CE for cytokinin analyses: a review

Interkingdom Hormonal Regulations between Plants and Animals Provide New Insight into Food Safety

Food safety has become an attractive topic among consumers. Raw material production for food is also a focus of social attention. As hormones are widely used in agriculture and human disease control, consumers' concerns about the safety of hormone agents have never disappeared. The present review focuses on the interkingdom regulations of exogenous animal hormones in plants and phytohormones in animals, including physiology and stress resistance. We summarize these interactions to give the public, researchers, and policymakers some guidance and suggestions. Accumulated evidence demonstrates comprehensive hormonal regulation across plants and animals. Animal hormones, interacting with phytohormones, help regulate plant development and enhance environmental resistance. Correspondingly, phytohormones may also cause damage to the reproductive and urinary systems of animals. Notably, the disease-resistant role of phytohormones is revealed against neurodegenerative diseases, cardiovascular disease, cancer, and diabetes. These resistances derive from the control for abnormal cell cycle, energy balance, and activity of enzymes. Further exploration of these cross-kingdom mechanisms would surely be of greater benefit to human health and agriculture development.

Beneficial Effects of Young Coconut Juice on Increasing Skin Thickness, Enhancing Skin Whitening, and Reducing Skin Wrinkles in Ovariectomized Rats

It has been previously demonstrated in light microscopic and immunohistochemical studies that ovariectomized rats receiving young coconut juice at 100 mL/kg BW showed much better wound healing and improved skin complexion. Nevertheless, it was found that young coconut juice at 100 mL/kg BW/day caused unfavorable side effects, such as glycogen deposition in the liver. Therefore, in the current study, 3 lower doses (10, 20, and 40 mL/kg BW/day) were optimized, and the ultrastructure was further investigated. Compared to normal rats, all the parameters regarding skin changes, including epidermal and dermal thickness, the number of hair follicles, the diameters of collagen fibrils, perimeters, and nuclei of fibroblast and keratinocyte cells, and ultrastructural changes in keratinocyte and fibroblast cells were significantly reduced in ovariectomized rats. Those parameters in the ovariectomized rats were restored to normal by injecting estradiol benzoate or by feeding young coconut juice to the rats, where the effect was found to be dose-related but not in the case of all the parameters. In most cases, a dose of young coconut juiceof 40 mL/kg BW/day was the optimal dose. The results suggest that young coconut juice may be as effective as estradiol benzoate in reducing skin atrophy/aging, probably as a selective estrogen receptor moderator.

Young Coconut Juice Reduces Some Histopathological Changes Associated with Alzheimer's Disease through the Modulation of Estrogen Receptors in Orchidectomized Rat Brains

Propose. This study aimed to evaluate the protective role of young coconut juice (YCJ) against the pathological changes in Alzheimer's disease (AD) in orchidectomized (orx) rats. Methods and Results. Animals were divided into 7 groups including: baseline normal control group, sham control, orx rat group, orx rat group injected with 2.5 μg/kg b.w. estradiol benzoate (EB) 3 days a week for 10 weeks, and the orx rat groups treated orally with 10, 20, and 40 ml/kg b.w. of YCJ for 10 weeks. At the end of treatment period, animals were sacrificed and the brain of each rat was removed, fixed in 10% neutral formalin, and stained by specific antibodies against NF200, parvalbumin (PV), β-amyloid (Aβ), and estrogen receptors (ERα and ERβ). The results showed that the number of NF200- and PV-reactive neurons in the hippocampus and cerebral cortex was significantly reduced in orx rats. However, it restored to normal in orx rats injected with EB or those administrated with YCJ in a dose-related manner. Neurons containing β-amyloid (Aβ), a hallmark of Alzheimer's disease (AD), were found to be increased in the orx rats; however; they were reduced by EB injection or YCJ administration. These results suggested the binding of the YCJ active ingredient(s) with estrogen receptors (ERs) in the brain as indicated by the detection of ERα and ERβ in neurons since a significant correlation was detected between NF200-/PV-reactive neurons vs ERα-/ERβ-reactive neurons.Conclusion. It could be concluded that YCJ is effective as EB in reducing AD pathology, probably by being selective estrogen receptor modulators.

