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At least 19 recordsLinked to original sources

PubMed1999

Evolutionary Changes in Floral Structure within Lepidium L. (Brassicaceae).

The basic floral ground plan is remarkably constant across Brassicaceae. However, within Lepidium (ca. 175 species), deviations from this ground plan are common, with over half of Lepidium species having only two stamens rather than the usual six and a further eighth of the species having only four stamens. Furthermore, petals are reduced in size in a majority of Lepidium species. In order to determine the frequency and direction of changes in floral structure within Lepidium, we have inferred the phylogeny within the genus from sequences of the internal transcribed spacers of the nuclear ribosomal DNA. On the basis of this inferred phylogeny, we conclude that floral structure within Lepidium is relatively fluid. In order to account for the phylogenetic distributions of the different floral ground plans, at least two independent reductions to the two-stamen condition and at least one reversal to flowers with increased organ numbers are likely to have occurred. To account for the frequency of morphological evolution observed within the genus, we propose that some clades within Lepidium may be predisposed to changes in floral structure. In addition, several transoceanic dispersals are needed to explain the geographic distributions of the clades inferred from the phylogeny.

Journal Article↗

PubMed2006

Endosperm-limited Brassicaceae seed germination: abscisic acid inhibits embryo-induced endosperm weakening of Lepidium sativum (cress) and endosperm rupture of cress and Arabidopsis thaliana.

The endosperm is a barrier for radicle protrusion of many angiosperm seeds. Rupture of the testa (seed coat) and rupture of the endosperm are two sequential events during the germination of Lepidium sativum L. and Arabidopsis thaliana (L.) Heyhn. Abscisic acid (ABA) specifically inhibits the endosperm rupture of these two closely related Brassicaceae species. Lepidium seeds are large enough to allow the direct measurement of endosperm weakening by the puncture force method. We found that the endosperm weakens prior to endosperm rupture and that ABA delays the onset and decreases the rate of this weakening process in a dose-dependent manner. An early embryo signal is required and sufficient to induce endosperm weakening, which afterwards appears to be an organ-autonomous process. Gibberellins can replace this embryo signal; de novo gibberellin biosynthesis occurs in the endosperm and weakening is regulated by the gibberellin/ABA ratio. Our results suggest that the control of radicle protrusion during the germination of Brassicaceae seeds is mediated, at least in part, by endosperm weakening. We propose that Lepidium is an emerging Brassicaceae model system for endosperm weakening and that the complementary advantages of Lepidium and Arabidopsis can be used in parallel experiments to investigate the molecular mechanisms of endosperm weakening.

Abscisic Acid↗

PubMed2001

Effect of Lepidium meyenii (maca) roots on spermatogenesis of male rats.

AIM: To determine the effect of oral administration of an aqueous extract from the roots of Lepidium meyenii (maca) on spermatogenesis in adult male rats. METHODS: Male rats received an aqueous extract of the root (66.7 mg in one mL) twice a day for 14 consecutive days. RESULTS: Treatment with Lepidium meyenii resulted in an increase in the weights of testis and epididymis but not the seminal vesicle weight. The length and frequency of stages IX-XIV seminiferous tubules, where mitosis occurred, were increased and stages I-VI were reduced in rats treated with Lepidium meyenii. CONCLUSION: The Lepidium meyenii root invigorates spermatogenesis in male rats by acting on its initial stages (IX-XIV).

Administration, Oral↗

PubMed2002

Allopolyploidization and evolution of species with reduced floral structures in Lepidium L. (Brassicaceae).

Understanding the pattern of speciation in a group of plants is critical for understanding its morphological evolution. Lepidium is the genus with the largest variation in floral structure in Brassicaceae, a family in which the floral ground plan is remarkably stable. However, flowers in more than half of Lepidium species have reduced stamen numbers, and most of these also have reduced petals. The species with reduced flowers are geographically biased, distributed mostly in the Americas and Australia New Zealand. Previous phylogenetic studies using noncoding regions of chloroplast DNA and rDNA internal transcribed spacer were incongruent in most New World species relationships. These data, combined with the presence of many polyploid Lepidium species, implied a reticulate history of the genus but did not provide enough information to infer the evolutionary pattern of flower structures. To address this question more thoroughly, sequences of the first intron of a single copy nuclear gene, PISTILLATA, were determined from 43 species. Phylogenetic analysis of the PI intron suggests that many species in the New World have originated from allopolyploidization, and that this is correlated with floral reduction. Interspecific hybrids were generated to understand why allopolyploidization is associated with reduced flowers. The phenotypes of F1 flowers indicate allelic dominance of the absence of lateral stamens, suggesting that propagation of dominant alleles through interspecific hybridization could account for the abundance of the allopolyploid species without lateral stamens.

