Structural identification and combination mechanism of iron (II)-chelating Atlantic salmon (Salmo salar L.) skin active peptides.

In order to utilize salmon skin for high value, and investigate the structural identification and combination mechanism of iron (II)-chelating peptides systemically, Atlantic salmon (Salmo salar L.) skin, a by-product of Atlantic salmon processing, was treated by two-step enzymatic hydrolysis to obtain salmon skin active peptides (SSAP). Then they reacted with iron (II) to obtain iron (II)-chelating salmon skin active peptides (SSAP-Fe) with a high iron (II) chelating ability of 98.84%. The results of Fourier transform infrared spectroscopy (FTIR), circular dichroism (CD) spectroscopy, 8-anilino-1-naphthalenesulfonic acid ammonium salt hydrate (ANS) combined fluorescence measurement, isothermal titration calorimetry (ITC) and full wavelength ultraviolet (UV) scanning showed that the structural characteristics of SSAP changed before and after chelating iron (II). Reverse phase high performance liquid chromatography (RP-HPLC) and mass spectrometry were used to identify and quantify the peptides in SSAP-Fe. Four peptide sequences (STEGGG, GIIKYGDDFMH, PGQPGIGYDGPAGPPGPPGPPGAP and QNQRESWTTCRSQSSLPDG) were identified. The content of PGQPGIGYDGPAGPPGPPGPPGAP was the highest, at 25.17 µg/mg. The pharmacokinetic and pharmacodynamic properties of these four peptides were also investigated, and the results indicated that they have satisfactory predicted ADMET properties. Molecular docking technology was used to analyze the binding sites between iron (II) and SSAP, and it was found that PGQPGIGYDGPAGPPGPPGPPGAP had the lowest predicted binding energy with iron (II) and the most stable predicted binding energy with iron (II). This results showed that the stability of SSAP-Fe were closely related to the number of covalent bonds and the types of amino acids. This study revealed the structure and combination mechanism of SSAP-Fe, and indicated that SSAP-Fe prepared by chelation may be used as a Fe supplement that can be applied in functional foods or ingredients.

Role of Dorsomedial Hypothalamus GABAergic Neurons in Sleep-Wake States in Response to Changes in Ambient Temperature in Mice.

Good sleep quality is essential for maintaining the body's attention during wakefulness, which is easily affected by external factors such as an ambient temperature. However, the mechanism by which an ambient temperature influences sleep-wake behaviors remains unclear. The dorsomedial hypothalamus (DMH) has been reported to be involved in thermoregulation. It also receives projection from the preoptic area, which is an important region for sleep and energy homeostasis and the suprachiasmatic nucleus-a main control area of the clock rhythm. Therefore, we hypothesized that the DMH plays an important role in the regulation of sleep related to ambient temperatures. In this study, we found that cold exposure (24/20/16/12 °C) increased wakefulness and decreased non-rapid eye movement (NREM) sleep, while warm exposure (32/36/40/44 °C) increased NREM sleep and decreased wakefulness compared to 28 °C conditions in wild-type mice. Then, using non-specific and specific apoptosis, we found that lesions of whole DMH neurons and DMH γ-aminobutyric acid (GABA)-ergic neurons induced by caspase-3 virus aggravated the fluctuation of core body temperature after warm exposure and attenuated the change in sleep-wake behaviors during cold and warm exposure. However, chemogenetic activation or inhibition of DMH GABAergic neurons did not affect the sleep-wake cycle. Collectively, our findings reveal an essential role of DMH GABAergic neurons in the regulation of sleep-wake behaviors elicited by a change in ambient temperature.

[Clinical research of Pinggan Jiangya decoction combined with penetrating needling at Baihui (GV20) in a period of day from 7 am to 9 am in the treatment of grade 1 and 2 essential hypertension].

