring the antioxidant potential of isolated chemicals and extracts derived from natural products. Peroxyl radicals generated by thermal homolysis of 2,2'-azobis-amidinopropane (ABAP) oxidize $\alpha$-keto-${\gamma}$-methiolbutyric acid (KMBA) to ethylene, which is monitored by gas chromatography. Inhibition of ethylene formation in the presence of antioxidants that compete with KMBA for peroxyl radicals is the basis of the Total Oxyradical Scavenging Capacity Assay (TOSCA; Winston et al., 1998). Antioxidative activities of water-soluble extracts of American green tea, the anti-hepatotoxic flavonolignan from milk thistle (Silybum marianum) silybin, Ginkgo biloba extract EGb 761, and a series of naturally occuring sesquiterpene lactones (all ger-macranolides found in in fungi, liverworts, and plants) were studied. The specific TOSC value per $\mu$M silybin was 5.2, which is essentially comparable to that of Trolo $x^{ⓡ}$, a water-soluble vitamine E analog. Tea and Ginkgo extracts exhibited potent peroxyl radical scavenging capacity with values, respectively of =1700 and 1000 $\mu$mols Trolo $x^{ⓡ}$ equivalent per gram dry matter. The known anti-inflammatory activity of some germacranolides prompted study of their antioxidant capacity. None of the lactones exhibited antioxidant capacity toward peroxyl radicals comparable to Trolo $x^{ⓡ}$; costunilide, the most lipophilic, had a TOSC value = to glutathione. The potential role of peroxyl radicals in lipidperoxidation, other cellular damage, and var-ious disease states suggest a possible preventive role for silybin, green tea and Ginkgo biloba in oxidative stress caused by these free radical species.ecies.

• YAKHAK HOEJI
• /
• v.42 no.1
• /
• pp.82-88
• /
• 1998

The effect of hepatoprotective agents and bile acids on tumor necrosis factor-alpha, (TNF-${\alpha}$) production in murine and human macrophage cell line (RAW264.7 and U937) was inve stigated. The hepatoprotective agents including silymarin and its major component, silybin, significantly inhibited TNF-alpha production in a concentration dependent manner ($IC_50$ of silybin=67.7${\mu}g$/ml (140.3${\mu}g$M)). In differentiated U937 cells, especially, silybin showed more effective inbitory activity ($IC_50$=35.1${\mu}g$g/ml (72.7${\mu}g$M)). These results suggest that silymarin and silybin may inhibit TNF-alpha production in the process of hepatic diseases in human. However, biphenyldimethyl dicarboxylate (DDB) was not effective. In the case of bile acids, chenodeoxycholic acid (CDCA) showed a concentration dependent inhibitory effect on TNF-alpha production ($IC_50$ of CDCA= 71.5${\mu}g$g/ml (182.1${\mu}g$M)). In contrast, glycine or taurine conjugated form (G-CDCA or T-CDCA) restored to the control level or significantly increased TNF-${\alpha}$ production. And also ursodeoxycholic acid (UDCA) and its conjugated forms (G-UDCA and T-UDCA) showed a variety of patterns on TNF-${\alpha}$ production by changes of functional groups and concentration. These results also indicate that bile acids may regulate TNF-${\alpha}$ production in normal hepatic function or disease conditions.

• Biomolecules & Therapeutics
• /
• v.5 no.3
• /
• pp.272-277
• /
• 1997

The effect of nonionic surfactant(polyoxyl 40 hydrogenated castor oil, PHCO), a common solubi-lizer, on the solubility of silymarin in the combined preparation containing ursoseoxycholic acid(UDCA) and silymarin was investigated in vivo using HPLC. The solubility of silybin, a major component of silymarin, was enhanced by increasing the amount of PHCO. The effect of PHCO on bioavailability was also evaluated in rats. The bioavailability was calculated by silybin content in bile juice that was excreted for 24 hr after oral administration. It was found that the bioavailability of silymarin containing PHCO was significantly increased compared to that of control. These results suggest that PHCO may improve the solubility and bioavailabilty of silymarin when it is combined with UDCA and silymarin.

