Angiotensin II type-2 receptor signaling facilitates liver injury repair and regeneration via inactivation of Hippo pathway.

The angiotensin II type 2 receptor (AT2R) is a well-established component of the renin-angiotensin system and is known to counteract classical activation of this system and protect against organ damage. Pharmacological activation of the AT2R has significant therapeutic benefits, including vasodilation, natriuresis, anti-inflammatory activity, and improved insulin sensitivity. However, the precise biological functions of the AT2R in maintaining homeostasis in liver tissue remain largely unexplored. In this study, we found that the AT2R facilitates liver repair and regeneration following acute injury by deactivating Hippo signaling and that interleukin-6 transcriptionally upregulates expression of the AT2R in hepatocytes through STAT3 acting as a transcription activator binding to promoter regions of the AT2R. Subsequently, elevated AT2R levels activate downstream signaling via heterotrimeric G protein Gα12/13-coupled signals to induce Yap activity, thereby contributing to repair and regeneration processes in the liver. Conversely, a deficiency in the AT2R attenuates regeneration of the liver while increasing susceptibility to acetaminophen-induced liver injury. Administration of an AT2R agonist significantly enhances the repair and regeneration capacity of injured liver tissue. Our findings suggest that the AT2R acts as an upstream regulator in the Hippo pathway and is a potential target in the treatment of liver damage.

Molecular Characterization and Bioactivity of Coumarin Derivatives from the Fruits of Cucumis bisexualis.

Cucumis bisexualis (Cucurbitaceae) is known as "mapao egg" or "muskmelon egg", which has been widely used as a wild melon in Chinese folk. Nine new coumarin derivatives (1-9), named 7-hydroxy-3-(4',6'-dihydroxy-5'-isopropyl-3″,3″-dimethyl-2 H-chromen)-6-prenyl-2 H-chro-men-2-one (1), 7-hydroxy-3-(5'-prenyl-3″,3″-dimethyl-2 H-chromen)-6-prenyl-2 H-chromen-2-one (2), 3-(6'-hydroxy-5'-prenyl-3″,3″-dimethyl-2 H-chromen)-6-prenyl-2 H-chromen-2-one (3), 3-(5'-ethyl-3″,3″-dimethyl-2 H-chromen)-6-prenyl-2 H-chromen-2-one (4), 3-(4',6'-dihydroxy-5'-dimeth-ylallyl-3″,3″-dimethyl-2 H-chromen)-6-prenyl-2 H-chromen-2-one (5), 3-[4',6'-dihydroxy-5'-(2-pro-penyl)-3″,3″-dimethyl-2 H-chromen]-14,15-dimethyl-pyrano-chromen-2-one (6), 3-(6'-dihydroxy-5'-isopropanol-3″,3″-dimethyl-2 H-chromen)-14,15-dimethyl-pyrano-chromen-2-one (7), 3-(5'-iso-pentenol-3″,3″-dimethyl-2 H-chromen)-14,15-dimethyl-pyrano-chromen-2-one (8), 3-(4',6'-dihydr-oxy-5'-prenyl-3″,3″-dimethyl-2 H-chromen)-14,15-dimethyl-pyrano-chromen-2-one (9), together with 12 known compounds (10-21), were isolated and identified by spectroscopic analysis and references from the active site (EtOAc soluble fraction) of the fruits of C. bisexualis for the first time. Compounds (1-21) were evaluated for antiacetylcholinesterase (AChE) and hepatoprotective activities for the first time. Compounds 1, 3, 5, 6, 7, and 9 showed anti-AChE activities with IC50 values ranging from 11.23 to 89.69 µM, and compounds 2, 4, 12, 15, 17, 18, and 19 (10 µM) exhibited moderate hepatoprotective activities. These findings shed much light on a better understanding of the anti-AChE and hepatoprotective effects of these coumarin derivatives and provided new insights into developing better anti-AChE and hepatoprotective drugs in the future.

Association of VEGF Gene Polymorphisms with the Risk and Prognosis of Cutaneous Squamous Cell Carcinoma.

BACKGROUND Cutaneous squamous cell carcinoma (cSCC) is the second most common type of non-melanoma skin cancer (NMSC) globally. The aims of this study were to further systematically clarify the potential association of rs833061 (-460 C>T) and rs1570360 (-1154 G>A), two SNPs of VEGF, with the risk of cSCC and the prognostic impacts on cSCC patients. MATERIAL AND METHODS This hospital-based case-control study analyzed peripheral venous blood collected from 100 cSCC patients and 124 healthy controls, and gathered personal information on patients. Genotypes of the VEGF gene -460C>T and -1154G>A polymorphism were detected using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. Different distributions of allele frequencies and genotype in the case and control group were measured, comparing different genotype differences in the survival of patients with cSCC. RESULTS Distributions of allele frequencies and genotype of -460 C>T in the case and control group were statistically different; the TT + CT genotype was significantly correlated with a decrease risk of cSCC (OR=0.36, 95% CI=0.21-0.63, P<0.001). There was no difference in the distribution of allele frequencies and genotype of -1154 G>A between control and case groups. For -1154460C>T, the CC genotype was an adverse factor, associated with a significant decrease in the survival status of cSCC patients (P<0.001). For VEGF-1154 G>A, the AA genotype was significantly correlated with the reduced overall survival in cSCC patients, with the mean survival time of 23.88 months (P=0.009). CONCLUSIONS The VEGF gene -460 C>T polymorphism and -1154 G>A polymorphism may serve as potential genetic markers for the risk and prognosis of cSCC.