OBJECTIVE: To explore the clinical effect of Pinggan Jiangya decoction combined with penetrating needling at Baihui (GV20) in a period of day from 7 am to 9 am in the treatment of grade 1 and 2 essential hypertension (EH). METHODS: A total of 150 cases of grade 1 and 2 EH patients were randomized into an observation group and a control group, 75 cases in each group. In the control group, Pinggan Jiangya decoction was prescribed for oral administration one dose a day, while in the observation group, on the basis of the treatment as the control group, penetrating needling was exerted at GV20 once daily. The treatment duration was 8 weeks. Before and after treatment, the TCM syndrome score, 24 h average systolic blood pressure (24 h ASBP), 24 h average diastolic blood pressure (24 h ADBP), 24 h average pulse pressure difference (24 h PP), morning blood pressure surge (MBPS), 24 h SBP variability (24 h SBPV), 24 h DBP variability (24 h DBPV), serum levels of 5-hydroxytryptamine (5-HT) and melatonin (MT) were compared in the patients of the two groups. The clinical therapeutic effect was observed in the two groups. RESULTS: After the treatment, in the self-comparison of each group, the scores of headache, vertigo, backache, soft knees, tinnitus, 24 h ASBP， 24 h ADBP, 24 h PP, MBPS, 24 h SBPV and 24 h DBPV in the two groups were lower than those before treatment (P<0.01), and the above indexes in the observation group were lower than those in the control group (P<0.01). The level of serum 5-HT after the treatment was lower than that of before the treatment (P<0.01), while the level of MT was higher than that of before the treatment (P<0.01) in both two groups, and the level of 5-HT in the observation group was lower than that of the control group, while the level of MT was higher than that of the control group (P<0.01). The total effective rate of the observation group was 93.3% (70/75), better than 76.0% (57/75) of the control group (P<0.01). CONCLUSION: Pinggan Jiangya decoction combined with penetrating needling at GV20 in a period of day from 7 am to 9 am can regulate the levels of serum MT and 5-HT, effectively reduce blood pressure, improve blood pressure variability, control morning peak blood pressure, and has a remarkable effect in the treatment of grade 1 and 2 EH.

Optical Stimulation of Thalamic Spindle Circuitry Sustains Electroencephalogram Patterns of General Anesthesia but not Duration of Loss of Consciousness.

Alterations in thalamic GABAergic signaling are implicated in mediating the rise in 12-30 Hz electroencephalogram (EEG) activity that signals anesthetic-induced loss-of-consciousness with GABAA receptor-targeting general anesthetics. A number of modeling studies have identified that anesthetic-induced alterations in thalamocortico-corticothalamic signaling in the same network that generates sleep spindles would be sufficient to elicit this key EEG signature of anesthetic hypnosis with general anesthetic agents. Accordingly, we hypothesize that targeted stimulation of this thalamic GABAergic circuitry into a sleep-spindle mode of activity would promote the general anesthetic effects of etomidate. We recorded EEG activity and loss-of-righting reflex in transgenic mice expressing channel rhodopsin-2 on GABAergic neurons (ChR2-VGAT, n = 8) and control, wild-type mice (C57BL/6J, n = 8). On two consecutive days mice were randomly assigned to receive spindle-rhythm stimulation via an optical probe targeting the left reticular thalamic nucleus or no stimulation. After an initial 30-minute recording, mice were administered etomidate (12 mg/kg, intraperitoneal) and recorded for 90 min with or without optical stimulation. Etomidate elicited an increase in 12-30 Hz EEG power in wild-type and ChR2-VGAT mice for 20 min following administration (p < 0.001). Optical spindle-rhythm stimulation prolonged the increase in 12-30 Hz activity in ChR2-VGAT mice only (p = 0.023). Spindle-rhythm stimulation also increased the incidence and duration of sleep spindle-like oscillations in ChR2-VGAT mice only (all p ≤ 0.001). Despite the maintained anesthetic-like changes in EEG activity, optical spindle-rhythm stimulation was not associated with changes in the time to and duration of the loss-of-righting reflex, a behavioral endpoint of etomidate-induced general anesthesia in rodents.

A simple method for the isolation and purification of resveratrol from Polygonum cuspidatum.

Resveratrol, a polyphenol compound with strong biological activity, has been widely used in medicine, health products and cosmetic industries. It is also the main active component of Polygonum cuspidatum, a well-known traditional Chinese medicine. We developed a simple and effective method for the preparation of resveratrol from P. cuspidatum. The whole preparative process consisted of reflux extraction, filtering, hydrolyzing, liquid-liquid extraction and eluting. Filtering is to remove non polar or less polar compounds and debris fragments from the extract. Hydrolyzing is to transform polydatin to resveratrol to improve the yield of resveratrol. Eluting is to remove impurities including strong acidic and water-soluble compounds. By acid hydrolysis of glycoside (polydatin), the yield of resveratrol increased about 4-fold. The extraction recovery in different stages was high, and the content of resveratrol in the final product was over 73.8%. Compared with other methods reported, this technology is eco-friendly, easier to perform, and also has a lower cost.

[Protective effects of tetrandrine against congenital diaphragmatic hernia in rats].

