Isosilybin (Isosilybinin) is a flavonoid from Silybum marianum; inhibits CYP3A4 induction with an IC₅₀ of 74 μM.

The reporter gene assay shows that milk thistle’s components silybin and isosilybin are responsible for the inhibition of PXR-mediated CYP3A4 induction by milk thistle. Compared with silybin, its isomer isosilybin is a stronger inhibitor of PXR-mediated CYP3A4 induction. A solution of 89, 133, and 200 μM isosilybin significantly inhibits CYP3A4 induction by 64, 82, and 88%, respectively. Isosilybin inhibits CYP3A4 induction with an IC₅₀ of 74 μM^[1]. Isosilybin B and isosilybin A, two diastereoisomers isolated from silymarin, have anti-prostate cancer (PCA) activity that is mediated via cell cycle arrest and apoptosis induction. Isosilybin B and isosilybin A treatment results in growth inhibition and cell death together with a strong G(1) arrest and apoptosis in human prostate cancer LNCaP and 22Rv1 cells^[2]. Isosilybin B causes increased phosphorylation of Akt (Ser-473 and Thr-308) and Mdm2 (Ser-166), which is linked with androgen receptor degradation as pretreatment with PI3K inhibitor (LY294002)-restored androgen receptor level. Isosilybin B treatment enhances the formation of complex between Akt, Mdm2 and AR, which promotes phosphorylation-dependent AR ubiquitination and its degradation by proteasome^[3]. Isosilybin A is able to significantly activate PPARγ at a concentration of 30 μM (2.08±0.48 fold, p<0.01). Isosilybin A causes transactivation of a PPARγ-dependent luciferase reporter in a concentration-dependent manner. In silico docking studies suggests a binding mode for 3 distinct from that of the inactive silymarin constituents, with one additional hydrogen bond to Ser342 in the entrance region of the ligand-binding domain of the receptor^[4].

Shanghai Jinpan Biotech Co Ltd has not independently confirmed the accuracy of these methods. They are for reference only.

482.44

C₂₅H₂₂O₁₀

72581-71-6

固体

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异水飞蓟宾

• Flavonoids
• Flavanonols

• Phenols
• Polyphenols

• 植物
• 豆科
• Glycine soya

• 植物
• 豆科
• 瓜儿豆

• 植物
• 菊科

Room temperature in continental US; may vary elsewhere.

DMSO 中的溶解度 : 100 mg/mL (207.28 mM; 超声助溶; 吸湿的 DMSO 对产品的溶解度有显著影响，请使用新开封的 DMSO)

* 请根据产品在不同溶剂中的溶解度选择合适的溶剂配制储备液；一旦配成溶液，请分装保存，避免反复冻融造成的产品失效。
储备液的保存方式和期限：-80°C, 2 years; -20°C, 1 year。-80°C储存时，请在2年内使用， -20°C储存时，请在1年内使用。

• 方案 一

  请依序添加每种溶剂： 10% DMSO    40% PEG300    5% Tween-80    45% Saline

  Solubility: ≥ 2.5 mg/mL (5.18 mM); 澄清溶液

  此方案可获得 ≥ 2.5 mg/mL（饱和度未知）的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀；再向上述体系中加入 50 μL Tween-80，混合均匀；然后再继续加入 450 μL 生理盐水 定容至 1 mL。

  生理盐水的配制：将 0.9 g 氯化钠，溶解于 ddH₂O 并定容至 100 mL，可以得到澄清透明的生理盐水溶液。

• 方案 二

  请依序添加每种溶剂： 10% DMSO    90% (20% SBE-β-CD in Saline)

  Solubility: ≥ 2.5 mg/mL (5.18 mM); 澄清溶液

  此方案可获得 ≥ 2.5 mg/mL（饱和度未知）的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 900 μL 20% 的 SBE-β-CD 生理盐水水溶液 中，混合均匀。

  20% SBE-β-CD in Saline 的配制（4°C，储存一周）：2 g SBE-β-CD（磺丁基醚 β-环糊精）粉末定容于 10 mL 的生理盐水中，完全溶解至澄清透明。

• 方案 三

  请依序添加每种溶剂： 10% DMSO    90% Corn Oil

  Solubility: ≥ 2.5 mg/mL (5.18 mM); 澄清溶液

  此方案可获得 ≥ 2.5 mg/mL（饱和度未知）的澄清溶液，此方案实验周期在半个月以上的动物实验酌情使用。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 900 μL玉米油中，混合均匀。

• [1]. Mooiman KD, et al. Milk thistle’s active components silybin and isosilybin: novel inhibitors of PXR-mediated CYP3A4 induction. Drug Metab Dispos. 2013 Aug;41(8):1494-504.  [Content Brief]

  [2]. Deep G, et al. Isosilybin B and isosilybin A inhibit growth, induce G1 arrest and cause apoptosis in human prostate cancer LNCaP and 22Rv1 cells. Carcinogenesis. 2007 Jul;28(7):1533-42.  [Content Brief]

  [3]. Deep G, et al. Isosilybin B causes androgen receptor degradation in human prostate carcinoma cells via PI3K-Akt-Mdm2-mediated pathway. Oncogene. 2008 Jun 26;27(28):3986-98.  [Content Brief]

  [4]. Pferschy-Wenzig EM, et al. Identification of isosilybin a from milk thistle seeds as an agonist of peroxisome proliferator-activated receptor gamma. J Nat Prod. 2014 Apr 25;77(4):842-7.  [Content Brief]

LNCaP cells and 22Rv1 cells are plated and treated at 40–50% confluency with different doses of isosilybin B and isosilybin A (10–90 μM in medium) dissolved originally in Dimethyl sulfoxide (DMSO) for the desired time periods (24–48 h) in serum condition. An equal amount of DMSO (vehicle) is present in each treatment, including control; DMSO concentration did not exceed 0.1% (v/v) in any treatment. At the end of desired treatments, total cell number is determined by counting each sample in duplicate using a hemocytometer under an inverted microscope. Cell viability is determined using trypan blue exclusion method^[2].

Shanghai Jinpan Biotech Co Ltd has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Mooiman KD, et al. Milk thistle’s active components silybin and isosilybin: novel inhibitors of PXR-mediated CYP3A4 induction. Drug Metab Dispos. 2013 Aug;41(8):1494-504.  [Content Brief]

  [2]. Deep G, et al. Isosilybin B and isosilybin A inhibit growth, induce G1 arrest and cause apoptosis in human prostate cancer LNCaP and 22Rv1 cells. Carcinogenesis. 2007 Jul;28(7):1533-42.  [Content Brief]

  [3]. Deep G, et al. Isosilybin B causes androgen receptor degradation in human prostate carcinoma cells via PI3K-Akt-Mdm2-mediated pathway. Oncogene. 2008 Jun 26;27(28):3986-98.  [Content Brief]

  [4]. Pferschy-Wenzig EM, et al. Identification of isosilybin a from milk thistle seeds as an agonist of peroxisome proliferator-activated receptor gamma. J Nat Prod. 2014 Apr 25;77(4):842-7.  [Content Brief]