L-Arginine, N2-(2,3-dihydroxypropyl)-, monohydrochloride

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January 1973

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Remarks:

Non-guideline study although well conducted

Data source

Reference

Reference Type:

publication

Title:

Effect of Selected Amino Acids on Toxicity of Ethanol in Rats

Author:

Breglia, R., Ward, C., Jarowski, C

Year:

1973

Bibliographic source:

Journal of Pharmaceutical Sciences, 62(1), 49-55

Materials and methods

Principles of method if other than guideline:

Laboratory scientific investigation

GLP compliance:

no

Remarks:

The study was performed before the implementation of GLP

Test type:

other: Did not follow standard acute toxicity guidelines.

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

(+)-L-arginine hydrochloride

EC Number:

214-275-1

EC Name:

(+)-L-arginine hydrochloride

Cas Number:

1119-34-2

IUPAC Name:

(+)- L-arginine hydrochloride

Test material form:

not specified

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL

- Source and lot/batch No.of test material: Sigma Chemical Co. St. Louis, Mo.
- Expiration date of the lot/batch: Not reported

- Purity test date: Not reported


RADIOLABELLING INFORMATION (if applicable): n/a
- Radiochemical purity: n/a
- Specific activity: n/a
- Locations of the label: n/a
- Expiration date of radiochemical substance: n/a

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL: Not reported
- Storage condition of test material:
- Stability under test conditions:
- Solubility and stability of the test substance in the solvent/vehicle:
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: Diluted in water 6ml
- Preliminary purification step (if any): Not Reported
- Final dilution of a dissolved solid, stock liquid or gel: 140 mg/kg and 2880 mg/kg
- Final preparation of a solid: N/a

FORM AS APPLIED IN THE TEST (if different from that of starting material): n/a

OTHER SPECIFICS: No

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Not specified
- Females (if applicable) nulliparous and non-pregnant:Not specified
- Microbiological status of animals, when known: the animals were inspected for disease and diseased animals were discarded.
- Age at study initiation: 8 weeks
- Weight at study initiation: 125 to 150g
- Housing: Not reported
- Diet (e.g. ad libitum): Standard laboratory diet
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: At least 7 days
- Indication of any skin lesions: Not reported

ENVIRONMENTAL CONDITIONS: Not reported
- Temperature
- Humidity
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light):
- IN-LIFE DATES:

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 10 & 20% (w/v)
 - Amount of vehicle (if gavage): 1.3 ml/kg
 - Justification for choice of vehicle: Not reported
 - Lot/batch no. (if required): Not reported
 - Purity: Not reported
 
 MAXIMUM DOSE VOLUME APPLIED: The dosages of the amino acids employed were 140 mg./kg. and 2.88 g./kg. Dose levels are equimolar to the low and high dose levels of L- lysine to which they correspond. The dose of 120 mg./kg. of L- lysine was equal to two times the minimum daily requirement for the adult rat; the dose of 2.5 g./kg. was recommended by results from previous work.

 DOSAGE PREPARATION (if unusual): N/A
 
 CLASS METHOD (if applicable): N/A
 - Rationale for the selection of the starting dose:

Doses:

140 mg/kg and 2,880 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Remarks:

Ethanol alone

Details on study design:

- Duration of observation period following administration: 14 days (or other?): 72- hours
- Frequency of observations and weighing: 30 mins and an hour
- Necropsy of survivors performed: Not stated
- Other examinations performed: clinical signs, body weight,organ weights, histopathology: Not stated
- Other: Not stated

Statistics:

The statistical analysis (Student’s t-test) of intoxication was based on the following neurological parameters:
Ataxia - This was defined as the inability to maintain position by using four-leg motor coordination for one revolution of the modified “rotarod.” Each animal was subjected to this test individually throughout the experimental period, unless unconscious. A normal rat can maintain its equilibrium for an indefinite period, and a short training period of three to four trials was added to ensure uniform response.

Sleep time - This was defined as the total elapsed time from the initial loss of righting reflex to its return without remission. The righting reflex was said to be lost when the animal was placed on its back and did not immediately right itself fully.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

2 880 mg/kg bw

Based on:

test mat.

