Purification, Identification, and Mechanistic Investigation of Novel Selenium-Enriched Antioxidant Peptides from Moringa oleifera Seeds.

In this study, five novel Se-enriched antioxidant peptides (FLSeML, LSeMAAL, LASeMMVL, SeMLLAA, and LSeMAL) were purified and identified from Se-enriched Moringa oleifera (M. oleifera) seed protein hydrolysate. The five peptides showed excellent cellular antioxidant activity, with respective EC50 values of 0.291, 0.383, 0.662, 0.1, and 0.123 µg/mL. The five peptides (0.025 mg/mL) increased the cell viability from 78.72 to 90.71, 89.16, 93.92, 83.68, and 98.29%, respectively, effectively reducing reactive oxygen species accumulation and significantly increasing superoxide dismutase and catalase activities in damaged cells. Molecular docking results revealed that the five novel Se-enriched peptides interacted with the key amino acid of Keap1, thus directly blocking the interaction of Keap1-Nrf2 and activating the antioxidant stress response to enhance the ability of scavenging free radicals in vitro. In conclusion, Se-enriched M. oleifera seed peptides exhibited significant antioxidant activity and can be expected to find widespread use as a highly active natural functional food additive and ingredient.

Purification, identification and hypolipidemic activities of three novel hypolipidemic peptides from tea protein.

In this study, hypolipidemic peptides were obtained from tea protein by enzymatic hydrolysis, ultrafiltration and high-performance liquid chromatography. Subsequently, the hypolipidemic peptides were identified by mass spectrometry and screened through molecular docking technology, and the hypolipidemic activities and mechanisms of the active peptides were explored. The results showed that the hydrolysate of hypolipidemic peptides obtained by pepsin hydrolysis for 3 h had good bile salt binding ability. After purification, identification and molecular docking screening, three novel hypolipidemic peptides FLF, IYF and QIF were obtained. FLF, IYF and QIF can interact with the receptor proteins 1LPB and 1F6W through hydrogen bonds, π-π bonds, hydrophobic interactions and van der Waals forces, thus exerting hypolipidemic activities. Activity studies showed that, compared with the positive controls, FLF, IYF and QIF had excellent sodium taurocholate binding abilities, pancreatic lipase inhibitory activities and cholesterol esterase inhibitory activities. Moreover, FLF, IYF and QIF can effectively inhibit lipogenic differentiation of 3T3-L1 preadipocytes, reduce intracellular lipid and low-density lipoprotein content and increase high-density lipoprotein content. These results indicated that the three novel hypolipidemic peptides screened in this study had excellent hypolipidemic activities and were expected to be used as natural-derived hypolipidemic active ingredients for the development and application in functional foods.

Potential impacts of siltation by Spartina alterniflora on nutrient dynamics in its decomposing litters in coastal marsh of the Min River estuary, southeast China.

The Spartina alterniflora started to invade the Min River estuary (Southeast China) in 2002 and, thereafter, its invasion area showed an increasing trend. Since the siltation depths caused by S. alterniflora in the Min River estuary were much higher (4.8-7.2 cm yr-1) than the values reported in other coastal regions of China (3.5-6.5 cm yr-1), the impacts of siltation on nutrient cycle processes in this region might be more evident. In order to explore the potential effects of siltation by S. alterniflora on nutrient ((carbon (C), nitrogen (N), phosphorous (P) and sulfur (S)) variations in its decaying litters, three one-off siltation treatments (no siltation scenario (0 cm yr-1, NSS), current siltation scenario (5 cm yr-1, CSS) and strong siltation scenario (10 cm yr-1, SSS)) were designed in coastal marsh of the Min River estuary and the in-situ decomposition experiment was conducted from February 2016 to February 2017 by litterbag technique. Results showed that the siltation caused by S. alterniflora showed significant impact on its decomposition rate, following the sequence of NSS (0.005638 d-1) > SSS (0.003005 d-1) > CSS (0.002478 d-1) (p < 0.05). The total carbon (TC) contents in decomposing litters in the three siltation treatments showed dissimilar fluctuations and significantly higher values were observed in the CSS and SSS treatments compared to the NSS treatment. The contents of total nitrogen (TN) and total sulfur (TS) in decomposing detritus in the three siltation treatments generally showed increasing trend during the whole decomposition, while those of total phosphorus (TP) showed increasing trend after decomposing for 30 days. The differences in nutrient variations among the three siltation treatments, to a great extent, rested with the alterations of substrate quality in detritus during the experiment. Although the stocks of C, N, P and S in detritus in the three siltation treatments evidenced the release from litters to the surroundings during decomposition, the release amounts of these nutrients in some periods were at a lower level. With increasing siltation depths, the release of C, N and P from detritus was generally restrained during the whole decomposition, while that of S from decaying litters was inhibited only at the late stage of decomposition. This paper found that the siltation caused by S. alterniflora reduced the nutrient return (particularly for C, N and P) from its detritus, which, in turn, might greatly alter the nutrient cycle in S. alterniflora marsh.

