6-Hydroxydopamine-induced PC12 cell death is mediated by MEF2D down-regulation.

Recently, it was reported that in a 4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model, neuronal cell death is associated with the cdk5-mediated hyperphosphorylation of myocyte enhancer factor 2 (MEF2), a transcription factor that is critically required for neuronal survival. In the present study, we investigated the possible involvement of cdk5-mediated MEF2D down-regulation on 6-hydroxydopamine (6-OHDA)-induced PC12 cell death. 6-OHDA was found to significantly increase nitric oxide (NO) production and to induce apoptosis in a time-dependent manner in PC12 cells. Furthermore, 6-OHDA was found to markedly reduce MEF2D levels under conditions that could induce PC12 cell apoptosis. In addition, PC12 cell death and MEF2D degradation by 6-OHDA were prevented by the cdk5 inhibitor roscovitine, but roscovitine could not restore the 6-OHDA-induced inactivation of Akt. These results suggest that the cell death and MEF2D degradation caused by 6-OHDA are dependent on cdk5 activity. On the other hand, roscovitine enhanced the 6-OHDA-induced activations of ERK1/2 and JNK, but reduced the 6-OHDA-induced activation of p38. These results suggest that PC12 cell death by 6-OHDA appears to be regulated by the down-regulation of MEF2D via some interaction between cdk5 and MAP kinase.

Fucoidan from Undaria pinnatifida induces apoptosis in A549 human lung carcinoma cells.

Fucoidan, a sulfated polysaccharide, has various biological activities, such as anticancer, antiangiogenic and antiinflammatory effects; however, the mechanisms of action of fucoidan on anticancer activity have not been fully elucidated. The anticancer effects of fucoidan from Undaria pinnatifida on A549 human lung carcinoma cells were examined. Treatment of A549 cells with fucoidan resulted in potent antiproliferative activity. Also, some typical apoptotic characteristics, such as chromatin condensation and an increase in the population of sub-G1 hypodiploid cells, were observed. With respect to the mechanism underlying the induction of apoptosis, fucoidan reduced Bcl-2 expression, but the expression of Bax was increased in a dose-dependent manner compared with the controls. Furthermore, fucoidan induced caspase-9 activation, but decreased the level of procaspase-3. Cleavage of poly-ADP-ribose polymerase (PARP), a vital substrate of effector caspase, was found. The study further investigated the role of the MAPK and PI3K/Akt pathways with respect to the apoptotic effect of fucoidan, and showed that fucoidan activates ERK1/2 in A549 cells. Unlike ERK1/2, however, treatment with fucoidan resulted in the down-regulation of phospho-p38 expression. In addition, fucoidan resulted in the down-regulation of phospho-PI3K/Akt. Together, these results indicate that fucoidan induces apoptosis of A549 human lung cancer cells through down-regulation of p38, PI3K/Akt, and the activation of the ERK1/2 MAPK pathway.

Dammarane-type saponins from the flower buds of Panax ginseng and their effects on human leukemia cells.

Six dammarane-type saponins, including three new compounds, floralginsenosides Ta-Tc (1-3), and three known, floralginsenoside Td (4), ginsenoside F(1) (5), and ginsenoside F(5) (6), were isolated from the flower buds of Panax ginseng. Floralginsenoside Td (4) was first isolated from natural plant sources. Their structures were elucidated on the basis of extensive chemical and spectroscopic methods. Compounds 1, 5, and 6 showed cytotoxic activities towards the HL-60 human leukemia cell line with respective IC(50) values of 36.3, 23.2, and 62.4microM. In addition, after the HL-60 cells were treated with these compounds, several apoptosis events, including chromatin condensation and increase in the population of sub-G1 hypodiploid cells, were observed.

Triterpene compounds isolated from Acer mandshuricum and their anti-inflammatory activity.

In our preliminary screening study on the anti-inflammatory activity, a new triterpene compound, aceranol acetate (1), was isolated along with five known compounds: beta-amyrin acetate (2); glutinol acetate (3); friedelin (4); glutinol (5); (3beta)-d-glucopyranoside-stigmast-5-en-3-yl (6), from the stems and leaves of Acer mandshuricum. The structure of the new triterpene was determined to be 5alpha,6alpha-epidioxy-5beta,6beta-epoxy-9,13-dimethyl-25,26-dinoroleanan-3beta-ol acetate by spectroscopic studies. Compounds 2-6 were isolated from this plant for the first. Five triterpene compounds (1-5) showed significant cytotoxic activity with GI(50) in the range of 11.1-17.9microM, whereas steroid compound (6) exhibited moderate activity against four human cancer cell lines (HL-60, SK-OV-3, A549, and HT-29). Furthermore, the anti-inflammatory effects of compounds 1-6 in the non-cytotoxic concentrations (1-100nM) were evaluated for the inhibitory activity of TNF-alpha secretion in the lipopolysaccharide (LPS)-stimulated murine RAW264.7 macrophage cell line. Among the compounds tested, compound 2 showed the strongest anti-inflammatory activity with the inhibition rate up to 38.40% at the concentration of 100nM, whereas other five compounds (2-6) exhibited moderate activity.

