Warifteine and milonine, alkaloids isolated from Cissampelos sympodialis Eichl: cytotoxicity on rat hepatocyte culture and in V79 cells

Bisbenzylisoquinoline Alkaloids of Cissampelos Sympodialis With in Vitro Antiviral Activity Against Zika Virus

In search of new antiviral compounds against Zika virus we conducted a bioassay-guided fractionation of bisbenzyilisoquinoline alkaloids isolated from Cissampelos sympodialis (Menispermaceae), a medicinal plant species endemic to Brazil. Six subfractions were obtained from a tertiary alkaloidal fraction of the rhizomes (TAFrz) using preparative high-performance liquid chromatography. All the subfractions were tested against Zika virus-infected Vero cells as the cellular model to evaluate cytotoxicity and antiviral effective concentrations. The results showed that three of the six TAFrz subfractions tested were active. The most active ones were the subfraction 6 (that consisted of the alkaloids methylwarifteine and warifteine present as a mixture at a ratio of 8.8:1.2 respectively) and the subfraction 5, that was later identified as warifteine, the major tertiary alkaloid of this species. Warifteine was able to significantly reduce virus titer in Zika virus-infected Vero cells with an IC₅₀ of 2.2 μg/ml and this effect was selective (selectivity index, SI = 68.3). Subfraction 6 had an IC₅₀ = 3.5 μg/ml and was more cytotoxic than pure warifteine, with SI = 6.14. Fraction 5 and fraction 6 were more potent in decreasing the viral titer of Zika virus-infected Vero cells than 6-methylmercaptopurine riboside (IC₅₀ = 24.5 μg/ml and SI = 11.9), a mercaptopurine riboside with ZIKV antiviral activity used as a positive control. Our data demonstrate that alkaloids of the bisbenzylisoquinoline type may be explored as new antiviral agents or as an useful pharmacophore for investigating ZIKV antiviral activity.

Phytochemical Constituents and Biological Activities of Plants from the Genus Cissampelos

Cissampelos is a significant genus comprising of approximately 21 species of the medicinal plants (Menispermaceae). The plants of this genus are used in traditional medicine for the treatment of various ailments such as asthma, arthritis, dysentery, hyperglycemia, cardiopathy, hypertension and other related problems. These plants are rich in bioactive dibenzylisoquinoline and aborphine as well as small amounts of other ingredients. In recent years, the chemical constituents and pharmacological activities of Cissampelos genus have been paid more and more attention due to their diversity. Herein, we compile the chemical constituents and biological activities on this genus, and summarize the 13 C-NMR data of the main bioactive ingredients. All information comes from scientific databases such as Google Scholar, PubMed, Sci-Finder, ScienceDirect, Web of Science and CNKI. It provides valuable data for the future research and development of Cissampelos genus.

Toxicity and Antitumor Activity of a Thiophene-Acridine Hybrid

The antitumor effects of thiophene and acridine compounds have been described; however, the clinical usefulness of these compounds is limited due to the risk of high toxicity and drug resistance. The strategy of molecular hybridization presents the opportunity to develop new drugs which may display better target affinity and less serious side effects. Herein, 2-((6-Chloro-2-methoxy-acridin-9-yl)amino)-5,6,7,8-tetrahydro-4H-cyclohepta[b]-thiophene-3-carbonitrile (ACS03), a hybrid thiophene–acridine compound with antileishmanial activity, was tested for toxicity and antitumor activity. The toxicity was evaluated in vitro (on HaCat and peripheral blood mononuclear cells) and in vivo (zebrafish embryos and acute toxicity in mice). Antitumor activity was also assessed in vitro in HCT-116 (human colon carcinoma cell line), K562 (chronic myeloid leukemic cell line), HL-60 (human promyelocytic leukemia cell line), HeLa (human cervical cancer cell line), and MCF-7 (breast cancer cell line) and in vivo (Ehrlich ascites carcinoma model). ACS03 exhibited selectivity toward HCT-116 cells (Half maximal inhibitory concentration, IC50 = 23.11 ± 1.03 µM). In zebrafish embryos, ACS03 induced an increase in lactate dehydrogenase, glutathione S-transferase, and acetylcholinesterase activities. The LD50 (lethal dose 50%) value in mice was estimated to be higher than 5000 mg/kg (intraperitoneally). In vivo, ACS03 (12.5 mg/kg) induced a significant reduction in tumor volume and cell viability. In vivo antitumor activity was associated with the nitric oxide cytotoxic effect. In conclusion, significant antitumor activity and weak toxicity were recorded for this hybrid compound, characterizing it as a potential anticancer compound.