Base Sequence↗

PubMed2004

Lepidium peruvianum chacon restores homeostasis impaired by restraint stress.

Lepidium peruvianum root has been traditionally utilized by native Peruvians, since before the time of the Incas, for both nutritional and putative medicinal purposes as an adaptogen and also to enhance fertility in humans and animals. The present research was conducted to evaluate the anti-stress activity of the methanolic extract of Lepidium peruvianum. The drug is capable of attenuating or even eliminating variations in homeostasis produced by stress since it reduces or abolishes stress-induced ulcers, elevated corticosterone levels, the reduction of glucose and the increase in the weight of adrenal glands produced by stress. It also eliminates the decrease in free fatty-acids (FFA) in plasma produced by stress and we obtain a positive result in the forced-swimming test. Thus, it did not appear to affect restraint stress-induced immunosuppression.

Animals↗

PubMed2004

Assessment of toxic interactions of heavy metals in a multicomponent mixture using Lepidium sativum and Spirodela polyrrhiza.

The toxicities of copper, chromium, cadmium, nickel, manganese, zinc, and lead ions and various concentrations of mixtures of them were studied using the aquatic plant Spirodela polyrrhiza and the terrestrial plant Lepidium sativum. The composition of the model mixture was based on average analytical data of the annual amounts of representative heavy metals (HM) in wastewater discharged from the Ignalina Nuclear Power Plant (Lithuania) during 1996. The observed and predicted effects of the HM mixture on tested plants were evaluated and compared with the prediction models used in describing the toxic interactions of heavy metals in the mixture. The type of toxic interaction at each tested concentration of the mixture was assessed by a statistical approach that tested the null hypothesis of additive toxicity (Ince et al., 1999) and the mixture toxicity index (MTI; Könemann, 1981). For both plant organisms the effect of the HM mixture calculated using the MTI was synergistic. However, assessment of the HM interaction type at 50% effect concentrations using the hypothesis of additive toxicity showed a synergistic effect for Spirodela polyrrhiza and an additive effect for Lepidium sativum. Though the results obtained using both prediction models for assessing the HM mixture's toxicity were similar, in our opinion, the additive toxicity model is more suitable than the MTI model because the former allows evaluation of the impact of various mixture concentrations, not only those with a 50% effect.

Araceae↗

PubMed1984

Microtubules in statocytes from roots of cress (Lepidium sativum L.).

Statocytes in root caps of Lepidium sativum L. were examined by means of ultrathin serial sections to evaluate the amount and distribution of cortical microtubules. The microtubules encircle the cell, oriented normal to the root length axis. In the distal cell edges, microtubules form a network, separating the distal complex of endoplasmic reticulum from the plasmalemma. Preprophase bands in meristem cells are observable rarely, structures which can be regarded as nucleating sites for microtubules are lacking. During ageing of the root cap cells, the number of microtubules increases in combination with a decrease of microtubule length. Development of the roots on a horizontal clinostat preserves a "younger" developmental stage of the microtubule system regarding amount and length of the individual microtubules. Evidence for an involvement of microtubules in graviperception is low, whereas their role in orienting cellulose microfibrils cannot be ruled out. Compression of the distal network of microtubules after centrifugation of the roots indicates that microtubules in statocytes of Lepidium sativum L. roots might function in stabilizing the distal complex of endoplasmic reticulum.

Brassicaceae↗

PubMed1999

Effects of various levels of dietary Lepidium sativum L. seeds in rats.

A toxicity study was made on Lepidium sativum L. seeds used in Saudi traditional medicine for the treatment of various ailments. Lepidium sativum L. seed fed to Wistar albino rats at 2% (w/w) was non-toxic, Ten percent (w/w) was toxic but not fatal and 50% (w/w) of the diet for 6 weeks was lethal and caused depression in growth rate and entero-hepato-nephrotoxicity. Organ lesions accompanied by anemia and leukopenia were correlated with alterations in serum AST and ALT activities and concentrations of total protein, cholesterol, urea, and other serum constituents.

Animals↗

PubMed2000

Factors affecting establishment of a gypsophyte: the case of Lepidium subulatum (Brassicaceae).

