Two new flavonoid thioglucosides from the seeds of Lepidium apetalum.

Two previously undescribed flavonoid thioglucosides lepidiumflavonosides A and B (1-2) and two known megastigmane compounds (7E,9S)-9-hydroxy-5,7-megastigmadien-4-one 9-O-ß-D-glucopyranoside (3) and (9S)-4-oxo-ß-inol ß-D-glucopyranoside (4) were isolated from the water extract of the seeds of Lepidium apetalum Willd. The structural elucidation of isolated compounds was unambiguously determined based on extensive 1D and 2D NMR spectroscopic analyses. All compounds were evaluated for their estrogen-like effects on MCF-7 cells in vitro. The results showed that compounds 1-4 significantly promoted the proliferation of MCF-7 cells, and the proliferation was antagonized by the specific ER antagonist ICI182,780, suggesting that compounds 1-4 might have the estrogen-like effect in vitro potentially.

Tropaeolum tuberosum (Mashua) reduces testicular function: effect of different treatment times.

Tropaeolum tuberosum Ruiz & Pavon, along with other several species, is an edible-tuber crop that grows in the Andean region. Folk medicine describes the use of mashua to reduce reproductive function in men. The present study aimed to evaluate the effect of mashua (1 g kg(-1)) on sperm production in rats during 7, 12, 21 and 42 days of treatment. The following parameters were assessed: reproductive organ weights, spermatid count and daily sperm production (DSP), sperm count in epididymis and sperm transit and serum testosterone levels. Freeze-dried extract of mashua had 3.7 g 100 g(-1) of benzyl glucosinolate. Mashua-treated rats showed a reduction in testicular spermatid number and DSP from day 12 to day 42; meanwhile, the effect of mashua was noted in epididymal sperm count after 12 and 42 days of treatment. In addition, epididymal sperm transit time was delayed at day 7 and it was accelerated on days 12 and 21 of treatment. No differences in serum testosterone levels were found between rats treated with vehicle and mashua after 42 days of treatment. Finally, mashua reduces testicular function after one spermatogenic cycle by reducing spermatid and sperm number, DSP and epididymal sperm transit time.

Benzylglucosinolate, benzylisothiocyanate, and myrosinase activity in papaya fruit during development and ripening.

Papaya is a climacteric fruit that has high amounts of benzylglucosinolates (BG) and benzylisothiocyanates (BITC), but information regarding levels of BG or BITC during fruit development and ripening is limited. Because BG and BITC are compounds of importance from both a nutritional and a crop yield standpoint, the aim of this work was to access data on the distribution and changes of BG and BITC levels during fruit development and ripening. BG and BITC levels were quantified in peel, pulp, and seeds of papaya fruit. Volatile BITC was also verified in the internal cavity of the fruit during ripening. The influence of the ethylene in BG and BITC levels and mirosinase activity was tested by exposing mature green fruits to ethylene and 1-methylcyclopropene (1-MCP). The highest BG levels were detected in seeds, followed by the peel and pulp being decreased in all tissues during fruit development. Similarly, the levels of BITC were much higher in the seeds than the peel and pulp. The levels of BG for control and ethylene-treated fruit were very similar, increasing in the pulp and peel during late ripening but not changing significantly in seeds. On the other hand, fruit exposed to 1-MCP showed a decrease in BG amount in the pulp and accumulation in seed. The treatments did not result in clear differences regarding the amount of BITC in the pulp and peel of the fruit. According to the results, ethylene does not have a clear effect on BITC accumulation in ripening papaya fruit. The fact that BG levels in the pulp did not decrease during ripening, regardless of the treatment employed, and that papaya is consumed mainly as fresh fruit, speaks in favor of this fruit as a good dietary source for glucosinolate and isothiocyanates.

Effect of two different extracts of red maca in male rats with testosterone-induced prostatic hyperplasia.

