Inhibiting Angiogenesis by Anti-Cancer Saponins: From Phytochemistry to Cellular Signaling Pathways.

Saponins are one of the broadest classes of high-molecular-weight natural compounds, consisting mainly of a non-polar moiety with 27 to 30 carbons and a polar moiety containing sugars attached to the sapogenin structure. Saponins are found in more than 100 plant families as well as found in marine organisms. Saponins have several therapeutic effects, including their administration in the treatment of various cancers. These compounds also reveal noteworthy anti-angiogenesis effects as one of the critical strategies for inhibiting cancer growth and metastasis. In this study, a comprehensive review is performed on electronic databases, including PubMed, Scopus, ScienceDirect, and ProQuest. Accordingly, the structural characteristics of triterpenoid/steroid saponins and their anti-cancer effects were highlighted, focusing on their anti-angiogenic effects and related mechanisms. Consequently, the anti-angiogenic effects of saponins, inhibiting the expression of genes related to vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1-α (HIF-1α) are two main anti-angiogenic mechanisms of triterpenoid and steroidal saponins. The inhibition of inflammatory signaling pathways that stimulate angiogenesis, such as pro-inflammatory cytokines, mitogen-activated protein kinase (MAPKs), and phosphoinositide 3-kinases/protein kinase B (PI3K/Akt), are other anti-angiogenic mechanisms of saponins. Furthermore, the anti-angiogenic and anti-cancer activity of saponins was closely related to the binding site of the sugar moiety, the type and number of their monosaccharide units, as well as the presence of some functional groups in their aglycone structure. Therefore, saponins are suitable candidates for cancer treatment by inhibiting angiogenesis, for which extensive pre-clinical and comprehensive clinical trial studies are recommended.

Evaluation of the Cytotoxicity of Aqueous Extract and Oleo-Essential Oil of Dorema ammoniacum Plant Oleo-Gum Resin in Some Human Cancer Cell Lines.

Results: Aqueous extract and essential oil reduced the viability of A549 cancer cells in a concentration-dependent manner. The lowest inhibitory concentrations (IC50) for both samples of D. ammoniacum oleo-gum resin were 10 and 2.5 µg/ml for 24 hours in A549 cell line, respectively. After treatment with extract and essential oil of D. ammoniacum oleo-gum resin, ROS increased significantly compared to the control group. Although changes in caspase-3 did not show a significant increase in extract, the caspase-3 was found to be increased after exposure to essential oil and caspase-9 was downregulated after exposure to essential oil. Also, exposure to essential oil of D. ammoniacum caused a reduction in MMP level. Conclusion: Based on results, the cytotoxic effect of essential oil of D. ammoniacum can induce apoptosis toward A549 cell line via induction of oxidative stress, MMP depletion, and caspase-3 activation, which is independent to mitochondrial cytochrome c release and caspase-9 function.

Antioxidant Activity-guided Phytochemical Investigation of Artemisia aucheri Boiss.: Isolation of Ethyl Caffeate and a Spinacetin Glycoside.

Antioxidant activity of five different extracts (petroleum ether, dichloromethane, ethyl acetate, ethanol and ethanol-water) of Artemisia aucheri aerial parts was investigated by three various methods: ferrous ion chelating (FIC) assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method and ß-carotene bleaching (BCB) test. Total phenolic contents (TPC) were measured by Folin-Ciocalteu method. The hydroethanolic extract exhibited the stronger inhibitory activity in BCB and FIC assays than the other extracts. Among the extracts analyzed, the ethyl acetate and ethanolic extracts exhibited the highest TPC and DPPH radical scavenging activity, respectively. Reversed phase vacuum liquid chromatography of ethanolic extract (with the highest extraction yield) produced five fractions (A to E) which were subjected to all antecedent experiments. The same sample (Fraction C) showed the highest TPC and DPPH radical scavenging activity while there were no statistically significant correlations between TPC and EC50 values of various antioxidant assays. Ethyl caffeate and a spinacetin glycoside were isolated from the most active fraction and their structures were established using spectroscopic analysis including NMR and MS.

Salvigenin, a Trimethoxylated Flavone from Achillea Wilhelmsii C. Koch, Exerts Combined Lipid-Lowering and Mitochondrial Stimulatory Effects.

