Determination of Afzelin and Astragalin from Lespedeza cuneata on Aldose Reductase Inhibition.

The bioactive chemicals in L. cuneata were investigated by repeated column chromatography and their effect on aldose reductase (AR), obtained from rat lenses, was examined. Results showed that the ethyl acetate and n-butanol fractions of L. cuneata exhibited potential inhibitory effect against AR with IC50 values of 0.57 and 0.49 µg/mL, respectively. Phytochemical analysis of these two fractions resulted in the isolation of five flavonoids namely, acacetin (1), afzelin (2), astragalin (3), kaempferol (4) and scutellarein 7-O-glucoside (5). The AR inhibitory effect of compounds 1-5 was explored; compounds 2, 3 and 5 showed potential AR-inhibitory effects with IC50 values of 2.20, 1.91 and 12.87 µM, respectively. Quantitative analysis of afzelin (2) and astragalin (3) in L. cuneata by high performance liquid chromatography with ultraviolet detection revealed its content to be 0.722-11.828 and 2.054-7.006 mg/g, respectively. Overall, this study showed that L. cuneata is rich in flavonoids with promising AR-inhibitory activities, which can be utilized for the development of natural therapies for treating and managing diabetic complications.

Intracellular Zn2+ Signaling Facilitates Mossy Fiber Input-Induced Heterosynaptic Potentiation of Direct Cortical Inputs in Hippocampal CA3 Pyramidal Cells.

Repetitive action potentials (APs) in hippocampal CA3 pyramidal cells (CA3-PCs) backpropagate to distal apical dendrites, and induce calcium and protein tyrosine kinase (PTK)-dependent downregulation of Kv1.2, resulting in long-term potentiation of direct cortical inputs and intrinsic excitability (LTP-IE). When APs were elicited by direct somatic stimulation of CA3-PCs from rodents of either sex, only a narrow window of distal dendritic [Ca2+] allowed LTP-IE because of Ca2+-dependent coactivation of PTK and protein tyrosine phosphatase (PTP), which renders non-mossy fiber (MF) inputs incompetent in LTP-IE induction. High-frequency MF inputs, however, could induce LTP-IE at high dendritic [Ca2+] of the window. We show that MF input-induced Zn2+ signaling inhibits postsynaptic PTP, and thus enables MF inputs to induce LTP-IE at a wide range of [Ca2+]i values. Extracellular chelation of Zn2+ or genetic deletion of vesicular zinc transporter abrogated the privilege of MF inputs for LTP-IE induction. Moreover, the incompetence of somatic stimulation was rescued by the inhibition of PTP or a supplement of extracellular zinc, indicating that MF input-induced increase in dendritic [Zn2+] facilitates the induction of LTP-IE by inhibiting PTP. Consistently, high-frequency MF stimulation induced immediate and delayed elevations of [Zn2+] at proximal and distal dendrites, respectively. These results indicate that MF inputs are uniquely linked to the regulation of direct cortical inputs owing to synaptic Zn2+ signaling.SIGNIFICANCE STATEMENT Zn2+ has been mostly implicated in pathological processes, and the physiological roles of synaptically released Zn2+ in intracellular signaling are little known. We show here that Zn2+ released from hippocampal mossy fiber (MF) terminals enters postsynaptic CA3 pyramidal cells, and plays a facilitating role in MF input-induced heterosynaptic potentiation of perforant path (PP) synaptic inputs through long-term potentiation of intrinsic excitability (LTP-IE). We show that the window of cytosolic [Ca2+] that induces LTP-IE is normally very narrow because of the Ca2+-dependent coactivation of antagonistic signaling pairs, whereby non-MF inputs become ineffective in inducing excitability change. The MF-induced Zn2+ signaling, however, biases toward facilitating the induction of LTP-IE. The present study elucidates why MF inputs are more privileged for the regulation of PP synapses.

High-performance liquid chromatography analysis of phytosterols in Panax ginseng root grown under different conditions.

BACKGROUND: The Panax ginseng plant is used as an herbal medicine. Phytosterols of P. ginseng have inhibitory effects on inflammation-related factors in HepG2 cells. METHODS: Phytosterols (e.g., stigmasterol and ß-sitosterol) in the roots of P. ginseng grown under various conditions were analyzed using high-performance liquid chromatography. The P. ginseng roots analyzed in this study were collected from three cultivation areas in Korea (i.e., Geumsan, Yeongju, and Jinan) and differed by cultivation year (i.e., 4 years, 5 years, and 6 years) and production process (i.e., straight ginseng, red ginseng, and white ginseng). RESULTS: The concentrations of stigmasterol and ß-sitosterol in P. ginseng roots were 2.22-23.04 mg/g and 7.35-59.09 mg/g, respectively. The highest concentrations of stigmasterol and ß-sitosterol were in the roots of 6-year-old P. ginseng cultivated in Jinan (82.14 mg/g and 53.23 mg/g, respectively). CONCLUSION: Six-year-old white ginseng and white ginseng cultivated in Jinan containing stigmasterol and ß-sitosterol are potentially a new source of income in agriculture.

Functional Properties of Novel Epigallocatechin Gallate Glucosides Synthesized by Using Dextransucrase from Leuconostoc mesenteroides B-1299CB4.