Brazilian medicinal plants with corroborated anti-inflammatory activities: a review

CONTEXT

Inflammatory disorders are common in modern life, and medicinal plants provide an interesting source for new compounds bearing anti-inflammatory properties. In this regard, Brazilian medicinal plants are considered to be a promising supply of such compounds due to their great biodiversity.

OBJECTIVES

To undertake a review on Brazilian medicinal plants with corroborated anti-inflammatory activities by selecting data from the literature reporting the efficacy of plants used in folk medicine as anti-inflammatory, including the mechanisms of action of their extracts and isolated compounds.

METHODS

A search in the literature was undertaken by using the following Web tools: Web of Science, SciFinder, Pub-Med and Science Direct. The terms 'anti-inflammatory' and 'Brazilian medicinal plants' were used as keywords in search engine. Tropicos and Reflora websites were used to verify the origin of the plants, and only the native plants of Brazil were included in this review. The publications reporting the use of well-accepted scientific protocols to corroborate the anti-inflammatory activities of Brazilian medicinal plants with anti-inflammatory potential were considered.

RESULTS

We selected 70 Brazilian medicinal plants with anti-inflammatory activity. The plants were grouped according to their anti-inflammatory mechanisms of action. The main mechanisms involved inflammatory mediators, such as interleukins (ILs), nuclear factor kappa B (NF-κB), prostaglandin E2 (PGE2), cyclooxygenase (COX) and reactive oxygen species (ROS).

CONCLUSIONS

The collected data on Brazilian medicinal plants, in the form of crude extract and/or isolated compounds, showed significant anti-inflammatory activities involving different mechanisms of action, indicating Brazilian plants as an important source of anti-inflammatory compounds.

Milonine, a Morphinandienone Alkaloid, Has Anti-Inflammatory and Analgesic Effects by Inhibiting TNF-α and IL-1β Production

Milonine is a morphinandienone alkaloid from Cissampelos sympodialis Eichl (Menispermaceae), a plant used in Brazil to treat inflammatory disorders. In this study, we evaluated the anti-inflammatory and analgesic activity of milonine (MIL) by using classical experimental models of inflammation and nociception. The results showed that MIL reduced the paw edema formation induced by lipopolysaccharide, prostaglandin E₂, and bradykinin, without interfering with the serotonin-induced edema. With respect to the nociception experiments, MIL decreased the exudate into the peritoneum induced by acetic acid, maintaining the tissue morphology. The alkaloid was able to inhibit the peritonitis induced by carrageenan, decreasing mainly the migration of polymorphonuclear cells, without altering the mononuclear cell number, and reduced the levels of TNF-α and IL-1β in the peritoneum. In addition, MIL was able to decrease the frequency of abdominal writhing induced by acetic acid but did not increase the latency time of the animals in the hot plate test. MIL significantly reduced the nociceptive behavior of paw licking induced by formalin only at the second phase of the test. In conclusion, we demonstrate that milonine has anti-inflammatory and anti-nociceptive activities by inhibiting mediators essential for the inflammatory process.

