Guisheng Li

In vitro and in vivo antifibrotic effects of rosmarinic acid on experimental liver fibrosis.

This study was carried out to investigate whether rosmarinic acid (RA) has antifibrotic effect on experimental liver fibrosis in vitro and in vivo and its possible mechanism. Culture of hepatic stellate cells (HSCs) determine proliferation and expression of transforming growth factor-beta1 (TGF-beta1), connective transforming growth factor (CTGF) and alpha-smooth muscle actin (alpha-SMA). In carbon tetrachloride (CCL(4))-induced rat liver fibrosis model, determined biochemical indicator, liver fibrosis grade and histopathological changes, immunohistochemical detected liver TGF-beta1 and CTGF expression. The results indicated that RA could inhibit HSCs proliferation, inhibit TGF-beta1, CTGF and alpha-SMA expression in cultured HSCs. It has marked evident in reducing fibrosis grade, ameliorating biochemical indicator and histopathological morphology, reducing liver TGF-beta1 and CTGF expression in CCL(4)-induced liver fibrosis. These findings suggest that RA has potentially conferring antifibrogenic effects.

Hydroxysafflor Yellow A Inhibits Rat Brain Mitochondrial Permeability Transition Pores by a Free Radical Scavenging Action

Hydroxysafflor yellow A (HSYA), the major and most active antioxidant from Carthamus tinctorius L., has been clinically prescribed in China to treat patients with cerebral ischemia, but the detailed mechanism is not known. This study examines the effect of HSYA on mitochondrial permeability transition pores (mtPTP) in the rat brain. HSYA at 10–80 µmol·l–1 inhibited Ca2+- and H2O2-induced swelling of mitochondria isolated from rat brains. The addition of Ca2+ generated reactive oxygen species (ROS) in isolated mitochondria. HSYA (10–80 µmol·l–1) inhibited Ca2+-induced generation of ROS. At the same time, HSYA significantly improved mitochondrial energy metabolism, enhanced ATP levels and the respiratory control ratio. These results suggest that HSYA inhibits the opening of mtPTP by a free radical scavenging action in the brain, and this may contribute to the neuroprotective effect of HSYA.

Protective roles of Asperosaponin VI, a triterpene saponin isolated from Dipsacus asper Wall on acute myocardial infarction in rats.

Asperosaponin VI is a saponin of the medicinal herb Dipsacus asper (Xuduan), and no pharmacological activity has been reported yet. In this study, we investigated the anti-myocardial ischemia effects of Asperosaponin VI (ASA VI) both in vivo and in vitro. An animal model of myocardial ischemia(MI) injury was induced by coronary occlusion, pretreatment with ASA VI (10 and 20mg/kg, i.v.) could protect the heart from ischemia injury by decreasing the levels of creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), glutamic oxalacetic transaminase (GOT) and cardiac troponin T (cTnT) in serum, increasing the levels of catalase, glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) levels in heart, and decreasing that of malondialdehyde (MDA) level in acute MI rats. ASA VI also raised the activities of mitochondrial enzymes (succinate dehydrogenase (SDH), isocitrate dehydrogenase (ICDH), malate dehydrogenase (MDH) and alpha-ketoglutarate dehydrogenase (alpha-KGDH)) and those of adenosine triphosphate (ATP) content, but lowered Ca(2+) level. Electrocardiograph parameters and histopathological observations demonstrated the same protective effects. In vitro experiment, neonatal rat cardiomyocytes were incubated to test the direct cytoprotective effect of ASA VI against H(2)O(2) exposure. Pretreatment with ASA VI (30 and 60 microg/ml) prior to H(2)O(2) exposure increased cell viability and inhibited H(2)O(2)-induced reactive oxygen species increase. ASA VI (15, 30 and 60 microg/ml) also increased the activities of LDH in the cultured supernatant and SOD in cardiomyocytes, but decreased the cardiomyocytes MDA level. Our results suggested that ASA VI could provide significant cardioprotective effects against acute MI in rats. The mechanisms might be attributed to scavenging lipid peroxidation products and reactive oxygen species, increasing antioxidant defense enzymes and preventing mitochondrial damage.

20(S)-Ginsenoside Rg3, a Neuroprotective Agent, Inhibits Mitochondrial Permeability Transition Pores in Rat Brain