Phytochemical analysis of the Iranian plant Achillea wilhelmsii led to the isolation of 17 pure secondary metabolites belonging to the classes of sesquiterpenoids and phenolics. Two of these compounds, named wilhemsin (7) and wilhelmsolide (9), are new sesquiterpenoids, and the first shows undescribed structural features. Their structures were elucidated through extensive spectroscopic analysis, mainly based on 1D and 2D NMR, and chemical derivatization. Starting from plant traditional use and previous reports on the activity of the plant extracts, all the pure compounds were evaluated on endpoints related to the treatment of metabolic syndrome. The sesquiterpene hanphyllin (8) showed a selective cholesterol-lowering activity (-12.7% at 30 µM), santoflavone (13) stimulated glucose uptake via the GLUT transporter (+16.2% at 30 µM), while the trimethoxylated flavone salvigenin (14) showed a dual activity in decreasing lipid levels (-22.5% palmitic acid biosynthesis at 30 µM) and stimulating mitochondrial functionality (+15.4% at 30 µM). This study further confirms that, in addition to the antioxidants vitexin, isovitexin, and isoschaftoside, A. wilhelmsii extracts contain molecules that can act at different levels on the metabolic syndrome symptoms.

Comparison of the cytotoxic effects of different fractions of Artemisia ciniformis and Artemisia biennis on B16/F10, PC3 and MCF7 Cells.

BACKGROUND AND PURPOSE: Artemisia is one of the well-known herbal medicinal plants for antimicrobial, insecticidal, antioxidant, and antimalarial activities. The antiproliferative effects of dichloromethane extracts of Artemisia biennis (A. biennis) and A. ciniformis and the petroleum ether extract of A. ciniformis have been demonstrated previously on human cancerous cell lines. In the current study, further fractionation was carried out on the aforementioned extracts and their cytotoxic effects were evaluated on three human cancer cell lines; B16/F10, PC3, and MCF7. F1 to F16, F1' to F11', and F1" to F10" were resulted from the fractionation of dichloromethane extracts of A. biennis, A. ciniformis, and petroleum ether extract of A. ciniformis, respectively. EXPERIMENTAL APPROACH: The cytotoxic effects of 16 (F1-F16), 11 (F1'-F11') and 10 (F1"-F10") fractions, on B16/F10, PC3, and MCF7 cell lines were assessed using resazurin to measure viability and propidium iodide staining (sub G1) and flow cytometry to detect apoptosis. FINDINGS / RESULTS: The results showed that, some fractions at 100 µg/mL decreased cell viability. F2" in B16/F10 cells, F2, F4-F6, F10', F11', and F2" in PC3 cells, and F10', F11', and F2" in MCF7 significantly decreased cell viability in a concentration-dependent manner (12.5-50 µg/mL). Among different fractions, F2" demonstrated the most potent cytotoxic effects on cancer cell lines (P < 0.001). All of the mentioned fractions (except F11' on PC3 cells) increased the number of apoptotic cells and showed the cytotoxic effects on cancer cells compared with the control group. CONCLUSION AND IMPLICATIONS: A. biennis and A. ciniformis are suggested as the potential sources of cytotoxic phytochemicals. The probable presence of terpenoids, steroids, and alkaloids in the selected fractions is proposed based on the preliminary phytochemical study.

Isofraxidin: Synthesis, Biosynthesis, Isolation, Pharmacokinetic and Pharmacological Properties.

Isofraxidin (7-hydroxy-6, 8-dimethoxy coumarin) (IF) is a hydroxy coumarin with several biological and pharmacological activities. The plant kingdom is of the most prominent sources of IF, which, among them, Eleutherococcus and Fraxinus are the well-known genera in which IF could be isolated/extracted from their species. Considering the complex pathophysiological mechanisms behind some diseases (e.g., cancer, neurodegenerative diseases, and heart diseases), introducing IF as a potent multi-target agent, which possesses several herbal sources and the multiple methods for isolation/purification/synthesis, along with the unique pharmacokinetic profile and low levels of side effects, could be of great importance. Accordingly, a comprehensive review was done without time limitations until February 2020. IF extraction methods include microwave, mechanochemical, and ultrasound, along with other conventional methods in the presence of semi-polar solvents such as ethyl acetate (EtOAc). In addition to the isolation methods, related synthesis protocols of IF is also of great importance. From the synthesis point of view, benzaldehyde derivatives are widely used as precursors for IF synthesis. Along with the methods of isolation and biosynthesis, IF pharmacokinetic studies showed hopeful in vivo results of its rapid absorption after oral uses, leading to different pharmacological effects. In this regard, IF targets varieties of inflammatory mediators including nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), tumor necrosis factor-α (TNF-α), and matrix metalloproteinases (MMPs). thereby indicating anticancer, cardioprotective, and neuroprotective effects. This is the first review on the synthesis, biosynthesis, isolation, and pharmacokinetic and pharmacological properties of IF in combating different diseases.