AIM: To determine the effect of two different extracts of red maca in male rats. METHODS: Prostatic hyperplasia was induced in male rats with testosterone enanthate (TE). The study comprised six groups: one control group (group 1), one group treated with TE (group 2), two groups treated with TE and aqueous extract of red maca (groups 3 and 4), one group treated with hydroalcoholic extract of red maca (group 5) and one group treated with finasteride (0.1 mg, group 6). Differences in the aqueous extract dependent on the length of time of boiling, whether for 2 or 3 hours, for groups 3 and 4 was assessed. Extracts of red maca contained 0.1 mg of benzylglucosinolate. Thereafter, a dose-response effect of different doses of benzylglucosinolates (0.02-0.08 mg) in red maca extracts was assessed. RESULTS: Prostate weight was similar in rats treated with freeze-dried aqueous extract of red maca prepared after 2 and 3 hours of boiling. Freeze-dried aqueous extract of red maca, hydroalcoholic extract of red maca and finasteride reduced prostate weight in rats with prostatic hyperplasia. No difference was observed between the data obtained from aqueous extract or hydroalcoholic extract of red maca. A dose dependent reduction of prostate weight was observed with the increase of the dose of benzylglucosinolates in red maca extracts. CONCLUSION: The present study showed that hydroalcoholic or aqueous extract of red maca containing 0.1 mg of benzylglucosinolate can reduce prostate size in male rats in which prostatic hyperplasia had been induced by TE.

Effects of glucosinolates and flavonoids on colonization of the roots of Brassica napus by Azorhizobium caulinodans ORS571.

Plants of Brassica napus were assessed quantitatively for their susceptibility to lateral root crack colonization by Azorhizobium caulinodans ORS571(pXLGD4) (a rhizobial strain carrying the lacZ reporter gene) and for the concentration of glucosinolates in their roots by high-pressure liquid chromatography (HPLC). High- and low-glucosinolate-seed (HGS and LGS) varieties exhibited a relatively low and high percentage of colonized lateral roots, respectively. HPLC showed that roots of HGS plants contained a higher concentration of glucosinolates than roots of LGS plants. One LGS variety showing fewer colonized lateral roots than other LGS varieties contained a higher concentration of glucosinolates than other LGS plants. Inoculated HGS plants treated with the flavonoid naringenin showed significantly more colonization than untreated HGS plants. This increase was not mediated by a naringenin-induced lowering of the glucosinolate content of HGS plant roots, nor did naringenin induce bacterial resistance to glucosinolates or increase the growth of bacteria. The erucic acid content of seed did not appear to influence colonization by azorhizobia. Frequently, leaf assays are used to study glucosinolates and plant defense; this study provides data on glucosinolates and bacterial colonization in roots and describes a bacterial reporter gene assay tailored easily to the study of ecologically important phytochemicals that influence bacterial colonization. These data also form a basis for future assessments of the benefits to oilseed rape plants of interaction with plant growth-promoting bacteria, especially diazotrophic bacteria potentially able to extend the benefits of nitrogen fixation to nonlegumes.

Allelochemicals released in soil following incorporation of rapeseed (Brassica napus) green manures.

Plant-derived allelochemicals such as those produced by glucosinolate hydrolysis in Brassica napus, or rapeseed, are viable alternatives to synthetic compounds for the control of soil-borne plant pests. However, allelochemical production and residence times in field soils have not been determined. Soil samples were taken at 0-7.5 and 7.5-15 cm during a period of 3 weeks following plow-down of two winter rapeseed cultivars (Humus and Dwarf Essex). Soil samples were extracted with dichloromethane and analyzed using gas chromatography. Nine glucosinolate degradation products were identified-five isothiocyanates, three nitriles, and one oxazolidinethione. Maximum concentrations were observed 30 h after plow-down. Compounds derived from 2-phenylethyl glucosinolate, the principal glucosinolate in rapeseed roots, dominated the profile of degradation products. Shoot glucosinolates left few traces. This indicates that rapeseed roots may be a more important source of toxic fumigants than above-ground parts of the plant.

The effect of feeding brassica vegetables and intact glucosinolates on mixed-function-oxidase activity in the livers and intestines of rats.

Significant induction of mixed-function-oxidase (MFO) activity was observed in the small intestines of rats within 4-6 hr of ingestion of a single meal containing a Brassica vegetable (cabbage). Intact Brussels sprouts and a fractionated methanol-water extract of Brussels sprouts induced similar degrees of MFO activity in the livers, and small and large intestines of rats. However, the residue left after extraction of the polar compounds did not induce MFO activity. Different amounts of the various naturally-occurring thioglycosides and glucosinolates were found in the intact Brussels sprouts and in the extract, but virtually none were found in the extracted residue. When glucusinolates that were found in Brussels sprouts (sinigrin, progoitrin, glucobrassicin and glucotropaeolin) were fed separately to rats, only the indole glucosinolate, glucobrassicin, induced MFO activity (causing induction in the small intestines of the rats). This is consistent with the inducing activity of the various hydrolysis products of this glucosinolate. This is the first study in which an attempt has been made to define the inducing compounds in Brassica vegetables by feeding the individual purified glucosinolates.