Analytical methods for tracing plant hormones

Plant hormones play important roles in regulating numerous aspects of plant growth, development, and response to stress. In the past decade, more analytical methods for the accurate identification and quantitative determination of trace plant hormones have been developed to better our understanding of the molecular mechanisms of plant hormones. As sample preparation is often the bottleneck in analysis of plant hormones in biological samples, this review firstly discusses sample preparation techniques after a brief introduction to the classes, roles, and methods used in the analysis of plant hormones. The analytical methods, especially chromatographic techniques and immuno-based methods, are reviewed in detail, and their corresponding advantages, limitations, applications, and prospects are also discussed. This review mainly covers reports published from 2000 to the present on methods for the analysis of plant hormones.

Screening of endophytic bacteria isolated from leaves of Sambung Nyawa [Gynura procumbens (Lour.) Merr.] for cytokinin-like compounds

Endophytic bacteria are harmless in most plant species; and known to boost the growth and development of the host plants probably by secreting growth hormones. The isolation, identification and screening of endophytic bacteria for the plant growth regulators like cytokinin are needed to get the leads for their applications in agriculture sector. We describe the isolation and identification of the bacterial endophytes from the leaves of Sambung Nyawa [Gynura procumbens (Lour.) Merr.] and their screening for cytokinin-like compounds. We isolated three endophytic bacteria from the leaves of G. procumbens collected from the forest research institute of Malaysia (FRIM). They were further identified using amplified 16S rRNA gene sequence based method of bacterial identification. The ethyl acetate extracts of the isolates-broth were analyzed using cucumber cotyledon greening bioassay (CCGB) to determine the presence of cytokinin-like compounds. Consequently, the bacterial putative endophytes were identified as Psuedomonas resinovorans, Paenibacillus polymaxa, and Acenitobacter calcoaceticus. Broth-extracts from two (Psuedomonas resinovorans and Paenibacillus polymaxa) of the three putative bacterial endophytes show the positive results in their screening for cytokinin-like compounds using CCGB. Thus, we hypothesize that the bacterial putative endophytes of G. procumbens that produce cytokinin-like compounds might have a role in the growth and development of G. procumbens.

ABBREVIATIONS

CCGB - Cucumber cotyledon greening bioassay, rDNA - Ribosomal DNA, K12, BAP - 6-Benzylaminopurine, Db1, MSA - Multiple sequence alignment. 8081.

The chemical composition and biological properties of coconut (Cocos nucifera L.) water

Coconut water (coconut liquid endosperm), with its many applications, is one of the world's most versatile natural product. This refreshing beverage is consumed worldwide as it is nutritious and beneficial for health. There is increasing scientific evidence that supports the role of coconut water in health and medicinal applications. Coconut water is traditionally used as a growth supplement in plant tissue culture/micropropagation. The wide applications of coconut water can be justified by its unique chemical composition of sugars, vitamins, minerals, amino acids and phytohormones. This review attempts to summarise and evaluate the chemical composition and biological properties of coconut water.

Contemporary sample stacking in CE

Sample stacking techniques remain an important tool for enhancement of the selectivity and sensitivity of analyses in contemporary CZE. This contribution reviews new knowledge on this topic published since 2006. It is organized according to the operational principles used, which include concentration adjustment, application of a pH step, MEKC and sweeping, and transient ITP. Techniques combining several of these principles and comparative studies are also included.

