In vitro cytotoxic activity of Salsola oppositifolia Desf. (Amaranthaceae) in a panel of tumour cell lines

The aim of the present study was to evaluate for the first time the in vitro cytotoxic activity of fractions and isolated flavonols from Salsola oppositifolia Desf. (Amaranthaceae). The n-hexane fraction demonstrated an effective cytotoxic activity on the large lung carcinoma and amelanotic melanoma cell lines with IC50 values of 19.1 microg/ml and 24.4 microg/ml, respectively. Also the dichloromethane fraction exhibited cytotoxic activity against COR-L23 (IC50 30.4 microg/ml) and C32 (IC50 33.2 microg/ml) cells, while the EtOAc fraction demonstrated a selective cytotoxic activity against MCF-7 cells (IC50 67.9 microg/ml). The major active constituents of this fraction were isorhamnetin-3-O-glucoside (1) and isorhamnetin-3-O-rutinoside (2), which showed an interesting activity against the cell line MCF-7 with IC50 values of 18.2 and 25.2 microg/ml, respectively. Compound 2 exhibited a strong activity against the hormone-dependent prostate carcinoma LNCaP cell line with an IC50 of 20.5 microg/ml. Constituents of S. oppositifolia were identified by GC-MS and NMR analyses.     

Cytotoxicity and detection of damage to DNA by 3-(5-nitro-2-thienyl)-9-chloro-5-morpholin-4-yl[1,2,4]triazolo[4,3-c] quinazoline on human cancer cell line HeLa

Quinazolines - 1,3-benzodiazines are biological active compounds, which are used in the phamaceutical industry, in agriculture and in the medicine. As documented in the literature, many derivatives demonstrated anticancer activity and they act as multitarget agents. 3-(5-Nitro-2-thienyl)-9-chloro-5-morpholin-4-yl[1,2,4]triazolo[4,3-c] quinazoline (NTCHMTQ) - a new synthetically prepared quinazoline derivative was the most effective derivative in our primary cytotoxic screening. In this study, we evaluated cytotoxic/antiproliferative activity of NTCHMTQ using human tumor cell line HeLa. Possible interaction of 3-(5-nitro-2-thienyl)-9-chloro-5-morpholin-4-yl[1,2,4]triazolo[4,3-c] quinazoline with calf thymus DNA was tested by the DNA - modified screen - printed electrode. Quinazoline derivative acted cytotoxically on tumor cell line HeLa. The IC(100) value was 10 microg/ml. The IC(50) values was found to be less than 4 microg/ml, a limit put forward by the National Cancer Institute (NCI) for classification of he compound as a potential anticancer drug. Quinazoline at micromolar concentrations induced morphological changes and necrosis of HeLa cells. Using the DNA based electrochemical biosensor, we have not found damage to DNA under in vitro conditions at an incubation of the biosensor in mixture with quinazoline.     

Bioactive deoxypreussomerins and dimeric naphthoquinones from Diospyros ehretioides fruits: deoxypreussomerins may not be plant metabolites but may be from fungal epiphytes or endophytes