Isolation of Two Isochlorogenic Acid Isomers from Phenolic Rich Fraction of Artemisia turanica Krasch.

Total phenolic content (TPC) and antioxidant capacity of five different extracts (petroleum ether (40-60), dichloromethane, ethyl acetate, ethanol and ethanol-water (1:1 v/v)) of Artemisia turanica (A. turanica) aerial parts were determined and phytochemical study on the most promising extract was carried out. Folin-Ciocalteu method, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test, ß-carotene bleaching (BCB) method, and ferrous ion chelating (FIC) assay were performed. Vacuum liquid chromatography (VLC) and semi-preparative HPLC were used for bioassay-guided phytochemical isolation. Structures of isolated compounds were established using spectroscopic analysis including NMR and MS. Among all the extracts analyzed, the hydroethanolic extract exhibited the highest phenolic content and antioxidant activity. VLC of this extract yielded seven fractions (A to G) which were subjected to all antecedent experiments. The same sample (Fraction D) showed the highest total phenolic content and free radical scavenging activity but the only statistically significant correlation between TPC and EC50 values was observed for BCB. 3,5-dicaffeoylquinic acid (isochlorogenic acid A), and 4,5-dicaffeoylquinic acid (isochlorogenic acid C) was isolated from the most active fraction. Antioxidant activity of A. turanica is probably partly due to the presence of isomers of isochlorogenic acid.

Cytotoxic and Apoptogenic Sesquiterpenoids from the Petroleum Ether Extract of Artemisia aucheri Aerial Parts.

Different types of Artemisia aucheri extracts were reported to have various biological activities including a cytotoxic effect on some cancer cell lines. We investigated the antiproliferative activity of isolated sesquiterpenoids from petroleum ether extract of Artemisia aucheri (A. aucheri) aerial parts on SK-N-MC, MCF-7, and A2780 cell lines. Phytochemicals from the petroleum ether cold macerated extract were isolated using normal phase vacuum liquid chromatography and high pressure liquid chromatography (VLC and HPLC) and the structures of the components were determined by spectroscopic means. Cell viability was determined by 3-(4,5- dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide assay. Activation of caspases-3 and -9 was evaluated using a spectrophotometer. Mitochondrial membrane potential (MMP) was measured using rhodamine 123 fluorescent dye. Two tetrahydrofuran- type sesquiterpenoids, hydroperoxide of davanone (1) and hydroxydavanone (2) were isolated and characterized. Between these compounds, compound 1 exhibited more potent activity against the MCF-7, SK-N-MC and A2780 cell lines with IC50 values of 8.45 ± 0.81 µg/mL, 9.60 ± 1.32 µg/mL and 10.9 ± 2.03 µg/mL in A2780, MCF-7 and SK-N-MC cells, respectively. Compound 1 inhibited the growth of human cancer cells by induction of apoptosis. To the best of our knowledge, this is the first comprehensive study on cytotoxic and apoptotic mechanism of two davanone derivatives isolated from A. aucheri in human cancer cells. Overall, our data suggest that hydroperoxide of davanone (1) should be further studied in-vivo as a potential antitumor agent.

The Protective Effect of Different Extracts of Three Artemisia Species against H2O2-Induced Oxidative Stress and Apoptosis in PC12 Neuronal Cells.

