Mingyan Yang

Cardioprotective effects of salvianolic Acid a on myocardial ischemia-reperfusion injury in vivo and in vitro.

Salvianolic acid A (SAA), one of the major active components of Danshen that is a traditional Chinese medicine, has been reported to possess protective effect in cardiac diseases and antioxidative activity. This study aims to investigate the cardioprotection of SAA in vivo and in vitro using the model of myocardial ischemia-reperfusion in rat and hydrogen peroxide (H2O2)-induced H9c2 rat cardiomyoblasts apoptosis. It was found that SAA significantly limited infarct size of ischemic myocardium when given immediately prior to reperfusion. SAA also significantly suppressed cellular injury and apoptotic cell death. Additionally, the results of western blot and phospho-specific antibody microarray analysis showed that SAA could up-regulate Bcl-2 expression and increase the phosphorylation of proteins such as Akt, p42/p44 extracellular signal-related kinases (Erk1/2), and their related effectors. The phosphorylation of those points was related to suppress apoptosis. In summary, SAA possesses marked protective effect on myocardial ischemia-reperfusion injury, which is related to its ability to reduce myocardial cell apoptosis and damage induced by oxidative stress. The protection is achieved via up-regulation of Bcl-2 expression and affecting protein phosphorylation. These findings indicate that SAA may be of value in cardioprotection during myocardial ischemia-reperfusion injury, which provide pharmacological evidence for clinical application.

In vitro and in vivo anti-inflammatory effects of 4-methoxy-5- hydroxycanthin-6-one, a natural alkaloid from Picrasma quassioides.

In the present study, we evaluated the anti-inflammatory effect of 4-methoxy-5- hydroxycanthin-6-one (CAN), a natural alkaloid isolated from Picrasma quassioides. CAN significantly inhibited the production of NO and the release of TNF-α induced by LPS in macrophage RAW 264.7. Western blot showed that CAN can downregulate the expression of iNOS protein. After oral administration, CAN (3, 9, and 27 mg/kg) reduced the development of carrageenan-induced paw edema and complete Freunds adjuvant (CFA)-induced chronic arthritis in rats. The observed results indicated that pre-treatment with CAN might be an effective therapeutic intervention against inflammatory diseases including chronic arthritis.

Salvianolic acid A as a multifunctional agent ameliorates doxorubicin-induced nephropathy in rats

Nephrotic syndrome (NS) is still a therapeutic challenge. To date there is no ideal treatment. Evidence suggest that multidrug therapy has more effect than monotherapy in amelioration of renal injury. Salvianolic acid A (SAA) is the major active component of Salviae Miltiorrhizae Bunge. Previous studies have demonstrated that SAA is a multi-target agent and has various pharmacological activities. The pleiotropic properties of SAA predict its potential in the treatment of NS. The study investigated the effect of SAA on doxorubicin-induced nephropathy. The kidney function related-biochemical changes, hemorheological parameters and oxidative stress status were determined, and histological examination using light and transmission electron microcopies and western blot analysis were also performed. Results revealed that treatment with SAA alleviated histological damages, relieved proteinuria, hypoalbuminemia and hyperlipidemia, reduced oxidative stress, as well as improving hemorheology. Furthermore, SAA restored podocin expression, down-regulated the expression of NF-κB p65 and p-IκBα while up-regulating IκBα protein expression. Overall, as a multifunctional agent, SAA has a favorable renoprotection in doxorubicin-induced nephropathy. The anti-inflammation, antioxidant, amelioration of podocyte injury, improvement of hemorheology and hypolipidemic properties may constituent an important part of its therapeutic effects. All these indicate that SAA is likely to be a promising agent for NS.

Therapeutic effect of a hydroxynaphthoquinone fraction on dextran sulfate sodium-induced ulcerative colitis.