Promotion effect of norgalanthamine, a component of Crinum asiaticum, on hair growth.

This study was conducted to evaluate the effect of Crinum asiaticum, a plant native to Jeju Island, Korea, on the promotion of hair growth. When rat vibrissa follicles were treated with a 95% ethanol (EtOH) extract of C. asiaticum, the hair-fiber lengths of the vibrissa follicles increased significantly. In addition, after daily topical application of the EtOH extract of C. asiaticum onto the back of C57BL/6 mice, anagen progression of the hair shaft was induced. Moreover, the extract increased the proliferation of immortalized vibrissa dermal papilla cells. When the vibrissa follicles in the anagen phase were treated with the extract, immunohistochemical analysis revealed that the extract was found to increase the expression of proliferating cell nuclear antigen (PCNA) in the bulb region of the 7-day cultured follicles. In particular, norgalanthamine, a principal of the extract, showed activity that increased the hair-fiber lengths of vibrissa follicles and the proliferation of dermal papilla cells. These results suggest that norgalanthamine, a principal of C. asiaticum, has the potential to promote hair growth via the proliferation of dermal papilla.

Lupane-type triterpene glycosides from the leaves of Acanthopanax koreanum and their in vitro cytotoxicity.

Three new lupane triterpene glycosides, acankoreosides J-L ( 1- 3), were isolated from the leaves of Acanthopanax koreanum. Based on the spectroscopic data, the chemical structures were determined as 3 alpha-hydroxy-20-oxo-30-norlupane-23,28-dioic 28- O- alpha- L-rhamnopyranosyl-(1 --> 4)- beta- D-glucopyranosyl-(1 --> 6)- beta- D-glucopyranosyl ester ( 1); 3 alpha,20,29-trihydroxylupane-23,28-dioic 28- O- alpha- L-rhamnopyranosyl-(1 --> 4)- beta- D-glucopyranosyl-(1 --> 6)- beta- D-glucopyranosyl ester ( 2); and (20S)-3 alpha-hydroxy-29,29-dimethoxylupane-23,28-dioic 28- O- alpha- L-rhamnopyranosyl-(1 --> 4)- beta- D-glucopyranosyl-(1 --> 6)- beta- D-glucopyranosyl ester ( 3). Compounds 1- 3 were evaluated for their cytotoxicity and showed moderate activity against four cell lines, A549 (lung), HL-60 (leukemia), MCF-7 (breast), and U937 (leukemia), with IC (50) values of 23.4, 36.5, 22.6, and 18.5 microM for 1; 6.8, 18.6, 23.1, and > 100 microM for 2; and 28.9, 21.8, 11.0, and 27.5 microM for 3, respectively.

C29 sterols with a cyclopropane ring at C-25 and 26 from the Vietnamese marine sponge Ianthella sp. and their anticancer properties.

Two new C(29) sterols with a cyclopropane ring at C-25 and C-26, petrosterol-3,6-dione (1) and 5alpha,6alpha-epoxy-petrosterol (2), along with petrosterol (3), were isolated from the Vietnamese marine sponge Ianthella sp. The structures of the new compounds were elucidated by comprehensive spectroscopic analyses. Compounds 1-3 showed cytotoxic activities on A549, HL-60, MCF-7, SK-OV-3, and U937 cancer cell lines with IC(50) in the range of 8.4-22.6 microM, whereas compounds 1-3 exhibited only weak cytotoxic activities on HT-29 cell. After HL-60 cells were treated with the compounds, several apoptosis events like chromatin condensation and the increase of the population of sub-G1 hypodiploid cells were observed. These data supported that the compounds might have potential for leukemia treatment.

Apoptosis inducing activity of fucoidan in HCT-15 colon carcinoma cells.