Ginseng, the root of Panax ginseng C.A. Meyer (Araliaceae), is a well‐known traditional Chinese herbal medicine. Ginsenosides, which are triterpene derivatives that contain sugar moieties, are the main active ingredients of ginseng. 20(S)‐Ginsenoside Rg3, a triterpene glycoside which chemically belongs to the protopanaxadiol ginsenoside group, is effective in attenuating brain infarction after cerebral ischemia, but the detailed mechanism is not known. This study examined the effect of 20(S)‐ginsenoside Rg3 on mitochondrial permeability transition pore (MPTP) in the rat brain. 20(S)‐Ginsenoside Rg3 at 2–16 µm inhibited Ca2+‐ and H2O2‐induced swelling of mitochondria isolated from rat brains. The addition of Ca2+ generated reactive oxygen species (ROS) in isolated mitochondria. 20(S)‐Ginsenoside Rg3 (2–16 µm) inhibited Ca2+ induced generation of ROS. At the same time, 20(S)‐ginsenoside Rg3 significantly improved mitochondrial energy metabolism, enhanced ATP levels and the respiratory control ratio. These results suggest that 20(S)‐ginsenoside Rg3 inhibits the opening of MPTP by free radical scavenging action in the brain, and this implies that inhibition of MPTP may contribute to the neuroprotective effect of 20(S)‐ginsenoside Rg3. Copyright

Asperosaponin VI protects cardiac myocytes from hypoxia-induced apoptosis via activation of the PI3K/Akt and CREB pathways

Cardiomyocyte apoptosis plays a critical role in the progress of heart diseases. Asperosaponin VI (ASA VI), a triterpene saponin isolated from Dipsacus asper Wall, has shown cardioprotective effects in vivo. However, whether ASA VI has a protective effect against cardiomyocyte apoptosis is poorly understood. The present study was aimed to investigate the cardioprotective role of ASA VI and the underlying mechanisms in hypoxia-induced cardiomyocyte apoptosis. Cardiomyocytes were exposed to hypoxic condition for 6 h and then cell viability markedly decreased, lactate dehydrogenase (LDH) and creatine phosphokinase (CK) activities in the culture supernatant significantly increased. Hypoxia-activated apoptosis were confirmed by Hoechst 33258 nuclear staining and Annexin V-FITC staining. These changes were associated with the decrease of the Bcl-2/Bax ratio, active caspase-3 expression, phosphorylations of Akt and cAMP response element-binding protein (CREB). Moreover, ASA VI significantly attenuated increased LDH and CK activities, and increased cell viability in hypoxia treated myocytes in a dose-dependent fashion. Hoechst 33258 nuclear staining and Annexin V-FITC staining observations demonstrated the same protective effects. ASA VI treatment inhibited apoptosis in hypoxia-induced cardiomyocyte by increasing the Bcl-2/Bax ratio and decreasing active caspase-3 expression, as well as enhancing of p-Akt and p-CREB. Furthermore, the protective effects of ASA VI were prevented by phosphatidylinositol-3-kinase (PI3K) inhibitor LY294002 treatment. In consequence, we demonstrated that ASA VI had protective effect against hypoxia-induced cardiomyocytes apoptosis probably by activating the PI3K/Akt and CREB pathways.

Effect of astilbin on experimental diabetic nephropathy in vivo and in vitro.

Astilbin, a flavonoid compound, was isolated from the rhizome of Smilax glabra Roxb. This study was conducted to investigate the efficacy of astilbin on experimental diabetic nephropathy (DN) in vivo and in vitro and its possible mechanisms. Astilbin was added in high glucose stimulated HK-2 cells, streptozotocin-induced experimental DN, randomized to receive intragastric ( I. G.) astilbin to observe its anti-renal lesion effect. Results showed that astilbin inhibited high glucose stimulated HK-2 cell production of transforming growth factor-beta1 (TGF-beta1) and connective tissue growth factor (CTGF) in vitro, especially CTGF; analogic results was also found in vivo. I. G. of astilbin 2.5 mg/kg or 5 mg/kg significantly ameliorated renal function, reduced kidney index, while it increased body weight and survival time in animals. In addition there was no significant difference in blood glucose level between the STZ-treated group and the astilbin groups. Furthermore, astilbin ameliorated the pathological progress of renal morphology. Astilbin can exert an early renal protective role to DN, inhibit production of TGF-beta1 and especially of CTGF. We suggest that astilbin inhibition of CTGF may be a potential target in DN therapy. This work provides the first evidence for astilbin as a new candidate of DN therapeutic medicine.

Protections of SMND-309, a novel derivate of salvianolic acid B, on brain mitochondria contribute to injury amelioration in cerebral ischemia rats

SMND-309, a novel compound named (2E)-2-{6-[(E)-2-carboxylvinyl]-2,3-dihydroxyphenyl}-3-(3,4-dihydroxyphenyl) propenoic acid, is a new derivate of salvianolic acid B. The present study was conducted to investigate whether SMND-309 has a protective effect on brain injury after focal cerebral ischemia, and if it did so, to investigate its effects on brain mitochondria. Adult male SD rats were subjected to middle cerebral artery occlusion (MCAO) by bipolar electro-coagulation. Behavioral tests and brain patho-physiological tests were used to evaluate the damage to central nervous system. Origin targets including mitochondria production of reactive oxygen species, antioxidant potentia, membrane potential, energy metabolism, mitochondrial respiratory enzymes activities and mitochondria swelling degree were evaluated. The results showed that SMND-309 decreased neurological deficit scores, reduced the number of dead hippocampal neuronal cells in accordance with its depression on mitochondria swelling degree, reactive oxygen species production, improvements on mitochondria swelling, energy metabolism, membrane potential level and mitochondrial respiratory chain complex activities. All of these findings indicate that SMND-309 exerted potent neuroprotective effects in the model of permanent cerebral ischemia, contributed to its protections on brain mitochondrial structure and function.

