Ultrasonic-assisted extraction of flavonoids from Nitraria sibirica leaf using response surface methodology and their anti-proliferative activity on 3T3-L1 preadipocytes and antioxidant activities.

As both an edible and medicinal plant, Nitraria sibirica has been used as a natural remedy for indigestion and hypertension since ancient times in Central Asia. The ethanolic extract of N. sibirica leaves lowers blood pressure and blood lipids. We assume that these bioactivities are most likely related to the composition of flavonoids due to their dominant content. Therefore, we investigated bioactivity-oriented extraction parameters of flavonoids from N. sibirica. In this study, the ultrasonic-assisted extraction variables were optimized using a response surface methodology for optimal recoveries of total flavonoid content (TFC), anti-proliferative activity on 3T3-L1 preadipocytes and antioxidant capacities (DPPH) of N. sibirica leaf extract (NLE). The optimal extraction conditions of NLEs were as follows: ethanol concentration of 71.33%, feed-to-solvent ratio of 30.36 mL/g, extraction temperature of 69.48°C, extraction time of 25.27 min, extraction number of two times, the TFCs were 1.73 ± 0.01 mg RE/g d.w. (n = 4), IC50 value of preadipocytes was 259.42 ± 3.62 µg/mL (n = 4), and antioxidant capacity of 86.55 ± 3.71% (n = 4). After the purification of NLEs, the TFCs were 7.52 mg RE/g d.w., the inhibition capacity of IC50 was 143.50 µg/mL, and DPPH scavenging rate was 86.99%, which were approximately 4.34, 1.81, and 1.01 folds higher than before the purification of NLEs, respectively. Bioactive-oriented extraction of NLEs possessed the potential lipid lowering and antioxidant activities, which hold high research value for the development of natural medicines or new functional foods to treat or prevent metabolic diseases such as obesity.

Mussel-Inspired Caries Management Strategy: Constructing a Tribioactive Tooth Surface with Remineralization, Antibiofilm, and Anti-inflammation Activity.

Dental caries is a common chronic oral disease in humans resulting from tooth demineralization caused by acid production of bacterial plaque, which leads to the destruction of enamel and dentin and oral inflammation. However, it is still a challenge that the function of natural active ingredients in currently available oral care products is not comprehensive, especially the lack of remineralization. Here, inspired by the strong biological adhesion ability of mussels and ancient oral disease plant therapy, a multifunctional strategy is proposed to construct a bioactive tooth surface to treat dental caries. It has been demonstrated that the Turkish gall extract (TGE) can inhibit adhesion of cariogenic bacteria Streptococcus mutans and Actinomyces viscosus and destroy biofilms on the tooth surface. Meanwhile, TGE can reduce the expression of inflammatory factors. Notably, the TGE coating can induce the growth of hydroxyapatite (HAP) crystals in vivo and in vitro, recovering the enamel mechanical properties under normal oral conditions. MD simulations interpreted the adsorption mechanism by which the hydroxyl groups in TGE bind to phosphate group (PO43-) on the tooth surface, attracting calcium ions (Ca2+) as nucleation sites for remineralization. This work underlines the importance of TGE coating in remineralization, antibiofilm, and anti-inflammation activity as a promising strategy for dental caries.

Identification of the chemical constituents in Cullen corylifolium ethanolic extract by LC-MS/MS and GC-MS.

Cullen corylifolium has been used to treat bronchial asthma, vitiligo, nephritis and leucopenia from ancient times in China. However, its chemical composition has not been fully understood. In this study, both LC-MS and GC-MS were used to identify the chemical composition in C. corylifolium. Consequently, 31 compounds were qualified by LC-MS/MS, 8 representative compounds of which were quantified, 62 compounds including hydrocarbons, terpenoids and coumarins were identified by GC-MS. Among a total of 93 compounds, 32 compounds (8 by LC-MS/MS and 24 by GC-MS) are undocumented for this herb. Our results will provide a crucial foundation for further studies related to its pharmaceutical activities and quality control.

