Scopolamine hydrobromide

Scopolamine hydrobromide is a high affinity (nM) muscarinic antagonist. 5-HT3 receptor-responses are reversibly inhibited by Scopolamine with an IC50 of 2.09 μM.

Signaling Pathways >> GPCR/G Protein >> 5-HT Receptor

Signaling Pathways >> Neuronal Signaling >> 5-HT Receptor

Signaling Pathways >> GPCR/G Protein >> mAChR

Signaling Pathways >> Neuronal Signaling >> mAChR

Natural Products >> Alkaloid

Research Areas >> Neurological Disease

5-HT3 Receptor:2.09 μM (IC50)

mAChR

Application of Scopolamine to oocytes expressing 5-HT3 receptors does not elicit a response when applied alone, but causes a concentration-dependent inhibition of the response during a co-application of 2 μM 5-HT. The pIC50 value for Scopolamine is 5.68±0.05 (IC50=2.09 μM, n=6) with a Hill Slope of 1.06 ± 0.05. This gave a Kb of 3.23 μM. The same concentration-dependent effect is also seen when Scopolamine is applied during the 5-HT application. To further test for a competitive binding at the 5-HT3 receptor, the competition of unlabelled Scopolamine is measured with [3H]granisetron, an established high-affinity competitive antagonist at these receptors. Scopolamine displays concentration-dependent competition with 0.6 nM [3H]granisetron (~Kd), yielding an average pKi of 5.17±0.24 (Ki=6.76 μM, n=3)[1].

In the histopathology study, there is no significant change in the histology of the brain. However, it is observed that there is a reduction in density of cells in the hippocampus of the control mice pretreated with Scopolamine who received only distilled water[2]. Scopolamine administration alone significantly increases the activity of Acetylcholinesterase enzyme (AchE) (7.98±0.065; P<0.001) when compared to the normal group (3.06±0.296). The animals treated with Scopolamine report a significant increase (34.61±4.85; P<0.01) in levels of malondialdehyde (MDA) as compared to the normal group (12.82±2.86). The Scopolamine-treated group shows significant decrease in reduced glutathione (GSH) level (P<0.001; 0.1504±0.03) as compared to the normal group (0.3906±0.02). The Scopolamine-treated rats show a significant increase in the concentration ofβ amyloid (Aβ1-42) (P<0.001; 146.2±1.74) as compared to the normal group (43.21±3.46)[3].

Saturation binding (8 point) curves are measured by incubating either crude extracts of HEK 293 cells stably expressing 5-HT3 receptors, or Guinea pig membrane preparations, in 0.5 mL incubations containing 10 mM HEPES buffer (pH 7.4) and 0.1-1 nM [3H]granisetron or 1-10 nM [3H]N-methylScopolamine. Competition binding (10 point) is determined by incubating the same receptors preparations in 0.5 mL HEPES buffer containing either 0.6 nM [3H]granisetron or 0.6 nM [3H]N-methylScopolamine, and differing concentrations of competing ligands. Non-specific binding is determined with 1 mM quipazine or 10 μM Scopolamine respectively. Incubations are terminated by filtration onto Whatman GF/B filters wetted with HEPES buffer+0.3% polyethyleneimine, followed by two rapid washes with ice-cold HEPES buffer. Protein concentration is calculated using a Lowry protein assay with bovine serum albumin standards. Radioactivity is measured using a Tri-Carb 2100 TR scintillation counter[1].

Mice[2] The mice are weighed, labeled and grouped into seven groups of 5 animals each after which all animals are pre-injected intraperitoneally with 3 mg/kg Scopolamine. Groups 1-3 are administered 0.2 mL equivalent doses of 4 mg/kg, 6 mg/kg and 8 mg/kg of the extract of Morinda lucida while groups 4-6 are given same doses of Peltophorum pterocarpum extract and group 7 is given 0.2 mL of distilled water (negative control) for 3 consecutive days. Rats[3] Healthy male Wistar rats (12 months old) weighing 180–200 g are used in this study. Rats are divided into five groups (n=6/group); Group I-normal control, Group II-disease control (Scopolamine hydrobromide 3 mg/kg, i.p.), Group III-Scopolamine+Quercetin (25 mg/kg, p.o.), Group IV-standard treatment (Scopolamine+Donepezil hydrochloride 3 mg/kg, p.o.), and Group V-Scopolamine+Quercetin (25 mg/kg, p.o.)+Donepezil (3 mg/kg, p.o.). Group III, IV, and V rats are dosed every 24 h interval with respective drugs for 14 consecutive days. The acquisition trail for Morris water maze, elevated plus maze, and passive avoidance paradigm is carried out on the 14th day, and Scopolamine (3 mg/kg, i.p.) is administered on the 14th day after the acquisition trail to all groups except normal control group, which provoke the cognitive impairment in rats. Retention of memory is tested on the 15th day, and on the same day, rats are sacrificed and brain tissues are isolated to estimate acetylcholinesterase enzyme (AchE) and brain oxidative stress markers such as lipid peroxidase (LPO), glutathione (GSH) (reduced). ELISA kit is used to estimate β amyloid (Aβ1-42) level. The hippocampus of rat brains is dissected out and studied for histopathological changes.

