Diosmin

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1957

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Unnamed

Year:

1957

Report date:

1957

Reference 2

Reference Type:

review article or handbook

Title:

Absorption, metabolism, and bioavailability of flavonoids

Author:

Hollman PCH, Katan MB

Year:

1998

Bibliographic source:

Flavonoids in Health and Disease (Rice-Evans CA and Paker L eds) pp 483–522, Marcel Dekker, Inc., New York

Materials and methods

Objective of study:

toxicokinetics

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Method described previously by Booth [Booth AN, Murray CW, Jones FT, DeEds F, 1956. J. Biol. Chem., 223: 251, see 'attached background material']: Breakdown products were identified after diosmin was ingested by rats, using ascending two-dimensional paper chromatograms of the ether extracts of acid urines which were developed with bottom phase of a mixture of chloroform, acetic acid, and water (2:1L1) in the first direction, followed by 20 per cent aqueous potassium chloride in the second direction.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Diosmin

EC Number:

208-289-7

EC Name:

Diosmin

Cas Number:

520-27-4

Molecular formula:

C28H32O15

IUPAC Name:

diosmin

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: obtained from Dr. R.M. Horowitz, Pasadena Laboratory, Agricultural Research Service. Obtained by isolation from lemon peel. Before use, these compounds were again crystallized, if necessary, until found to be chromatographically homogeneous in the two-dimensional TLC system used.

Radiolabelling:

no

Test animals

Species:

rat

Strain:

not specified

Sex:

not specified

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Diet: purified diet consisting of starch, Cerelose, casein, Cellu flour, salts’ (including potassium acetate and magnesium oxide), oil, and vitamins.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on exposure:

DIET PREPARATION
Administration by stomach tube of 400 mg of diosmin per rat on a purified diet.

Duration and frequency of treatment / exposure:

Single dose administration.

Doses / concentrations

Dose / conc.:

400 other: mg/rat

Remarks:

approximately 1200 mg/kg bw (estimated).

No. of animals per sex per dose / concentration:

no data.

Control animals:

no

Details on dosing and sampling:

PHARMACOKINETIC STUDY (excretion)
- Tissues and body fluids sampled: urine.
- Time and frequency of sampling: urine samples were collected at 0 to 7, 7 to 21, 21 to 31, and 31 to 45 hour intervals.
- Analysis: use of ascending two-dimensional paper chromatograms of the ether extracts of acid urines which were developed with the bottom phase of a mixture of chloroform, acetic acid, and water (2: 1: 1) in the first direction, followed by 20 per cent aqueous potassium chloride in the second direction.

METABOLITE CHARACTERISATION STUDIES
- Tissues and body fluids sampled: urine.
- Time and frequency of sampling: urine samples were collected at 0 to 7, 7 to 21, 21 to 31, and 31 to 45 hour intervals.
- Method type(s) for identification: TLC.

TREATMENT FOR CLEAVAGE OF CONJUGATES: systematic screening of the ether extracts of urine for conjugates of phenolic acids involved hydrolysis with 20 per cent HCl (usually for 2 hours under a reflux), followed by ether extraction of the hydrolysate and migration in the two-dimensional paper chromatographic system. After the air-dried chromatogram was first examined and all fluorescent and absorbing areas visibleunder ultraviolet light were marked, it was sprayed with diazotized sulfanilic acid to form dyes with the phenolic compounds. A direct comparison could then be made between the chromatograms before and after hydrolysis for the appearance of new areas and the disappearance of other areas. The hydrolysis procedure was also applied to specific areas cut out of unsprayed chromatograms of ether extracts of urine, in which case the phenolic acid or flavonoid released could be specifically associated with the suspected conjugate.

Results and discussion

Main ADME results

Type:

metabolism

Results:

major metabolite: m-hydroxyphenylpropionic acid; traces of m-coumaric acid and diosmetin.

Toxicokinetic / pharmacokinetic studies

Details on absorption:

Diosmin can be absorbed in the gastrointestinal tract.

Metabolite characterisation studies

Metabolites identified:

yes

Details on metabolites:

The major metabolite was m-hydroxyphenylpropionic acid (m-HPPA), and only traces of m-coumaric acid and diosmetin were found on the chromatogram.

Applicant's summary and conclusion

Conclusions:

Under test conditions, the test substance can be absorbed in the gastrointestinal tract, and the compounds excreted through urine as m-hydroxyphenylpropionic acid, along with traces of m-coumaric acid and diosmetin.

Executive summary:

The metabolic fate of six flavonoids (hesperidin, hesperetin, diosmin, diosmetin, eriodictyol, and homoeriodictyol) has been studied after oral ingestion by rats, at a dose of 400 mg/rat (no guideline available, no GLP). Urine samples were collected at 0 to 7, 7 to 21, 21 to 31, and 31 to 45 hour intervals and examined by two-dimensional thin layer chromatography. Under test conditions, the test substance was absorbed in the gastrointestinal tract, and excreted through urine as m-hydroxyphenylpropionic acid, along with traces of m-coumaric acid and diosmetin.