Deoxypreussomerin derivatives, palmarumycins JC1 (1) and JC2 (2), and two dimeric naphthoquinones, isodiospyrin (3) and its new derivative isodiospyrol A (4), were isolated from dried fruits of Diospyros ehretioides. Structures of the isolated compounds were elucidated by spectroscopic analyses. Palmarumycins were not found in the extract of freshly collected fruits; however, they were present in dried fruit extract. The absence of palmarumycins in fresh fruits of D. ehretioides, together with the chemotaxonomic point of view, we proposed that palmarumycins JC1 (1) and JC2 (2) are more likely to be fungal metabolites, i.e., endophytes or epiphytes. The isolation of palmarumycins 1 and 2 from dried D. ehretioides fruits could be reproducible; both plant samples collected in the years 2002 and 2004 provided the same result, and, therefore, symbiont fungal strains should be specific to the plant host, D. ehretioides, and they can grow on the fruits during drying the sample. Palmarumycin JC1 (1) did not exhibit antimalarial, antifungal, antimycobacterial, and cytotoxic activities. Palmarumycin JC2 (2) exhibited antimalarial (IC50 4.5 microg/ml), antifungal (IC50 12.5 microg/ml), antimycobacterial (MIC 6.25 microg/ml), and cytotoxic (IC50 11.0 microg/ml for NCI-H187 cell line) activities. In our bioassay systems, isodiospyrin (3) did not exhibit antimycobacterial, antifungal, antimalarial, and cytotoxic activities. Isodiospyrol A (4) exhibited antimalarial (IC50 2.7 microg/ml) and antimycobacterial (MIC 50 microg/ml) activities, but was inactive towards Candida albicans. Compound 4 also exhibited cytotoxicity against BC cells (IC50 12.3 microg/ml), but not towards KB and Vero cell lines.     

Trypanosoma cruzi: antiprotozoal activity of parthenolide obtained from Tanacetum parthenium (L.) Schultz Bip. (Asteraceae, Compositae) against epimastigote and amastigote forms

This study reports the activity of crude extracts, fractions and parthenolide (pure compound) obtained from Tanacetum parthenium against two forms of the parasite Trypanosoma cruzi. Feverfew is a traditional herbal medicine that has been used for the treatment of migraine, fever and arthritis. Activity against epimastigote forms was observed for crude extracts, fractions and parthenolide, and a progressive increase in the antitrypanosomal effect was observed in the course of the purification process. The pure compound showed IC50/96h and IC90/96h of 0.5 microg/ml and 1.25 microg/ml, respectively. The cytotoxic effect of parthenolide in LLMCK2 cells was 3.2 microg/ml (CC50/96h) and the selectivity index was 6.4. No hemolysis was detected for the pure compound. The internalization index of T. cruzi in LLMCK2 cells was reduced almost 51% at the concentration of 2 microg/ml of parthenolide, and 96.6% at 4 microg/ml. Scanning and transmission electron microscopy permitted observation of morphological modifications and ultrastructural alterations.     

Cytotoxic activity of some lichen extracts on murine and human cancer cell lines

Eight lichens were extracted successively with n-hexane, diethyl ether and methanol using a Soxhlet process. The cytotoxic activity of the 24 lichen extracts was evaluated in vitro using two murine (the L1210: lymphocytic leukaemia, and the 3LL: Lewis lung carcinoma) and four human (the K-562: chronic myelogenous leukaemia, the U251: glioblastoma, the DU145: prostate carcinoma, and the MCF7: breast adenocarcinoma) cancer cell lines and non-cancerous cells, the Vero cell line (African green monkey kidney cell line). The MTT assay revealed significant cytotoxicity (IC50 < or = 20 microg/ml) on one of the tested cancer cell lines for at least one extract of each lichen species. Some extracts of Cladonia convoluta, Cladonia rangiformis, Parmelia caperata, Platismatia glauca and Ramalina cuspidata demonstrated interesting activities particularly on human cancer cell lines as good selectivity indices were recorded (SI > 3).     

Novel biologically active bibenzyls from Bauhinia saccocalyx Pierre

Four new bibenzyls, bauhinols A-D (1-4), together with the two known bibenzyls 5 and 6, were isolated from the roots of Bauhinia saccocalyx, and their structures were elucidated by analyses of spectroscopic data. Bauhinol A (1) exhibits significant cytotoxicity towards NCI-H187 (small-cell lung cancer), BC (breast cancer), and KB (oral-cavity cancer) cell lines, with IC50 values of 2.7-4.5 microg/ml. Bauhinol B (2) is cytotoxic against NCI-H187 (IC50 = 1.1 microg/ml) and BC (IC50 = 9.7 microg/ml) cell lines, but inactive toward the KB cell line (at 20 microg/ml). Compound 2 also is mildly antifungal towards Candia albicans (IC50 = 28.9 microg/ml). Bibenzyl 6 is active against NCI-H187 (IC50 = 14.1 microg/ml) and BC (IC50 = 4.0 microg/ml) cells, but inactive (at 20 microg/ml) toward the KB cell line. Compounds 1, 2, and 6 show mild antimycobacterial activities, with MIC values of 25-50 microg/ml, but are inactive at 20 microg/ml against the K1 malarial parasite strain (Plasmodium falciparum). While bauhinol A (1) is inactive against cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2), compounds 2 and 6 inhibit both COX-1 and COX-2, with IC50 values comparable to those of the standard drug, aspirin (Table 3).     