Purification, identification, and antioxidative mechanism of three novel selenium-enriched oyster antioxidant peptides.

Natural organic selenium (Se) has multiple physiological health benefits and has become a hotspot of research in recent years. In this study, the Se-enriched antioxidant peptides were purified from Se-enriched oyster hydrolysate. Three novel Se-enriched antioxidant peptides LLVSeMY (685.2953 Da), MMDSeML (687.1875 Da) and VSeMDSeML (703.1599 Da) were identified from fraction F6-4, which all exhibited strong cellular antioxidant activity (CAA) with EC50 values of 0.739, 0.423, and 0.395 µg/mL, respectively. These three Se-enriched antioxidant peptides (0.025 mg/mL) could significantly enhanced cell viability to 84.60 ± 3.32% âˆ¼ 86.18 ± 1.36% compared with the AAPH injury group (75.99 ± 0.79%), and the cytoprotective effects were even better than that of GSH (80.47 ± 2.78%). Moreover, these three Se-enriched peptides also significantly protected HepG2 cells from AAPH-induced oxidative injury by inhibiting ROS production and enhancing the activities of antioxidant enzymes. The molecular docking results showed that these three Se-enriched peptides can form stable hydrogen and hydrophobic bonds with key amino acid residues of Keap1 protein, thereby potentially regulating the Keap1-Nrf2 pathway. In conclusion, the three novel Se-enriched oyster antioxidant peptides are expected to be used in medicine or functional food, providing a new theoretical basis for the high-value utilization of natural organic Se.

[Phosphorus forms in marsh soils with different years of Spartina alterniflora invasion in the Minjiang River estuary, China]. / é—½æ±Ÿæ²³å£äº’èŠ±ç±³è‰ä¸åŒå ¥ä¾µå¹´é™æ¹¿åœ°åœŸå£¤ç£·èµ‹å­˜å½¢æ€.

We examined the effects of Spartina alterniflora invasion on phosphorus forms of marsh soils, based on the method of space-for-time substitution by selecting S. alterniflora marshes with different invasion years (SA1, 5-6 years; SA2, 8-10 years; and SA3, 12-14 years) in Shanyutan of the Minjiang River estuary. The results showed that in marsh soils of different invasion years, the proportion of hardly decomposable phosphorus (HCl-Pi and Residual-P) was the highest (46.4%-46.7%), followed by moderately decomposable phosphorus (NaOH-Pi, NaOH-Po and Sonic-Pi) (40.0%-44.0%), and the easily decomposable phosphorus (Resin-Pi, NaHCO3-Pi and NaHCO3-Po) was the lowest (9.5%-13.3%). With increasing invasion years of S. alterniflora, soil phosphorus forms and their spatial distributions were greatly altered. The contents of moderately decomposable phosphorus, hardly decomposable phosphorus, and total phosphorus (TP) generally increased, while easily decomposable phosphorus content generally decreased. Compared with SA1, the contents of moderately decomposable phosphorus, hardly decomposable phosphorus and TP in SA2 increased by 11.5%, 9.7% and 10.5%, while those in SA3 increased by 24.8%, 13.2% and 13.5%, respectively. The distribution of phosphorus forms was greatly altered with increasing invasion years, which was dependent on the variations of key factors such as EC, pH value and grain composition. The implementation of regular mowing activities for S. alterniflora in the Minjiang River estuary in recent years, to some extent, reduced the return of phosphorus from residues to soils and decreased the availability of the easily decomposable phosphorus in soils.

