β-adrenergic receptor (β-AR)

Propranolol (10-9 M-10-3 M; 24 and 48 hours): After 24 hours of 10-4 M propranolol and 48 hours of 10-9 M propranolol, significantly reduces HemSCs cell proliferation [4]. Propranolol (10-7 M-10-3 M; 24 and 48 hours) increases total ERK1/2 levels in a dose-dependent manner and vibrationally activates ERK1/2 in HemSCs at 10-5 M concentration. (50 μM–200 μM; 24 hours) Activates caspase-3, increases HemSC activity that is activated by Annexin V, and causes HemSC inflammation quickly [4].

Propranolol (powder medication; 40 mg/kg; daily) significantly reduced vascular diameter and increased the number of cells expressing phosphorylated ERK1/2 in IH Matrigel inlets relative to vehicle-treated inlets [4].

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Propranolol Affects Vascular Development in a Xenograft Mouse Model of IH [4]
To assess how propranolol affects HemSCs and IH development in vivo, we adapted a previously described mouse model [20]. In the IH mouse model, HemSCs resuspended in Matrigel are implanted subcutaneously in immunocompromised mice, and IH vessel development progresses over 3 weeks. The mice were treated with propranolol or vehicle 40 mg/kg daily. Using the surface area conversion factor of 1/12 [37–39], the mice received a human equivalent dose of 3.3–4.8 mg/kg daily. IH Matrigel implants from propranolol-treated mice had reduced blood flow at 14 and 21 days after implantation, measured by Doppler ultrasound, compared with vehicle (data not shown; Fig. 7A). Histological analysis of the 21-day IH Matrigel implants (Fig. 7B) demonstrated that propranolol did not affect blood vessel density (Fig. 7C) but did significantly reduce the vessel diameter relative to the vehicle-treated implants (Fig. 7D). The reduced vessel caliber correlated with a loss of Doppler-detectable flow in the propranolol treatment group. Propranolol also significantly increased the number of cells that expressed phosphorylated ERK1/2 within the IH Matrigel implant (Fig. 7E), consistent with the results from our in vitro studies. Thus, propranolol improved vessel development in the IH mouse model that correlated with MAPK pathway activation. [4]

Caspase-3 Assay [4]
HemSCs were seeded in EGM-2 with 20% FBS media and allowed to settle for 4 hours. HemSCs were treated at increasing concentrations of propranolol in SFM with 0.1% FBS for 24 hours. The protein lysates were collected, and caspase-3 activation was quantified using the Caspase-3 Human ELISA Kit.

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cAMP Assay [4]
The cAMP levels in HemSCs were determined using the LANCE Ultra cAMP kit. The HemSCs were washed and resuspended in the provided stimulation buffer (Hanks’ balanced saline solution, bovine serum albumin, isobutylmethylxanthine, HEPES buffered saline solution) and seeded (1,000 per well) on a 96-well plate. The cells were then treated with drugs for 30 minutes. Tracer and ULight-anti-cAMP working solutions were added and incubated at room temperature for 1 hour. The time-resolved fluorescence resonance energy transfer signal was determined using the EnVision Multilabel Plate Reader. cAMP levels were determined using a standard curve, and data were interpolated using a comprehensive curve fitting (nonlinear regression) and Prism. Each condition was used in triplicate, and the experiments were performed at least two times. A representative experiment is presented in the figures. To determine whether βARs are coupled to Gαs or Gαi in HemSCs, the cells were treated with isoprenaline, with or without 10 μM forskolin, over a 6-log dose range by serial dilutions with water for 30 minutes. Next, the cAMP levels were measured as described to determine whether βARs were coupled to Gαs or Gαi in HemSCs.