Cytotoxicity and DNA topoisomerase inhibitory activity of benz[f]indole-4,9-dione analogs

A series of benz[f]indole-4,9-diones, based on the antitumor activity of 1,4-naphthoquinone, were synthesized and evaluated for their cytotoxic activity in cultured human cancer cell lines A549 (lung cancer), Col2 (colon cancer), and SNU-638 (stomach cancer), and also for the inhibition of human DNA topoisomerases I and II activity in vitro. Several compounds including 2-amino-3-ethoxycarbonyl-N-methyl-benz[f]indole-4,9-dione showed a potential cytotoxic activity judged by IC50<20.0 microg/ml in the panel of cancer cell lines. Especially, 2-hydroxy-3-ethoxycarbonyl-N-(3,4-dimethylphenyl)-benz[f]indole-4,9-dione had potential selective cytotoxicity against lung cancer cells (IC50=0.4 microg/ml)) compared to colon (IC50>20.0 microg/ml) and stomach (IC50>20.0 microg/ml) cancer cells. To further investigate the cytotoxic mechanism, the effects of test compounds on DNA topoisomerase I and II activities were used. In a topoisomerase I-mediated relaxation assay using human placenta DNA topoisomerase I and supercoiled pHOTI plasmid DNA, 2-amino-3-ethoxycarbonyl-N-(4-fluorophenyl)-benz[f]indole-4,9-dione had the most potent inhibitory activity among the compounds tested. However, most of the compounds showed only weak inhibition of the DNA topoisomerase II-mediated KDNA (Kinetoplast DNA) decatenation assay, except for 2-amino-3-ethoxycarbonyl-N-(4-methylphenyl)-benz[f]indole-4,9-dione and 2-amino-3-ethoxycarbonyl-N-(2-bromoehtyl)-benz[f]indole-4,9-dione with a moderate inhibitory activity. These results suggest that several active compounds had relatively selective inhibitory activity against toposiomearse I compared to toposiomerase II. No obvious correlation was observed between the cytotoxicity of the individual compound and the inhibitory activity of DNA relaxation and decatenation by topoisomerase I and II, respectively, in vitro.     

Minor cytotoxic and antibacterial compounds from the rhizomes of Amomum aculeatum.

A new cytotoxic 1,7-dioxa-dispiro[5.1.5.2]pentadeca-9,12-dien-11-one derivative, aculeatin D, and a new alkenone, 5-hydroxy-hexacos-1-en-3-one, have been isolated as minor compounds from the rhizomes of Amomum aculeatum. Their structures have been determined mainly by NMR spectroscopy and mass spectrometry. Aculeatin D showed high cytotoxicity against the KB and the L-6 cell line with IC(50) of 0.38 microg/ml and 1 microg/ml, respectively. Additionally, it revealed remarkable activity against two Plasmodium falciparum strains, as well as against Trypanosoma brucei rhodesiense and Trypanosoma cruzi. 5-Hydroxy-hexacos-1-en-3-one exhibited neither cytotoxic nor antiprotozoal activity, whereas antibacterial testing against Bacillus cereus, Escherichia coli and Staphylococcus epidermidis showed moderate to strong activity for both compounds.     