Herbacetin Broadly Blocks the Activities of CYP450s by Different Inhibitory Mechanisms.

Herbacetin is a bioactive flavanol compound that has various pharmacological effects. However, the pharmacokinetic characteristics have not been thoroughly investigated. Previously, we screened a natural compound library and identified herbacetin as a potent CYP blocker. Herein, we aimed to mechanistically determine the inhibitory effects of herbacetin on CYP450 and its potential application. A human liver microsome incubation system was developed based on a UPLC-MS/MS method. Moreover, an in silico docking assay and a human CYP recombinase reaction system were developed and used to investigate binding affinity and inhibitory efficacy. Subsequently, the effects of the combination of herbacetin and sorafenib on HepG2 cells were assessed by MTT and immunoblotting assays. The concentration of sorafenib and its main metabolite were measured by UPLC-MS/MS after incubation with or without herbacetin. As a result, we found herbacetin almost completely inhibited the functions of major CYPs at 100 µM. Moreover, through analysis of the structure-activity relationship, we found 4-, 6-, and 8-hydroxyl were essential groups for the inhibitory effects. Herbacetin inhibited CYP3A4, CYP2B6, CYP2C9, and CYP2E1 in a mixed manner, but non-competitively blocked CYP2D6. These results are in good agreement with the recombinase reaction in vitro results, with an IC50 < 10 µM for each tested isoenzyme. Interestingly, the stimulatory effects of sorafenib on HepG2 cell apoptosis were significantly enhanced by combining with herbacetin, which was associated with increased sorafenib exposure. In summary, herbacetin is a potent inhibitor of a wide spectrum of CYP450s, which may enhance the exposure of drugs in vivo.

[Mechanism of Huanglian Wendan Decoction in improving impaired glucose tolerance based on skeletal muscle NLRP3/caspase-1/IL-1ß, IL-18 pathway].

This study investigated the mechanism of improving impaired glucose tolerance(IGT) of rats by Huanglian Wendan Decoction from the perspective of the skeletal muscle Nod-like receptor protein 3(NLRP3)/cysteinyl aspartate specific proteinase-1(caspase-1)/interleukin-1ß(IL-1ß), interleukin-18(IL-18) pathway. Healthy male SD rats were fed with the diet containing 45% fat for 20 weeks, accompanied by a high-temperature and high-humidity environment and an inactive lifestyle, for the establishment of the IGT rat model. The rats were divided into the blank control group, model control group, metformin hydrochloride group(positive drug group, 0.05 g·kg~(-1)·d~(-1)) and Huanglian Wendan Decoction group(7.8 g·kg~(-1)·d~(-1)). After continuous intragastric administration for 4 weeks, the obesity and glycemic indexes of all the rats were measured. The fasting serum insulin(FINS) level was determined by ELISA, with the insulin sensitivity index(ISI) and insulin resistance index(IRI) calculated. The mRNA and protein expression le-vels of nuclear factor kappaB(NF-κB), NLRP3, caspase-1, IL-1ß and IL-18 in skeletal muscle tissue were detected by real-time polymerase chain reaction(PCR), Western blot and immunofluorescence. Compared with the blank control group, the model control group witnessed significantly increased mRNA and protein expression of NF-κB, NLRP3, caspase-1, IL-1ß and IL-18. As revealed by the comparison with the model control group, Huanglian Wendan Decoction could effectively regulate the obesity status, reduce body weight, correct the abnormal levels of 2-hour plasma glucose(2 hPG), insulin resistance index(IRI), insulin sensitivity index(ISI), and lower the mRNA and protein expression of NF-κB, NLRP3, caspase-1, IL-1ß and IL-18 in the skeletal muscle tissue of IGT rats. Combined with previous studies, the above results showed that the occurrence and development of IGT was closely related to inflammatory response and the classic pyroptosis pathway in skeletal muscle, such as NLRP3/caspase-1/IL-1ß, IL-18. It is inferred that the mechanism of Huanglian Wendan Decoction was to alleviate insulin resistance(IR) and then reverse the course of IGT lies in the regulation of the abnormal insulin receptor signaling pathway based on the NLRP3 inflammasome pathway.