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ERK1/2 Western Blotting [4]
Cells were cultured on fibronectin-coated plates and treated with various concentrations of βAR antagonists and incubated for 30 minutes. The cells were lysed in TENT buffer (50 mM Tris [pH 8.0], 2 mM EDTA, 150 mM NaCl, 1% Triton-X-100) with 1% Halt Protease Inhibitor, 1% phosphatase inhibitor, and 0.5% sodium orthovanadate. Western blotting was performed for ERK1/2 (p44/42, 1:1,000) and pERK1/2 (P-p44/42, 1:500). The blots were stripped and then probed for α-tubulin (1:10,000) to normalize protein loading. Experiments were performed at least three times, and a representative experiment is presented in the figures.

Western Blot Analysis[4]
Cell Types: HemSC cells
Tested Concentrations: 10-7 M-10- 3 M
Incubation Duration: 24 and 48 hrs (hours)
Experimental Results: Total ERK1/2 levels increased in a dose-dependent manner.

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Cell proliferation assay[4]
Cell Types: HemSC Cell
Tested Concentrations: 10-9 M-10-3 M
Incubation Duration: 24 and 48 hrs (hours)
Experimental Results: HemSC proliferation was inhibited.

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Apoptosis analysis [4]
Cell Types: HemSC Cell
Tested Concentrations: 50 μM, 100 μM or 200 μM
Incubation Duration: 24 hrs (hours)
Experimental Results: HemSC cell death was induced through the apoptotic pathway.

Animal/Disease Models: IH (infant hemangioma) xenograft mouse model of HemSC cells [4]
Doses: 40 mg/kg
Route of Administration: Oral administration; 40 mg/kg; daily
Experimental Results: IH mouse model with MAPK Vascular development associated with pathway activation is improved.

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IH Mouse Model [4]
To study the effects of propranolol on HemSCs in vivo, a xenograft mouse model of IH was used as previously described. In brief, 1.5 × 106 HemSCs (n = 2) suspended in 200 µL of Corning Matrigel Matrix was implanted subcutaneously into the flanks of female 6–8-week-old NCrNude immunodeficient mice. Propranolol, which was provided in drinking solution, was initiated the day of IH xenografting. Propranolol was diluted to 270 µM in 5% dextrose water (vehicle), and daily consumption was measured to calculate the treatment dosage, which averaged 40 mg/kg daily. Blood flow within the IH Matrigel implant was analyzed using a VEVO 2100 Ultrasound Imaging System on a Doppler setting on days 14 and 21 of IH development. The mice were anesthetized with isoflurane and restrained in a supine position. The region of interest was fully scanned, with the transducer positioned at its largest longitudinal section over the implant to optimize the spatial resolution of the image, maximizing the detail. Next, two-dimensional images were captured in uniform steps of 0.05 mm. The images of blood flow were analyzed using software provided by VisualSonics. The mice were sacrificed after 21 days. The Matrigel implants were collected and fixed overnight at 4°C in 10% formalin. The implants were dehydrated and embedded in paraffin for histological analysis. Vessel density and caliber were counted in 3–4 HPFs per implant (n = 4 for each group). Vessel density was determined as the number of vessels (whether longitudinally or axially oriented) per HPF. The vessel diameter was measured according to the orientation. For longitudinally oriented vessels, the width was measured at three points and averaged, and the cross-section (axial) vessels were measured once. Vessels were identified as tubular structures with erythrocytes within.

Absorption, Distribution and Excretion
Patients taking doses of 40mg, 80mg, 160mg, and 320mg daily experienced Cmax values of 18±15ng/mL, 52±51ng/mL, 121±98ng/mL, and 245±110ng/mL respectively. Propranolol has a Tmax of approximately 2 hours, though this can range from 1 to 4 hours in fasting patients. Taking propranolol with food does not increase Tmax but does increase bioavailability.
91% of an oral dose of propranolol is recovered as 12 metabolites in the urine.
The volume of distribution of propranolol is approximately 4L/kg or 320L.
The clearance of propranolol is 2.7±0.03L/h/kg in infants <90 days and 3.3±0.35L/h/kg in infants >90 days. Propranolol clearance increases linearly with hepatic blood flow. Propranolol has a clearance in hypertensive adults of 810mL/min.