Cytotoxicity, genotoxicity and mechanism of action (via gene expression analysis) of the indole alkaloid aspidospermine (antiparasitic) extracted from Aspidosperma polyneuron in HepG2 cells

Aspidospermine is an indole alkaloid with biological properties associated with combating parasites included in the genera Plasmodium, Leishmania and Trypanossoma. The present study evaluated the cytotoxicity (resazurin test), genotoxicity (comet assay) and mechanism of action (gene expression analysis via qRT-PCR) of this alkaloid in human HepG2 cells. The results demonstrated that treatment with aspidospermine was both cytotoxic (starting at 75 μM) and genotoxic (starting at 50 μM). There was no significant modulation of the expression of the following genes: GSTP1 and GPX1 (xenobiotic metabolism); CAT (oxidative stress); TP53 and CCNA2 (cell cycle); HSPA5, ERN1, EIF2AK3 and TRAF2 (endoplasmic reticulum stress); CASP8, CASP9, CASP3, CASP7, BCL-2, BCL-XL BAX and BAX (apoptosis); and PCBP4, ERCC4, OGG1, RAD21 and MLH1 (DNA repair). At a concentration of 50 μM (non-cytotoxic, but genotoxic), there was a significant increase in the expression of CYP1A1 (xenobiotic metabolism) and APC (cell cycle), and at a concentration of 100 μM, a significant increase in the expression of CYP1A1 (xenobiotic metabolism), GADD153 (endoplasmic reticulum stress) and SOD (oxidative stress) was detected, with repression of the expression of GR (xenobiotic metabolism and oxidative stress). The results of treatment with aspidospermine at a 100 μM concentration (the dose indicated in the literature to achieve 89 % reduction of the growth of L. amazonensis) suggest that increased oxidative stress and an unfolded protein response (UPR) occurred in HepG2 cells. For the therapeutic use of aspidospermine (antiparasitic), chemical alteration of the molecule to achieve a lower cytotoxicity/genotoxicity in host cells is recommended.

From arrow poison to herbal medicine--the ethnobotanical, phytochemical and pharmacological significance of Cissampelos (Menispermaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Cissampelos species have a rich history of traditional use, being used for both therapeutic and toxic properties. It is traditionally applied therapeutically in a diverse range of conditions and diseases including asthma, cough, fever, arthritis, obesity, dysentery, snakebite, jaundice and heart, blood pressure and skin-related problems. Conversely, it was traditionally included in preparations of curare applied as arrow poison during hunting to cause death of animals by asphyxiation. This review unites the ethnobotanical knowledge on Cissampelos with the phytochemistry and pharmacological activity which has been explored thus far. In addition, it identifies knowledge gaps and suggests further research opportunities.

METHODS

The available electronic literature on the genus Cissampelos was collected using database searches including Scopus, Google Scholar, Pubmed, Web of Science, etc. The searches were limited to peer-reviewed English journals with the exception of books and a few articles in foreign languages which were included.

RESULTS

The literature revealed that pharmacological activity including analgesic and antipyretic, anti-inflammatory, anti-allergic, bronchodilator, immunomodulatory, memory-enhancing, antidepressant, neuroprotective, antimicrobial, antimalarial, antiparasitic, anti-ulcer, anticancer, anti-oxidant, cardiovascular, muscle-relaxant, hepatoprotective, antidiabetic, antidiarrhoeal, antifertility, and antivenom activity have been confirmed in vitro and/or in vivo for various Cissampelos species. Cissampelos pareira L. and Cissampelos sympodialis Eichl. are the most explored species of this genus and the smallest number of studies have been conducted on Cissampelos laxiflora Moldenke and Cissampelos tenuipes Engl. Many alkaloids isolated from Cissampelos such as warifteine, methylwarifteine, berberine, hayatin and hayatidin showed promising anti-allergic, immunosuppressive, antidepressant, anticancer, vasodilatory and muscle-relaxant activities.

CONCLUSION

The plants of this genus are used in traditional medicine for the treatment of various ailments. These plants are a rich source of bioactive bisbenzylisoquinoline and aporphine alkaloids together with other minor constituents. Although these plants are reputable and revered in various traditional medicine systems, many have not yet been screened chemically or pharmacologically and so there is a vast amount of research still to be conducted to validate their traditional use.