Antileishmanial activity, cytotoxicity and QSAR analysis of synthetic dihydrobenzofuran lignans and related benzofurans

A series of synthetic dihydrobenzofuran lignans and related benzofurans were evaluated for their cytotoxicity in a screening panel consisting of various human tumour cell lines, and for their antiprotozoal activity against L. donovani (axenic amastigotes), chloroquine resistant Plasmodium falciparum (strain K1), Trypanosoma brucei rhodesiense and T. cruzi, and for cytotoxicity on L6 cells. No promising cytotoxicities against human tumour cell lines were observed for newly synthesised compounds, but the dimerisation product of some lipophylic esters of caffeic acid, such as compound 2g, showed a high activity against chloroquine-resistant P. falciparum (strain K1) (IC50 0.43 microg/mL) and L. donovani (axenic amastigotes) (IC50 0.12 microg/mL), which was confirmed in an infected macrophage assay (IC50 0.19 microg/mL). QSAR models for the cytotoxic and antileishmanial activity were generated using Quasar receptor surface modelling.     

Leishmanicidal cycloartane-type triterpene glycosides from Astragalus oleifolius

Two new cycloartane-type glycosides oleifoliosides A (1) and B (2) were isolated from the lower stem parts of Astragalus oleifolius. Their structures were identified as 3-O-[beta-xylopyranosyl-(1 --> 2)-alpha-arabinopyranosyl]-6-O-beta-xylopyranosyl-3beta,6alpha,16beta,24(S),25-pentahydroxycycloartane and 3-O-[beta-xylopyranosyl-(1 --> 2)-alpha-arabinopyranosyl]-6-O-beta-glucopyranosyl-3beta,6alpha,16beta,24(S),25-pentahydroxycycloartane, respectively, by means of spectroscopic methods (IR, 1D and 2D NMR, ESI-MS). Three known cycloartane glycosides cyclocanthoside E (3), astragaloside II (4) and astragaloside IV (5) were also isolated and characterized. All five compounds were evaluated for in vitro trypanocidal, leishmanicidal and antiplasmodial activities as well as their cytotoxic potential on primary mammalian (L6) cells. Except for the compound 5, all compounds showed notable growth inhibitory activity against Leishmania donovani with IC50 values ranging from 13.2 to 21.3 microg/ml. Only weak activity against Trypanosoma brucei rhodesiense was observed with the known compounds astragaloside II (4, IC50 66.6 microg/ml) and cyclocanthoside E (3, IC50 85.2 microg/ml), while all compounds were inactive against Trypanosoma cruzi and Plasmodium falciparum. None of the compounds were toxic to mammalian cells (IC50's > 90 microg/ml). This is the first report of leishmanicidal and trypanocidal activity of cycloartane-type triterpene glycosides.     

Synthesis and antiproliferative evaluation of 7-aminosubstituted pyrroloiminoquinone derivatives

Coupling of five amines on the 7-methoxy-1,3,4,5-tetrahydropyrrolo[4,3,2-de]quinoline core was achieved and afforded, in particular, an opened analogue of the natural alkaloid wakayin. Evaluation of cytotoxic activity of compounds 2, 10-13 on L1210 cells afforded IC50 in the range 0.25 5.3 microM.     

Triterpenic acids and flavonoids from Satureja parvifolia. Evaluation of their antiprotozoal activity

Bioassay-guided fractionation of a Satureja parvifolia MeOH extract led to the isolation of eriodictyol, luteolin and ursolic and oleanolic acids as its active components against Plasmodium falciparum K1. This is the first time these compounds are reported as constituents of S. parvifolia. Ursolic acid showed an IC50 of 4.9 microg/ml, luteolin 6.4 microg/ml, oleanolic acid 9.3 microg/ml and eriodictyol 17.2 microg/ml. Antiplasmodial activity of eriodictyol and luteolin is reported here for the first time. Besides, the four compounds showed activity against P. falciparum 3D7 strain and Trypanosoma brucei rhodesiense. Eriodictyol showed moderate activity on all the parasites but was the most selective compound as a result of its rather low cytotoxicity (IC50 174.2 microg/ml) on the mammalian KB cell line.     

