A colorimetric sensing strategy based on chitosan-stabilized platinum nanoparticles for quick detection of α-glucosidase activity and inhibitor screening.

α-Glucosidase (α-Glu) is implicated in the progression and pathogenesis of type II diabetes (T2D). In this study, we developed a rapid colorimetric technique using platinum nanoparticles stabilized by chitosan (Ch-PtNPs) to detect α-Glu activity and its inhibitor. The Ch-PtNPs facilitate the conversion of 3,3',5,5'-tetramethylbenzidine (TMB) into oxidized TMB (oxTMB) in the presence of dissolved O2. The catalytic hydrolysis of 2-O-α-D-glucopyranosyl-L-ascorbic acid (AA-2G) by α-Glu produces ascorbic acid (AA), which reduces oxTMB to TMB, leading to the fading of the blue color. However, the presence of α-Glu inhibitors (AGIs) hinders the generation of AA, allowing Ch-PtNPs to re-oxidize colorless TMB back to blue oxTMB. This unique phenomenon enables the colorimetric detection of α-Glu activity and AGIs. The linear range for α-Glu was found to be 0.1-1.0 U mL-1 and the detection limit was 0.026 U mL-1. Additionally, the half-maximal inhibition value (IC50) for acarbose, an α-Glu inhibitor, was calculated to be 0.4769 mM. Excitingly, this sensing platform successfully detected α-Glu activity in human serum samples and effectively screened AGIs. These promising findings highlight the potential application of the proposed strategy in clinical diabetes diagnosis and drug discovery.

Guanxinning tablet inhibits the interaction between leukocyte integrin Mac-1 and platelet GPIbα for antithrombosis without increased bleeding risk.

Recent studies have showed that thrombosis is closely related to leucocytes involved in immunity. Interfering with the binding of leukocyte integrin Mac-1 and platelet GPIbα can inhibit thrombosis without affecting physiological coagulation. Mac-1-GPIbα is proposed as a potential safety target for antithrombotic agents. Guanxinning tablet (GXNT) is an oral Chinese patent medicine used for the treatment of angina pectoris, which contains phenolic acid active ingredients, such as salvianolic acids, ferulic acid, chlorogenic acid, caffeic acid, rosmarinic acid, tanshinol, and protocatechualdehyde. Our previous studies demonstrated that GXN exhibited significant antithrombotic effects, and clinical studies suggested that it did not increase bleeding risk. In addition, GXN exerted a significantly regulatory effect on immune inflammation. In the current study, we intended to evaluate the effects of GXN on bleeding events and explore the safety antithrombotic mechanism of GXN based on leukocyte-platelet interaction. First, we established a gastric ulcer model induced by acetic acid in rats and found that GXN not only did not increase the degree of gastrointestinal bleeding when gastric ulcer occurred, but also had a certain promoting effect on the healing of gastric ulcer. Second, in vitroexperiments showed that after pretreatment with GXN and activation by phorbol 12-myristate-13-acetate (PMA), the adhesion and aggregation of leukocytes with human platelets were reduced. It was also found that GXN reduced the expression and activation of Mac-1 in leucocytes, and inhibited platelet activation due to leukocyte engagement via Mac-1. Overall, the results suggest that GXN may be a safe antithrombotic agent, and its low bleeding risk mechanism is probably related to inhibited leukocyte-platelet aggregation and its interaction target Mac-1-GPIbα.

Dissection of Closely Linked Quantitative Trait Locis Controlling Grain Size in Rice.