Warifteine, an alkaloid purified from Cissampelos sympodialis, inhibits neutrophil migration in vitro and in vivo

Cissampelos sympodialis Eichl is a plant from the Northeast and Southeast of Brazil. Its root infusion is popularly used for treatment of inflammatory and allergic diseases. We investigated whether warifteine, its main alkaloid, would have anti-inflammatory effect due to a blockage of neutrophil function. In vivo warifteine treatment inhibited casein-induced neutrophil migration to the peritoneal cavity but did not inhibit neutrophil mobilization from the bone marrow. Analysis of the direct effect of warifteine upon neutrophil adherence and migration in vitro demonstrated that the alkaloid decreased cell adhesion to P and E-selectin-transfected cells. In addition, fLMP-induced neutrophil migration in a transwell system was blocked by warifteine; this effect was mimicked by cAMP mimetic/inducing substances, and warifteine increased intracellular cAMP levels in neutrophils. The production of DNA extracellular traps (NETs) was also blocked by warifteine but there was no alteration on PMA-induced oxidative burst or LPS-stimulated TNFα secretion. Taken together, our data indicate that the alkaloid warifteine is a potent anti-inflammatory substance and that it has an effect on neutrophil migration through a decrease in both cell adhesion and migration.

Total synthesis of 8,14-dihydromorphinandienone alkaloids

A collective synthesis of 8,14-dihydronorsalutaridine, 8,14-dihydrosalutaridine, norisosinomenine, and isosinomenine is reported. The strategy provides direct access to the correct oxidation level of the products. The combination of an organocatalyst guanidine superbase, a tertiary amine base, and a dehydrating agent was necessary for the successful Henry-Michael-dehydration cascade to form the phenanthrene motif. The required selective aliphatic nitro reduction could only be achieved under heterogeneous transfer-hydrogenation conditions.

Antileishmanial activity of warifteine: a bisbenzylisoquinoline alkaloid isolated from Cissampelos sympodialis Eichl. (Menispermaceae)

Leishmania (L.) chagasi is the etiological agent of visceral leishmaniasis, an important endemic zoonosis in the American continent, as well as in many other countries in Asia, Africa, and Mediterranean Europe. The treatment is difficult due to the high toxicity of the available drugs, high costs, and emergence of resistance in the parasites. Therefore, there is an urgent need for new leishmanicidal agents. The bisbenzylisoquinoline alkaloids have been related to antibacterial, antiprotozoal, and antifungal activities. The aim of this study was to evaluate the growth inhibitory activity of warifteine (bisbenzylisoquinoline alkaloid) against L. chagasi promastigotes in axenic cultures and the occurrence of drug-induced ultrastructural changes in the parasite. This bisbenzylisoquinoline alkaloid was isolated from the leaves and roots of Cissampelos sympodialis Eichl. (Menispermaceae), a plant commonly used for the treatment of various diseases in Brazilian folk medicine. Using the purified warifteine, the 50% inhibitory concentration (IC₅₀) was determined at 0.08 mg/mL after 72 h in culture, inducing significant changes in the parasite morphology, like aberrant multisepted forms and blebs in the plasma membrane. In conclusion, warifteine represents an attractive candidate for future pharmacological studies aiming new leishmanicidal drugs.

Inhaled Cissampelos sympodialis down-regulates airway allergic reaction by reducing lung CD3+ T cells

Cissampelos sympodialis Eichl. (Menispermaceae) root infusion is used in Northeast Brazil to treat allergic asthma. We have previously shown that oral use of the plant extract reduces eosinophil infiltration into the lung of ovalbumin (OVA)- sensitized mice. However, drugs taken by inhalation route to treat asthma achieve better outcomes. Thereby, in this study, we evaluated the inhaled C. sympodialis alcoholic extract as a therapeutic treatment in OVA-sensitized BALB/c mice. The parameters which were analyzed consisted of leukocyte recruitment to the airway cavity, tissue remodeling and cell profile. The inhaled extract inhibited mainly eosinophil recruitment to the pleural cavity, bronchoalveolar lavage and peripheral blood. This treatment reduced the OVA-specific IgE serum titer and leukocyte infiltration in the peribronchiolar and pulmonary perivascular areas as well as mucus production. In addition, we also tested isolated alkaloids from the plant extract. The flow cytometric analysis showed that methylwarifteine (MW) and, mainly, the inhaled extract reduced the number of CD3+T cells and eosinophil-like cells. Therefore, inhaled C. sympodialis extract and MW lead to down-regulation of inflammatory cell infiltration with remarkable decrease in the number of T cells in an experimental model of respiratory allergy, suggesting that the plant can be delivered via inhalation route to treat allergic asthma.