Phytohormones as important biologically active molecules--their simple simultaneous detection

Phytohormones, their functions, synthesis and effects, are of great interest. To study them in plant tissues accurate and sensitive methods are required. In the present study we aimed at optimizing experimental conditions to separate and determine not only plant hormones but also their metabolites, by liquid chromatography coupled with a UV-VIS detector. The mixture we analyzed was composed of benzyladenine, kinetin, trans-zeatin, cis-zeatin, dihydrozeatin, meta-topolin, ortho-topolin, alpha-naphthalene acetic acid, indole-3-acetic acid, trans-zeatin-7-glucoside, trans-zeatin-O-glucoside, trans-zeatin-9-riboside, meta-topolin-9-riboside and ortho-topolin-9-riboside. We measured the calibration dependences and estimated limits of detection and quantification under the optimal chromatographic conditions (column: Polaris C(18); mobile phase: gradient starting at 2:98 (methanol:0.001% TFA) and was increasing to 55:45 during twenty minutes, and then decreasing for 10 min to 35:65, flow rate: 200 microL x min(-1), temperature: 50 degrees C, wavelength: 210 nm). The detection limits for the target molecules were estimated as tens of ng per mL. We also studied the effect of flax extracts on the phytohormones' signals. Recovery of aliphatic and aromatic cytokinins, metabolites of cytokinins and auxins were within the range from 87 to 105 %. The experimental conditions were tested on a mass selective detector. In addition we analysed a commercial product used for stimulation of roots formation in cuttings of poorly rooting plants. The determined content of alpha-naphthalene acetic acid was in good agreement with that declared by the manufacturer.

Determination of nucleosides and nucleobases in different species of Cordyceps by capillary electrophoresis-mass spectrometry

In present study, a capillary electrophoresis-mass spectrometry (CE-MS) method was developed for the simultaneous analysis of 12 nucleosides and nucleobases including cytosine, adenine, guanine, cytidine, cordycepin, adenosine, hypoxanthine, guanosine, inosine, 2'-deoxyuridine, uridine and thymidine in natural and cultured Cordyceps using 5-chlorocytosine arabinoside as an internal standard (IS). The CE separation conditions and MS parameters were optimized systematically for achieving good CE resolution and MS response of the investigated compounds. The optimum CE electrolyte was 100 mM formic acid containing 10% (v/v) methanol. The optimum MS parameters were as follows: 75% (v/v) methanol containing 0.3% formic acid with a flow rate of 3 microL/min was selected as the sheath liquid; the flow rate and temperature of drying gas were 6 L/min and 350 degrees C, respectively. The optimized CE-MS method was successfully applied for the simultaneous determination of 12 nucleosides and nucleobases in natural and cultured Cordyceps. On the basis of quantitative results, the total content of nucleosides is much higher in cultured Cordyceps (9138+/-4823 microg/g for cultured C. sinensis; 3722+/-1446 microg/g for C. militaris) than in natural ones (2167+/-412 microg/g). However, the hypoxanthine (131+/-47 microg/g) and inosine (335+/-90 microg/g) are much higher in natural C. sinensis. Cordycepin, which is abundant in cultured C. militaris (2276.5+/-842.6 microg/g), is only found in natural C. sinensis with very low content and cannot be detected in the cultured ones.

Electrophoretic migration of proteins in semidilute polymer solutions

We present a systematic study of the electrophoretic migration of 10-200 kDa protein fragments in dilute-polymer solutions using microfluidic chips. The electrophoretic mobility and dispersion of protein samples were measured in a series of monodisperse polydimethylacrylamide (PDMA) polymers of different molecular masses (243, 443, and 764 kDa, polydispersivity index <2) of varying concentration. The polymer solutions were characterized using rheometry. Prior to loading onto the microchip, the polymer solution was mixed with known concentrations of SDS (SDS) surfactant and a staining dye. SDS-denatured protein samples were electrokinetically injected, separated, and detected in the microchip using electric fields ranging from 100 to 300 V/cm. Our results show that the electrophoretic mobility of protein fragments decreases exponentially with the concentration c of the polymer solution. The mobility was found to decrease logarithmically with the molecular weight of the protein fragment. In addition, the mobility was found to be independent of the electric field in the separation channel. The dispersion is relatively independent of polymer concentration and it first increases with protein size and then decreases with a maximum at about 45 kDa. The resolution power of the device decreases with concentration of the PDMA solution but it is always better than 10% of the protein size. The protein migration does not seem to correspond to the Ogston or the reptation models. A semiempirical expression for mobility given by van Winkle fits the data very well.