OBJECTIVE: To study the protective effect of the prenatal use of tetrandrine (TET) against congenital diaphragmatic hernia (CDH) in rats and possible mechanisms. METHODS: Pregnant female Sprague-Dawley rats were randomly divided into 3 groups: control, nitrofen and TET treatment. The later two groups were administered with nitrofen by gavage on day 9.5 of gestation. On day 18.5 of gestation, TET (30 mg/kg) was given by gavage (once a day, for three days) in the TET treatment group. On day 21 of gestation, parts of pregnant rats were delivered by cesarean section and amniotic fluid was collected. The fetal rats were examined for a diaphragmatic hernia. Lung histologic evaluations with microscope and immunohistochemistry staining of TNF-α were performed. TNF-α in amniotic fluid was detected using ELISA. The remaining pregnant rats were allowed to deliver spontaneously at term. The survival of pup rats was observed until 24 hrs of age. RESULTS: In the nitrofen group, significant lung hypoplasia was presented not only in fetuses with CDH but also in those without CDH. Stronger expression of TNF-α was observed in fetal lungs and amniotic fluid in the nitrofen group, even when CDH was absent. The TET treatment group showed improved lung development compared with the nitrofen group. The incidence of large diaphragmatic hernia in the TET treatment group was lower than that in the nitrofen group (P<0.05), and the expression of TNF-α in fetal lungs and amniotic fluid in the TET treatment group was also lower than in the nitrofen group (P<0.01). The 24-hr survival rate of pup rats in the TET group was higher than that in the nitrofen group (P<0.01). CONCLUSIONS: Prenatal use of TET can improve nitrofen-induced pulmonary hypoplasia, decrease the incidence of large diaphragmatic hernia and increase the survival rate of pup rats, possibly through a reduction in the production of TNF-α in fetal lungs and amniotic fluid in rats with CDH.

[Study on LC-MS fingerprint for quality assessment of Aristolochia manshuriensis with chemical pattern recognition].

OBJECTIVE: To analyze LC-MS fingerprints of Aristolochia manshuriensis for quality assessment with two different chemical pattern recognition models. METHOD: LC-MS fingerprints of A. manshuriensis were established from 24 batches of samples from different habitats. SIMCA and Clustering analysis were used to compare the parameters of the 29 common peaks. RESULT: Two methods had good consistency, while they reflected the inherent sample information from different perspectives, respectively. CONCLUSION: Modern equipment analysis technology and multivariable chemical pattern recognition would be an efficient way for quality control and variety identification of A. manshuriensis.

[Effect of tetrandrine on lung development: experiment of nitrofen-induced congenital diaphragmatic hernia fetal rat model].

OBJECTIVE: To assess the efficacy of prenatal administration of tetrandrine (TET) on pulmonary hypoplasia in the nitrofen-induced congenital diaphragmatic hernia (CDH) fetal rat model. METHODS: Six timed-pregnant female Sprague-Dawley rats were randomly divided into 3 equal groups: CDH group (receiving gavage of nitrofen 125 mg dissolved in seed fat on day 9.5), and TET group (receiving gavage of nitrofen 125 mg on day 9.5 and then gavage of TET 30 mg/kg on days 11.5 - 14.5), and control group (given the same dose of peanut oil on day 9.5 and the same dose of normal saline on days 11.5 - 14.5). The fetuses were delivered by cesarean section on day 21 to undergo light microscopy and electron microscopy. The numbers of type II pneumocytes were recorded and compared. RESULTS: CDH were detected in 32 of the 41 fetuses from the CDH and TET groups with a teratogenic rate of 78%, however, without a significant difference between the CDH and TET groups (P = 0.645). Microscopy showed significant lung hypoplasia in both histologic structure and cellular structure in the CDH group; however the lung development of the TET group was improved in comparison to the CDH group. There was no significant difference in numbers of type II pneumocytes among the 3 groups (P = 0.779). CONCLUSION: Prenatal administration of TET can improve the lung development of CDH rats in both histological structure and cellular structure. This may provide a new idea for the clinical treatment of CDH.

[Study on the extraction recovery of ginsenoside Re in plasma by different solid-phase cartridges].

OBJECTIVE: To optimize the solid-phase extraction method by comparison of the extraction recovery of ginsenoside Re plasma samples. METHOD: After extracted by different solid-phase cartridges with water, acetonitrile, and different content methanol elution, the plasma samples were analyzed on an Zorbax SB-C18 column with acetonitrile-water gradient elution. From the recovery achieved, the best solid phase cartridge was found. RESULT: This method consists of using 40% methanol as the wash solvent, and 80% methanol for the elution. Among the three kinds of solid-phase being tested, Waters Oasis HLB cartridge was found to be the best one. CONCLUSION: The average extraction recovery of the Waters Oasis HLB cartridges was between 103%-113%, it can be used in the analysis of ginsenoside Re in plasma samples.