Cardiovascular effects elicited by milonine, a new 8,14-dihydromorphinandienone alkaloid

The mechanisms underlying the cardiovascular responses evoked by milonine (i.v.), an alkaloid, were investigated in rats. In normotensive rats, milonine injections produced hypotension and tachycardia, which were attenuated after N(w) -nitro-L-arginine methyl esther (L-NAME; 20 mg/kg, i.v.). In phenylephrine (10 μM), pre-contracted mesenteric artery rings, milonine (10⁻¹⁰ M to 3 × 10⁻⁴ M) caused a concentration-dependent relaxation (EC₅₀ = 1.1 × 10⁻⁶ M, E(max) = 100 ± 0.0%) and this effect was rightward shifted after either removal of the vascular endothelium (EC₅₀ = 1.6 × 10⁻⁵, p < 0.001), or after L-NAME 100 μM (EC₅₀ = 6.2 × 10⁻⁵, p < 0.001), hydroxocobalamin 30 μM (EC₅₀ = 1.1 × 10⁻⁴, p < 0.001) or ODQ 10 μM (EC₅₀ = 1.9 × 10⁻⁴ p < 0.001). In addition, in rabbit aortic endothelial cells, milonine increased NO₃⁻ levels. The relaxant effect induced by milonine was attenuated in the presence of KCl (20 mM), a modulator efflux K(+) (EC₅₀ = 1.2 × 10⁻⁵, p < 0.001), or different potassium channel blockers such as glibenclamide (10 μM) (EC₅₀ = 6.3 × 10⁻⁵, p < 0.001), TEA (1 mM) (EC₅₀ = 2.3 × 10⁻⁵ M, n = 6) or Charybdotoxin (0.2 μM) plus apamin (0.2 μM) (EC₅₀ = 3.9 × 10⁻⁴ M, n = 7). In addition, pre-contraction with high extracellular potassium concentration prevented milonine-induced vasorelaxation (EC₅₀ = 1.0 × 10⁻⁴, p < 0.001). Milonine also reduced CaCl₂ -induced contraction in Ca²(+) -free solution containing KCl (60 mM). In conclusion, using combined functional and biochemical approaches, we demonstrated that the hypotensive and vasorelaxant effects produced by milonine are, at least in part, mediated by the endothelium, likely via nitric oxide release, activation of nitric oxide-cGMP pathway and opening of K(+) channels.

The antinociceptive and anti-inflammatory activities of caulerpin, a bisindole alkaloid isolated from seaweeds of the genus Caulerpa

The antinociceptive and anti-inflammatory activity of caulerpin was investigated. This bisindole alkaloid was isolated from the lipoid extract of Caulerpa racemosa and its structure was identified by spectroscopic methods, including IR and NMR techniques. The pharmacological assays used were the writhing and the hot plate tests, the formalin-induced pain, the capsaicin-induced ear edema and the carrageenan-induced peritonitis. Caulerpin was given orally at a concentration of 100 micromol/kg. In the abdominal constriction test caulerpin showed reduction in the acetic acid-induced nociception at 0.0945 micromol (0.0103-1.0984) and for dypirone it was 0.0426 micromol (0.0092-0.1972). In the hot plate test in vivo the inhibition of nociception by caulerpin (100 micromol/kg, p.o.) was also favorable. This result suggests that this compound exhibits a central activity, without changing the motor activity (seen in the rotarod test). Caulerpin (100 micromol/kg, p.o.) reduced the formalin effects in both phases by 35.4% and 45.6%, respectively. The possible anti-inflammatory activity observed in the second phase in the formalin test of caulerpin (100 micromol/kg, p.o.) was confirmed on the capsaicin-induced ear edema model, where an inhibition of 55.8% was presented. Indeed, it was also observed in the carrageenan-induced peritonitis that caulerpin (100 micromol/kg, p.o.) exhibited anti-inflammatory activity, reducing significantly the number of recruit cells by 48.3%. Pharmacological studies are continuing in order to characterize the mechanism(s) responsible for the antinociceptive and anti-inflammatory actions and also to identify other active principles present in Caulerpa racemosa.