The restriction of vascular plants to gypsum-rich soils under arid or semiarid climates has been reported by many authors in different parts of the world. However, factors controlling the presence of gypsophytes on these soils are far from understood. We investigated the establishment of Lepidium subulatum, a gypsophyte, in a nondisturbed semiarid gypsum-soil landscape in central Spain, both from spatial and temporal perspectives. Over 1400 seedlings were tagged, and their growth and survival were monitored for a 2-yr period. Several biotic and abiotic variables were measured to determine the factors controlling the emergence and early survival. These variables included the cover of annual plants, bryophytes, lichens, litter, gypsum crystals, bare fraction and cover of each perennial plant, and several soil properties (gravel, fine gravel, and fine-earth fraction, conductivity, pH, gypsum content, organic matter and penetrometer soil resistance). Our results support the linkage of gypsophily with some physical properties of the surface crust. Seedlings tended to establish on the gypsum surface crust, and their survival was size dependent, probably as a consequence of the necessity of rooting below the surface crust before summer drought arrives. However, once seedlings emerged, a higher survival rate occurred on the alluvial soils of the piedmont-slope boundary where soil crusts are absent or thinner. We conclude that Lepidium subulatum may be considered a refuge model endemic with a distribution range that occupies a reduced fraction of a wider habitat from which it is probably excluded by competition.

Journal Article↗

PubMed1998

Effects of microgravity on the growth of Lepidium roots.

The normal growth dynamics of plant roots is partly controlled by the gravitational force. In order to study the detailed growth behavior in absence of gravity, the growth of Lepidium sativum roots was recorded by time lapse photography at 1h intervals in a Spacelab ESA-experiment (IML-2). Plants were germinated and kept in microgravity during the experiments, while control roots were at 1 g with normal static gravistimulation. Extended image analyses allowed new information to be achieved about movements of all parts of the roots, extending earlier published results. Root contours were extracted from the images and divided into 0.6mm segments. Deviation angles were calculated for each root segment, both for the first 8-10 h (phase I) and for the last 6-8 h of the experiment (phase II). For phase I, the present analysis confirmed that the average square deviation increased linearly with time for roots in microgravity, while for roots under 1 g conditions it stayed constant. This was consistent with a random walk hypothesis for the bending pattern. In phase II, roots in microgravity stopped their spontaneous curvatures and showed more straight growth or even diminished the root curvatures that had occurred during phase I. Thus, the growth is distinctly different in the two phases and is thought to be controlled by autotropic reactions in phase II. Root hairs developed when the roots passed into phase II. During phase I, the root growth rates were equal in microgravity and on the ground (0.50 mm h-1 with SE 0.04 and 0.51 mm h-1 with SE 0.03, respectively). In phase II the growth rate on the ground was higher than in microgravity (1.44 mm h-1 with SE 0.10 and 1.07 mm h-1 with SE 0.04 in microgravity). Microgravity conditions, therefore, clearly affect Lepidium root growth: In phase I the bending pattern is random in contrast to the normal straight growth under 1g. In phase II the growth rate is reduced, as compared to the growth rate under 1 g.

Brassicaceae↗

PubMedDate not supplied

Analysis of macamides in samples of Maca (Lepidium meyenii) by HPLC-UV-MS/MS.

The macamides are a distinct class of secondary metabolites that have so far been found only in Lepidium meyenii Walp. (Maca). Using HPLC-UV-MS/MS, the main macamides have been identified as n-benzylhexadecanamide, n-benzyl-(9Z)-octadecenamide, n-benzyl-(9Z, 12Z)-octadecadienamide, n-benzyl-(9Z, 12Z, 15Z)-octadecatrienamide and n-benzyloctadecanamide. The identities of n-benzyl-(9Z)-octadecenamide and n-benzyl-(9Z, 12Z)-octadecadienamide were confirmed by comparison of chromatographic and spectral properties with synthetic analogues. Total macamides have been quantified by HPLC-UV in plant material from different vendors using n-benzylhexadecanamide as an external standard. The amount of macamides in the dried plant material ranged from 0.0016 to 0.0123%.

Amides↗

PubMed2003

Antiamoebic activity of benzyl glucosinolate from Lepidium virginicum.

In a continuation of our search for potential antiprotozoal agents from plants, we found that a crude extract from the roots of Lepidium virginicum exhibited antiprotozoal activity against Entamoeba histolytica trophozoites (IC(50) of 100.1 micro g/mL). Bioassay-guided fractionation resulted in the isolation of one known glucosinolate responsible for such activity. This compound was identified as benzyl glucosinolate. It showed in vitro activity against Entamoeba histolytica strain HM1-IMSS (IC(50) of 20.4 micro g/mL). The results support the anecdotal reports for the traditional use of L. virginicum roots in the control of diarrhoea and dysentery in the highlands of Chiapas, Mexico.

