Cryptoporic acid S, a new drimane-type sesquiterpene ether of isocitric acid from the fruiting bodies of Cryptoporus volvatus.

A new drimane-type sesquiterpene with an isocitric acid moiety, cryptoporic acid S (1), together with six known compounds, cryptoporic acid D (2), ß-sitosterol (3), ß-daucosterol (4), stigmast-4-en-3-one (5), ergosterol (6), and (22E,24R)-ergosta-7,22-diene-3ß,5α,6ß-triol (7), was isolated from the fruiting bodies of Cryptoporus volvatus. The structures of these compounds were established on the basis of UV, IR, MS, 1D and 2D NMR analysis. In the meanwhile, compounds 1 and 2 were evaluated for antioxidant activity using the methods of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH-RSA) and ferric reducing antioxidant power (FRAP) assay, and they exhibited moderate antioxidant activities.

Synergistic anti-tumor activity and mechanisms of total glycosides from Cimicifuga dahurica in combination with cisplatin.

OBJECTIVE: To determine the effect and mechanism of combination treatment of the total glycosides from Cimicifuga dahurica (TGCD) and cisplatin (CDDP) in vitro in human colon cancer cells (HCT-8) and in vivo in mouse hepatoma cells (H22)-bearing mice. METHODS: H22 tumor-bearing imprinting control region (ICR) mice were treated with TGCD, CDDP, and TGCD + CDDP for 10 days. Tumor volume and tumor weight were evaluated. TGCD and CDDP in different concentrations were added separately and in combination to cultures of different cancer cell lines, including the HCT-8. Effects of TGCD and CDDP on cell proliferation were detected by 3-(4,5-dimethyl-2-thiazole)-2-5-biphenly-tetrazole bromide (MTT) method and effects on cell apoptosis were tested by flfl ow cytometry and western blotting at 24 h after treatment. RESULTS: Combination index values (CI<0.8) suggested the synergistic effects of the TGCD + CDDP. This combination resulted in the highest increase in the percentage of apoptotic HCT-8 cells, caused cell cycle arrest in G2/M phase and increased expression of cleaved caspase-3, -8, and -9, Bax, phospho-c-Jun N-terminal kinase (p-JNK), and phospho-p38 mitogen-activated protein kinase (p-p38 MAPK), as well as decreased expression of Bcl-2, JNK, p38 MAPK, Poly (ADP-ribose) polymerase 1 (PARP1), caspase-3, and caspase-8 compared with single-agent treated and control groups. TGCD + CDDP treatment reduced tumor weight by 86.1%±7.2% compared with 64.5%±6.8% by CDDP or 46.9%±6.9% by the TGCD alone in vivo. CONCLUSIONS: TGCD enhanced the anticancer activity of CDDP in an additive-to-synergistic manner by activating multiple signaling pathways (including apoptosis). These fifi ndings suggest the potential benefifi t of combined treatment of the TGCD and CDDP against cancer of the colon and liver.

Cajaninstilbene acid prevents corticosterone-induced apoptosis in PC12 cells by inhibiting the mitochondrial apoptotic pathway.

BACKGROUND/AIMS: Cajaninstilbene acid (3-hydroxy-4-prenyl-5-methoxystilben-2 -carboxylic acid, CSA), a natural stilbene isolated from the leaves of Cajanus cajan, has attracted considerable attention for its wide range of pharmacological activities. This study investigated whether CSA protects against corticosterone (CORT)-induced injury in PC12 cells and examined the potential mechanisms underlying this protective effect. METHODS: Cell viability and cytotoxicity were detected using a 3-(4,5-desethyithiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and a lactate dehydrogenase (LDH) assay kit, respectively. PC12 cell apoptosis was measured using Hoechst 33342 staining and a DNA fragmentation assay kit, and intracellular Ca(2+) concentrations were assessed by fluorescent labelling. Next, the mitochondrial permeability transition pores (mPTPs) and mitochondrial membrane potentials (∆Ψm) were detected using a colorimetric mPTP detection kit and a 5,5',6,6'-tetrachloro-1,1',3,3'- tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) kit, respectively. Finally, cytochrome c, caspase-3 and inhibitor of caspase-activated deoxyribonuclease (ICAD) expression levels were monitored by western blot analysis. RESULTS: Treatment with 100 µmol/l CORT induced cytotoxicity in PC12 cells. However, CSA dose-dependently increased cell viability and decreased LDH release as well as CORT-induced apoptosis. Mechanistically, compared with the CORT-treated group, CSA strongly attenuated intracellular Ca(2+) overload and restored mitochondrial functions, including mPTPs and ∆Ψm. Furthermore, the down-regulation of cytochrome c and ICAD protein expression and the blockage of caspase-3 activity were observed upon CSA treatment. CONCLUSIONS: In summary, our data are the first to show that the in vitro antidepressant-like effect of CSA may be attributed to the cytoprotection of neurons and that such neuroprotective mechanisms are correlated with intracellular Ca(2+) homeostasis and mitochondrial apoptotic pathways.

Oxidative stress suppression by luteolin-induced heme oxygenase-1 expression.