The antitumor activity of fucoidan from Fucus vesiculosus was investigated in human colon carcinoma cells. The crude fucoidan, a polysaccharide composed predominantly of sulfated fucose, markedly inhibited the growth of HCT-15 cells (human colon carcinoma cells). After HCT-15 cells were treated with fucoidan, several apoptotic events such as DNA fragmentation, chromatin condensation and increase of the population of sub-G1 hypodiploid cells were observed. In the mechanism of fucoidan-induced apoptosis, we examined changes in Bcl-2 and Bax protein expression levels and activation of caspases. Fucoidan decreased Bcl-2 expression, whereas the expression of Bax was increased in a time-dependent manner compared to the control. In addition, the active forms of caspase-9 and caspase-3 were increased, and the cleavage of poly(ADP-ribose) polymerase (PARP), a vital substrate of effector caspase, was observed. Furthermore, the induction of apoptosis was also accompanied by a strong activation of extracellular signal-regulated kinase (ERK) and p38 kinase and an inactivation of phosphatidylinositol 3-kinase (PI3K)/Akt in a time-dependent manner. These findings provide evidence demonstrating that the pro-apoptotic effect of fucoidan is mediated through the activation of ERK, p38 and the blocking of the PI3K/Akt signal pathway in HCT-15 cells. These data support the hypothesis that fucoidan may have potential in colon cancer treatment.

Promotion effect of Schisandra nigra on the growth of hair.

This study was conducted to evaluate the effect of Schisandra nigra, a plant native to Jeju Island, South Korea, on the promotion of hair growth. When rat vibrissa follicles were treated with 85% ethanol (EtOH) extract of S. nigra, the hair-fiber lengths of the vibrissa follicles increased significantly. In addition, after topical application of the EtOH extract of S. nigra onto the back of C57BL/6 mice every other day, anagen progression of the hair shaft was induced. Moreover, the extract increased both the expression of proliferating cell nuclear antigen (PCNA) in the bulb matrix region and the proliferation of immortalized vibrissa dermal papilla cells. In order to determine the mechanism by which S. nigra promotes hair growth, we examined its relationship with the transforming growth factor-beta2 (TGF-beta2) signal pathway, which is known to be a regulator of catagen induction. When the vibrissa follicles in the anagen phase were treated with S. nigra extract for 7 days, the expression of TGF-beta2 in the bulb matrix region was found to be lower than that of the control follicles that were expected to be in the anagen-catagen transition phase. These results suggest that S. nigra extract has the potential to promote hair growth via down regulation of TGF-beta2 and the proliferation of dermal papilla.

Lupane triterpene glycosides from leave of Acanthopanax koreanum and their cytotoxic activity.

One new lupane-triterpene glycoside, acankoreoside I (1), and four known compounds, acankoreoside A (2), acankoreoside D (3), acankoreoside F (4), and acantrifoside A (5), were isolated from the leaves of Acanthopanax koreanum (Araliaceae). Their chemical structures were elucidated by mass, 1D- and 2D-NMR spectroscopy. The structure of new compound 1 was determined to be 3alpha,11alpha,30-trihydroxylup-23-al-20(29)-en-28-oic acid 28-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl] ester. The cytotoxic activities of these compounds were evaluated with four cancer cell lines such as A-549 (lung), HL-60 (acute promyelocytic leukemia), MCF-7 (breast), and U-937 (leukemia). Compound 1 showed growth inhibitory effect in A-549, HL-60, and MCF-7 cell lines with the IC(50) values of 8.2 microM, 12.1 microM, and 28.6 microM, respectively, whereas it was less active in the U937 cell line (the IC(50) >100 microM).

Inhibitory effects of indirubin derivatives on the growth of HL-60 leukemia cells.

Six indirubin derivatives have been synthesized and their inhibitory effects on the growth of HL-60 human promyelocytic leukemia cells investigated. Cell viability was determined using the trypan blue exclusion method. Indirubin-3'-oxime (I-1) inhibited the growth of HL-60 cells with a GI50 value of 36.6 microM, whereas I-0, I-2, I-3, I-4 and I-6 showed only weak cytotoxic activities against HL-60 cancer cells with GI50 values in the range of 97.3 to over 100 microM. These results indicate that indirubin derivatives might be useful candidate agents for exploring potential antileukemic drugs.

Chemical components from the Vietnamese soft coral Lobophytum sp.

Chromatographic separation resulted in the identification of one new squalene derivative, named lobophytene (1), three cembranoid diterpenes (2-4), and two sterols (5 and 6) from the Vietnamese marine soft coral Lobophytum sp. Their structures were identified on the basis of extensive spectroscopic data and comparison of those with reported data. Compounds 1 and 2 showed significant cytotoxic activities against lung (A549) and colon (HT-29) cell lines with IC(50) values of 8.2 and 5.6 microM for 1; 5.1 and 1.8 microM for 2, respectively.