Characterization of Chalcones from Medicago sativa L. and Their Hypolipidemic and Antiangiogenic Activities.

Medicago sativa L. is the most important cultivated herbage, known as "the king of forage" and "feed queen", in the world. A total of 8 new chalcones (1-8), and 12 known chalcones (9-20) were isolated from the aerial parts of M. sativa for the first time. Their structures were identified by extensive spectral data and references. The hypolipidemic and antiangiogenic activities of compounds (1-20) were evaluated for the first time. Compounds 3, 4, 11, 12, and 20 (10 µM) exhibited significant hypolipidemic activities by measuring the triglyceride content in HepG2 cells, with simvastatin as the positive control. Moreover, compounds 6, 8, 18, and 19 exhibited moderate antiangiogenic activities, which inhibited vascular-endothelial-growth-factor-induced human umbilical vein endothelial cell proliferation in vitro, with IC50 values of 13.86 ± 0.43, 15.53 ± 0.19, 39.52 ± 0.24, and 45.04 ± 0.51 µM, respectively. These research results may guide the search for new natural products with hypolipidemic and antiangiogenic attributes.

Alkenes with antioxidative activities from Murraya koenigii (L.) Spreng.

Four new alkenes (1-4), and six known alkenes (5-12) were isolated from Murraya koenigii (L.) Spreng. Their structures were elucidated on the basis of spectroscopic analyses and references. Compounds (1-12) were evaluated for antioxidative activities. Among them, compounds 1, 2, 4, and 7 exhibited significant antioxidative activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with IC50=21.4-49.5 µM. The known compounds (5-12) were isolated from this plant for the first time.

[Studies on flavonoids from Cirsium setosum].

To investigate the chemical constituents of ethyl acetate from Cirsium setosum, fifteen flavonoids were obtained by column chromatography on silica gel, MCI, Sephadex LH-20, and preparative HPLC. Their structures were identified as 4',5,6-trihydroxy-7-methoxyflavone(1), 4',5-dihydroxy-7,8-dimethoxyflavone(2), sorbifolin-6-O-ß-glucopyranoside(3), kaempferol-7-O-α-L-rhamnoside(4), kaempferol(5), quercetin-3-O-ß-D-glucosyl-7-O-α-L-rhamnoside(6), myricetin(7), myricetin-3-O-ß-D-glucoside(8), 5,7- dihydroxy -3',4'- dimethoxyflavone(9), 3',4',5- trihydroxy-3,7-dimethoxyflavone(10), 3',3,4',5-tetrahydroxy-7-methoxyflavone(11), 3'-hydroxy-4',5,7-trimethoxyflavone(12), 7-hydroxy-3',4',5-trimethoxyflavone(13), 4',5-dihydroxy-2',3',7,8-tetramethoxylflavone(14), and 5-hydroxy-2',3',7,8-tetramethoxylflavone(15) by spectroscopic data analysis. All compounds were isolated from this plant for the first time.Compounds(1-15) were evaluated for their hypoglycemic activities by PTP1B enzyme model. Among them, compounds 2, 12, and 14 showed significant PTP1B inhibitory activities with IC50 values of 2.54, 1.85, 2.11 µmol•L⁻¹, respectively.

Hepatoprotective sesquiterpenes and rutinosides from Murraya koenigii (L.) Spreng.

Three new sesquiterpenes (1-3) and two new rutinosides (4 and 5) along with 17 known compounds (6-22) were isolated from the leaves of Murraya koenigii (L.) Spreng. The new compounds were elucidated as (3R,5S,6R)-3,5,6-trihydroxy-1,1,5-trimethylcyclohexyl-8-butyn-9-one (1), (8E,9R)-ethyl-7-(3S,5R,6S)-3,6-dihydroxy-1,1,5-trimethylcyclohexyl-9-hydroxybut-8-enoate (2), (3R)-3-O-ß-D-glucoside-6'-D-apiose-ß-ionone (3), 4-O-ß-D-rutinosyl-3-methoxyphenyl-1-propanone (4), and 1-O-ß-D-rutinosyl-2(R)-ethyl-1-pentanol (5) based on their spectroscopic data. Compounds 1, 4, 5, 18, and 21 (10 µM) exhibited moderate hepatoprotective activities.

Analysis of optical purity and impurity of synthetic D-phenylalanine products using sulfated beta-cyclodextrin as chiral selector by reversed-polarity capillary electrophoresis.

A new capillary electrophoresis (CE) method has been achieved for simultaneous separation and quantification of phenylalanine, N-acetylphenylalanine enantiomers, and prochiral N-acetylaminocinnamic acid, possibly co-existent in reaction systems or synthesized products of D-phenylalanine. The separation was carried out in an uncoated capillary under reversed-electrophoretic mode. Among the diverse charged cyclodextrins (CDs) examined, highly sulfated (HS)-beta-CD as the chiral selector exhibited the best enantioselectivity. The complete separation of the analytes was obtained under the optimum conditions of pH 2.5, 35 mM Tris buffer containing 4% HS-beta-CD, applied voltage -15 kV, and capillary temperature 25 degrees C. Furthermore, the proposed method was applied to the determination of optical purity and trace impurities in three batches of the asymmetric synthetic samples of D-phenylalanine, and satisfactory results were obtained. The determination recoveries of the samples were in the range of 97.8-103.8%, and precisions fell within 2.3-5.0% (RSD). The results demonstrate that this CE method is a useful, simple technique and is applicable to purity assays of D-phenylalanine.