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Objective: To investigate the chemical constituents of the rhizomes of Actaea asiatica in order to obtain a more comprehensive understanding of its effective components., Method: Compounds were separated by silica gel chromatography, RP-C18 chromatography and semi-preparative high performance liquid chromatography, and their structures were established by spectral analysis and chemical evidence., Result: Six compounds were isolated from the ethyl acetate extract. Their structures were identified as 25-O-acetylcimigenol (1), 12beta-hydroxycimigenol (2), 23-epi-26-deoxyactein (3), 27-deoxyacetylacteol (4), 26-deoxycimicifugenin (5) and beta-sitosterol (6)., Conclusion: All these compounds mentioned above were isolated from the plant for the first time.

Objective: To study the antioxidative and antitumor activities of flavonoids isolated from Epimedium koreanum., Method: The compounds were separated by column chromatography with silica gel and Sephadex LH-20, and identified by spectral a- nalysis (ESI-MS, 1H-NMR and 13C-NMR) respectively. DPPH radical scavenging assay and MTT assay were used to observe the antioxidative and antitumor abilities., Result: Six compounds were isolated from the the ethyl acetate extract of the aerial part. Their structures were identified as icariin (I), luteolin (II), baohuoside II (III), hyperoside (IV), epimedokoreanin B (V) and baohuoside I (VI). The results indicated that at concentrations of 3. 125-200 micromol x L(-1), compound I, III and VI had no ability to scavenge the DPPH radical, but the scavenging ability of compounds II, IV and V were stronger than that of Vit C in dose-dependant manner. Compounds I, II, V and VI could inhibit the proliferation of MCF-7 and HepG2 in dose-dependant manner, but compounds III and IV had no effect on the proliferation., Conclusion: The antitumor activity of E. koreanum may be partially related to the antioxidantive activity of flavonoids.

To investigate the correlation between genotype and distribution of Pogostemon cablin by sequencing ITS1 and ITS2 genes, and provide molecular information for its germplasm evaluation, ITS1 and ITS2 genes of Pogostemon cablin from different localities were identified by PCR direct sequencing. The sequences of ITS1 and ITS2 genes were 424 bp and 380 bp in length, respectively. And nineteen base substitutions were observed in ITS1 gene, and five in ITS2 gene. The results showed a good correlation between genotype and distribution of Pogostemon cablin, and ITS gene sequencing could provide useful molecular information for germplasm evaluation of the plant species verification.

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.

The anti-osteoporosis activity and mechanism of traditional Chinese medicine and medicinal plants were discussed. It is hoped that we can provide some reference for future drug development and introduction of traditional Chinese medicine to world.

Cycloartane triterpenoids, which exist widely in nature, are mainly distributed in Astragalus (Leguminosae) species, Trib. Cimicifuga (Ranunculaceae) and Thalictrium (Ranunculaceae) species and possess various bioactivities. Along with the development of isolation techniques of phytochemistry, more and more this kind of compounds are isolated and identified. However, bioactivity researches on the compounds are relatively lagged behind. Most researches are still in screening level, deficient in mechanism elucidation, short of action proven in vivo and SAR analysis. The author summarized the bioactivity of this kind of compounds from all aspects: anti-tumor, anti-virus, antibacterial, anti-inflammation, immune-regulatory, cardiovascular system, hepatic protection and so forth. This will be benefit for the further research and development of the compounds.

Aim: To investigate the anti-tumor activity of ursolic acid (UA) and its derivatives isolated from Aralia decaisneana on hepatocellular carcinoma both in vitro and in vivo., Methods: In vivo cytotoxicity was first screened by 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay. Morphological observation, DNA ladder, flow cytometry analysis, Western blot and real time PCR were employed to elucidate the cytotoxic mechanism of UA. Implanted mouse hepatoma H22 was used to evaluate the growth inhibitory effect of UA in vivo., Results: UA could significantly inhibit the proliferation of HepG2 and its drug-resistance strain, R-HepG2 cells, but had no inhibitory effect on primarily cultured normal mouse hepatocytes whereas all the six derivatives of UA could not inhibit the growth of all tested cell lines. Further study on mechanism demonstrated that apoptosis and G0/G1 arrest were involved in the cytotoxicity and cleavage of poly-(ADP-ribose)-polymerase (PARP). Downregulation of cyclooxygenase-2 (COX-2) protein and upregulation of heat shock protein (HSP) 105 mRNA correlated to the apoptosis of HepG2 cells treated with UA. In addition, UA also could inhibit the growth of H22 hepatoma in vivo., Conclusion: UA is a promising anti-tumor agent, but further work needs to be done to improve its solubility.