• Journal of Pharmaceutical Investigation
• /
• v.33 no.1
• /
• pp.61-65
• /
• 2003

Silybin is the main component of Cardus marianus extracts originated from Silybum marianum and has a hepato-protective effect. It is a water-insoluble compound and poorly absorbed from the gastrointestinal tract, resulting in very low oral bioavailability(BA). Polymeric mixed-micelle precursor formulation was made to enhance the dissolution rate of silybin, showing the results of pH-independent release profile with increased dissolution. Oral BA of different preparations in rats was evaluated, revealing that the new formulation showed increased BA more than 2-fold and 4-fold compared to the marketed product and Cardus marianus extracts itself, respectively.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.35 no.2
• /
• pp.151-158
• /
• 2009

We found that silymarin exhibited the inhibitory effect on melanogenesis in a spontaneously immortalized mouse melanocyte cell line, Mel-Ab. Silymarin is a standardized extract obtained from the dried seeds of milk thistle (Silybum marianum Gaertn.). Silymarin significantly prevented melanin production in a dose-dependent manner with an $IC_{50}$ value of 28.2 ${\mu}g/mL$ without effects on cell viability. Also, silymarin inhibited tyrosinase activity in melanocyte, while it did not affect the catalytic activity of cell-free tyrosinase. Furthermore, Western blot analysis indicated that silymarin decreased the expression of tyrosinase protein. Silybin A/B and isosilybin A/B were also able to inhibit melanin production and tyrosinase expression in protein level. Double blind study on the clinical efficacy of a cream containing 2 % silymarin showed that silymarin have a significant skin whitening effect. Therefore, this study suggests that silymarin may be useful as a natural skin whitening agent.

• Proceedings of the PSK Conference
• /
• 2003.10a
• /
• pp.56-56
• /
• 2003

Carduus marianus extract (formally called silymarin) have been used mainly as a medicament for hepatobiliary diseases. The major component of silymarin is silybin, which constitutes between 50 and 70% of the drug and is the major active component. Many experiments show the efficacy of silybin parenterally administerated. But, its bioavailability is low after oral administration due to its low solubility in water. (omitted)

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.296.2-296.2
• /
• 2003

Carduus marianus extract (formally called silymarin) have been used mainly as a medicament for hepatobiliary diseases. The major component of silymarin is silybin, which constitutes between 50 and 70％ of the drug and is the major active component. Many experiments show the efficacy of silybin parenterally administerated. But, its bioavalability is low after oral administration due to its low solubility in water. (omitted)

• Korean Journal of Pharmacognosy
• /
• v.51 no.4
• /
• pp.297-301
• /
• 2020

Silymarin (SM) and silybin diastereomers (SD) in milk thistle (Silybum marianum) were determined using high-performance liquid chromatography and quantified using a reverse-phase column in a gradient elution system. UV detection was performed at 288 nm. The content of SM and SD in milk thistle was 3.236 and 0.553 mg/g DW, respectively. Determining the presence and quantifying the content of SM and SD in milk thistle are vital for the pharmaceutical industry to identify optimal sources for developing health supplements or therapeutics.

• Proceedings of the PSK Conference
• /
• 2000.04a
• /
• pp.186.2-186.2
• /
• 2000

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.312.1-312.1
• /
• 2003

Silybin is the main component of Cardus marianus extracts (Silymarin) originated from Silybum marianum, called as milk thistle. It has a hepato-protective effect and is used clinically for the treatment of liver disease. But it is water-insoluble and is poorly absorbed from the gastrointestinal tract, resulting in very low oral bioavailability. Polymeric mixed-micelle precursor formulation containing surfactants, co-solvents, and block-co polymers with Cardus marianus extracts was made to enhance the dissolution rate of silybin and encapsulated with soft gelatin capsule. (omitted)