AIM To evaluate the therapeutic effect of hydroxynaphthoquinone mixture (HM) on dextran sulfate sodium (DSS)-induced colitis and explore the underlying mechanisms. METHODS BALB/c mice received 3.5% DSS for 6 d to induce ulcerative colitis. Groups of mice were orally administered HM 3.5, 7 and 14 mg/kg and mesalazine 200 mg/kg per day for 7 d. During the experiment, clinical signs and body weight, stool consistency and visible fecal blood were monitored and recorded daily. A disease activity index score was calculated for each animal. At the conclusion of the experiment, the colonic histopathological lesions were evaluated. Myeloperoxidase (MPO) activity and tumor necrosis factor-α (TNF-α) levels were determined. Protein expression levels of TNF-α, nuclear factor-κB (NF-κB) p65, inhibitor of κB (IκB) and phosphorylation of IκB (p-IκB) were analyzed by Western blot analysis. RESULTS Administration of 3.5% DSS for 6 d successfully induced acute colitis associated with soft stool, diarrhea, rectal bleeding, and colon shortening, as well as a loss of body weight. Administration of HM effectively attenuated the severity of colonic mucosa injury. For histopathological analysis, HM treatment improved histological alterations and lowered pathological scores compared with the DSS only group. This manifested as a reduction in the extent of colon injury and inflammatory cell infiltration, as well as the degree of mucosal destruction. In addition, HM at doses of 7 and 14 mg/kg significantly decreased MPO activity in colonic tissue (0.98 ± 0.22 U/g vs 1.32 ± 0.24 U/g, 0.89 ± 0.37 U/g vs 1.32 ± 0.24 U/g tissue, P < 0.05) and serum TNF-α levels (68.78 ± 7.34 ng/L vs 88.98 ± 17.79 ng/L, 64.13 ± 14.13 ng/L vs 88.98 ± 17.79 ng/L, P < 0.05). Furthermore, HM down-regulated the expression of TNF-α, NF-κB p65 and p-IκBα in colonic tissue while up-regulating IκBα protein expression. These results suggest that the significant anti-inflammatory effect of HM may be attributable to its inhibition of TNF-α production and NF-κB activation. CONCLUSION HM had a favorable therapeutic effect on DSS-induced ulcerative colitis, supporting its further development and clinical application in inflammatory bowel disease.

Activity study of a hydroxynaphthoquinone fraction from Arnebia euchroma in experimental arthritis

Although various drugs for the treatment of rheumatoid arthritis (RA) have been used in clinics, RA is not completely curable to date. Thus, to seek new drugs for the treatment of RA has been a hotspot. Hydroxynaphthoquinones are the major anti-inflammatory active constituents in Arnebia euchroma (Royle) Johnst. The present study aims to evaluate the anti-arthritic activity of a hydroxynaphthoquinone mixture (HM) of A. euchroma (Royle) Johnst, including its anti-inflammatory and analgesic effects. The anti-arthritic efficacy of HM was examined using complete Freunds adjuvant- and bovine type II collagen-induced arthritic models. The paw edema, polyarthritis index and histopathological change were evaluated. The analgesic effect was assessed using the chemical and thermal models of nociception. Results found that HM administered prophylactically and curatively showed marked anti-arthritic activity by suppressing the paw swelling and development of inflammation, lowering the levels of TNF-α and IL-1β and protecting cartilage and bone from damage. The protection of HM was superior to that of reference drugs such as prednisone acetate or etanercept, and showed no direct deleterious effect. Similarly, HM showed significant analgesic effects. In summary, HM possessed potent anti-arthritic activity. It could relieve inflammatory symptoms and protect against joint destruction. These findings indicate that HM would be a potential therapeutic agent for arthritic disease, which provide pharmacological evidence for its clinical application.

Effectiveness of a hydroxynaphthoquinone fraction from Arnebia euchroma in rats with experimental colitis

AIM To evaluate the potential effectiveness of hydroxynaphthoquinone mixture (HM) in rats with 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis. METHODS Colitis was induced by intracolonic administration of TNBS (80 mg/kg, dissolved in 50% ethanol). Rats were treated daily for 7 d with HM (2.5, 5, 10 mg/kg) and mesalazine 100 mg/kg 24 h after TNBS instillation. Disease progression was monitored daily by observation of clinical signs and body weight change. At the end of the experiment, macroscopic and histopathologic lesions of rats were scored, and myeloperoxidase (MPO) activity was determined. We also determined inflammatory cytokine tumor necrosis factor (TNF)-α level by ELISA, Western blotting and immunochemistry to explore the potential mechanisms of HM. RESULTS After intracolonic instillation of TNBS, animals developed colitis associated with soft stool, diarrhea and marked colonic destruction. Administration of HM significantly attenuated clinical and histopathologic severity of TNBS-induced colitis in a dose-dependent manner. It abrogated body weight loss, diarrhea and inflammation, decreased macroscopic damage score, and improved histological signs, with a significant reduction of inflammatory infiltration, ulcer size and the severity of goblet cell depletion (all P < 0.05 vs TNBS alone group). HM could reduce MPO activity. In addition, it also decreased serum TNF-α level and down-regulated TNF-α expression in colonic tissue. This reduction was statistically significant when the dose of HM was 10 mg/kg (P < 0.05 vs TNBS alone group), and the effect was comparable to that of mesalazine and showed no apparent adverse effect. The underlying mechanism may be associated with TNF-α inhibition. CONCLUSION These findings suggest that HM possesses favourable therapeutic action in TNBS-induced colitis, which provides direct pharmacological evidence for its clinical application.