Changes in differently processed soya bean (Glycine max.) and lima bean (Phaseolus lunatus) with particular reference to their chemical composition and their mineral and some inherent anti-nutritional constituents.

The effects of 3 processing techniques: cooking, roasting and autoclaving on the proximate chemical composition, the mineral content and some inherent toxic factors of soya and lima beans were investigated. The processing techniques generally reduced the crude fibre levels and enhanced the extractable fat in the soya and lima beans. The coefficients of variability for crude fibre and ether extract due to the processing techniques of soya and lima beans were 20.9%, 16.0% and 22.3%, 38.1%, respectively. In parallel with decreased ash content in the cooked bean samples, there was a decrease in the K, Mg, Na and P levels relative to the raw bean and also relative to the other processing techniques. Mineral contents of the autoclaved bean samples were generally similar to those of the raw (unprocessed) samples. Under the processing conditions, roasting caused the highest reduction in thioglucoside content (59%) in soya bean while cooking caused the highest reduction in lima bean (78%). Trypsin inhibitor activity (TIA) ranged between 0.59 mg/g sample in the cooked soya bean and 11.6 mg/g sample in the raw bean while the corresponding values for lima bean ranged between 0.59 and 6.3 mg/g sample. Cooking and roasting caused over 90% reduction of TIA, while autoclaving caused 64-69% reduction in both bean samples. Under the assay conditions, haemagglutinating activity was not detected in the cooked and autoclaved soya and lima beans. The need to prevent both functional and nutritional damage to food proteins and other nutrients, resulting from excessive heating, was discussed.

Compositional evaluation of some cowpea varieties and some under-utilized edible legumes in Nigeria.

The nutritive potentials of some cowpea varieties such as Ife Brown, Ife Bimpe, IT84E-124, K59 and TVX716 and some under-utilized edible legumes grown in Nigeria such as pigeon pea (Cajanus cajan), lima bean (Phaseolus lunatus), lablab bean (Dolichos lablab), mucuna bean (Mucuna sp.) and Sphenostilis sternocarpa have been evaluated with respect to their proximate chemical composition, mineral content and some endogenous toxic constituents. The cowpea varieties contained on the average 22.5 g crude protein (CP), 2.60 g crude fibre (CF), 5.89 g either extract (EE) and 3.36 g ash/100 g DM while the under-utilized legumes contained 21.7, 6.10, 2.86, and 3.56 g/100 g DM for CP, CF, EE and ash respectively. Distinct varietal differences were observed for EE values as indicated by the coefficients of variation (CV) of 102% for cowpea and 60.8% for the under-utilized legumes. The CF content of the under-utilized legumes were generally higher than those of the cowpea varieties. Potassium was the most abundant mineral in both the cowpea varieties and the under-utilized legumes with mean values of 1.45 and 1.66% respectively, while P was the least abundant with 13.1 and 8.50 ppm, respectively. There were marked intra-varietal differences in the P content as shown by the high CV of 84.0 and 73.9% for the cowpea varieties and the other legumes. The cowpea varieties generally had higher levels of thioglucosides, trypsin inhibitor activity (TIA) and lower haemagglutinating activity (mean values of thioglucosides: 3.86%, of TIA: 13.9 mg/g protein and of haemagglutinating activity: 13.0 HU/mg N respectively), than the under-utilized legumes with mean respective values of 1.22%, 9.84 mg/g protein and 22.7 HU/mg N. The nutritional implications of these anti-nutritional components were discussed and some reasons adduced for the under-utilization of some of these legumes inspite of their apparent similarity in nutritional quality to the more commonly consumed grain legumes.

Studies on the effects of rapeseed meal on thyroid status of cattle, glucosinolate and iodine content of milk and other parameters.