Aim: To elucidate the molecular mechanism of cell cycle arrest and apoptosis of MCF-7 cells induced by paclitaxel., Methods: Flow cytometry was used to determine the cell cycle changes of MCF-7 cells upon paclitaxel treatment. Gene expression profiles of MCF-7 cells induced by paclitaxel were obtained by using cDNA microarrays containing 9984 genes and expressed sequence tags (ESTs)., Results: Cell cycle analysis showed that 77.8% of cells arrested at G2/M phase and 1.3% of cells underwent apoptosis upon 100 nmol x L(-1) paclitaxel treatment for 24 hours; cDNA microarray results revealed that 27 and 77 genes were differentially expressed upon 12.5 nmol x L(-1) (IC50) and 100 nmol x L(-1) paclitaxel treatment, respectively., Conclusion: Paclitaxel stabilized microtubules and caused G2/M cell cycle arrest and apoptotic cell death in a concentration-dependent manner, which is associated with the regulation of selected genes related to microtubule assembly and cytoskeleton, cell cycle regulation, and DNA repair and apoptosis.

Surface plasmon resonance biosensor technique was used to study the binding of Moloney murine leukemia virus reverse transcriptase without RNase H domain (MMLV RT-) with DNA in the absence and in the presence of inhibitors. Different DNA substrates, including single-stranded DNA (ssDNA), DNA template-primer (T-P) duplex and gapped DNA, were immobilized on the biosensor chip surface using streptavidin-biotin, and MMLV RT(-)-DNA binding kinetics were analyzed by different models. MMLV RT-; could bind with ssDNA and the binding was involved in conformation change. MMLV RT-; binding DNA T-P duplex and gapped DNA could be analyzed using the simple 1:1 Langmuir model. The lack of RNase H domain reduced the affinity between MMLV RT-; and T-P duplex. The effects of RT inhibitors, including efavirenz, nevirapine and quercetin, on the interaction between MMLV RT-; and gapped DNA were analyzed according to recovered kinetics parameters. Efavirenz slightly interfered with the binding between RT and DNA and the affinity constant in the presence of the inhibitor (K(A) = 1.21 x 10(6) M(-1)) was lower than in the absence of the inhibitor (KA = 4.61 x 10(6) M(-1)). Nevirapine induced relatively tight binding between RT and DNA and the affinity constant in the presence of the inhibitor (K(A) = 1.47 x 10(7) M(-1)) was approximately three folds higher than without nevirapine, mainly due to rapid association and slow dissociation. Quercetin, a flavonoid originating from plant which has previously shown strong inhibition of the activity of RT, was found to have minimal effect on the RT-DNA binding.

Objective: To elucidate the potential molecular mechanism responsible for the early time of tumor promotion, gene expression profile was studied in the transformed BALB/c 3T3 cells induced by 12-O-tetradecanoylphorbol-13-acetate (TPA)., Methods: The two-stage cell transformation model was established by using the initiator of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and promoter of TPA. Cell proliferation was measured by trypan blue staining and cell cycle analysis was carried out by flow cytometry assay. A cDNA microarray representing 1 152 genes was used to investigate the gene expression profiles of BALB/c 3T3 cells exposed to TPA at 4 h and 24 h respectively., Results: TPA could effectively inhibit cell proliferation and induce the G1 and S cell cycle arrested in the early time. Moreover 19 genes were found differentially expressed at least twofold in the TPA treated cells as compared with the control cells, 9 of them were upregulated and 10 downregulated. Most of the differentially expressed genes were involved in cell proliferation, differentiation or apoptosis, and related to ras or p53 signal transduction pathway., Conclusion: TPA could influence the transcriptional expression of some genes related to cell cycle modulation and ultimately result in the cell growth arrest.