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Metabolism / Metabolites
Propranolol undergoes side chain oxidation to α-naphthoxylactic acid, ring oxidation to 4’-hydroxypropranolol, or glucuronidation to propranolol glucuronide. It can also be N-desisopropylated to become N-desisopropyl propranolol. 17% of a dose undergoes glucuronidation and 42% undergoes ring oxidation.
Propranolol has known human metabolites that include (2S,3S,4S,5R)-3,4,5-Trihydroxy-6-[1-naphthalen-1-yloxy-3-(propan-2-ylamino)propan-2-yl]oxyoxane-2-carboxylic acid.

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Biological Half-Life
The elimination half-life of propranolol is approximately 8 hours. The plasma half-life of propranolol is 3 to 6 hours.

Hepatotoxicity
Mild-to-moderate elevations in serum aminotransferase levels occur in less than 2% of patients on propranolol and are usually transient and asymptomatic, resolving even with continuation of therapy. Despite its widespread use, propranolol has not been convincingly linked to instances of clinically apparent liver injury; the few cases reported have generally occurred in patients who were receiving other well known hepatotoxic agents or were associated with elevations in serum enzymes only without jaundice.
Likelihood score: E (unlikely cause of clinically apparent liver injury).

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Because of the low levels of propranolol in breastmilk, amounts ingested by the infant are small and would not be expected to cause any adverse effects in breastfed infants. Studies during breastfeeding have found no adverse reactions in breastfed infants clearly attributable to propranolol. No special precautions are required. Propranolol has been used successfully in cases of persistent pain of the breast during breastfeeding.
◉ Effects in Breastfed Infants
A study of mothers taking beta-blockers during nursing found a numerically, but not statistically significant increased number of adverse reactions in those taking any beta-blocker. Although the ages of infants were matched to control infants, the ages of the affected infants were not stated. Of 8 mothers taking propranolol, one reported sleepiness in her breastfed infant, but she was also taking other unspecified drugs for hypertension.
A case of bradycardia in a 2-day-old breastfed infant was reported to the French pharmacovigilance system. However it is not clear from the report whether the mother had been taking propranolol near term and might have transmitted the drug to the infant transplacentally.
A prospective study of pregnant patients taking a beta-blocker asked mothers to complete a questionnaire about postpartum breastfeeding and any side effects in their breastfed infants. Sixteen mothers reported taking propranolol in unreported dosages while breastfeeding. Three women reported hypoglycemia in their infant with “a favorable outcome” and one reported bradycardia in her child with discontinuation of propranolol after 3 weeks of breastfeeding.
◉ Effects on Lactation and Breastmilk
Relevant published information on the effects of beta-blockade or propranolol during normal lactation was not found as of the revision date. A study in 6 patients with hyperprolactinemia and galactorrhea found no changes in serum prolactin levels following beta-adrenergic blockade with propranolol.
◈ What is propranolol?
Propranolol is a medication that has been used to treat high blood pressure, some heart conditions, overactive thyroid, tremors, glaucoma, and migraines. It belongs to the class of medications called beta-blockers. Some brand names for propranolol are Inderal®, InnoPran XL®, Detensol®, Novo-Pranol®, Deralin®, and Cardinol®.Sometimes when people find out they are pregnant, they think about changing how they take their medication, or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take this medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy.
◈ I take propranolol. Can it make it harder for me to get pregnant?
It is not known if propranolol can make it harder to get pregnant.
◈ Does taking propranolol increase the chance for miscarriage?
Miscarriage can occur in any pregnancy for many different reasons. Studies have not been done to see if propranolol increases the chance for miscarriage.
◈ Does taking propranolol increase the chance of birth defects?
Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. It is not known if propranolol increases the chance for birth defects above the background risk. Studies on the use of beta-blockers in general during pregnancy have not reported an increased chance of birth defects.
◈ Does taking propranolol in pregnancy increase the chance of other pregnancy-related problems?
Propranolol has been linked with reduced growth of the baby. However, it is not clear if this happens because of the medication, the condition being treated, or other factors. Studies have not shown an increased chance for other pregnancy-related problems, like preterm delivery (birth before week 37).The use of propranolol in late pregnancy may cause the baby to have symptoms of the drug acting on its heart, blood vessels, and metabolism. These symptoms could include a slowed heart rate and low blood sugar. Not all babies exposed to propranolol will have these symptoms. It is important that your healthcare providers know you are taking propranolol so that if symptoms occur your baby can get the care that is best for them.
◈ Does taking propranolol in pregnancy affect future behavior or learning for the child?
Studies have not been done to see if propranolol can cause behavior or learning issues for the child.
◈ Breastfeeding while taking propranolol:
Propranolol passes into breastmilk in small amounts. Studies on propranolol have not found adverse health reactions in infants fed breastmilk from someone exposed to propranolol. If you suspect that the baby has symptoms such as being too sleepy or having trouble with feeding, contact the child’s healthcare provider. Be sure to talk to your healthcare provider about all your breastfeeding questions.
◈ If a male takes propranolol, could it affect fertility or increase the chance of birth defects?
Propranolol may cause some males to develop erectile dysfunction (ED), which could make it harder to conceive a pregnancy. In general, exposures that fathers or sperm donors have are unlikely to increase the risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.