Animals↗

PubMed2002

Basipetal propagation of gravity-induced surface pH changes along primary roots of Lepidium sativum L.

While there is ample evidence for a role of auxin in root gravitropism, the seeming rapidity of gravi-induced changes in electrical parameters has so far been an argument against auxin being a primary signal in gravitropic signal transmission. To address this problem, we re-investigated the effect of gravistimulation on membrane voltages of Lepidium sativum L. and Vigna mungo L. root cells. In our hands, gravistimulation did not induce changes in membrane voltage in cells of the root cap statenchyma, root meristem or apical elongation zone that can be correlated with the orientation of the cells relative to the gravity vector. While these results challenge a model of rapid electrically based signal transmission, there is evidence for a slower signal propagation along gravistimulated L. sativum roots. Using multiple proton-selective microelectrodes to simultaneously measure surface pH on opposite root flanks at different distances from the root tip, we observed gravi-induced asymmetric pH changes at the surface of all investigated root zones. Upon gravistimulation, the surface pH decreased on the physically upper root flank and increased on the lower flank. The pH asymmetry appeared first [2.1+/-0.4 min (mean +/- SD) after tilting] at the root cap and then - with incrementing lag times - at the meristem (after 2.5+/-0.3 min at 300 micro m from root tip; after 3.7+/-0.4 min at 700 micro m) and apical elongation zone (4.8+/-0.5 min at 1,000 micro m), suggesting a basipetal progression of differential surface acidification at a rate of 250-350 micro m min(-1), consistent with reported auxin transport rates.

Biological Transport↗

PubMed2006

Subnucleolar location of fibrillarin and NopA64 in Lepidium sativum root meristematic cells is changed in altered gravity.

Fibrillarin and the plant nucleolin homolog NopA64 are two important nucleolar proteins involved in pre-rRNA processing. In order to determine the effects of the altered gravity environment on the nucleolus, we have investigated the location of fibrillarin and NopA64 in nucleolar subcomponents of cress (Lepidium sativum L.) root meristematic cells grown under clinorotation, which reproduces an important feature of microgravity, namely, the absence of the orienting action of a gravity vector, and compared it to the location in control cells grown in normal 1 g conditions. Prior to these experiments, we report here the characterization of cress fibrillarin as a 41 kDa protein which can be isolated from meristematic cells in three nuclear fractions, namely, the soluble ribonucleoprotein fraction, the chromatin fraction, and the nuclear-matrix fraction. Furthermore, as reported for other species, the location of both fibrillarin and NopA64 in the cress cell nucleolus was in zones known to contain complex ribonucleoprotein particles involved in early pre-rRNA processing, i.e., processomes. Under altered gravity, a decrease in the quantity of both fibrillarin and NopA64 compared to controls was observed in the transition zone between fibrillar centers and the dense fibrillar component, as well as in the bulk of the dense fibrillar component. These data suggest that altered (reduced) gravity results in a lowered level of functional activity in the nucleolus.

Blotting, Western↗

PubMed2006

The in vitro biological activity of Lepidium meyenii extracts.

The biological activity of methanolic and aqueous extracts from dehydrated hypocotyls of Lepidium meyenii (Brassicaceae, vernacular name "maca"), was studied on rat hepatocytes and human breast cancer MCF-7 cells. The extracts did not exhibit cytotoxicity in hepatocyte primary cultures up to 10 mg/ml as measured by the MTT viability test, and lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) leakage. Moreover, after 72 h, extracts inhibited LDH and AST leakage from the hepatocytes. When hepatocytes were intoxicated by t-butyl hydroperoxide, neither extract prevented oxidative damage. Both extracts showed weak antioxidant activity in the DPPH radical scavenging test with IC(50) values of 3.46 +/- 0.16 and 0.71 +/- 0.10 mg/ml, for aqueous and methanolic extracts, respectively. Thus, the observed effect on spontaneous enzyme leakage is probably mediated through mechanisms other than antioxidant activity. Both methanolic and aqueous extracts have shown estrogenic activity comparable with that of silymarin in MCF-7 cell line. Maca estrogenicity was exhibited in the range from 100 to 200 mug of extract per ml. The findings in the present study show that maca does not display in vitro hepatotoxicity. In contrast, a slight cytoprotective effect, probably not mediated by antioxidant capacity, was noted. Maca extracts exhibited estrogenic activity comparably to the effect of silymarin in MCF-7 cells.

Animals↗

PubMed2006

Possible mechanism of inhibition of 6-methoxy-benzoxazolin-2(3H)-one on germination of cress (Lepidium sativum L.).