Cytotoxic cholestane and pregnane glycosides from Tribulus macropterus

The methanol extract of the whole parts of Tribulus macropterus Boiss. (family Zygophyllaceae) showed cytotoxic activity against a human tumour cell line (hepatocyte generation 2, HepG2) (IC50 = 2.9 microg/ml). The n-butanolic fraction obtained from successive fractionation of the methanolic extract exhibited activity against HepG2 (IC50 = 2.6 microg/ml). Therefore, this fraction was subjected to separation using different chromatographic techniques. Five compounds, 1-5, were isolated and identified as: (22S,25S)-16beta,22,26-trihydroxy-cholest-4-en-3-one-16-O-beta-D-glucopyranosyl-(1-->3)-beta-D-xylopyranoside (1), (22S,25S)-16beta,22,26-trihydroxy-cholest-4-en-3-one-16-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranoside (2), sucrose (3), D-pinitol (4) and 3beta-hydroxy-5a-pregn-16(17)en-20-one-3-O-beta-D-xylopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucopyranosyl-(1-->4)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-ga-lactopyranoside (5) on the basis of spectroscopic and chemical data. The three steroidal compounds 1, 2 and 5 were also tested against the same cell line HepG2 and their IC50 values were 2.4, 2.2 and 1.1 microg/ml, respectively.     

The effect of turmeric extracts on inflammatory mediator production.

Major compounds of several commonly used botanicals, including turmeric, have been purported to have anti-inflammatory actions. In order to test the anti-inflammatory activity of compounds isolated from rhizomes of Curcuma longa L. (Zingiberaceae), we have established an in vitro test system. HL-60 cells were differentiated and exposed to lipopolysaccharide (LPS) from Escherichia coli (1 microg/ml) in the presence or absence of botanical compounds for 24 h. Supernatants were collected and analyzed for the production of tumor necrosis factor alpha (TNF-alpha) and prostaglandin E2 (PGE2) using standard ELISA assays. Water-soluble extracts were not cytotoxic and did not exhibit biological activity. Organic extracts of turmeric were cytotoxic only at concentrations above 50 microg/ml. Crude organic extracts of turmeric were capable of inhibiting LPS-induced TNF-alpha (IC50 value = 15.2 microg/ml) and PGE2 (IC50 value = 0.92 microg/ml) production. Purified curcumin was more active than either demethoxy- or bisdemethoxycurcumin. Fractions and subfractions of turmeric extracts collected via preparative HPLC had differing biological activity, ranging from no activity to IC50 values of < 1 microg/ml. For some fractions, subfractionation resulted in a loss of activity, indicating interaction of the compounds within the fraction to produce an anti-inflammatory effect. A combination of several of the fractions that contain the turmeric oils was more effective than the curcuminoids at inhibiting PGE2. While curcumin inhibited COX-2 expression, turmeric oils had no effect on levels of COX-2 mRNA.     

Isolation and characterization of an L1210 cell line retaining the sodium-dependent carrier cif as its sole nucleoside transport activity