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Protein Binding
Approximately 90% of propranolol is protein bound in plasma. Other studies have reported ranges of 85-96%.

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4946 women TDLo oral 3200 ug/kg/2D- ENDOCRINE: HYPOGLYCEMIA Israel Journal of Medical Sciences., 18(725), 1982 [PMID:7107213]
4946 human TDLo oral 2300 ug/kg/D BEHAVIORAL: HALLUCINATIONS, DISTORTED PERCEPTIONS British Medical Journal., 1(1182), 1978 [PMID:638680]
4946 child LDLo oral 800 ug/kg/12H CARDIAC: PULSE RATE INCREASE WITHOUT FALL IN BP; VASCULAR: BP LOWERING NOT CHARACTERIZED IN AUTONOMIC SECTION; LUNGS, THORAX, OR RESPIRATION: ACUTE PULMONARY EDEMA British Medical Journal., 2(254), 1978
4946 child TDLo oral 400 mg/kg BEHAVIORAL: CONVULSIONS OR EFFECT ON SEIZURE THRESHOLD; CARDIAC: ARRHYTHMIAS (INCLUDING CHANGES IN CONDUCTION) Medical Journal of Australia., 1(82), 1981 [PMID:7231257]
4946 man TDLo oral 8343 mg/kg/4Y- ENDOCRINE: EVIDENCE OF THYROID HYPERFUNCTION Archives of Internal Medicine., 143(2193), 1983 [PMID:6639243]

[1]. Distinct signaling profiles of beta1 and beta2 adrenergic receptor ligands toward adenylyl cyclase and mitogen-activated protein kinase reveals the pluridimensionality of efficacy. Mol Pharmacol. 2006 Nov;70(5):1575-84.

[2]. Evidence against beta-adrenoceptor blocking activity of diltiazem, a drug with calcium antagonist properties. Br J Pharmacol. 1980 Aug;69(4):669-73.

[3]. Propranolol. Profiles Drug Subst Excip Relat Methodol. 2017;42:287-338.

[4]. Propranolol Targets Hemangioma Stem Cells via cAMP and Mitogen-Activated Protein Kinase Regulation. Stem Cells Transl Med. 2016 Jan;5(1):45-55.