Dammarane-type saponins from Gynostemma pentaphyllum.

Dammarane-type saponins, gypenosides VN1-VN7 (1-7), were isolated from the total saponin extract of Gynostemma pentaphyllum aerial parts, with their structures elucidated on the basis of spectroscopic and chemical methods. These compounds showed moderate cytotoxic activity against four human cancer cell lines, A549 (lung), HT-29 (colon), MCF-7 (breast), and SK-OV-3 (ovary), with IC(50) values ranging from 19.6+/-1.1 to 43.1+/-1.0 microM. Regarding the HL-60 (acute promyelocytic leukemia) cell line, compounds 1, 5, and 6 showed weakly active with IC(50) values of 62.8+/-1.9, 72.6+/-3.6, and 82.4+/-3.2 nM, respectively, while 2, 3, 4, and 7 were less active with IC(50) values>100 microM.

A new C29-sterol with a cyclopropane ring at C-25 and 26 from the Vietnamese marine sponge lanthella sp.

One new C(29) sterol with a cyclopropane ring at C-25 and C-26, aragusteroketal B (1), and aragusterol B (2) were isolated from the Vietnamese marine sponge Ianthella sp. Their structures were elucidated by extensive spectroscopic analyses. Both 1 and 2 showed moderate cytotoxic activity against MCF-7, SK-Hep-1, and HeLa cell lines with IC(50) in the range of 12.8-27.8 microM.

New triterpenoid saponins from Glochidion eriocarpum and their cytotoxic activity.

Combined chromatographic methods led to the isolation of two new triterpenoid saponins, glochieriosides A and B (1, 2), from the aerial parts of Glochidion eriocarpum, along with three known triterpenes, glochidone (3), lup-20(29)-en-3beta,23-diol (4), and lup-20(29)-en-1beta,3beta-diol (5). The structures of the new saponins were determined to be 22beta-benzoyloxy-3beta,16beta,28-trihydroxyolean-12-ene 3-O-[beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranoside] (1) and 22beta-benzoyloxy-3beta,16beta,28-trihydroxyolean-12-ene 3-O-[beta-D-glucopyranosyl-(1-->3)-beta-D-xylopyranoside] (2). The structural elucidation was accomplished by using a combination of the 1D-NMR (1H-, 13C-NMR, distortionless enhancement by polarization transfer (DEPT) 90 degrees , and DEPT 135 degrees ), 2D-NMR (1H-1H correlation spectroscopy, heteronuclear multiple quantum correlation, heteronuclear multiple bond correlation, and rotating frame Overhouser effect spectroscopy), ESI-MS, and HR-FAB-MS experiments. Glochieriosides A and B exhibited significant cytotoxic activity against HL-60, HT-29, MCF-7 and SK-OV-3 human cancer cell lines with the IC50 values of 5.5, 6.8, 29.1, and 22.7 microM for glochierioside A, respectively, and 6.6, 18.6, 36.1, and 16.0 microM for glochierioside B. Glochidone was less active with IC50 values greater than 100 microM while lup-20(29)-en-1beta,3beta-diol was moderately active with IC50 values of 43.3, 67.0, 66.1, and 48.0 microM, respectively.

The Effects of Crinum asiaticum on the Apoptosis Induction and the Reversal of Multidrug Resistance in HL-60/MX2.

The present study investigated the anti-proliferative and chemosensitizing effects of Crinum asiaticum var. japonicum against multi-drug resistant (MDR) cancer cells. The 80% methanol extract, chloroform (CHCI3) fraction and butanol (BuOH) fraction of C asiaticum inhibited the growth of mitoxantrone (MX) resistant HL-60 (HL-60/MX2) cells. When HL-60/MX2 cells were treated with the CHCI3 and BuOH fractions, DNA ladder and sub-G1 hypodiploid cells were observed. Furthermore, the fractions reduced Bcl-2 mRNA levels, whereas Bax mRNA levels were increased. These results suggest that the inhibitory effect of C. asiaticum on the growth of the HL-60/MX2 cells might arise from the induction of apoptosis. Treatment of HL-60/MX2 cells with the fractions markedly decreased the mRNA levels of the multi-drug resistance protein-1 and breast cancer resistance protein. The CHCI3 fraction and hexane fraction increased MX accumulation in HL-60/MX2 cells. These results imply that the CHCI3 fraction of C asiaticum plays a pivotal role as a chemosensitizer. We suggest that components of C asiaticum might have a therapeutic potential for the treatment of MDR leukemia.