BACKGROUND: Oxidative stress causes cell damage and is involved in many neurological diseases. The antioxidant properties of plant materials for the maintenance of health and protecting against different diseases stimulated scientist to investigate different herbs. Different Artemisia species have exhibited antioxidant activity. This study aims to investigate whether different Artemisia species could protect the PC12 cells against oxidative stress mediated by H2O2. METHODS: For this purpose, different extracts of three Artemisia species (Artemisia aucheri, Artemisia turanica, and Artemisia turcomanica) were prepared using petroleum ether, dichloromethane, ethyl acetate, ethanol, and Water: Ethanol mixture (1:1 volume ratio). The protective effect of the prepared extracts against H2O2-induced cytotoxicity and reactive oxygen species production were compared. The effect of treatment of PC12 cells with different extracts on total glutathione (GSH) level, caspase-3 activity, and mitochondrial membrane potential were also compared. RESULTS: The A. aucheri extracts could not rescue the PC12 cells from oxidative stress consequences. The A. turanica and A. turcomanica extracts were found potent in suppressing the toxicity and apoptosis of PC12 cells mediated by H2O2 and significantly antagonized the H2O2-induced GSH depletion. The hydroethanolic and ethyl acetate extracts of A. turanica and the petroleum ether and hydroethanolic extracts of A. turcomanica more efficiently suppressed cytotoxicity and loss of GSH caused by H2O2. CONCLUSION: This study shows the protective effects of Artemisia extracts on PC12 cell line and suggested that these species could be also considered as promising neuroprotective agents in treatment of different neurodegenerative diseases. SUMMARY: Artemisia turanica and Artemisia turcomanica extracts were found to potentially exert neuroprotective effect on PC12 cells. The results exhibited that the cytoprotective potential and anti-apoptotic mechanism of these species is not the same for different extracts, and suggested that based on the type of species and the type of solvents used in extraction, both intrinsic and extrinsic pathways could be included in the anti-apoptotic mechanism of these species. Abbreviations Used: GSH: Glutathion. ROS: Reactive Oxygen Species. GSSG: Glutathione disulfide. DCF-DA:2',7'-Dichlorofluorescin diacetate. FBS: Fetal Bovin Serum. MMP: Mitochondrial Membrane Potential. H-Et: Hydro-ethanolic. DCM: Dichloromethane. PE: Petroleum Ether. Et: Etanolic. EA: Ethyl Acetate.

2-Methylpyridine-1-ium-1-sulfonate from Allium hirtifolium: An anti-angiogenic compound which inhibits growth of MCF-7 and MDA-MB-231 cells through cell cycle arrest and apoptosis induction.

Natural products have well been recognized as sources of drugs in cancer treatment. Some medicinal plants contain the constituents with potent anti-angiogenic and anti-cancer effects, which have offered great hopes of being used as drugs for treating various cancers. The present study aims at identifying the anti-angiogenic effects of 2-Methylpyridine-1-ium-1-sulfonate (MPS) isolated from the ethyl acetate extract (EA) of Persian shallot (Allium hirtifolium). In a concentration-dependent manner, the MPS was able to inhibit endothelial cell migration and angiogenesis in both in vivo and in vitro assays, and also significantly suppressed proliferation of MCF-7 and MDA-MB-231 human breast cancer cell lines. Additionally, treatment with MPS showed a significant reduction in the vascular endothelial growth factor (VEGF) secretion level and production/activity of matrix metalloproteinases (MMP-2 and MMP-9) in the studied cells. The flow cytometry analysis indicated that MPS suppressed growth of MCF-7 and MDA-MB-231 cells at G0/G1 and S phases, respectively. Our results indicated that the induction of cell cycle arrest was correlated with the obvious changes in expression of p21, p27 and p53. According to the DNA fragmentation assay, MPS caused apoptosis in both cell lines, which confirms the results obtained with the growth assay. Moreover, the compound-mediated apoptosis accompanied with the increase in the Bax/Bcl-2 ratio and caspase-3 and -9 activities. Molecular docking results indicated that the MPS compound can surprisingly bind to VEGF and VEGF receptors and interacts with their critical amino acids. Finally, compounds with anticancer inhibitory activity (e.g. MPS) are abundant in nature and can be obtained from several sources. So, our data can be clinically developed for treating angiogenesis and cancer significantly.

Cytotoxic Properties of Three Isolated Coumarin-hemiterpene Ether Derivatives from Artemisia armeniaca Lam.

