The oestrogenic activity of white clover (<i>Trifolium repens</i>L.)

Wong, E.; Flux, D. S.; Latch, G. C. M.

doi:10.1080/00288233.1971.10421658

Cited by 16 publications

(14 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The level of coumestan (25 ppm) in the diet significantly depressing ovulation rate is lower than any previously reported effects. This suggests that the effective level of coumestan in the diet may be much lower than that previously expected (Wong et at, 1971). In Trials 1 and 2 of this report and in most other publications, however, the levels referred to were for leaf material only.…”

Section: Discussioncontrasting

confidence: 48%

Coumestans in lucerne and ovulation in ewes

Smith¹,

Jagusch²,

Brunswick³

et al. 1979

New Zealand Journal of Agricultural Research

View full text Add to dashboard Cite

Four trials with a total of 1750 Perendale ewes were conducted to determine the effect of feeding lucerne on ovulation rate and lambing performance. Levels of up to 600 ppm coumestans in lucerne leaf, associated with fungal infection, depressed ovnlation rate and lambing by 34% and 14.6% respectively. In the absence of fungal infestation no coumestans were found and stage of regrowth had 110 effect on lambing performance. A negative linear relationship between coumestan ccntent of the diet (x) and ovulation rate (y) was determined (y = 1.382 -O.004x). Levels of coumestans as low as 25 ppm in the diet depressed the ovulation rate of ewes fed lucerne pellets for 35 days. The depression in ovulation rate of ewes fed a high (100 ppm) level of coumestans was overcome by treatment with pregnant mare's serum gonadotrophin. It is suggested that coumestans exert their effect by interference with the release of follicle stimulating hormone from the pituitary gland.

show abstract

Section: Discussioncontrasting

confidence: 48%

Coumestans in lucerne and ovulation in ewes

Smith¹,

Jagusch²,

Brunswick³

et al. 1979

New Zealand Journal of Agricultural Research

View full text Add to dashboard Cite

show abstract

“…Pasture containing~1000 mg/kg will inhibit oestrus and ovulation [24] but pasture containing 200-400 mg/kg will only depress ovulation [27]. Smith et al (1980) [140] reported that a coumestrol concentration of 25 mg/kg DM was sufficient to suppress the ovulation rate of ewes, a claim supported by earlier work [22,141].…”

Section: Tolerance Levelssupporting

confidence: 56%

“…With white clover, coumestrol can increase in autumn without obvious disease signs [5] but infection by foliar pathogens increases the concentration of coumestans [21] and increases the plant's oestrogenic activity in mice, rat and sheep [5,22]. Similar effects occur with lucerne.…”

Section: Coumestrol Production Stimulimentioning

confidence: 67%

“…), peas (Pisum sativum), soybean, limabeans (Phaseolus lunatus), pinto beans (P. vulgaris), and some clovers (e.g., white clover [5,19,20] and strawberry clover (T. fragiferum) [6]). The relative abundance of particular coumestans and flavones that white clover produces in the field varies considerably depending on which plant pathogen stimulates their production [21,22]. The coumestrol content in white clover was considered insufficient to explain the oestrogenic activity it was responsible for [5,20] 4'-methoxy-coumestrol is considered the second most important coumestan for oestrogenic activity.…”

Section: Phytoestrogenic Compoundsmentioning

confidence: 99%

See 1 more Smart Citation

Fertility of Herbivores Consuming Phytoestrogen-containing Medicago and Trifolium Species