6-Methoxy-benzoxazolin-2(3H)-one (MBOA) inhibited the germination of cress (Lepidium sativum L.) seeds at concentrations greater than 0.03 mM. Inhibition was overcome by sucrose, suggesting that MBOA may inhibit sugar metabolism in cress seeds. Induction of alpha-amylase activity in seeds was also inhibited by MBOA at concentrations greater than 0.03 mM. Inhibition of both germination and induction of alpha-amylase activity increased with increasing concentrations of MBOA, and the extent of germination correlated positively with the activity of alpha-amylase in the seeds. MBOA added to a reaction mixture for alpha-amylase assay did not affect enzyme activity, indicating that MBOA does not inhibit in vitro alpha-amylase activity. Cress seeds germinated approximately 16 hr after incubation, and inhibition of alpha-amylase by MBOA occurred within 6 hr after incubation. These results suggest that MBOA may inhibit the germination of cress seeds by inhibiting the induction of alpha-amylase activity, because alpha-amylase plays a key role in the conversion of reserve carbohydrate into soluble sugars, a prerequisite for seed germination.

Benzoxazoles↗

PubMed2006

Glucosinolate hydrolysis in Lepidium sativum--identification of the thiocyanate-forming protein.

Glucosinolates are a class of thioglycosides found predominantly in plants of the order Brassicales whose function in anti-herbivore defense has been attributed to the products formed by myrosinase-catalyzed hydrolysis upon plant tissue damage. The most common type of hydrolysis products, the isothiocyanates, are toxic to a wide range of organisms. Depending on the glucosinolate side-chain structure and the presence of certain protein factors, other types of hydrolysis products, such as simple nitriles, epithionitriles and organic thiocyanates, can be formed whose biological functions are not well understood. Of the proteins controlling glucosinolate hydrolysis, only epithiospecifier proteins (ESPs) that promote the formation of simple nitriles and epithionitriles have been identified on a molecular level. We investigated glucosinolate hydrolysis in Lepidium sativum and identified a thiocyanate-forming protein (TFP) that shares 63-68% amino acid sequence identity with known ESPs and up to 55% identity with myrosinase-binding proteins from Arabidopsis thaliana, but differs from ESPs in its biochemistry. TFP does not only catalyze thiocyanate and simple nitrile formation from benzylglucosinolate but also the formation of simple nitriles and epithionitriles from aliphatic glucosinolates. Analyses of glucosinolate hydrolysis products in L. sativum autolysates and TFP transcript accumulation revealed an organ-specific regulation of thiocyanate formation. The identification of TFP defines a new family of proteins that control glucosinolate hydrolysis and challenges the previously proposed reaction mechanism of epithionitrile formation. As a protein that promotes the formation of a wide variety of hydrolysis products, its identification provides an important tool for further elucidating the mechanisms of glucosinolate hydrolysis as well as the ecological role and the evolutionary origin of the glucosinolate-myrosinase system.

Amino Acid Sequence↗

PubMed2004

Chemical composition of garden cress (Lepidium sativum) seeds and its fractions and use of bran as a functional ingredient.

Garden cress (Lepidium sativum) belonging to the family Cruciferae grown in India, Europe and US is an underutilized crop. The edible whole seed is known to have health promoting properties. Hence, it was assumed that these seeds can be a functional food. A preliminary work on chemical composition of seeds was carried out and the possibility of using it as nutraceutical food ingredient in dietary fiber formulation was explored. Three fractions namely whole meal (WM), endosperm and bran were analyzed for chemical composition. The yield of the endosperm and the bran fraction were 72 and 28%, respectively. The WM, endosperm and bran had 22.5, 27.7 and 12.6% protein, 27.5, 33.1 and 6% fat, 30, 13.6 and 75% dietary fibre (DF), and 1193.00, 945.15 and 1934.57 mg% potassium respectively. The major protein on SDS-PAGE was of 29.5 kDa. The most abundant amino acid was glutamic acid (19.3%) and the essential amino acid, leucine was the highest (8.21 +/- 0.01%) and methionine the lowest (0.97 +/- 0.02%). The major fatty acid was linolenic acid (30.2%) and low amount of erucic acid (3.9%) was also present. Bran having high water holding capacity and high DF, its use as source of DF was explored. The product contained 12% protein, 4% fat and 74.3% DF and exhibited desirable functional properties such as dispersibility, gelling ability, stability, formed homogenous mild alkaline suspension and was comparable to proprietary DF.

Amino Acids↗