[Effects of spatial expansion of Phragmites australis and Cyperus malaccensis on distributions and stocks of phosphorus in marshes in the Minjiang River estuary, China.] / 闽江河口芦苇与短叶茳芏空间扩展对湿地系统磷赋存特征的影响.

To investigate the distributions and stocks of total phosphorus (TP) in plant-soil systems of marshes in Shanyutan of the Minjiang River estuary and explore its influencing factors, Phragmites australis (PA) marsh and Cyperus malaccensis (CM) marsh before spatial expansion and ecotonal marsh (EM, P. australis and C. malaccensis in EM were denoted by PA' and CM', respectively) during spatial expansion were studied. Results showed that, as affected by spatial expansion, the contents of TP in both plant and soil in different marshes showed great variations. Compared with PA and CM marshes, soil TP in EM increased by 20.0% and 7.1%, respectively. The variation of soil TP in EM might be attributed to the alteration of soil particle composition, plant bio-mass and root/shoot ratio during spatial expansion. Except for leaves, TP in organs of P. australis in P. australis-C. malaccensis community (PA') was lower than that in C. malaccensis in P. australis-C. malaccensis community (CM'), due to the differences in absorption, utilization and translocation way of P among organs between the two species. The competition effect caused by spatial expansion greatly changed plant P allocation ratio of the two species. Compared with PA and CM, the allocations of P in roots and leaves of PA' increased, while only that in roots of CM' rose. During spatial expansion, the two species might adopt different adaptation strategies for P absorption and utilization to maintain their competitiveness. The PA might compete primarily by strengthening the P accumulation capacities of its roots and promoting leaf photosynthesis, whereas the CM might resist the spatial expansion of PA by increasing its underground biomass to enhance P absorption.

Tetrahydroxy stilbene glucoside protected against diabetes-induced osteoporosis in mice with streptozotocin-induced hyperglycemia.

Tetrahydroxy stilbene glucoside (TSG), an active component from medicinal herb Polygonum multiflorum Thunb, could block the activity of the tissue renin-angiotensin system (RAS), which plays a critical role in development of diabetic osteoporosis. This study aimed to determine if TSG therapy could alleviate bone deteriorations in diabetic mouse model induced by streptozotocin. The diabetic mice showed the loss of trabecular bone mass and the changes of trabecular bone microarchitectural parameters as well as the increase in amount of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts at the distal metaphysis of femur when compared with those of nondiabetic mice. Treatment with TSG significantly elevated calcium content in serum and bone and improved biological parameters of trabecular bone, accompanied by increasing messenger RNA (mRNA) expression of RUNX-2, COL-I, and OCN and protein expression of ß-catenin as well as down-regulating protein expression of RAS components including renin and AT1R. In addition, TSG repressed diabetes-induced decrease in ratio of OPG/RANKL expression and increase in sclerostin expression in bone. The similar effects of TSG on osteoblasts-specific genes were found in MC3T3-E1 cells. Taken together, the present study demonstrated the osteopreserve effects of TSG in diabetic mice, and the underlying mechanism might be attributed to its regulation on osteogenesis and osteoclastogenesis.

Gushukang exerts osteopreserve effects by regulating vitamin D and calcium metabolism in ovariectomized mice.