Reed¹

2016

Agriculture

View full text Add to dashboard Cite

Despite their unrivalled value in livestock systems, certain temperate, pasture, legume species and varieties may contain phytoestrogens which can lower flock/herd fertility. Such compounds, whose chemical structure and biological activity resembles that of estradiol-17α, include the isoflavones that have caused devastating effects (some of them permanent) on the fertility of many Australian sheep flocks. While the persistence of old 'oestrogenic' ecotypes of subterranean clover (Trifolium subterraneum) in pasture remains a risk, genetic improvement has been most effective in lowering isoflavone production in Trifolium species; infertility due to 'clover disease' has been greatly reduced. Coumestans, which can be produced in Medicago species responding to stress, remain a potential risk in cultivars susceptible to, for example, foliar diseases. In the field, coumestrol is often not detected in healthy vegetative Medicago species. Wide variation in its concentration is influenced by environmental factors and stage of growth. Biotic stress is the most studied environmental factor and, in lucerne/alfalfa (Medicago sativa), it is the major determinant of oestrogenicity. Concentrations up to 90 mg coumestrol/kg (all concentrations expressed as DM) have been recorded for lucerne damaged by aphids and up to 600 mg/kg for lucerne stressed by foliar disease(s). Other significant coumestans, e.g., 4'-methoxy-coumestrol, are usually present at the same time. Concentrations exceeding 2000 mg coumestrol/kg have been recorded in diseased, annual species of Medicago. Oestrogenicity of some Medicago species is also influenced by maturity and senescence. Studies in Israel, North America, Europe, New Zealand and Australia have confirmed that coumestans in lucerne, represent an acute or sub-acute loss of reproductive efficiency in herbivores, e.g., sheep, cattle, and possibly horses. When sufficiently exposed peri-conception, coumestrol, sometimes present in lucerne, be it as pasture, hay, silage, pellets, meal, and sprouts, is associated with what can be an insidious, asymptomatic, infertility syndrome. Most livestock research with oestrogenic lucerne has been conducted with sheep. Ewes may be at risk when the coumestrol concentration in their diet exceeds 25 mg/kg. In studies where lambing was compared for lucerne and a phytoestrogen-free treatment, the mean decrease in lambs born/ewe was 13%; ewes on lucerne, exhibited a lower frequency of multiple births.

show abstract

“…9-Omethylcoumestrol and trifoliol are relatively inactive in mice. The potency of diseased white clover in sheep ) and mice Wong et al, 1971) has shown a relationship to coumestan levels, while no similar relationship was found for coumestrol in grazing sheep (Bennet et al, 1967).…”

Section: Biological Effects Of Coumestansmentioning

confidence: 98%

Biologically active secondary metabolites in white clover (Trifolium repens L.) – a review focusing on contents in the plant, plant–pest interactions and transformation

Carlsen

Fomsgaard

2008

Chemoecology

View full text Add to dashboard Cite

To exploit biologically active compounds from white clover (Trifolium repens L.) for suppressing weeds and soil-borne diseases, either as isolated products (biopesticides) or through cultivars with enhanced production of these compounds, the biologically active compounds must be identified, plant content measured, and their fate in soil known. The present review summarizes the published knowledge needed for such exploitation; providing essential information on structure and concentration of flavonols, flavones, condensed tannins, isoflavones, isoflavanones, pterocarpans, coumestans, cyanogenic glucosides, and saponins in healthy and stressed white clover plants. Various stresses and particular cultivars affect the concentrations of several of the compounds. Information on biological effects and the degradation/transformation of these compounds in plants or by microorganisms is available. There is no information on the degradation pathway in soil, the mechanisms of exudation and leaching of compounds from plants, and soil sorption properties of the compounds. The clover soil fatigue problem is increasing in grasslands and causes problems especially in organic farming. Research efforts focused on biological elements of clover soil fatigue have not explained it, and the influence of secondary metabolites has not been investigated. There are few investigations into the interaction between beneficial fungi/fungal-diseases and the occurrence of biologically active secondary metabolites in white clover plants. Such studies are critical to better understand beneficial fungi and pathogens.

show abstract

The oestrogenic activity of white clover (Trifolium repensL.)

Abstract: Oestrogenic activity in samples of diseased white clover has been demonstrated in mice and sheep. Relative potencies were found to parallel, in general, concentrations of coumestan compounds.

Cited by 16 publications

References 12 publications

Coumestans in lucerne and ovulation in ewes

Coumestans in lucerne and ovulation in ewes

Fertility of Herbivores Consuming Phytoestrogen-containing Medicago and Trifolium Species

Biologically active secondary metabolites in white clover (Trifolium repens L.) – a review focusing on contents in the plant, plant–pest interactions and transformation

Contact Info

Product

Resources

About