Considering multiple reports on cytotoxic activity of the Artemisia genus and its phytochemicals, in the current study A. armeniaca Lam. and the three components isolated from the plant were subjected to cytotoxic studies. Analytical fractionation of A. armeniaca aerial parts for the first time was directed to the isolation of 7-hydroxy-8-(4-hydroxy-3-methylbutoxy) comarin (armenin), 8-hydroxy-7-(4-hydroxy-3-methylbutoxy) comarin (isoarmenin) and deoxylacarol. Cytotoxicity assessed with alamalBlue® assay and apoptosis was detected by PI staining and western blot analysis of Bax and PARP proteins. Extracts and all compounds exhibited cytotoxic activity against apoptosis-proficient HL-60 and apoptosis-resistant K562 cells, with the lowest cytotoxic activity on J774 cell line as non-malignant cell. Armenin as the most potent component decreased the viability of cell with IC50 of 22.5 and 71.1 µM for K562 and HL-60 cells respectively and selected for further mechanistic study. Armenin increased the sub-G1 peak in flow cytometry histogram of HL-60 and K562 treated cells and increase in the amount of Bax protein and the cleavage of PARP in comparison with the control after treatment for 48 h in K562 treated cells verified the apoptotic activity of the armenin. Taken together, according to the finding of this study armenin was introduced as a novel cytotoxic compound with apoptotic activity, which is encouraging for further mechanistic and clinical studies.

Cytotoxic and apoptotic effects of different extracts of Artemisia biennis Willd. on K562 and HL-60 cell lines.

OBJECTIVES: Artemisia is a genus of herbs and small shrubs forms an important part of natural vegetation in Iran. It has been reported that several Artemisia species possess anti-proliferative effects. Considering the value of this genus in anti-cancer researches we have chosen Artemisia biennis for cytotoxic and mechanistic studies. MATERIALS AND METHODS: In this study we have investigated the cytotoxic and apoptotic effects of petroleum ether, dichloromethane, ethyl acetate, ethanol, and ethanol: water (1:1 v/v) extracts of A. biennis Willd. on two cancer human cell lines (K562 and HL-60) and J774 as normal cells. RESULTS: CH2Cl2 extract was found to have the highest anti-proliferative effect on cancer cells. IC50 values obtained in AlamarBlue® assay for CH2Cl2 extract were 64.86 and 54.31 µg/ml on K562 and HL-60 cells respectively. In flow cytometry histogram of the cells treated with CH2Cl2 extract, sub-G1 peak was induced. DNA fragmentation, increased in the level of Bax and cleavage of PARP protein all showed the induction of apoptosis with CH2Cl2 extract after 48 hr contact with cells. CONCLUSION: The results can corroborate the cytotoxic and apoptotic effects of the CH2Cl2 extract of A. biennis on the K562 and HL-60 cancer cell lines.

Protective effects of fractions from Artemisia biennis hydro-ethanolic extract against doxorubicin-induced oxidative stress and apoptosis in PC12 cells.

OBJECTIVES: This study was designed to indicate whether different fractions from Artemisia biennis hydroethanolic extract could provide cytoprotection against oxidative stress and apoptosis induced by doxorubicin (DOX) in rat pheochromocytoma cell line (PC12). MATERIAL AND METHODS: Cell viability was determined by MTT assay. Also, activation of caspase-3 and superoxide dismutase were evaluated by spectrophotometry. Detection of reactive oxygen species (ROS) and measurement of mitochondrial membrane potential (MMP) were performed by flowcytometry. RESULTS: Treatment of PC12 cells with DOX reduced viability dose dependently. For evaluation of the effect of fractions (A-G) on DOX-induced cytotoxicity, PC12 cells were pretreated for 24 hr with the A. biennis fractions and then cells were treated with DOX. The fractions C and D increased PC12 cells viability significantly compared to DOX treated cells. Moreover, pretreatment with fractions C and D for 24 hr attenuated DOX-mediated apoptosis and the anti-apoptotic action of A. biennis fractions was partially dependent on inhibition of caspase 3 activity and also increasing the mitochondrial membrane potential (MMP). Selected A. biennis fractions also suppressed the generation of ROS and increased superoxide dismutase (SOD) activity. CONCLUSION: Taken together our observation indicated that subtoxic concentration of aforementioned fractions of A. biennis hydroetanolic extract has protective effect against apoptosis induced by DOX in PC12 cell. The results highlighted that fractions C and D may exert cytoprotective effects through their antioxidant actions.

Evaluation of anti-aphthous activity of decoction of Nicotiana tabacum leaves as a mouthwash: a placebo-controlled clinical study.

