Assessment of the Diuretic Properties of Rice Bean Accessions Using a Mouse Model and Identification of Active Polyphenolic Compounds.

Rice bean [Vigna umbellata (Thunb.) Ohwi and Ohashi], an annual legume in the genus Vigna, is a promising crop suitable for cultivation in a changing climate to ensure food security. It is also a medicinal plant widely used in traditional Chinese medicine; however, little is known about the medicinal compounds in rice bean. In this study, we assessed the diuretic effect of rice bean extracts on mice as well as its relationship with the contents of eight secondary metabolites in seeds. Mice gavaged with rice bean extracts from yellow and black seeds had higher urinary output (5.44-5.47 g) and water intake (5.8-6.3 g) values than mice gavaged with rice bean extracts from red seeds. Correlation analyses revealed significant negative correlations between urine output and gallic acid (R = -0.70) and genistein (R = -0.75) concentrations, suggesting that these two polyphenols negatively regulate diuresis. There were no obvious relationships between mice diuresis-related indices (urine output, water intake, and weight loss) and rutin or catechin contents, although the concentrations of both of these polyphenols in rice bean seeds were higher than the concentrations of the other six secondary metabolites. Our study findings may be useful for future research on the diuretic effects of rice bean, but they should be confirmed on the basis of systematic medical trials.

Assessment of the Effect of Leonurine Hydrochloride in a Mouse Model of PCOS by Gene Expression Profiling.

Polycystic ovary syndrome (PCOS) is an endocrine disease commonly associated with metabolic disorders in females. Leonurine hydrochloride (Leo) plays an important role in regulating immunity, tumours, uterine smooth muscle, and ovarian function. However, the effect of Leo on PCOS has not been reported. Here, we used dehydroepiandrosterone to establish a mouse model of PCOS, and some mice were then treated with Leo by gavage. We found that Leo could improve the irregular oestros cycle of PCOS mice, reverse the significantly greater serum testosterone (T) and luteinising hormone (LH) levels, significantly reduce the follicle-stimulating hormone (FSH) level, and significantly increase the LH/FSH ratio of PCOS mice. Leo could also change the phenomenon of ovaries in PCOS mice presented with cystic follicular multiplication and a lacking corpus luteum. Transcriptome analysis identified 177 differentially expressed genes related to follicular development between the model and Leo groups. Notably, the cAMP signalling pathway, neuroactive ligand-receptor interactions, the calcium signalling pathway, the ovarian steroidogenesis pathway, and the Lhcgr, Star, Cyp11a, Hsd17b7, Camk2b, Calml4, and Phkg1 genes may be most related to improvements in hormone levels and the numbers of ovarian cystic follicles and corpora lutea in PCOS mice treated by Leo, which provides a reference for further study of the mechanism of Leo.

In vitro elicitation and detection of apigenin, catalpol and gallic acid in hairy root culture of Plantago major L. and assessment of cytotoxicity and anti-bacterial activity of its methanolic extract.

The aim of this study was to establish the hairy root (HR) culture of Plantago major to evaluate the accumulation of apigenin, catalpol and gallic acid after elicitation and investigate the biological activity of its methanolic extraction. The highest transformation frequency was obtained by Agrobacterium rhizogenes strain A4, 0.5 mg/L 6-Benzylaminopurine in pre-cultivation medium, 150 µM acetosyringone in co-cultivation medium (1/2 MS), and immersion method for inoculation of leaf explants. The production of apigenin, catalpol and gallic acid compounds were significantly affected by treatment of 1.18 mM AgNO3 at 24 h which yielded 4.30, 8.24 and 2.89-fold increase, respectively. The assessment of anti-bacterial activity showed that the methanolic extracts of the HRs elicited with 1.18 mM AgNO3 were significantly active against Proteus vulgaris (PTCC 1182) (MIC = 25 mg/mL and MBC = 25 mg/mL). Furthermore, the MTT assay revealed that the methanolic extracts of the HRs were cytotoxic on the SW-480 cell (IC50=337.56 ± 1.82 µg/mL).

[A Method Based on Ru(bpy)3 3+ Electrogenerated Chemiluminescence for Assessment of Antioxidant Property of Naturally Occurring Antioxidants].

