Three stilbenes from pigeon pea with promising anti-methicillin-resistant Staphylococcus aureus biofilm formation activity.

Cajaninstilbene acid (CSA), longistylin A (LLA), and longistylin C (LLC) are three characteristic stilbenes isolated from pigeon pea. The objective of this study was to evaluate the antibacterial activity of these stilbenes against Staphylococcus aureus and even methicillin-resistant Staphylococcus aureus (MRSA) and test the possibility of inhibiting biofilm formation. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these stilbenes were evaluated. And the results showed that LLA was most effective against tested strains with MIC and MBC values of 1.56 µg/mL followed by LLC with MIC and MBC values of 3.12 µg/mL and 6.25 µg/mL as well as CSA with MIC and MBC values of 6.25 µg/mL and 6.25-12.5 µg/mL. Through growth curve and cytotoxicity analysis, the concentrations of these stilbenes were determined to be set at their respective 1/4 MIC in the follow-up research. In an anti-biofilm formation assay, these stilbenes were found to be effectively inhibited bacterial proliferation, biofilm formation, and key gene expressions related to the adhesion and virulence of MRSA. It is the first time that the anti-S. aureus and MRSA activities of the three stilbenes have been systematically reported. Conclusively, these findings provide insight into the anti-MRSA mechanism of stilbenes from pigeon pea, indicating these compounds may be used as antimicrobial agents or additives for food with health functions, and contribute to the development as well as application of pigeon pea in food science.

Euryachincoside, a Novel Phenolic Glycoside with Anti-Hepatic Fibrosis Activity from Eurya chinensis.

Eurya chinensis has been recorded as a folk medicine traditionally used for treatment of a variety of symptoms. However, the phytochemical and pharmacological investigations of this plant are still scarce. A novel phenolic glycoside named Euryachincoside (ECS) was isolated by chromatographic separation from E. chinensis, and its chemical structure was identified by analysis of HRMS and NMR data. Its anti-hepatic fibrosis effects were evaluated in both HSC-T6 (rat hepatic stellate cells) and carbon tetrachloride (CCl4)-induced mice with Silybin (SLB) as the positive control. In an in vitro study, ECS showed little cytotoxicity and inhibited transforming growth factor-beta (TGF-ß)-induced Collagen I (Col1) along with alpha-smooth muscle actin (α-SMA) expressions in HSC-T6. An in vivo study suggested ECS significantly ameliorated hepatic injury, secretions of inflammatory cytokines, and collagen depositions. Moreover, ECS markedly mediated Smad2/3, nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways both in vitro and vivo. These present findings confirmed that ECS is a novel phenolic glycoside from E. chinensis with promising curative effects on hepatic fibrosis, and its mechanisms may include decreasing extracellular matrix accumulation, reducing inflammation and attenuating free radicals via Smad2/3, NF-κB and Nrf2 signaling pathways, which may shed light on the exploration of more effective phenolic glycoside-based anti-fibrotic agents.

Two new withanolides from the whole plants of Physalis peruviana.

Two new withaphysalin-type withanolides (18-O-ethylwithaphysalin R and 5-O-ethylphysaminimin C, 1 and 2), along with twelve known withanolides (3-14), were purified and identified from Physalis peruviana L. The chemical structures of these new isolates were elucidated through analyzing spectroscopic and HRESIMS data. All the obtained metabolites were appraised for their potential antiproliferative activity against the human breast cancer cell line MCF-7. Compound 7 was discovered to exhibit potent activity with an IC50 value of 3.51 µM and compounds 2, 6 and 14 showed weak cytotoxic effect.

A Review on the Phytochemical and Pharmacological Properties of Rosa laevigata: A Medicinal and Edible Plant.

Rosa laevigata Michx., a medicinal and edible plant in China, has exerted a variety of medicinal values and health benefits. This present review aims to achieve a comprehensive and up-to-date investigation in the phytochemistry and pharmacology of R. laevigata. According to these findings in the literature, approximately 123 chemical ingredients covering triterpenoids, flavonoids, tannis, lignans and polysaccharides, have been characterized from various parts of this species. Among these isolates, 77 triterpenoids have been isolated and thus regarded as the primary and characteristic substance. Based on the chemical structures, most of the obtained triterpenoids can be classified into polyhydroxy triterpenoids and readily divided into four categories: ursane-type, oleanane-type, lupinane-type, as well as seco-triterpenoids. The crude extracts and the purified compounds have demonstrated various pharmacological effects in vitro and in vivo, such as antioxidant activity, immunomodulatory effect, anti-inflammatory effect, liver protection, kidney protection, cardiovascular protection, neuroprotective effect and improvement of diabetic cataract. Noticeably, these pharmacological results of R. laevigata provide evidences for its traditional uses. In addition, these different chemical ingredients existing in the title plant may have synergistic effects. In conclusion, the chemical profiles, including ingredients and structures, together with the modern pharmacological properties have been adequately summarized. These evidences have revealed this plant to be a valuable source for therapeutic foodstuff and more attention should be paid to a better utilization of this plant.

Callistemonols A and B, Potent Antimicrobial Acylphloroglucinol Derivatives with Unusual Carbon Skeletons from Callistemon viminalis.