Luteolin, a flavonoid that exhibits antioxidative properties, exerts myocardial protection effects. However, the underlying molecular mechanisms are not yet fully understood. To investigate the effects of luteolin on myocardial injury protection and its possible mechanisms, a myocardial injury model was established with intragastric administration of 4 mg/kg isoproterenol (ISO) to male Sprague-Dawley rats (200-220 g) daily for 2 days. We found that pretreatment of luteolin (160, 80 and 40 mg/kg, i.g., respectively) daily for 15 days can prevent ISO-induced myocardial damage, including decrease of serum cardiac enzymes, improvement electrocardiography and heart vacuolation. Luteolin also improved the free radical scavenging and antioxidant potential, suggesting one possible mechanism of luteolin-induced cardio-protection is mediated by blocking the oxidative stress. To clarify the mechanisms, we performed the in vitro study by hydrogen peroxide (H(2)O(2))-induced cytotoxicty model in H9c2 cells. We found that luteolin pretreatment prevented apoptosis, increased the expression of heme oxygenase-1 (HO-1), and enhanced the binding of Nrf2 to the antioxidant response element, providing an adaptive survival response against H(2)O(2)-derived oxidative cytotoxicity. The addition of Znpp, a selective HO-1 competitive inhibitor, reduced the cytoprotective ability of luteolin, indicating the vital role of HO-1 on these effects. Luteolin also activated Akt and ERK, whereas the addition of LY294002 and U0126, the pharmacologic inhibitors of PI3K and ERK, attenuated luteolin-induced HO-1 expression and cytoprotective effect. Taken together, the above findings suggest that luteolin protects against myocardial injury and enhances cellular antioxidant defense capacity through the activation of Akt and ERK signal pathways that leads to Nrf2 activation, and subsequently HO-1 induction.

[Neuroprotective effect of longistyline A against corticosterone-induced neurotoxicity in PC12 cells].

This study is to investigate the protective effect of longistyline A against corticosterone-induced neurotoxicity in PC12 cells. While PC12 cells were exposed to 100 micromol x L(-1) corticosterone for 48 h, cell survival rate was reduced and lactate dehydrogenase (LDH) release increased. In parallel, corticosterone caused significant elevations of DNA fragmentation, [Ca2+]i and caspase-3 activity. However, when the PC12 cells were incubated with longistyline A (4.0, 8.0 and 16.0 micromol x L(-1)) in the presence of 100 micromol x L(-1) corticosterone for 48 h, the effects were evidently alleviated, but dose-dependent manner was not obvious. In summary, longistyline A could generate a neuroprotective effect against corticosterone-induced neurotoxicity in PC12 cells possibly by decreasing [Ca2+]i and caspase-3 activity.

[Advances in study on chemical constituents from plants of genus Pfaffia and their bioactivities].

The progress in the studies on chemical constituents and pharmacological activity of the genus Pfaffia is summarized in recent 20 years. These plants contain various chemical constituents and have broad bioactivities such as sthenic, anti-tumor, analgesic and anti-inflammatory and should be further investigated.

[Cytotoxicity and mechanism of 23-O-acetylcimigenol-3-O-beta-D-xylopyranoside on HepG2 cells].

OBJECTIVE: To elucidate the cytotoxicity and mechanism of 23-O-acetylcimigenol-3-O-beta-D-xylopyranoside isolated from C. dahurica on HepG2 cells and to find the leading compound for new drug development. METHOD: MTT, AO/EB staining observation, flow cytometry and western blot methods were used to study the cytotoxicity, morphological changes, cell cycle distribution and protein expression profile of 23-O-acetylcimigenol-3-O-beta-D-xylopyranoside on HepG2 cells. RESULT: 23-O-acetylcimigenol-3-O-beta-D-xylopyranoside could inhibit the proliferation of HepG2 cells with IC50 at 16 micromol x L(-1), and could also induce apoptosis and G2-M cell cycle arrest. Further study demonstrated that the compound could cleavage PARP, regulate protein expression of bcl-2 family and decrease the expression of cdc 2 and cyclin B. CONCLUSION: 23-O-acetylcimigenol-3-O-beta-D-xylopyranoside exerts its cytotoxicity on HepG2 cells via apoptosis and G2-M arrest. In addition, caspases family activation, regulation of protein expression of bcl-2 family and down regulation of cdc 2 and cyclin B were involved in apoptosis and G2-M arrest induced by it.

[Studies on new trierpenoid constituents from the Rhizoma of Cimicifuga foetida].

OBJECTIVE: To find new active constituents from Rhizome of Cimicifuga foetida. METHOD: Various column chromatographic techniques were employed for isolation and purification. The structures were elucidated on the basis of spectral and chemical evidences. RESULT: Four triterpenoid compounds were isolated and identified as 7,8-didehydro-27-deoxyactein(1), 24-O-acetylshengmanol-3-O-beta-D-xyl (23R, 24R)[2], cimigenol(3), cimigenol-3-O-beta-D-xyl(4). CONCLUSION: Compound 1 is a new compound, 2-4 were obtained from this medicinal material for the first time. The antiosteoporosis activity screening in vitro(by the method of SRB) indicates that Compounds 1, 2 and 4 can promote the proliferation for rat Osteoblastoma cell line (UMR106) at the concentration of 10(-9) kg.L-1.