OBJECTIVE: To determine the effects of decoction derived from the leaves of Nicotiana tabacum (L.) as a mouthwash on minor recurrent aphthous. METHODS: A randomized double-blinded placebo-controlled clinical trial was conducted on 60 patients with minor recurrent aphthous. Treatment comprised of application of tobacco or placebo mouthwash (10 mL 3 times a day) for 5 days. Clinical evaluation included pain level using a visual analog scale and ulcer size on days 1, 3, and 5 were measured. Adverse effects after mouthwash application were recorded, and the oral mucosa was examined by the investigator at each visit. RESULTS: A total of 54 subjects with the mean age (38 ± 10) years fulfilled the study. No minor and major adverse effects were observed. In the treatment group, ulcer pain score was decreased by 79.2% and 93.8% and ulcer size was reduced by 69.1% and 92.2% (days 3 and 5, respectively), which was significantly greater than the control group (P < 0.01). CONCLUSION: The decoction prepared with of Nicotiana tabacum leaves, used as mouthwash are well-tolerated and safe, and can be used for the management of recurrent aphthous.

Evaluation of antioxidant and cytoprotective activities of Artemisia ciniformis extracts on PC12 cells.

OBJECTIVES: In the current study antioxidant capacities of five different extracts of Artemisia ciniformis aerial parts were evaluated by cell-free methods. Then seven fractions of the potent extract were selected and their antioxidant capacity was assayed by cell free and cell based methods. MATERIALS AND METHODS: Antioxidant ability was measured using the: 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging test, ß-carotene bleaching (BCB) method and ferrous ion chelating (FIC) assay. Total phenolic contents (TPC) of all the samples also were determined. The cytoprotective effect of fractions was evaluated by measuring the viability of cells after exposure to doxorubicin (DOX). The mechanism of action was studied by investigating caspase-3, mitochondrial membrane potential (MMP), the level of super-oxide dismutase (SOD) and intracellular reactive oxygen species (ROS). RESULTS: Hydroethanolic extract exhibited a notably higher antioxidant activity and phenolic content. Among the fractions (A to G) of hydroethanolic extract, the highest antioxidant capacity was observed in the Fraction E. Moreover, 24 hr pretreatment of PC12 cells with fractions B, C and D decreased DOX-induced cytotoxicity. In addition, pre-treatment of cells with fraction B resulted in significant decrease in generation of the reactive oxygen species (ROS) and increase in the activity of SOD. We were able to demonstrate remarkable reduction in the activity of caspase-3 and increase in MMP in PC12 cells following pretreatment with fraction B. CONCLUSION: Our observations indicated that the fraction B of A. ciniformis hydroetanolic extract possessed protective effect on oxidative stress and apoptosis induced by DOX in PC12 cells.

A semipolar fraction of petroleum ether extract of Artemisia aucheri induces apoptosis and enhances the apoptotic response to doxorubicin in human neuroblastoma SKNMC cell line.

Artemisia is an important genus of Iranian flora whose potent anti-proliferative effect has been demonstrated previously on human cancerous cell lines. In the current study, further fractionation was carried out on the petroleum ether extract of A. aucheri and their cytotoxic effects were evaluated on three human cancer cell lines. Cell viability was determined by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide assay. Real time polymerase chain reaction (RT-PCR) was used to evaluate the expression of apoptotic related genes. Activation of caspases and detection of intracellular doxorubicin (DOX) accumulation were evaluated using a spectrophotometer. Mitochondrial membrane potential (MMP) was measured using flow cytometry. The fraction NO-7 (F7) of petroleum ether extract showed the highest anti-proliferative effect, especially against SKNMC cells. Therefore, we focused on a description of the cytotoxic mechanism of the most potent fraction on SKNMC cells. The results indicated that F7 was able to induce apoptosis through MMP disruption, activation of caspases and increament of proapoptotic genes Bax and Smac/DIABLO. Moreover, our observation indicated that F7 is able to increase the cytotoxicity of DOX in SKNMC cells. The combination of F7+DOX significantly increased the intracellular accumulation of DOX. These results indicated that F7 induces apoptosis in SKNMC cells. Moreover, it might enhance the antitumor activity of DOX, through modulating the activity of multidrug resistant cancer cells and inducing apoptosis.

Screening of different extracts from artemisia species for their potential antimalarial activity.