Cytotoxicity of materials used in perforation repair tested using the V79 fibroblast cell line and the granulocyte-macrophage progenitor cells

AIM

To compare the cytotoxicity of materials used to repair perforations using permanent V79 fibroblasts and murine granulocyte-macrophage progenitor cells (CFU-GM).

METHODOLOGY

Set specimens from amalgam, glass-ionomer, SuperEBA, N-Rickert, MTA and gutta-percha were eluted with culture medium for 72 h and their cytotoxicities were assessed by incubating the extracts with V79 and bone marrow-derived progenitors for 24 h and 7 days, respectively. Cytotoxicity on V79 cells was judged using the total nucleic acid content (NAC), neutral red uptake (NRU) and reduction of the tetrazolium salt (MTT). The number of bone marrow CFU-GM colonies determined in clonal cultures stimulated with recombinant murine granulocyte-macrophage colony-stimulating factor was used to assess cytotoxicity to progenitor cells. Statistical analyses were conducted using the one-way analysis of variance and Tukey's test where appropriate.

RESULTS

All materials were cytotoxic in both cell systems; however, CFU-GM was more sensitive to the extracts than V79 cells. A similar rank order of toxicity was observed in V79 cells using the NAC and the MTT assays: glass-ionomer > N-Rickert congruent with SuperEBA > gutta-percha > amalgam congruent with MTA (P < 0.05). In contrast, the NRU test exhibited a lower sensitivity to MTA, gutta-percha and amalgam extracts. In the clonal culture assay, the toxicity was less pronounced in the presence of gutta-percha, SuperEBA and MTA. Similar cellular responses were found by placing the set specimens directly in the clonal culture dishes.

CONCLUSIONS

The sensitivity of toxicity depended on the choice of the endpoint and the cell-culture system. Nevertheless, MTA was ranked as the least cytotoxic cement in both cell systems.

Anti-allergic properties of Cissampelos sympodialis and its isolated alkaloid warifteine

Development of new agents capable of regulating eosinophilic inflammation can uncover novel therapeutic approaches for the treatment of allergic diseases, such as asthma. Here, we evaluated the anti-allergic properties of an extract of the Brazilian Menispermaceae Cissampelos sympodialis, focusing on its effects on allergic eosinophilia. By studying two models of allergic inflammation, an asthma model and the allergic pleurisy in actively sensitized Balb/c mice, we observed that the oral pre-treatment with C. sympodialis reduced pleural eosinophil influx triggered by allergen challenge in a dose-dependent manner. The mechanism involved in C. sympodialis inhibitory effect appeared to be independent of a direct effect on eosinophil locomotory machinery, but depend on a blockage of eotaxin production, a key eosinophil chemoattractant with important roles in allergic reactions. C. sympodialis was also able to affect eosinophil activation, as attested by its ability of inhibiting formation of new cytoplasmic lipid bodies and the secretion of cysteinyl leukotrienes. The alkaloid warifteine isolated from the C. sympodialis extract represents an active component responsible for the anti-eosinophilic effects of the extract, since warifteine was able to reproduce C. sympodialis inhibitory effects on allergic eosinophilia and cysteinyl leukotrienes production. Of interest, C. sympodialis and warifteine post-treatments also effectively inhibited eosinophilic reaction observed after allergic challenge. Therefore, C. sympodialis/warifteine may be a promising anti-allergic therapy, inasmuch as it presents potent anti-eosinophil and anti-leukotrienes activities.