A phytochemical investigation on the leaves of Callistemon viminalis resulted in the isolation of two unusual compounds, callistemonols A (1) and B (2). Callistemonol A (1) possesses a novel skeleton of a furan ring fusing both an α,ß-triketone and a phloroglucinol unit, while callistemonol B (2) is an acylphloroglucinol derivative featuring two methyl substituents on a five-membered ring and an isovaleryl side chain. Their structures were fully characterized on the basis of extensive spectroscopic analysis, including 1D and 2D NMR parameters, as well as the IR and HRESIMS data. Callistemonol A (1) represents an example of a natural dibenzofuran with two phenyl moieties, and a plausible biogenetic pathway to generate this novel dibenzofuran through a C-C bond-forming radical SAM enzyme is proposed. Moreover, antimicrobial assays, in conjunction with time-killing and biophysical studies, revealed that 1 and 2 exert potent bactericidal activities against a panel of methicillin-resistant pathogenic microbes.

Three new kavalactone dimers from Piper methysticum (kava).

Three new dimeric kavalactones, designated as diyangonins A-C (1-3), along with two known analogs were isolated from the roots of Piper methysticum. Their structures were elucidated by means of extensive analysis of their 1D, 2D NMR, and mass spectroscopic data. All these dimers possess a skeleton featuring a cyclobutane ring connecting two kavalactone units in head-to-tail or head-to-head mode. Compounds 1-5 were evaluated for their cytotoxic activities against human tumor cell lines.

Two new ent-kaurane diterpenes from the stems of Eurya chinensis.

Two new ent-kaurane diterpenes (1-2), together with five known analogs, were isolated from the stems of Eurya chinensis. The structures of new compounds were established by extensive analysis of mass spectrometric and 1D and 2D NMR spectroscopic data. Compound 3 exhibited noticeable anti-inflammatory activity as denoted by inhibiting LPS-induced nitric oxide (NO) production in RAW264.7 cells with an IC50 value of 7.82 µM. Compound 4 showed potent cytotoxic activity against human cancer cell lines NCI-H46, HepG2 and SW480 with IC50 values ranging from 7.45 to 8.54 µM.

MiR-107 down-regulates SIAH1 expression in human breast cancer cells and silencing of miR-107 inhibits tumor growth in a nude mouse model of triple-negative breast cancer.

We have reported that SIAH1 is down-regulated and associated with apoptosis and invasion in human breast cancer. However, the molecular mechanisms leading to SIAH1 down-regulation remain to be elucidated. Here, we demonstrated that miR-107 directly down-regulates SIAH1 expression in human breast cancer cells. Over- expression of miR-107 reduced SIAH1 expression, promoted human breast cancer cell proliferation, colony formation, migration and invasion, and inhibited apoptosis. On the contrary, silencing of miR-107 increased SIAH1 expression and inhibited the tumor growth of MDA-MB-231 cells, a kind of triple-negative breast cancer (TNBC) cells, in vitro and in vivo. Our results reveal that miR-107 is an upstream regulator for SIAH1 down-regulation in human breast cancer cells and miR-107 provides a potential effective target for the treatment of TNBC.

Three new glycosides from the stems of Eurya chinensis R. Br.

Two new phenolic glycosides (1 and 2), one known analogue (3), along with a new diterpene glucoside (4) were obtained from ethanolic extract of the stems of Eurya chinensis R. Br. The structures of these isolated compounds were identified by extensive analysis of HRESIMS and NMR spectroscopic data. The cytotoxicities of these compounds were evaluated on MCF-7, A549, HepG2, CaCo2 and 5-8 F cell lines by MTT method, but no obvious activities were observed.

Pulmonary artery haemodynamic properties in patients with pulmonary hypertension secondary to rheumatic mitral stenosis.

We sought to explore the pulmonary haemodynamic changes in rheumatic mitral stenosis patients with secondary pulmonary hypertension. The pulmonary artery resistance and compliance of 35 patients with rheumatic mitral stenosis and 12 controls without cardiopulmonary vascular disease were evaluated by using an improved method, which is based on making calculations with parameters obtained from right heart catheterisation. The results are as follows: (1) pulmonary artery compliance in patients with secondary pulmonary hypertension was significantly lower than that of the control group (P<0.01); (2) linear correlation analyses showed that preoperative mean pulmonary artery pressure (mPAP) closely correlated with zero-pressure compliance in the mitral stenosis group (r=-0.745, P<0.05); (3) PAP and pulmonary vascular resistance decreased significantly in both groups with mitral stenosis after infusing 0.5 µg kg(-1) min(-1) of sodium nitroprusside (P<0.01). The pulmonary zero pressure compliance and mean pressure compliance increased significantly in the group with mild pulmonary hypertension; whereas in the severe group, the mean compliance changed with significance as the mPAP decreased (1.51 ± 0.59 vs 1.81 ± 0.77 ml/mmHg), however no significant change occurred in the pulmonary zero pressure compliance (2.35 ± 1.24 ml/mmHg vs. 2.24 ± 1.53 ml/mmHg, P>0.05) The walls of pulmonary artery vessels in patients with pulmonary hypertension secondary to rheumatic mitral stenosis appeared to be remodelled by varying degrees as indicated by their haemodynamic properties. Structural remodelling may be a factor affecting preoperative pulmonary artery pressure. Mitral stenosis patients with severe pulmonary hypertension have significantly lower responses to sodium nitroprusside possibly due to aggradation and deposition of collagen in the artery walls, decreasing constriction and dilation, or atrophy of smooth muscle cells.