Andrographolide derivative CX-10 ameliorates dextran sulphate sodium-induced ulcerative colitis in mice: Involvement of NF-κB and MAPK signalling pathways

&NA; Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD), which is characterized by chronic intestinal inflammation and leads to an increased risk of colon cancer. There are many studies using phyto‐ingredients as a novel approach for the treatment of UC. The plant Andrographis paniculata (Acanthaceae) is a safe and edible vegetable that has been extensively adopted in traditional Chinese medicine for conditions involving inflammation, and the most active phytochemical agent is andrographolide. The andrographolide derivative 3,14,19‐triacetyl andrographolide, which is known as CX‐10 (a hemi chemical synthesized from andrographolide), has been found to possess strong anti‐inflammatory properties. In the present study, we investigated the therapeutic potential of CX‐10 as a complementary and alternative medicine against dextran sulphate sodium (DSS)‐induced ulcerative colitis in mice. Our results revealed that CX‐10 treatment reduced body weight loss, reduced colon length shortening, decreased colon weight, decreased the spleen index, decreased the disease activity index (DAI), and alleviated histological damage in the colon. The expression of TNF‐&agr; and IL‐6 and the activity of myeloperoxidase (MPO) in colonic tissues were significantly reduced in CX‐10 supplemented mice. It is noteworthy that the efficacy of 200 mg/kg of CX‐10 was equivalent to that of the mesalazine positive control (200 mg/kg). Furthermore, western blot analysis revealed that CX‐10 treatment reduced the expression of nuclear factor‐&kgr;B (NF‐&kgr;B) p65 and p‐I&kgr;B&agr;, increased the expression of I&kgr;B&agr; and down‐regulated the phosphorylation of p38 mitogen‐activated protein kinase (MAPK), ERK and JNK. In conclusion, CX‐10 treatment attenuated DSS‐induced UC in mice through inhibiting the activation of NF‐&kgr;B and MAPK pathways and reducing TNF‐&agr; and IL‐6 levels, suggesting that CX‐10 is a potential therapeutic drug for UC. Graphical abstract Figure. No caption available. HighlightsCX‐10: monomer with stronger anti‐inflammatory effect than andrographolideCX‐10 attenuated symptoms of UC mice; superior to mesalazine in inhibiting TNF‐&agr;.Our team has independent intellectual property rights of CX‐10 medical application.Low cost and good effect makes CX‐10 possess a broad market prospects.CX‐10 inhibited NF‐&kgr;B and MAPKs in UC mice, laid foundation for CX‐10 development.

Evaluation of the Antidepressant Activity, Hepatotoxicity and Blood Brain Barrier Permeability of Methyl Genipin

Geniposide (GE) is the main bioactive component of Gardeniae Fructus. The hepatotoxicity of geniposide limited clinical application. In order to get a new geniposide derivative that has less hepatotoxicity and still possesses the antidepressant activity, a new C-1 hydroxyl methylation derivative named methyl genipin (MG) was synthesized from geniposide. In the present study, we demonstrated that MG did not increase the liver index, alanine aminotransferase (ALT) and aspirate aminotransferase (AST). Histopathological examination suggested that no toxic damages were observed in rats treated orally with MG (0.72 mmol/kg). More importantly, a 7-day treatment with MG at 0.13, 0.26, and 0.52 mmol/kg/day could reduce the duration of immobility. It showed that the antidepressant-like effects of MG were similar to GE in the tail suspension test and the forced swim test. Furthermore, we found MG could be detected in the brain homogenate of mice treated orally with MG 0.52 mmol/kg/day for 1 day by HPLC. The area under the curve (AUC) of MG in the brain homogenate was enhanced to 21.7 times that of GE. The brain amount and distribution speed of MG were improved significantly after oral administration. This study demonstrated that MG possessed the antidepressant effects and could cross the blood–brain barrier, but had less hepatotoxicity.

Protective effect of Salvianolic acid A on ischaemia‐reperfusion acute kidney injury in rats through protecting against peritubular capillary endothelium damages

Renal ischaemia‐reperfusion (I/R) injury is the most common cause of acute kidney injury (AKI). Peritubular capillary (PTC) endothelium damages are an important pathogenesis during I/R AKI. Salvianolic acid A (SAA) possesses various pharmacological activities. The study investigated whether SAA ameliorated I/R AKI through protecting against PTC endothelium damages. Male Sprague–Dawley rats were divided into 6 groups: control, sham, I/R, and I/R plus SAA (2.5, 5, 10 mg/kg) groups. Rats were subjected to bilateral renal pedicle clamping for 60 min, and killed at 24 hr after reperfusion. Kidney injury, PTC endothelium damages and factors affecting PTC endothelium were evaluated. SAA significantly decreased blood urea nitrogen and serum creatinine levels, and reduced urine kidney injury molecule‐1 concentration. Simultaneously, SAA alleviated histological damages, prevented PTC endothelium damages, preserved the density of PTC and improved renal hypoxia. Furthermore, SAA inhibited platelet activation, elevated Klotho protein expression and up‐regulated vascular endothelial growth factor A expression. Overall, SAA has protective effects on AKI induced by I/R. Preventing PTC endothelium damages and preserving PTC integrity to improve the renal hypoxia may be the ways for SAA to ameliorate AKI. All these indicate that SAA is likely to be a promising agent for AKI.