ND-309, a novel compound, ameliorates cerebral infarction in rats by antioxidant action

Extract of danshen (Salvia miltiorrhiza Bunge.) has been clinically prescribed in China to treat patients with stroke. The novel compound designated ND-309, namely isopropyl-beta-(3,4-dihydroxyphenyl)-alpha-hydroxypropanoate is a new metabolite of danshen in rat brain. The present study was conducted to investigate whether ND-309 has a protective effect on brain injury after focal cerebral ischemia, and to determine the possible mechanism. Adult male SD rats were subjected to middle cerebral artery occlusion (MCAO) by bipolar electro-coagulation. Behavioral tests were used to evaluate the damage to central nervous system. The cerebral infarct volume and edema were assessed to evaluate the brain patho-physiological changes. Spectrophotometric or spectrofluorometric assay methods were used to determine the generation of reactive oxygen species (ROS), activities of superoxide dismutase (SOD) and glutathione-peroxidase (GSH-Px), contents of malondialdehyde (MDA) and adenosine triphosphate (ATP), as well as respiratory control ratio of the brain mitochondria. The results showed that treatment with ND-309 significantly decreased neurological deficit scores, reduced infarct volume and the edema compared with the model group. Meanwhile, ND-309 significantly increased the brain ATP content, improved mitochondrial energy metabolism, attenuated the elevation of MDA content, the decrease in SOD, GSH-Px activity and the generation of ROS in brain mitochondria. All of these findings indicate that ND-309 has the protective potential against cerebral ischemia injury and its protective effects may be due to the amelioration of cerebral energy metabolism and its antioxidant property.

SMND-309, a novel derivate of salvianolic acid B, ameliorates cerebral infarction in rats: Characterization and role

(2E)-2-{6-[(E)-2-carboxylvinyl]-2,3-dihydroxyphenyl}-3-(3,4-dihydroxyphenyl) propenoic acid, a novel compound designated SMND-309, is a new degradation product of salvianolic acid B. The present study was conducted to evaluate whether SMND-309 has a protective effect on permanent focal cerebral ischemia in rats. The results showed that SMND-309 at doses higher than 4.0 mg/kg (i.v.) produced a significant neuroprotection in focal ischemia rats when administered 30 min after the onset of ischemia. SMND-309 (25.0 mg/kg, i.v.) demonstrated significant neuroprotective activity even after delayed administration at 1 h, 3 h and 6 h after ischemia. The neuroprotective effect of SMND-309 (25.0 mg/kg, bolus injection intravenous at 30 min after middle cerebral artery occlusion) was still present 7 days after ischemia. Meanwhile, SMND-309 significantly increased the brain ATP content, improved mitochondrial energy metabolism and mitochondrial respiratory chain complex activities and attenuated the elevation of malondialdehyde (MDA) content, the decrease in superoxide dismutase (SOD) and glutathione-peroxidase (GSH-Px) activity in brain mitochondria. All of these findings indicate that SMND-309 exerts potent and long-term neuroprotective effects with a favorable therapeutic time-window in the model of permanent cerebral ischemia, and its protective effects may be due to the amelioration of cerebral mitochondrial energy metabolism and the antioxidant property.

SMND-309, a novel derivate of salvianolic acid B, attenuates apoptosis and ameliorates mitochondrial energy metabolism in rat cortical neurons.

SMND-309, a novel compound (2E)-2-[6-[(E)-2-carboxyvinyl]-2,3-dihydroxyphenyl]-3-(3,4-dihydroxyphenyl) acrylic acid, is a new derivate of salvianolic acid B. The present study elucidates the effects of SMND-309 on the cultured rat cortical neuron damage induced by oxygen-glucose deprivation. The results show that SMND-309 treatment obviously attenuates apoptosis and ameliorates mitochondrial energy metabolism in rat cortical neurons by increasing cell survival rate, mitochondrial antioxidant enzyme activities, mitochondrial respiratory enzymes activities, mitochondrial respiratory control ratio and the adenosine triphosphate content, and by decreasing mitochondrial malondialdehyde content, lactate dehydrogenase release, intracellular Ca(2+) level and caspase-3 activity in a concentration-dependent manner. Moreover, SMND-309 exhibits significantly higher potency as compared to salvianolic acid B. These findings indicate that SMND-309 has a protective potential against cerebral ischaemic injury and its protective effects may be due to the suppression of intracellular Ca(2+) elevation and caspase-3 activity, and improvement of mitochondrial energy metabolism and antioxidant property.