Propranolol is a propanolamine that is propan-2-ol substituted by a propan-2-ylamino group at position 1 and a naphthalen-1-yloxy group at position 3. It has a role as a beta-adrenergic antagonist, an anxiolytic drug, an anti-arrhythmia drug, a vasodilator agent, an antihypertensive agent, a xenobiotic, an environmental contaminant and a human blood serum metabolite. It is a secondary amine, a propanolamine and a member of naphthalenes. It is functionally related to a 1-naphthol.
Propranolol is a racemic mixture of 2 enantiomers where the S(-)-enantiomer has approximately 100 times the binding affinity for beta adrenergic receptors. Propranolol is used to treat a number of conditions but most commonly is used for hypertension. Propranolol was granted FDA approval on 13 November 1967.
Propranolol is a beta-Adrenergic Blocker. The mechanism of action of propranolol is as an Adrenergic beta-Antagonist.
Propranolol is a nonselective beta-adrenergic receptor blocker (beta-blocker) that is widely used for the therapy of hypertension, cardiac arrhythmias, angina pectoris and hyperthyroidism. Propranolol has yet to be convincingly associated with clinically apparent liver injury and is often used in patients with liver disease and cirrhosis.
Propranolol has been reported in Asimina triloba with data available.
Propranolol is a synthetic, nonselective beta-adrenergic receptor blocker with antianginal, antiarrhythmic, antihypertensive properties. Propranolol competitively antagonizes beta-adrenergic receptors, thereby causing negative chronotropic and inotropic effects leading to a reduction in cardiac output.
A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for MYOCARDIAL INFARCTION; ARRHYTHMIA; ANGINA PECTORIS; HYPERTENSION; HYPERTHYROIDISM; MIGRAINE; PHEOCHROMOCYTOMA; and ANXIETY but adverse effects instigate replacement by newer drugs.
See also: Propranolol Hydrochloride (has salt form).

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Drug Indication
Propranolol is indicated to treat hypertension. Propranolol is also indicated to treat angina pectoris due to coronary atherosclerosis, atrial fibrillation, myocardial infarction, migraine, essential tremor, hypertrophic subaortic stenosis, pheochromocytoma, and proliferating infantile hemangioma.
FDA Label
Hemangiol is indicated in the treatment of proliferating infantile haemangioma requiring systemic therapy: , , , Life- or function-threatening haemangioma,, Ulcerated haemangioma with pain and/or lack of response to simple wound care measures,, Haemangioma with a risk of permanent scars or disfigurement. , , , It is to be initiated in infants aged 5 weeks to 5 months. ,

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Mechanism of Action
Propranolol is a nonselective β-adrenergic receptor antagonist. Blocking of these receptors leads to vasoconstriction, inhibition of angiogenic factors like vascular endothelial growth factor (VEGF) and basic growth factor of fibroblasts (bFGF), induction of apoptosis of endothelial cells, as well as down regulation of the renin-angiotensin-aldosterone system.

C16H21NO2

259.3434445858

259.157

C, 74.10; H, 8.16; N, 5.40; O, 12.34

525-66-6

Propranolol hydrochloride;318-98-9;Propranolol-d7;98897-23-5; 525-66-6

4946

White to off-white solid powder

1.093 g/cm3

434.9ºC at 760 mmHg

163-164ºC

216.8ºC

1.5500 (estimate)

2.968

2

3

6

19

257

0

CC(C)NCC(COC1=CC=CC2=CC=CC=C21)O

AQHHHDLHHXJYJD-UHFFFAOYSA-N

InChI=1S/C16H21NO2/c1-12(2)17-10-14(18)11-19-16-9-5-7-13-6-3-4-8-15(13)16/h3-9,12,14,17-18H,10-11H2,1-2H3

1-naphthalen-1-yloxy-3-(propan-2-ylamino)propan-2-ol

propranolol; 525-66-6; Propanolol; beta-Propranolol; Betalong; Euprovasin; Proprasylyt; Reducor;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~100 mg/mL (~385.59 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (9.64 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (9.64 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (9.64 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)