Comparison of the metabolism of baicalin in rats orally administered with Radix scutellariae extract and Shuang-Huang-Lian extract.

Shuang-Huang-Lian (SHL) is a traditional Chinese formula containing Flos lonicerae, Radix scutellariae (RS) and Fructus forsythiae, and is commonly used for treating acute upper respiratory tract infection, acute bronchitis and light pneumonia. The aim of the present study is to compare the metabolites of baicalin in rats when orally administered with SHL and Radix scutellariae, and try to explore the principle of SHL compatibility. By using LC-MS(n) and HPLC-DAD, the metabolites of baicalin were analyzed from bile, urine and feces of rats dosed with SHL and RS. Our results showed significant difference of baicalin metabolism between RS and SHL. However, baicalein was found to be the main metabolites of baicalin in intestinal tract after oral administration of RS and SHL, glucuronide, glucoside and methylated products were also found in rat urine after administration of either RS or SHL. Meanwhile, several sulphates were found in rat urine after RS administration, but not found after SHL. Among the metabolites of the SHL, potentially there existed a isomerized baicalin and methylated product: 5,7-dihydroxy-6-methoxyisoflavone-7-O-beta-glucopyranuronoside, but without unidentified metabolite M3. Baicalein-6-O-beta-glucopyranuronoside-7-O-beta-glucopyranuronoside and baicalein-6-O-beta-glucose-7-O-beta-glucopyranuronoside were first reported by this study. The major metabolites of baicalin of RS and SHL in rat bile were the same, including baicalin-6-O-beta-glucopyranuronoside-7-O-beta-glucopyranuronoside, baicalin-6-beta-glucopyranuronoside and 6-O-methyl-baicalin-7-O-beta-glucopyranuronoside. Moreover, baicalein-6-O-beta-glucose-7-O-beta-glucopyranuronoside was also first found in rat bile by this study. Although baicalin-6-O-sulfate-7-O-beta-glucopyranuronoside was found in rat bile after RS administration, no sulphated products were found after oral administration of SHL. These differences of baicalin metabolism between RS and SHL indicated that compatibility of medicines could result in the differences of metabolites.

[Determination of nucleosides in siweilingzhi mixture by HPCE].

OBJECTIVE: To establish a method for determining nucleosides (adenoside and guanoside) in Siweilingzhi Mixture by HPCE. METHOD: Adenoside and guanoside were separated within 25 min using an 20 mmol.L-1 borate buffer with 30 mmol.L-1 SDS and 5% Ethanol (adjusted to pH 10.0 with sodium hydroxide solution), with an operation voltage of 10 kV, temperature of 20 degrees C and a hydrodynamic injection time of 15 s. Seperations were carried out in a fused-silica capillary 75 microns id x 57 cm (effective length 50 cm) with peak detection by direct UV at 254 nm. RESULT: Regression equation of adenoside and that of guanoside were Y = 0.0705 + 0.01707X (r = 0.9995) and Y = 0.0232 + 0.01864X (r = 0.9999) respectively. The average recovery rate was 99.22% (RSD = 3.66%) and 104.3% (RSD = 1.91%) respectively. Nine samples were determined with the method. CONCLUSION: The method is simple, rapid and accurate with good repeatability and it can be used to determine nucleosides.

[Isolation and identification of steroidal saponins in total saponin from Dioscorea nipponica Makino].

AIM: To investigate the water-soluble steroidal saponins in total saponin from Dioscorea nipponica Makino and look for new active compounds. METHODS: The compounds were isolated with silica gel, PTLC and HPLC, and their structures were elucidated by acid hydrolysis, physical and chemical data and spectral analysis (IR, NMR, MS, HMQC, HMBC) as well as chemical correlations. RESULTS: The two steroidal saponins (water-insoluble saponin and water-soluble saponin) were isolated from the total saponin of Dioscorea nipponica Makino. The structures were elucidated as diosgenin 3-O-[alpha-L-rhamnopy ranosyl (1-->2)-[beta-D-glucopyranosyl(1-->3)]]-beta-D-glucopyranoside (I), diosgenin 3-O-[alpha-L-rhamnopyranosyl (1-->3)-alpha-L-rhamnopyranosyl (1-->4)-alpha-L-rhamnopyranosyl (1-->4)]-beta-D-glucopyranoside (II). CONCLUSION: Compound II is a new steroidal saponin and firstly isolated from Dioscorea nipponica Makino. It was named as dioscin Dc.