Epigallocatechin gallate (EGCG) is the most abundant catechin found in the leaves of green tea, Camellia sinensis. In this study, novel epigallocatechin gallate-glucocides (EGCG-Gs) were synthesized by using dextransucrase from Leuconostoc mesenteroides B-1299CB4. Response surface methodology was adopted to optimize the conversion of EGCG to EGCG-Gs, resulting in a 91.43% conversion rate of EGCG. Each EGCG-G was purified using a C18 column. Of nine EGCG-Gs identified by nuclear magnetic resonance analysis, five EGCG-Gs (2 and 4-7) were novel compounds with yields of 2.2-22.6%. The water solubility of the five novel compounds ranged from 229.7 to 1878.5 mM. The 5'-OH group of EGCG-Gs expressed higher antioxidant activities than the 4'-OH group of EGCG-Gs. Furthermore, glucosylation at 7-OH group of EGCG-Gs was found to be responsible for maintaining tyrosinase inhibitory activity and increasing browning-resistant activities.

Isolation and identification of phytochemicals and biological activities of Hericium ernaceus and their contents in Hericium strains using HPLC/UV analysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Hericium ernaceus has been traditionally used for the treatment of dyspepsia, gastric ulcer and enervation in traditional Chinese medicine for a long time. AIM OF THE STUDY: To examine the effect of Hericium strains on their ability to inhibit LPS and interferon-γ induced NO production in cell culture and the bioassay correlation of hericenone C, D, F, isolated from H. ernaceus. MATERIALS AND METHODS: Hericenone C, D, F were isolated from H. ernaceus by open column chromatography and identified on the basis of spectroscopic analyses including (1)H NMR, (13)C NMR and MS. The amounts of hericenone C, D, and F in Hericium strains were determined by HPLC/UV analysis. In order to investigate the anti-inflammatory effect of Hericium strains extracts, RAW 264.7 cells were treated with 200µg/mL of Hericium strains extracts for 48h. Cell growth was assessed by MTT assay. RESULTS: Phytochemical constituents were isolated from H. ernaceus by open column chromatography. Their structures were elucidated as hericenones C, D, and F on the basis of spectroscopic analyses including (1)H NMR, (13)C NMR and MS. The amounts of hericenones C, D, and F in Hericium strains were determined by HPLC/UV analysis. Hericenones C, D, and F contents were highest in Norugungdenglee-2 (8.289±0.593mg/g), KFRI-1453 (4.657±0.462mg/g), and KFRI-1093 (5.408±0.420mg/g) strains, respectively. All Hericium strains extracts tested inhibited the lipopolysaccharide- and interferon-γ-induced inflammatory activity of RAW264.7 cells. The strain KFRI-1093 about 39.6% reduced NO generation with compared to control. CONCLUSION: We believe that the anti-inflammatory effect of KFRI-1093 was due to hericenone F content. Our results contribute towards validation of the traditional use, natural drugs and health supplements. And also, the developed simple, accurate and rapid LC method can be used determinate the content of hericenones from other Hericium strains.

Novel Dammarane-Type Triterpene Saponins from Panax ginseng Root.

Four phytochemical constituents were isolated from Panax ginseng root by repeated column chromatography (CC), medium pressure liquid chromatography (MPLC), high-speed counter current chromatography (HSCCC), and semi-preparative HPLC. Their structures were elucidated as the dammarane-type triterpene saponins ginsenoside-Rg18 (1), 6-acetyl ginsenoside-Rg3 (2), ginsenoside-Rs11 (3), and ginsenoside-Re7 (4) based on spectral data. Compounds 1-4 from P. ginseng root were new compounds from nature. They showed good hydroxyl radical scavenging activity and anti-bacterial activity against Escherichia coli and Staphylococcus aureus. However, they did not show any anti-inflammatory activity. In addition, they inhibited the growth of adenocarcinoma gastric stomach cells. Among them, ginsenoside-Rs11 (3) showed the best anti-oxidative, anti-bacterial, and anti-cancer activities.

Petasites japonicus Stimulates the Proliferation of Mouse Spermatogonial Stem Cells.

Oriental natural plants have been used as medical herbs for the treatment of various diseases for over 2,000 years. In this study, we evaluated the effect of several natural plants on the preservation of male fertility by assessing the ability of plant extracts to stimulate spermatogonial stem cell (SSC) proliferation by using a serum-free culture method. In vitro assays showed that Petasites japonicus extracts, especially the butanol fraction, have a significant effect on germ cells proliferation including SSCs. The activity of SSCs cultured in the presence of the Petasites japonicus butanol fraction was confirmed by normal colony formation and spermatogenesis following germ cell transplantation of the treated SSCs. Our findings could lead to the discovery of novel factors that activate SSCs and could be useful for the development of technologies for the prevention of male infertility.

The n-Butanol Fraction and Rutin from Tartary Buckwheat Improve Cognition and Memory in an In Vivo Model of Amyloid-ß-Induced Alzheimer's Disease.

This study examined the beneficial effects of the n-butanol fraction and rutin extracted from tartary buckwheat (TB) on learning and memory deficits in a mouse model of amyloid ß (Aß)-induced Alzheimer's disease (AD). Learning and memory were assessed using the T-maze, object recognition, and Morris water maze tests. Animals administered Aß showed impaired cognition and memory, which were alleviated by oral administration of an n-butanol fraction and rutin extracted from TB. Similarly, Aß-induced increases in nitric oxide formation and lipid peroxidation in the brain, liver, and kidneys were attenuated by treatment with n-butanol fraction and rutin from TB in addition to antioxidant effects observed in control (nonAß-treated) animals. The results of the present study suggest that the n-butanol fraction and rutin extracted from TB are protective against and have possible therapeutic applications for the treatment of AD.