Comparative toxicity of effluents processed by different treatments in V79 fibroblasts and the algae Selenastrum capricornutum

The efficacy of ozonation and of photocatalysis processing in the treatment of pulp mill ECF (elementary chlorine free) bleaching and textile effluents was evaluated by determining total organic carbon reduction (TOC) and the toxicity. The chronic toxicity of the effluents was evaluated by the ability to inhibit the growth of algae Selenastrum capricornutum. Cultured hamster V79 fibroblasts were used to assess the cytotoxicity of effluents submitted to different detoxification processes. Two endpoints were measured in V79 cells: 3-(4,5-dimethylthiazole-2-yl)-2,5-biphenyl tetrazolium bromide (MTT) reduction and neutral red uptake (NRU). Both treatment processes were able to reduce the TOC, although ozonization was less effective for pulp mill ECF bleaching. The pulp mill ECF bleaching and textile effluents reduced the growth of S. capricornutum by 39% and 27%, respectively. However, at the highest concentration tested, the textile effluents treated by photochemical process for 60 min showed increased cytotoxicity in V79 cells compared to the untreated effluent when assessed by the NRU and MTT reduction assays (increases of 30% and 40%, respectively). Pulp mill ECF bleaching effluent treated by ozonization had a similar cytotoxicity to that of untreated effluent in the NRU assay. In contrast, the MTT reduction assay indicated that effluents treated with ozone were around 20% more cytotoxic than untreated effluents. These results show that cultured fibroblasts may be useful for studying cellular responses to pollutants and may be included in tests to monitor the efficiency of effluent detoxification processes.

Effect of a standardized extract of red orange juice on proliferation of human prostate cells in vitro

A standardized extract of red orange juice (ROE) was shown to inhibit proliferation of fibroblast and epithelial prostate cells. These data suggest that the antiproliferative properties of ROE cannot be ascribed to cytotoxic effect and highlight its potential usefulness in the management of benign prostatic hyperplasia.

Cytotoxicity of the phytosterol diosgenin and its derivatives in rat cultured hepatocytes and V79 fibroblasts

In this work, the cytotoxic effects of some spirostane derivatives were examined in cultured hepatocytes and V79 fibroblasts using different viability assays. The derivatives were obtained by modifying the A and B rings of diosgenin. Diosgenin and its derivatives were more toxic in V79 fibroblasts (IC50 40-300 microM) than in hepatocytes (IC50 280-1000 microM). Inhibition of cytochrome P450IIIA in cultured hepatocytes by incubation with 1 mM cimetidine did not alter the toxicity of these compounds in these cells. These observations suggest that other pathways of detoxification may be involved in hepatocytes. In conclusion, the compounds studied merit investigation for their potential pharmacological and industrial applicability.

In vitro assessment of copper-induced toxicity in the human hepatoma line, Hep G2

Copper, though essential, is highly toxic when present in excess, as in Wilson disease, a genetic disorder of hepatic copper metabolism. We hypothesized that mitochondria are a major target of copper-induced cytotoxicity in Wilson disease. We used the human hepatoma line Hep G2 to examine copper-mediated cytotoxicity and three different methods to assess organelle damage: MTT assay (mitochondria), neutral red (NR; lysosomes) and Trypan blue exclusion assay (TB; plasma membrane). For all assays, cells at approximately 60% confluence in microtitre plates were incubated with CuCl(2) (concentration range: 50-100-150-200 microM) for 24 or 48 h. Results were expressed as percent of untreated control. At 24 h, cytotoxicity as detected by NR assay was significantly higher at all concentrations of copper than for MTT or TB ( p<0.005 at all concentrations). Cytotoxicity as detected by MTT was higher than that detected by TB at all concentrations except at 200 microM (p<0.05 for 50 microM, p<0.005 for 100 microM, p = 0.001 for 150 microM). Results at 48 h were similar (NR versus others: p <0.001 MTT versus TB: NS except at 150 microM where p<0.01). We investigated reactive oxygen species (ROS) production in copper-associated hepatocytoxicity by incubating sub-confluent cells with 2('),7(')-dichlorodihydrofluorescein diacetate dye plus copper (concentration range: 0-200 microM) for 1-1.5 h. Copper, but not zinc, produced significant increases in ROS (p<0.001). In summary, Hep G2 lysosomes appeared more susceptible to Cu-mediated damage than mitochondria; the cell membrane was highly resistant to damage.