The formation of hemozoin (malaria pigment) has been proposed as an ideal drug target for antimalarial screening programs. In this study, we used an improved, cost-effective and high-throughput spectrophotometric assay to screen plant extracts for finding novel antimalarial plant sources. Fifteen extracts with different polarity from three Iranian Artemisia species, A. ciniformis, A. biennis and A. turanica, were assessed for their antimalarial activity by in-vitro ß-hematin formation assay. The most potent effect was observed in dichloromethane (DCM) extract of A. ciniformis with IC50 and IC90 values of 0.92 ± 0.01 and 1.29 ± 0.02 mg/mL, respectively. Ethyl acetate (EtOAC) extracts of A. biennis and A. turanica also showed significant antimalarial activities with IC50 values of 1.11 ± 0.02 and 1.35 ± 0.08 mg/mL and IC90 values of 1.22 ± 0.04 and 2.81 ± 0.21 mg/mL, respectively. Based on these results, it is possible to conclude that the components with strong antimalarial activity have been concentrated in the medium-polar extracts.

Cytotoxic and apoptotic effects of extracts of Artemisia ciniformis Krasch. and Popov ex Poljakov on K562 and HL-60 cell lines.

Artemisia, as one of the largest genera in the tribe Anthemideae of the Asteraceae comprises an important part of Iranian flora. While cytotoxic and apoptotic properties have already been reported for some species of the genus there is not any report on cytotoxic effects of A. ciniformis. Petroleum ether (40-60), dichloromethane, ethyl acetate, ethanol and ethanol-water (50:50) extracts of the aerial parts of A. cinformis were subjected to cytotoxic and apoptotic evaluations on two cancer human cell lines (K562 and HL-60) and on J774 normal cells. Among multiple extracts evaluated for cytotoxicity, dichloromethane (CH2Cl2) and petroleum ether (PE) extracts were shown to possess the highest anti-proliferative effects on HL-60 and K562 cells with IC50 values of 31.3 and 25.5 µg/ml respectively. Apoptosis induction verified by sub-G1 peaks was seen in flow cytometry histograms. Increase in the amount of Bax protein, formation of DNA fragments, and cleavage of PARP to 24 and 89 kDa sub units all confirmed induction of apoptosis by A. cinformis extracts. Taken together according to the result of the present study some extracts of A. cinformis could be considered as sources for natural cytotoxic compounds and further mechanistic and phytochemical studies are recommended to fully understand the underlying mechanisms of cancer cell death as well as identification of responsible phytochemicals.

Total Phenolic Contents and Antioxidant Activities of Different Extracts and Fractions from the Aerial Parts of Artemisia biennis Willd.

Total phenolic contents (TPC) of five different extracts (petroleum ether, dichloromethane, ethyl acetate, ethanol and ethanol-water) of Artemisia biennis Willd were measured in this work. The antioxidant activity was investigated by three different methods: ß-carotene bleaching (BCB) test, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method and ferrous ion chelating (FIC) assay. Among all the extracts analyzed, the hydroethanolic extract exhibited a significantly higher phenolic content and antioxidant activity than other samples. Vacuum liquid chromatography of this extract yielded seven fractions (A to G) which were subjected to all aforementioned experiments. The highest total phenolic content and free radical scavenging activites were present in the same sample (Fraction D) but the only statistically significant correlation between TPC and EC50 values was observed for BCB.

Evaluation of in vitro antimalarial activity of different extracts of Artemisia aucheri Boiss. and A. armeniaca Lam. and fractions of the most potent extracts.

Ten extracts with different polarity from two Iranian Artemisia species, A. armeniaca Lam. and A. aucheri Boiss, were screened for their antimalarial properties by in vitro ß -hematin formation assay. Dichloromethane (DCM) extracts of both plants showed significant antimalarial activities with IC50 values of 1.36±0.01 and 1.83±0.03 mg/mL and IC90 values of 2.12±0.04 and 2.62±0.09 mg/mL for A. armeniaca and A. aucheri, respectively. Bioactivity-guided fractionation of DCM extracts of both plants by vacuum liquid chromatography (VLC) over silica gel with solvent mixtures of increasing polarities afforded seven fractions. Two fractions from DCM extract of A. armeniaca and four fractions from DCM extract of A. aucheri showed potent antimalarial activity with reducing IC50 and IC90 values compared to extracts. The most potent fraction belonged to DCM extract of A. armeniaca with IC50 and IC90 values of 0.47±0.006 and 0.71±0.006 mg/mL, respectively.