Phenolic glycosides from Nitraria sibirica leaves and their in vitro biological activities.

Seventeen phenolic glycosides were isolated from the Nitraria sibirica. Their structures were identified by the spectroscopic data and comparison with literatures as isovanillyl alcohol-7-O-ß-d-glucopyranoside (1), benzyl ß-primeveroside (2), benzyl-O-ß-d-glucopyranoside (3), 1-O-ß-d-glucopyranosyl-4-(8-hydroxyethyl)-2-methoxyphenyl (4), dehydrosyringin (5), trans-ferulic acid-4-O-ß-d-glucoside (6), cis-ferulic acid 4-O-ß-d-glucopyranoside (7), glucosyringic acid (8), 1-O-feruloyl-ß-d-glucoside (9), sachaloside VII (10), (3S, 5R, 6R, 7E, 9S)-megastigmane-7-ene-3-hydroxy-5,6-epoxy-9-O-ß-d-glucopyranoside(11), 3-hydroxy-4,5-dimethoxybenzyl alcohol (12), pinoresinol 4-O-ß-d-glucopyranoside (13), eucommin A (14), isoeucommin A (15), acanthoside (16), liriodendrin (17). All these compounds except compound 13 were isolated from the Nitraria genus for the first time. In bioactivity assays for all compounds, the compounds 8 and 15 were exhibited strong antioxidant activity (IC50 = 18.11 and 16.29 µM respectively), while compounds 3 and 11 were exhibited strong PTP1B enzymatic inhibition (IC50 = 6.97 and 11.76 µM, respectively). Furthermore, the compounds 10 and 17 were presented strong inhibitory capacities against Candida albicans (14.5 and 13.5 mm, respectively).

Comprehensive characterisation of phenolics from Nitraria sibirica leaf extracts by UHPLC-quadrupole-orbitrap- MS and evaluation of their anti-hypertensive activity.

ETHNOPHARMACOLOGICAL RELEVANCE: For more than ten scores years, the leaves and fruits of Nitraria sibirica have been used as a natural remedy for indigestion, irregular manes, and hypertension in the Middle East and Central Asia, especially, are recommended for hypertension treatment in the northwest region, China. AIM OF THE STUDY: we aimed to support the traditional usage of N. sibirica leaves as pharmaceuticals or dietary supplements in treatment of hypertension by investigating their chemical constituents and anti-hypertensive activity. METHODS: We identified the chemical composition of N. sibirica leaves ethanolic purified extract (NSL-EPE) using UHPLC-quadrupole-orbitrap-MS, and quantified the main chemical constituents by an analytical method established and validated. We also evaluated anti-hypertensive activity of NSL-EPE using spontaneously hypertensive rats (SHR): blood pressure was measured weekly by non-invasive blood pressure (NIBP) measurements; hemodynamic parameters, biochemical and clinical chemistry variables in plasma, serum and kidney tissue were measured after 10 weeks of treatment with NSL-EPE as well. RESULTS: UHPLC-quadrupole-orbitrap-MS analysis identified 52 compounds, of which 40 compounds were reported for the first time in N. sibirica. 11 phenolic compounds further quantitatively analyzed, among which the most abundant compound was found to be clovin (8.8%). Systolic blood pressure decreased progressively from the second treatment week compared to that in non-treated SHRs. The plasma endothelin, aldosterone, angiotensin II levels were significantly increased, while the level of NOX was significantly decreased; glutathione to oxidized glutathione ratio, superoxide dismutase and total catalase levels in the kidney tissue were markedly accelerated, while malondialdehyde level was significantly reduced in NSL-EPE treated SHRs. Moreover, the serum cholesterol, triglyceride, blood uria nitrogen and creatinine were attenuated in NSL-EPE treated SHRs (P < 0.05), but in sharp contrast to those values in the water-treated SHRs. CONCLUSION: This study screened out leading compounds from N. sibirica and offered a new understanding of the antihypertensive properties of N. sibirica leaves, by which inhibit oxidative stress-induced endothelial dysfunction and improve lipid profiles.