Extract obtained from defatted powder of Theobroma cacao (Malvaceae) by extraction with water and ethanol

Toxicity to microorganisms

Administrative data

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptably documented study which meets basic scientific principles and contains sufficient basic detail to be able to judge the results reliable as a contribution to the understanding of the toxicity to micro-organisms of this substance.

Data source

Reference

Reference Type:

publication

Title:

Cytotoxicity of certain organic solvents and organophosphorus insecticides to the ciliated Protozoan Paramecium caudatum

Author:

Rajini, P.S., Krishnakumari, M.K., Majumder, S.K.

Year:

1989

Bibliographic source:

Microbios 59:157-163

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Assessment of the toxicity of a number of test substances, including organophosphorus pesticides and carrier solvents used to dissolve them, to a cilliated protozoa using a 10 minute and 4 hour exposure times.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Ethanol

EC Number:

200-578-6

EC Name:

Ethanol

Cas Number:

64-17-5

Molecular formula:

C2H6O

IUPAC Name:

ethanol

Details on test material:

- Analytical purity: commercial absolute alcohol
- Source: SISCO Research laboratories, India

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Paramaecium caudatum

Details on inoculum:

- Laboratory culture: stock culture maintained in split-pea medium.
- Method of cultivation: new cultures initiated by seeding 100ml of culture medium with 1ml of a stationary phase Paramecium culture containing 1000-2000 cells/ml. Maintained at 25C (+/-2C). loosely covered.
- Preparation of inoculum for exposure: Aliquots of culture drawn after 48hrs and cells resuspended in Chalkley's isotonic inorganic salt solution (Patterson, Feeding strategies in free living ciliated Protozoa - in - source book of experiments for the teaching of microbiology, ed Primrose & Warlaw, Academic Press) and concentrated by negative geotaxis.
- Pretreatment: none
- Initial biomass concentration: no data

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

4 h

Test conditions

Test temperature:

25 (+/-) 2C

Salinity:

not applicable

Details on test conditions:

TEST SYSTEM
- Test vessel: Petri dish
- Type (delete if not applicable): open / closed
- Material, size, headspace, fill volume: 10ml Chalkley's solution
- No. of organisms per vessel: 50 for LC10 test, 10 for LC50 test.
- No. of vessels per concentration (replicates): 5

TEST MEDIUM / WATER PARAMETERS
- no data

OTHER TEST CONDITIONS
- no data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : death (cessation of swimming or cell rupture)

TEST CONCENTRATIONS
- Test concentrations: 5 for LC100 test (not specified). Number of concentrations for 4hr LC50 evaluation: 0.1, 0.2, 0.4, 0.8, 1.2, 2 % v/v (790 to 15,800 mg/l) .

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

10 min

Dose descriptor:

EC100

Effect conc.:

39.5 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: mortality

Remarks on result:

other: EC100 effectively the same as LC100

Effect concentrations 2

Duration:

4 h

Dose descriptor:

EC50

Effect conc.:

5.8 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: mortality

Remarks on result:

other: EC50 effectively the same as LC50

Details on results:

Published 10 minute EC100 was 5% (v/v) and the EC50 (4 hour) 0.74% (v/v). Equivalent g/l figures shown above.

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

This toxicity study is classified as acceptable and satisfies the requirements as a supporting study for the invertebrate toxicity end point

Executive summary:

In a reliable test on micro-organisms, the cilliated protozoa Paramecium caudatum was exposed to ethanol at concentrations up to 40g/l in order to obtain a 10 minute LC100 and a 4 hour LC50. The values obtained based on an end point of mortality were 39.5 and 5.8g/l respectively. This toxicity study is classified as acceptable and satisfies the requirements as a supporting study for the miro-organism toxicity end point.

Synopsis

LC50 (4hr) = 5800mg/l