Nucleoside permeation across mammalian cell membranes is complex with at least four distinct transporters known. Two of these (es and ei) are equilibrative (facilitated diffusion) carriers that have been studied is considerable detail. The other two (cif and cit) are concentrative, Na(+)-dependent carriers. A major obstacle to the characterization of the latter two mechanisms has been the lack of suitable model systems expressing only a single nucleoside transport activity. The present study describes the isolation of a cell line that has cif as its sole nucleoside transporter. L1210/MC5-1 cells, which have es and cif transport activity, were mutagenized and plated in soft agar containing two cytotoxic nucleosides (tubercidin (7-deazaadenosine) and cytosine arabinoside) that are substrates for es but not cif. A clonal line (L1210/MA-27.1) was isolated which retained the capacity for Na(+)-dependent [3H]formycin B transport but was unable to transport [3H]thymidine, a substrate for es but not cif. Failure of the mutant to transport thymidine was also demonstrated by the inability of thymidine (with adenine as a purine source) to rescue these cells from methotrexate toxicity. Furthermore, the mutant lacked nitrobenzylthioinosine (NBMPR) binding activity (an integral part of the es transporter) as demonstrated by reversible NBMPR binding and photoaffinity labeling with [3H]NBMPR. Loss of es transport activity was also demonstrated by the failure of NBMPR to affect the toxicity of 2-chlorodeoxyadenosine (IC50 approximately 30 nM) in L1210/MA27.1 cells. In contrast, NBMPR decreased the IC50 for 2-chlorodeoxyadenosine from 100 to 30 nM in the parental L1210/MC5-1 cell line. These results are consistent with the mechanism of NBMPR potentiation of 2-chlorodeoxyadenosine toxicity in L1210 cells being a blockade of efflux via es while the nucleoside is pumped into the cells by the concentrative cif carrier.     

Design, synthesis, and biological testing of pyrazoline derivatives of combretastatin-A4

Fourteen N-acetylated and non-acetylated 3,4,5-tri- or 2,5-dimethoxypyrazoline analogs of combretastatin-A4 (1) were synthesized. A non-acetylated derivative (5a) with the same substituents as CA-4 (1) was the most active compound in the series, with IC(50) values of 2.1 and 0.5 microM in B16 and L1210 cell lines, respectively. In contrast, a similar compound with an acetyl group at N1 of the pyrazoline ring (6g) showed poor activity in the cell lines studied. A cell-based assay indicated that compound 5a caused extensive microtubule depolymerization with an EC(50) value of 7.1 microM in A-10 cells while no activity was seen with the acetylated compound. Molecular modeling studies showed that these compounds possess a twisted conformation similar to CA-4 (1).     

Structure–Activity Relationships for Six Ketolide Antibiotics

Six structurally related 3-keto-substituted macrolide antibiotics (ketolides) were compared for concentration-dependent inhibitory effects on growth rate, viable cell number, and protein synthesis rates in Staphylococcus aureus cells. Inhibitory effects on 50S ribosomal subunit formation were also examined, as this is a second target for these antibiotics. A concentration range of 0.01 to 0.1 microg/ml was tested. An IC50 for inhibition of translation and 50S synthesis was measured for each compound, to relate structural features to inhibitory activity. ABT-773 was the most effective of the six compounds tested with an IC50 = 0.035 microg/ml. HMR 3004 was almost as effective with an IC50 = 0.05 microg/ml. Two 2-fluoroketolides (HMR 3562 and HMR 3787) were equivalent in their inhibitory activity with an IC50 = 0.06 microg/ml. Telithromycin (HMR 3647) had an IC50 = 0.08 microg/ml, and HMR 3832 was least effective with an IC50 = 0.11 microg/ml. Each antibiotic had an equivalent inhibitory effect on translation and 50S subunit formation. These results indicate specific structural features of these antimicrobial agents, which contribute to defined inhibitory activities against susceptible organisms.     

Xanthatin and xanthinosin from the burs of Xanthium strumarium L. as potential anticancer agents