Grain size is a key constituent of grain weight and appearance in rice. However, insufficient attention has been paid to the small-effect quantitative trait loci (QTLs) on the grain size. In the present study, residual heterozygous populations were developed for mapping two genetically linked small-effect QTLs for grain size. After the genotyping and the phenotyping of five successive generations, qGS7.1 was dissected into three QTLs and two were selected for further analysis. The qTGW7.2a was finally mapped into a 21.10 kb interval containing four annotated candidate genes. Transcript levels assay showed that the expression of the candidates LOC_Os07g39490 and the LOC_Os07g39500 were significantly reduced in the NIL-qTGW7.2aBG1 . The cytological observation indicated that qTGW7.2a regulated the grain width through controlling the cell expansion. Using the same strategy, qTGW7.2b was fine-mapped into a 52.71 kb interval containing eight annotated candidate genes, showing a significant effect on the grain length and width with opposite allelic directions, but little on the grain weight. Our study provides new genetic resources for yield improvement and for fine-tuning of grain size in rice.

Network Pharmacology-Based Approach Uncovers the Mechanism of GuanXinNing Tablet for Treating Thrombus by MAPKs Signal Pathway.

BACKGROUND: GuanXinNing tablet (GXNT), a traditional Chinese patent medicine, has been found to have remarkable antithrombotic effects and can effectively inhibit pro-thrombotic factors in previous studies. However, the mechanism of its antithrombotic effects remains little known. METHODS: In this study, we first determined and identified the sources of each main compound in GXNT using liquid chromatography-mass spectrometry (LC-MS). Through the approach of network pharmacology, we predicted the action targets of the active components, mapped the target genes related to thrombus, and obtained potential antithrombotic targets for active ingredients. We then performed gene ontology (GO) enrichment analyses and KEGG signaling pathway analyses for the action targets, and constructed networks of active component-target and active component-target-pathway for GXNT. Additionally, we evaluated the pharmacodynamic effects of GXNT on thrombus using the rat thrombus model induced by FeCl3, observed the effects of antiplatelet aggregation via platelet assay, and further verified the results predicted by network pharmacology via Western blot. RESULTS: In total, 14 active ingredients were identified in GXNT, and 83 action targets were predicted, 17 of which are antithrombotic targets that potentially participate in processes including response to oxidative stress and positive regulation of blood vessel endothelial cell migration. KEGG pathway analyses revealed that the predicted action targets were involved in multiple signal pathways, such as MAPK, IL-17, and platelet activation. Pharmacodynamics study found that GXNT could significantly reduce the thrombus length and weight, lower platelet aggregation function, and decrease the levels of Fbg and PAI-1. In addition, GXNT could significantly increase 6-keto-PGF1α content and regulate the ratio of TXB2/6-keto-PGF1α, while not having dramatic effects on TXB2. GXNT was also observed to visibly inhibit maximum platelet aggregation. Herein, we further studied the thrombus-related MAPKs signaling pathway and found that GXNT could significantly reduce the phosphorylation levels of p38MAPK, ERK, and JNK proteins in platelet. CONCLUSIONS: This study revealed the pharmacodynamic material basis of GXNT and its potential multicomponent-multitarget-multipath pharmacological effects, confirmed the antithrombotic effects of GXNT, and showed that its mechanism may be related to inhibiting phosphorylation of p38, ERK, and JNK proteins in MAPKs signaling pathway, partially verifying the results from network pharmacology. The results from this study could provide a theoretical basis for the development and clinical application of GXNT.

Differential expression of microRNA related to irritable bowel syndrome in a rabbit model.

