Loureirin B, a flavonoid extracted from Dracaena cochinchinensis, is an inhibitor of plasminogen activator inhibitor-1 (PAI-1), with an IC₅₀ of 26.10 μM; Loureirin B also inhibits K_ATP, the phosphorylation of ERK and JNK, and has anti-diabetic activity.

Loureirin B enhances the relative mRNA level of Pdx-1 and MafA. Loureirin B (1, 0.1, and 0.01 µM) increases insulin secretion in Ins-1 cells. Loureirin B (0.01 µM) almost causes no toxicity on cells. Loureirin B improves the level of expressions of MafA and Pdx-1 and ATP level. Loureirin B inhibits the KATP current but increases the [Ca²⁺]i level in Ins-1 cells^[1]. Loureirin B inhibits the expression of Col1 and FN, as well as the TGF-β1-mediated up regulation of p-JNK. Loureirin B also inhibits the up regulation of p-ERK that is induced by TGF-β1. Moreover, Loureirin B inhibits the contraction of TGF-β1-stimulated fibroblasts through the down regulation of p-ERK and p-JNK. However, Loureirin B does not suppress the up regulation of p-p38 that is induced by TGF-β1^[2]. Loureirin B downregulates both mRNA and protein levels of type I collagen, type III collagen and α-smooth muscle actin in a dose dependent manner in HS fibroblasts. Loureirin B also suppresses fibroblast proliferative activity and redistributes cell cycle, but does not affect cell apoptosis^[3].

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

Loureirin B significantly improves the arrangement and deposition of collagen fibres, decreases protein levels of ColI, ColIII and α-SMA and suppresses myofibroblast differentiation and scar proliferative activity, in a rabbit ear scar model. Loureirin B effectively inhibits TGF-β1-induced upregulation of ColI, ColIII and α-SMA levels, myofibroblast differentiation and the activation of Smad2 and Smad3, in NS fibroblasts^[3].

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

316.35

C₁₈H₂₀O₅

119425-90-0

固体

White to off-white

龙血素 B

• Flavonoids
• Dihydrochalcones

• Phenols
• Monophenols

• 植物
• 龙舌兰科
• 剑叶龙血树

Room temperature in continental US; may vary elsewhere.

DMSO 中的溶解度 : ≥ 150 mg/mL (474.16 mM; 吸湿的 DMSO 对产品的溶解度有显著影响，请使用新开封的 DMSO)

* “≥” means soluble, but saturation unknown.

* 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 (7.90 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 (7.90 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 (7.90 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]. Sha Y, et al. Loureirin B promotes insulin secretion through inhibition of KATP channel and influx of intracellular calcium. J Cell Biochem. 2017 Aug 17.  [Content Brief]

  [2]. He T, et al. Loureirin B Inhibits Hypertrophic Scar Formation via Inhibition of the TGF-β1-ERK/JNK Pathway. Cell Physiol Biochem. 2015;37(2):666-76.  [Content Brief]

  [3]. Bai X, et al. Loureirin B inhibits fibroblast proliferation and extracellular matrix deposition in hypertrophic scar via TGF-β/Smad pathway. Exp Dermatol. 2015 May;24(5):355-60.  [Content Brief]

  [4]. Yu Jiang, et al. Bioactivity-Guided Fractionation of the Traditional Chinese Medicine Resina Draconis Reveals Loureirin B as a PAI-1 Inhibitor. Evidence-Based Complementary and Alternative Medicine

Ins-1 cells are seeded onto 96-well plates and cultured for 48 h to approximately 80-90% confluence. Then, the cells are starved in a 2% FBS/DMEM for 12 h. Control group is cultured in medium without loureirin B, while the positive control group is received fresh medium with glimepiride. After the treatment of loureirin B and glimepiride for 4 and 8 h, the cell viability is measured by Cell Counting Kit-8 (CCK-8).

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

For short, 10 adult New Zealand white male rabbits (2.0-2.5 kg b.w./each) are acclimated and housed under the standard 12-h light: 12-h dark cycle with free access of water and SPF basal diet. Rabbit is first anaesthetized with 1% pentobarbital (1.5 mg/kg b.w.), and then, a dermal punch biopsy (10×4 mm) is created down to bare cartilage on the ventral surface of each ear to outline a full-thickness wound. Four punch wounds are made on each ear of the eight rabbits. A dissecting microscope is used to ensure the complete removal of epidermis, dermis and perichondrium in each wound. Forty-eight hours after surgery, wounded rabbits are randomLy divided into two groups with each being subcutaneously injected with DMSO solution (0.125% in PBS, 0.25 mL/kg b.w.) on the left ear or loureirin B solution (25 μg/mL in PBS, 0.25 mL/kg b.w.) on the right ear once every other day for total six times. Two rabbits are used for pilot experiment, four rabbits are sacrificed 14 days after injury (n = 4), and the rest four are sacrificed 28 days after injury (n=4). Two of the four scar tissues on the same ear are processed for Western blot, and the other two are used for Masson staining.

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

• [1]. Sha Y, et al. Loureirin B promotes insulin secretion through inhibition of KATP channel and influx of intracellular calcium. J Cell Biochem. 2017 Aug 17.  [Content Brief]

  [2]. He T, et al. Loureirin B Inhibits Hypertrophic Scar Formation via Inhibition of the TGF-β1-ERK/JNK Pathway. Cell Physiol Biochem. 2015;37(2):666-76.  [Content Brief]

  [3]. Bai X, et al. Loureirin B inhibits fibroblast proliferation and extracellular matrix deposition in hypertrophic scar via TGF-β/Smad pathway. Exp Dermatol. 2015 May;24(5):355-60.  [Content Brief]

  [4]. Yu Jiang, et al. Bioactivity-Guided Fractionation of the Traditional Chinese Medicine Resina Draconis Reveals Loureirin B as a PAI-1 Inhibitor. Evidence-Based Complementary and Alternative Medicine