We developed a flow injection analysis (FIA) method based on tris(2,2'-bipyridine)ruthenium(III) [Ru(bpy)3 3+] electrogenerated chemiluminescence for assessment of antioxidant property. The hydroxyl radical (∙OH) were generated by H2O photolysis using an ultraviolet/H2O photoreactor. The reactor comprised a polytetrafluoroethylene tube, a quartz container, and a low-pressure mercury lamp that predominantly emitted radiation at around 185 nm. When the hydroxyl radical and Ru(bpy)3 3+ were in contact, chemiluminescence was generated as background emission. The background emission decreased when antioxidant samples were injected to the system. The antioxidant property of the naturally occurring antioxidants tested are listed herein, starting with the highest: gallic acid>ascorbic acid>quercetin. Moreover, our method allowed a sample throughput of approximately 100 samples/h. The proposed high throughput method can be used to assess the antioxidant property of the naturally occurring antioxidants.

Assessment of neuroprotective effects of Gallic acid against glutamate-induced neurotoxicity in primary rat cortex neuronal culture.

Glutamate excitotoxicity plays a crucial role in the pathogenesis behind the development and progression of several neurodegenerative diseases. The study aimed to investigate the neuroprotective activity of Gallic acid (GA) against glutamate-induced neurotoxicity in primary rat cortex neurons (RCN). Treated the RCNs with GA 25 & 50 µg/ml for 2 h and later treated the cells with 100 µM glutamate (GLU) and incubated for 24 h at 37 °C. The results demonstrated that, the GA improved the antioxidant profile in the cortex neurons and inhibited the production of the proinflammatory cytokine. GA also maintained the Ca2+ homeostasis, IGF-1 expression, and protected the neurons from glutamate-induced neuronal toxicity. The neuroprotective activity of GA has further confirmed from the results of N-acetylaspartate and expression of microtubule-associated protein-2 expression. The reports suggest that, GA is significantly attenuated the glutamate-induced neurotoxicity and protected neurons from various chemical events that are involved in the pathogenesis of neurotoxicity.

Assessment of the content of phenolics and antioxidant actions of the Rubiaceae, Ebenaceae, Celastraceae, Erythroxylaceae and Sterculaceae families of Mauritian endemic plants.

There is continued interest in the assessment of the bioefficacy of the active principles in extracts from a variety of traditional medicine and food plants in order to determine their impact on the management of a variety of clinical conditions and maintenance of health. The polyphenolic composition and antioxidant potential of Mauritian endemic plants of the Rubiaceae, Ebenaceae, Celastraceae, Erythroxylaceae and Sterculaceae family were determined. The phenolics level of the plant extracts varied from 1 to 75 mg/g FW, the maximum level measured in Diospyros neraudii (Ebenaceae). Coffea macrocarpa showed the highest flavonoids content with 18+/-0.7 mg/g FW. The antioxidant capacity based on the TEAC and FRAP values were strongly related to total phenolics and proanthocyanidins content, while a weaker correlation was observed with (-) gallic acid. Erythroxylum sideroxyloides showed the highest protective effect in the lipid peroxidation systems with IC(50) of 0.0435+/-0.001 mg FW/ml in the Fe(3+)/ascorbate system and 0.05+/-0.002 mg FW/ml in the AAPH system. Cassine orientalis, E. sideroxyloides, Diospyros mellanida and Chassalia coriancea var. johnstonii were weakly prooxidant only at higher concentration greater of 10 g FW/L indicating potential safety. Mauritian endemic plants, particularly the genus Diospyros, are good sources of phenolic antioxidants and potential candidates for the development of prophylactic agents.

Antimicrobial constituents of Rhus glabra.

The antimicrobial activity of the methanol extract and isolated constituents of Rhus glabra (Anacardiaceae), a species used in folk medicine by North American native people, was evaluated against 11 microorganisms, including gram-positive and gram-negative bacteria. The extract was subsequently fractionated and monitored by bioassays leading to the isolation of three antibacterial compounds, the methyl ester of 3,4,5-trihydroxybenzoic acid (methyl gallate) (minimal inhibition concentration (MIC) 12.5 micrograms/ml), 4-methoxy-3,5-dihydroxybenzoic acid (MIC 25 micrograms/ml) and gallic acid (MIC > 1000 micrograms/ml). The first two compounds are reported here for the first time from Rhus glabra. Their structures were established using spectroscopic and chemical methods.