Xanthatin and xanthinosin, 2 sesquiterpene lactones isolated from the burs of Xanthiun strumarium L. (cocklebur), showed moderate to high in vitro cytotoxic activity in the human cancer cell lines WiDr ATCC (colon), MDA-MB-231 ATCC (breast), and NCI-417 (lung). Xanthatin and xanthinosin were purified as the result of a multi-screening bioassay-guided study of wild plant species of the family Asteraceae, collected from various sites in Saskatchewan, Canada. Seventy-five extracts at a single concentration of 100 microg/mL were evaluated for in vitro cytotoxicity to the human cancer cell lines used. The chloroform extract of Carduus nutans L. (nodding thistle) aerial parts (IC50, 9.3 microg/mL) and the hexane extract of Echinacea angustifolia DC. (narrow-leaved purple coneflower) root (IC50, 4.0 microg/mL) were moderately to highly cytotoxic to the lung cancer cell line. The chloroform extracts of X. strumarium L. burs and Tanacetum vulgare L. (tansy) aerial parts exhibited the highest cytotoxicity for all cell lines tested; their IC50 values, obtained from multidose testing, ranged from 0.1 to 6.2 microg/mL (X. strumarium) and from 2.4 to 9.1 microg/mL (T. vulgare). Further purification of the chloroform fraction of X. strumarium yielded xanthatin and xanthinosin in high yields. This is the first time that these compounds have been reported in the burs of X. strumarium. Their IC50 values are also reported herein.     

Protective effects of a standard extract of Mangifera indica L. (VIMANG) against mouse ear edemas and its inhibition of eicosanoid production in J774 murine macrophages

A standard aqueous extract of Mangifera indica L., used in Cuba as antioxidant under the brand name VIMANG, was tested in vivo for its anti-inflammatory activity, using commonly accepted assays. The standard extract of M. indica, administered orally (50-200mg/kg body wt.), reduced ear edema induced by arachidonic acid (AA) and phorbol myristate acetate (PMA) in mice. In the PMA model, M. indica extract also reduced myeloperoxidase (MPO) activity. In vitro studies were performed using macrophage cell line J774 stimulated with pro-inflammatory stimuli lipopolysaccharide-interferon gamma (LPS-IFNgamma) or calcium ionophore A23187 to determine prostaglandin PGE(2) or leukotriene LTB(4) release, respectively. The extract inhibited the induction of PGE(2) and LTB(4) with IC(50) values of 21.7 and 26.0microg/ml, respectively. Mangiferin (a glucosylxanthone isolated from the extract) also inhibited these AA metabolites (PGE(2), IC(50) value=17.2microg/ml and LTB(4), IC(50) value=2.1microg/ml). These results represent an important contribution to the elucidation of the mechanism involved in the anti-inflammatory and anti-nociceptive effects reported for the standard extract of M. indica VIMANG.     

The effect of betel nut extract on cell growth and prostaglandin endoperoxide synthase in human epidermoid carcinoma cells

The objective of this study was to find out whether prostaglandin endoperoxide synthase (PHS) involves the action of betel nut extract (BNE) on the growth of oral cancers. Therefore, growth and PHS activity were examined in two human oral carcinoma cell lines (OEC-M1 and KB) and one normal fibroblast cell line (NF) in the presence of increasing BNE concentration. BNE at concentrations above 50 microg/ml significantly inhibited the cell growth of OEC-M1 after 72 h in culture, of KB and NF after 48 h in culture. The IC50 of BNE in OEC-M1, KB and NF at 24 h in culture was about 406, 37.5 and 140 microg/ml respectively. PHS activity in OEC-M1 was significantly increased by low BNE concentrations (50 microg/ml, 114%; 100 microg/ml, 33%; 150 microg/ml, 30%) but significantly reduced at higher BNE concentrations (300 microg/ml, 33%; 500 microg/ml, 61%). The PHS activity in KB was significantly inhibited by BNE and this effect was intensified as concentrations increased (50 microg/ml, 31%; 100 microg/ml, 24%; 150 microg/ml, 43%; 300 microg/ml, 60%; 500 microg/ml, 92%). Similar to that in OEC-M1, the PHS activity in NF was significantly increased at low BNE concentrations (50 microg/ml, 139%; 100 microg/ml, 87%;150 microg/ml, 77%) but reduced at higher concentrations (300 microg/ml, 55%; 500 microg/ml, 72%). The PHS activity in all cell lines was almost completely blocked by indomethacin (5 x 10(-6) M). We conclude that these findings suggest that PHS may be an important biochemical mediator of the effect of BNE on the growth of two human oral carcinoma cell lines.