Calcium homeostasis plays vital roles in the management of bone health. Traditional herbal formula Gushukang (GSK) was clinically applied to treat primary osteoporosis. This study aimed to explore the osteoprotective effects of GSK and its roles in maintaining calcium homeostasis in ovariectomized (OVX) mice. The OVX mice were orally treated with low (0.38 g/kg), middle (0.76 g/kg) and high (1.52 g/kg) dose of GSK for 8 weeks. GSK treatment dramatically increased serum calcium level and decreased urinary calcium excretion as well as enhanced calcium content in bone of OVX mice. Serum level of 25-hydroxyvitamin D was significantly increased in OVX mice with exposure to GSK. Treatment with GSK improved bone mass and micro-structure of trabecular bone at distal metaphysis of femur and proximal metaphysis of tibia in OVX mice shown by safranin O staining and micro-CT measurement. GSK treatment at all doses up-regulated mRNA expression of calcium-binding protein-28k and vitamin D receptor in kidney of OVX mice, and dose-dependently decreased mRNA expression of claudin-14 and elevated mRNA expression of claudin-16 in duodenum of OVX mice. Taken together, GSK exerted beneficial effects on trabecular bone of OVX mice by improving calcium homeostasis via regulating paracellular calcium absorption in duodenum and transcellular calcium reabsorption in kidney.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-d-glucoside exerted protective effects on diabetic nephropathy in mice with hyperglycemia induced by streptozotocin.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-d-glucoside (TSG), an active component from the functional and medicinal herb Polygonum multiflorum Thunb, has the capacity of blocking angiotensin II (ANG II) signaling, a pathway within the renin-angiotensin system (RAS) which plays a critical role in the development of diabetic nephropathy (DN), and blockade of the RAS is currently used for the treatment of DN. Here we investigated the beneficial effect of TSG therapy on renal damage in the streptozotocin (STZ)-induced diabetes model. The STZ-treated C57BL/6J diabetic mice developed progressive albuminuria and renal tubular interstitial fibrosis within 10 weeks, accompanied by increased production of ANG II, fibronection, TGF-ß, CTGF, TNF-α, RANTES and MCP-1 and decreased expression of slit diaphragm proteins in the kidney. The treatment of the diabetic mice with a TSG ameliorated kidney mass increase prevented albuminuria, and reduced tubular interstitial fibrosis. The TSG treatment suppressed the induction of fibronection, CTGF, TGF-ß, and MCP-1 and reversed the decline of slit diaphragm proteins Neph-1, ZO-1, and FAT-1. These were accompanied by blockade of renal renin and ANG II accumulation induced by hyperglycemia. These data demonstrated that the inhibition of the RAS with TSG effectively prevented renal injury in diabetic nephropathy.

[Effect of Weifuchun on inhibiting inflammation of Helicobacter pylori-infected GES-1 cells and NF-kappaB signaling pathway].

OBJECTIVE: To study the effect of Weifuchun on inflammation of Helicobacter pylori (Hp)-infected gastric epithelial cells (GES-1) and its correlation with NF-kappaB signaling pathway. METHODS: Hp standard home-made strain (CagA +, VacA +) NCTCI 1637 infected GES-1 cells were used. Weifuchun was used as intervention. Weifuchun of different concentrations (5,10, and 20 microg/mL) were screened by MTT assay. A blank group and the model group were set up. Then the growth inhibition rate of drugs on gastric epithelial GES-1 cells was detected with MTT assay. Cell cycle was detected using flow cytometry. The supernatant liquid was separated to detect the contents of IL-8 and IL-4 by ELISA.The protein expression level of NF-kappaB was detected by Western blot analysis. RESULTS: MTT assay indicated significantly inhibitory effect of Weifuchun on GES-1 cells [5% inhibiting concentration (IC5)] was 10 microg/ml in the Weifuchun group. After GES-1 and Hp were cultured together,the contents of IL-8 in the supernatant were more obviously higher in the model group than in the blank group (P < 0.05), and then gradually decreased. After treatment with different concentrations of Weifuchun, the levels of IL-8 in the supernatant were less when compared with the model group at 12, 24, 48, and 72 h (P < 0.05). The decrement was the most significant in the high dose Weifuchun group. The IL-4 level in the supernatant was obviously lower in the model group than in the blank group. It obviously increased in the high concentration Weifuchun group (P < 0.05). There was no statistical difference in the IL-4 level between middle, low concentration Weifuchun group and the blank group (P > 0.05). The protein expression of intranuclear P65 increased and that of IkBalpha decreased 60 min after Hp infection. But the protein expression of intranuclear P65 decreased and the protein expression of IkBalpha increased after intervention of Weifuchun. CONCLUSIONS: Weifuchun adjusted H. pylori induced IL-8 and IL-4 production by gastric epithelial cells through blocking NF-kappaB pathways. Its mechanisms might possibly lie in inhibiting p65 from entry into nucleus and the degradation of IkBalpha. Weifuchun was an effective drug for treatment of Hp correlated chronic gastritis.