[1]. Lochner M, et al. The muscarinic antagonists Scopolamine and atropine are competitive antagonists at 5-HT3 receptors. Neuropharmacology. 2016 Sep;108:220-8.

[2]. O ET, et al. COGNITIVE-ENHANCING PROPERTIES OF MORINDA LUCIDA (RUBIACEAE) AND PELTOPHORUM PTEROCARPUM (FABACEAE) IN SCOPOLAMINE-INDUCED AMNESIC MICE. Afr J Tradit Complement Altern Med. 2017 Mar 1;14(3):136-141.

[3]. Pattanashetti LA, et al. Evaluation of neuroprotective effect of Quercetin with Donepezil in Scopolamine-induced amnesia in rats. Indian J Pharmacol. 2017 Jan-Feb;49(1):60-64.

Harmine | Pimavanserin | Carbachol | Serotonin hydrochloride | Sodium Ferulate | Thioridazine hydrochloride | Brexpiprazole | Darifenacin HBr | Risperidone | TG6-10-1 | Cariprazine | Quetiapine | SERTINDOLE | Arecoline hydrobromide | Alprenolol hydrochloride

MOLECULAR FORMULA :

C17-H21-N-O4.Br-H

MOLECULAR WEIGHT :

384.31

WISWESSER LINE NOTATION :

T C356 A AN DOTJ A1 HOVYR&1Q &EH

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

1270 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

3800 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraduodenal

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

670 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

1880 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

650 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

CLDND* Compilation of LD50 Values of New Drugs. (J.R. MacDougal, Dept. of National Health and Welfare, Food and Drug Divisions, 35 John St., Ottawa, Ont., Canada)

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

1650 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

203 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

TYPE OF TEST :

LDLo - Lowest published lethal dose

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Mammal - cat

DOSE/DURATION :

80 mg/kg

TOXIC EFFECTS :

Cardiac - other changes Vascular - BP lowering not characterized in autonomic section Lungs, Thorax, or Respiration - other changes

TYPE OF TEST :

LDLo - Lowest published lethal dose

ROUTE OF EXPOSURE :

Intravenous

SPECIES OBSERVED :

Rodent - rabbit

DOSE/DURATION :

100 mg/kg

TOXIC EFFECTS :

Behavioral - general anesthetic Behavioral - convulsions or effect on seizure threshold

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Subcutaneous

SPECIES OBSERVED :

Rodent - guinea pig

DOSE/DURATION :

850 mg/kg

TOXIC EFFECTS :

Autonomic Nervous System - parasympatholytic

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Unreported

SPECIES OBSERVED :

Rodent - rat

DOSE/DURATION :

975 mg/kg/13W-I

TOXIC EFFECTS :

Blood - changes in leukocyte (WBC) count Nutritional and Gross Metabolic - weight loss or decreased weight gain

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Unreported

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

975 mg/kg/13W-I

TOXIC EFFECTS :

Blood - changes in leukocyte (WBC) count Nutritional and Gross Metabolic - weight loss or decreased weight gain

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Intraperitoneal

DOSE :

300 ug/kg

SEX/DURATION :

male 1 day(s) pre-mating

TOXIC EFFECTS :

Reproductive - Fertility - mating performance (e.g. # sperm positive females per # females mated; # copulations per # estrus cycles)

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Subcutaneous

DOSE :

500 ug/kg

SEX/DURATION :

male 1 day(s) pre-mating

TOXIC EFFECTS :

Reproductive - Fertility - mating performance (e.g. # sperm positive females per # females mated; # copulations per # estrus cycles)

TYPE OF TEST :

TDLo - Lowest published toxic dose

ROUTE OF EXPOSURE :

Oral

DOSE :

2365 mg/kg

SEX/DURATION :

female 10-14 day(s) after conception

TOXIC EFFECTS :

Reproductive - Specific Developmental Abnormalities - Central Nervous System Reproductive - Specific Developmental Abnormalities - eye/ear

MUTATION DATA

TYPE OF TEST :

Cytogenetic analysis

TEST SYSTEM :

Human HeLa cell

DOSE/DURATION :

1 pph/5H

REFERENCE :

HUMAA7 Humangenetik. (Heidelberg, Fed. Rep. Ger.) V.1-30, 1964-75. For publisher information, see HUGEDQ. Volume(issue)/page/year: 4,371,1967 *** NIOSH STANDARDS DEVELOPMENT AND SURVEILLANCE DATA *** NIOSH OCCUPATIONAL EXPOSURE SURVEY DATA : NOHS - National Occupational Hazard Survey (1974) NOHS Hazard Code - 80511 No. of Facilities: 1011 (estimated) No. of Industries: 3 No. of Occupations: 11 No. of Employees: 7730 (estimated) NOES - National Occupational Exposure Survey (1983) NOES Hazard Code - 80511 No. of Facilities: 462 (estimated) No. of Industries: 1 No. of Occupations: 5 No. of Employees: 19132 (estimated) No. of Female Employees: 16485 (estimated)