OBJECTIVE: This study aimed to evaluate the differential expressions of microRNAs (miRNAs) in white hair black eye (WHBE) rabbits of irritable bowel syndrome (IBS). METHODS: WHBE and Japanese white (JW) rabbits were divided into the control and IBS groups. The IBS groups were exposed to moist heat, stress and low-dose laxatives. Their intestinal movement rate was measured. Blood samples were taken to detect serum 5-hydroxytryptamine (5-HT) and dopamine levels and colonic tissues were obtained to detect c-Fos expression by immunohistochemistry. Deep sequencing technology was used to obtain miRNA sequences in the intestinal tissues of WHBE and JW control groups. Expressions of 14 miRNAs were measured by real-time polymerase chain reaction in both the control and the IBS model groups. RESULTS: Serum 5-HT and dopamine levels, intestinal movement rate and c-Fos expressions in the WHBE rabbits were significantly increased compared with the control group. MiR-29a-3p, miR-24-3p, miR-221-3p, let-7f-5p, let-7g-5p, let-7i-5p, miR-192-5p, miR-126-3p and miR-130b-3p expressions in WHBE IBS rabbits at day 14 were significantly higher than those in the control group while miR-324-3p and miR-132 were downregulated. MiR-29a-3p, let-7i-5p, miR-192-5p and miR-126-3p were significantly upregulated only in JW IBS rabbits at day 14 and miR-324-3p, miR-223-3p and miR-132 were significantly downregulated in JW IBS group. MiR-24-3p, miR-221-3p, let-7f-5p, miR-126-3p and miR-130b-3p expressions in WHBE IBS rabbits were higher than that in JW IBS rabbits. CONCLUSIONS: Twelve miRNAs were differentially expressed in IBS rabbits. Five are specific in WHBE IBS rabbits, suggesting that they play a role in increased sensitivity to IBS.

Effects of Gnaphalium affine D. Don on hyperuricemia and acute gouty arthritis.

ETHNOPHARMACOLOGICAL RELEVANCE: The Gnaphalium affine D. Don is used in China as a folk medicine to treat gout, anti-inflammatory, antitussive and expectorant activities. The aim of this study was to evaluate the potential of the extract of G. affine to treat hyperuricemia and acute gouty arthritis in animal model. MATERIALS AND METHODS: G. affine extract was evaluated in an experimental model with potassium oxonate (PO) induced hyperuricemia in mice which was used to evaluate anti-hyperuricemia activity and xanthine oxidase (XO) inhibition. Therapies for acute gouty arthritis was also investigated on monosodium urate (MSU) crystal induced paw edema model. RESULTS: G. affine extract showed expressive results on active in reducing serum uric acid (Sur) through effect renal mGLUT9 and mURAT1 mainly and inhibit XO activity in vivo. The extract of G. affine also showed significant anti-inflammatory activity and reduced the paw swelling on MSU crystal-induced paw edema model. Meanwhile, eight major compounds were identified by HPLC-ESI-QTOF-MS/MS. CONCLUSIONS: The extract of G. affine showed significant effect on evaluated models and therefore may be active agents for the treatment of hyperuricemia and acute gouty arthritis.

Activation of 5-HT and NR2B contributes to visceral hypersensitivity in irritable bowel syndrome in rats.

The roles of 5-hydroxytryptamine (5-HT) and spinal N-methyl-D-aspartic acid receptor 2B (NR2B) in visceral hypersensitivity were investigated. A rat model with irritable bowel syndrome (IBS) was established by intracolonic injections of acetic acid onpost-natal days 8-21. Rats were randomly divided into five groups: normal intact (control) group, IBS model group, Ro25-6981-treated IBS rats (Ro25-6981, a NR2B antagonist) group, amitriptyline-treated IBS rats (amitriptyline, a 5-HT antagonist) and Ro25-6981 plus amitriptyline-treated IBS rats (Ro25-6981+amitriptyline) group. The expressions of 5-HT, NR2B, 5-HT2AR, 5-HT7R, SERT, TNF-α and IL-1ß in colon, dorsal root ganglion (DRG) and hypothalamus, respectively, were measured by Immunohistochemical staining, Real-Time Reverse Transcription-PCR and Western blotting. Our results showed increased DRG and hypothalamus expression of 5-HT, NR2B, 5-HT2AR, 5-HT7R in IBS model group and decreased expression of those in Ro25-6981 and amitriptyline alone or both treatment groups. Moreover, SERT expression was decreased in colorectal, DRG and hypothalamus of ISB model rats, but increased by Ro25-6981 and amitriptyline alone or both treatments. Ro25-6981 and amitriptyline treatment also decreased colorectal expression of TNF-α and IL-1ß induced by IBS model. In conclusion, activation of 5-HT and NR2B may play a crucial role in visceral hypersensitivity in irritable bowel syndrome in rats.