[Treatment of pectin wastewater by anaerobic biological process].

Anaerobic biological process was used to treat pectin wastewater with acclimated sludge. The effects of the influent pectin concentration and the degradation temperature were investigated, and the intermediate products in pectin degradation were measured. Compared with the unacclimated sludge, the results showed that using acclimated sludge, the pectin removal efficiency was increased by 59.2%. The degradation rate of pectin at influent concentrations of 100, 2500 and 4500 mg x L(-1) were 4.5, 49.8 and 74.0 mg x (L x h)(-1), respectively, indicating that the degradation rate increased with the increase of the influent pectin concentration. The COD removal efficiency was relatively low (41.6% -82.0%) when the influent pectin concentration was lower than 500 mg x L(-1), but it could maintain above 91% when the influent pectin concentration was beyond 1000 mg x L(-1). The higher the temperature was, the shorter the time was needed for pectin degradation. The COD removal efficiency of anaerobic sludge for pectin wastewater was increased from 38.6% to 91.5% when the temperature ranged from 5 degrees C to 35 degrees C, but it was gradually weakened when the temperature exceeded 35 degrees C. The main intermediate products in pectin degradation were supposed to be acetic acid, propionic acid, lower ester, and alkyl alcohols (C12-C40).

Effects of radix curcumae-derived diterpenoid C on Helicobacter pylori-induced inflammation and nuclear factor kappa B signal pathways.

AIM: To study effect of diterpenoid C extracted from radix curcumae on Helicobacter pylori (H. pylori)-infected inflammation, intestinal metaplasia, and nuclear factor kappa B (NF-κB) signaling pathway in vitro. METHODS: We used I-type H. pylori to infect human gastric epithelial gastric epithelium cell line (GES-1) cell lines, and then H. pylori-infected GES-1 cells were treated with radix curcumae (RC)-derived diterpenoid C of different concentrations (5, 10, 20 µg/mL) and amoxicillin. The expression of p65, IκB kinase (IKK) α and IKKγ proteins was detected with Western blotting, and the expression of interleukin (IL)-8, IL-6 and IL-4 was determined with enzyme-linked immunosorbent assay method. Data were analyzed using SPSS software ver18.0. For comparisons between groups of more than two unpaired values, one-way analysis of variance (ANOVA) was used. If an ANOVA F value was significant, post hoc comparisons were performed between groups. If results were not normally distributed, the Mann-Whitney U test was used to compare two groups of unpaired values, whereas for comparisons between groups of more than two unpaired values, the Kruskal-Wallis H test was used. Statistical significance was established at P < 0.05. RESULTS: The MTT assay results revealed the inhibited rate of GES-1, and indicated that the IC5 of RC-derived diterpenoid C and amoxicillin all were 5 µg/mL for gastric GES-1 cells. The expression of IL-8 was significantly increased, especially at 12 h time point; and the expression of IL-4 was decreased in H. pylori-infected GES-1 cells. After H. pylori-infected GES-1 cells were treated with RC-derived diterpenoid C of different concentrations and amoxicillin, the expression of IL-8 was decreased at 12, 24, 48, 72 h points (P < 0.01), especially in high-concentration diterpenoid C (20 µg/mL) group; and the expression of IL-4 was increased, especially in moderate and high-concentration diterpenoid C (10 and 20 µg/mL) groups. RC-derived diterpenoid C had the inhibitory effects on H. pylori-induced p65 translocation from cytoplasm into cell nucleus, H. pylori-stimulant IkBα degradation, the phosphorylation of p65 and IkBα, and the expression of IKKα and IKKß proteins. CONCLUSION: RC-derived diterpenoid C can block NF-κB signal pathway, effectively reducing the secretion of H. pylori-induced proinflammatory cytokine and increasing the secretion of anti-inflammatory cytokine.