The pyranocoumarin (+)-4'-O-acetyl-3 'O-angeloyl-cis-khellactone (PC) isolated from Radix Peucedani (root of Peucedanum praeruptorum Dunn) showed a dose-dependent effect at 10 -30 pg/mL on causing apoptotic DNA and nuclear fragmentations in HL-60 cells. After 24 h of PC treatment there were losses of mitochondrial membrane potential and cytochrome c. PC also increased total cellular and mitochondrial Bax protein, stimulated an increase in caspase-dependent Bcl-2 cleavage but showed no effect on Bcl-Xv. These observations strongly suggest activation of the mitochondria apoptotic pathway. The pan-specific caspase inhibitor, ZVAD-fmk, abolished the PC-induced apoptosis,whereas the caspase-8 inhibitor IETD-fmk showed no effect, implying the involvement of the caspase 9 pathway. PC caused a 2 to 12 hour transient increase in phospho-ERK, and a 72 h-long activation of JNK. Pre-treatment with the MEK inhibitor PD98059, which suppresses ERK activation, paradoxically promoted PC-induced mitochondrial cytochrome c release, procaspase-3 and -8 cleavage, and enhanced apoptosis. Our results show that PC triggers mitochondria-mediated apoptosis in HL-60 cells, and the involvement of ERK and JNK signal pathways in the process.

Aim: To elucidate the molecular mechanism of granulocytic differentiation of human promyelocytic leukemia HL-60 cells induced by all-trans-retinoic acid (ATRA)., Methods: Flow cytometry was used to determine the cell cycle changes of HL-60 cells upon ATRA treatment. Gene expression profiles of HL-60 cells induced by 1 mumol.L-1 ATRA were obtained by using cDNA microarrays containing 9,984 genes and expressed sequence tags (ESTs)., Results: Cell cycle analysis showed that 48%-73% of cells were arrested at G1/G0 phase upon ATRA treatment; cDNA microarray results demonstrated that the expression of genes encoding adhesion molecules, tissue remodeling proteins, transporters and ribosomal proteins were up-regulated in ATRA treated of HL-60 cells. Several genes involved in oxidase activation pathway were also differentially expressed., Conclusion: ATRA treatment induced growth arrest and differentiation in HL-60 cells, which is associated with regulation of the oxidase activation pathway and the expression of tissue remodeling proteins.

Aim: To investigate the genetic polymorphism of several species of Fritillaria and to develop a DNA chip for the genotyping and identification of the origin of various species of Fritillaria at molecular level., Methods: Genomic DNA from bulbs of several Fritillaria species was extracted and the polymorphisms of the D2 and D3 regions inside the 26S rDNA gene were identified by direct sequencing. Oligonucleotide probes specific for these polymorphisms were designed and printed on the poly-lysine coated slides to prepare the DNA chip. PCR products from the Fritillaria species were labeled with fluorescence by incorporation of dye-labeled dideoxyribonucleotides and hybridized to the immobilized probes on the chip., Results: The polymorphisms were used as markers for discrimination among various species. Specific oligonucleotide probes were designed and immobilized on a DNA chip. Differentiation of the various Fritillaria species was accomplished based on hybridization of fluorescent labeled PCR products with the DNA chip., Conclusion: The results demonstrated the reliability of using DNA chips to identify different species of Fritillaria, and the DNA chip technology can provide a rapid, high throughput tool for genotyping and quality assurance of the plant species verification.

Over the last decade, the lab-on-a-chip concept has received considerable attention. This technology promises significant advantages in terms of speed, cost, sample/reagent consumption, contamination, efficiency and automation. In this review, we focus on lab-on-a-chip with fluid flow along micro-scale channels (microfluidics) and its application on life science and biotechnology.