Mortality:

No effect observed

Clinical signs:

other: No effect observed

Gross pathology:

No effect observed

Other findings:

No effect observed

Any other information on results incl. tables

Table 2. Effect of Simultaneous Administration of Amino Acid-Ethanol Solution on Acute Ethanol Toxicity

Drug treatment	Doses of amino acid mg/kg.	LD50 of Ethanol^ag/kg
L-Arginine hydrochloride	140	10.05 ± 1.32

a = Dead animals per group counted at 72 hr. after drug administration. No difference in mortality between males and females was noted.

 

Table 3.  Onset of Ataxia

Treatment	Doses of amino acid mg/kg.	Onset of Ataxia with Amino Acid Pre-treatment before Single-Dose Administration of Ethanol		Onset of Ataxia with Amino Acid Pre-treatment before Serial Administration of Ethanol		Onset of Ataxia with After Single-Dose Administration of Amino Acid-Ethanol		Onset of Ataxia with After Serial Administration of Amino Acid-Ethanol
		Mean Onset^aof Ataxia, min	pValue^b	Mean Onset^aof Ataxia, min	pValue^b	Mean Onset^aof Ataxia, min	pValue^b	Mean Onset^aof Ataxia, min	pValue^b
L-Arginine hydrochloride	140	8.32 ± 3.27	0.2	26.76 ± 1.70	0.001	23.16±7.60	0.02	52.63±7.21	0.001
L-Arginine hydrochloride	2,880	30.98 ± 5.29	0.0001	66.32 ± 9.46	0.001	-	-	-	-

a=Onset of ataxia values (min.) ±SE. b= p value < 0.05 was significant. - = Not investigated

 

 

Table 4. Effect of treatment on sleeping time

Amino acid	Dose mg/kg	Sleeping Time with Amino Acid Pre-treatment before Single-Dose Administration of Ethanol			Effect of Amino Acid Pre-treatment on Sleeping Times Produced by Serial Administration of Ethanol			Sleeping Time after Single-Dose Administration of Amino Acid-Ethanol Solution			Sleeping Time after Serial Administration of Amino Acid-Ethanol Solution
		Mean sleeping time^amin	PValue^b	Percentage of rat responding	Mean sleeping time^amin	PValue^b	Percentage of rat responding	Mean sleeping time^amin	PValue^b	Percentage of rat responding	Mean sleeping time^amin	PValue^b	Percentage of rat responding
L- Arginine hydrochloride	140	116.56±48.8	0.001	70	293.39±30.9	0.6	100	315.79±58.1	0.9	90	203.92±35.2	0.01	100
L- Arginine hydrochloride	2,880	224.10± 50.3	0.05	50	167.89± 51.6	0.01	80	-	-	-	-	-	-

a.Sleeping time values (min), ± SE, b = p value <0.05 was significant, - = not investigated

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

No mortality was reported in the study up to 2,880 mg/kg bw, the highest tested dose which is established as the LD50. Based on this information the substance does not meet the criteria for acute oral toxicity in accordance with Regulation (EC) No. 1272/2008 on the Classification, Labelling and Packaging of Substances and Mixtures.

Executive summary:

Breglia et al 1973: The amino acid solutions in distilled water (dosage of 10 and 20% (w/v)) were administered orally to rats at two dose levels of 140 mg/kg and 2.88 g./kg L-arginine hydrochloride.  The rats were subject to neurological tests for signs of pharmacological effects. Saline (volume) controls were used as the basis for comparison for amino acid treatment.

All rats treated with L-arginine hydrochloride were found to be without pharmacological effect at the doses employed for treatment. At the high dose, some signs of toxicity such as ataxia, dyspnea, decreased muscle tonus and loss of righting reflex.

The amino acid controls for each amino acid administered demonstrated that no acute toxicological effects in this experimentation were due to the administration of amino acids alone.

It can be concluded that the acute exposure to L-arginine hydrochloride does not pose any significant toxicity via acute oral toxicity and the LD50 is considered at 2,880 mg/kg bw/day.