The effects of feeding rapeseed meals (RSM) containing low (Tower) or high (Target/Turret) levels of glucosinolates on thyroid status, iodine and glucosinolate content of milk and other parameters were studied in dairy cows and young calves. RSM (Tower and Turret) fed to dairy cows at 25% of the grain mixture reduced iodine content of milk. Diets containing Tower and Turret RSM tended to reduce plasma thyroxine (T4) in cows and increase the size of thyroids in rats. Calf diets containing Target and Tower RSM resulted in increased liver and thyroid weights, but only those containing Target tended to reduce plasma T4 levels. Feed intake, weight gain, hemoglobin, blood cell volume and erythrocyte count in calves were not affected by diets containing Tower RSM, but Target RSM reduced all these parameters. In addition, diets containing Target caused more pronounced histological changes of the calves' thyroid than those containing Tower RSM. No measurable amounts of intact glucosinolates were detected in milk of cows fed RSM. Similarly the glucosinolate aglucones, isothiocyanates or vinyl oxazolidinethione, were not transferred to milk although small amounts of unsaturated nitrile (1-cyano-2-hydroxy-3-butene) and inorganic thiocyanate were detected in milk. Rats receiving milk from cows fed Turret RSM developed larger thyroid than those receiving milk from control-fed cows. Supplemental iodine (61.0 microgram/d) in the rat prevented the thyroid enlargement.

Glucosinolates and derived products in cruciferous vegetables: total glucosinolates by retention on anion exchange resin and enzymatic hydrolysis to measure released glucose.

Details are given for determining total glucosinolates in Cruciferae plants by a procedure measuring released glucose. The glucosinolates are separated from about 90% of other material in the plant extract by adsorption on an anion exchange resin. Then, by a selective thioglucosidase hydrolysis of the glucosinolates retained on the exchange resin, the glucose and aglucons are separated from other substances retained by the resin. Glucose is released into an aqueous medium and is equivalent to the total glucosinolates. The aglucons formed by the hydrolysis are extracted into methylene chloride and determined by gas-liquid chromatography. Based on 29 determinations of the glucose from sinigrin, analyzed under different conditions, accuracy of the total glucosinolate determination was 94.8 +/- 7.3%. The coefficient of variation, determined by duplicate analyses on extracts from 58 cabbage samples, was 4.6%.

Rapeseed meal in complete feeds for dairy cows.

Three complete feeds containing low glucosinolate, low erucic acid rapeseed meal (Cultivar "1788"), high glucosinolate, low erucic acid rapeseed meal (Cultivar "Span"), or soybean meal as protein supplement were evaluated with lactating Holstein cows in a double 3 X 3 Latin square design. Lactation performance, hematology, blood chemistry, serum-free amino acids, rumen volatile fatty acid concentrations, and milk fatty acid composition were measured. The 1788 ration tended to increase yield of milk and of total solids. Hematology, blood chemistry, and serum-free amino acid data showed no differencein utilization of nitrogen. Concentrations of volatile fatty acids were not different. Feeding of the high glucosinolate Span ration did not reduce feed intake. However, there were indications that Span-fed cows may have experienced hypothyroidism. No differences were in erucic acid content of milk fat, and concentrations were low. Rapeseed meals 1788 and Span and soybean meal were equal as protein supplements.

Thiocyanate ion formation in rapeseed meals.

Meal prepared from unheated rapeseed (Brassica napus cv. Zephyr) showed the presence of t,iocyanate ion, while meal from heated seed of the same cultivar did not show detectable amounts. Unheated seed meal on autolysis, and heated seed meal on incubation with thioglucosidase, yielded increased amounts of thiocyanate ion. Various commercial rapeseed meals showed the presence of t,iocyanate ion only after enzyme incubation. Low glucosinolate, cv. Bronowski, and higher glucosinolate, cv. Zephyr on enzymic incubation yielded comparable amounts of thiocyanate ion, suggesting that the precursor responsible in the two varieties was the same and present in similar quantities. No formation of thiocyanate ion was observed on incubation of sinigrin with thioglucosidase. Rats dosed with heated meal, containing intact glucosinolate, showed a slight increase of thiocyanate ion in the urine as compared with control rats dosed with water, while a relatively large increase followed dosing with sinigrin. Rats dosed with meal containing free thiocyanate ion excreted the ingested thiocyanate ion almost quantitatively.