Antimycobacterial,antiprotozoal and cytotoxic potential of twenty‐one brown algae (phaeophyceae) from British and Irish waters

In the continuation of our research on seaweeds, crude extracts of 21 brown algae collected from the south coast of England and the west coast of Ireland were screened for in vitro trypanocidal, leishmanicidal and antimycobacterial activities. Mammalian stages of a small set of parasitic protozoa; i.e. Trypanosoma brucei rhodesiense, T. cruzi and Leishmania donovani, and the tubercle bacillus Mycobacterium tuberculosis were used as test organisms. The extracts were also evaluated for selectivity by testing on a mammalian cell line (L6 cells). Only four extracts were moderately active against T. cruzi, whereas all algal extracts showed significant activity against T. brucei rhodesiense, with Halidrys siliquosa and Bifurcaria bifurcata (Sargassaceae) being the most potent (IC₅₀ values 1.2 and 1.9 μg/mL). All algal extracts also displayed leishmanicidal activity, with H. siliquosa and B. bifurcata again being the most active (IC₅₀s 6.4 and 8.6 μg/mL). When tested against M. tuberculosis, only the B. bifurcata extract was found to have some antitubercular potential (MIC value 64.0 μg/mL). Only three seaweed extracts, i.e. H. siliquosa, B. bifurcata and Cystoseira tamariscifolia showed some cytotoxicity. To our knowledge, this is the first study on the antiprotozoal and antimycobacterial activity of brown algae from British and Irish waters. Copyright © 2010 John Wiley & Sons, Ltd.     

Antiprotozoal,antimycobacterial and cytotoxic potential of twenty‐three British and Irish red algae

As part of our continuing research on seaweeds, we have screened the crude extracts of 23 red marine algae collected from England and Ireland. The clinically important blood‐stage life forms of Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani and Mycobacterium tuberculosis were used as test organisms in the in vitro assays. The selectivity of the extracts was determined by using mammalian skeletal myoblast (L6) cells. All algal extracts showed activity against T. brucei rhodesiense, with Corallina officinalis and Ceramium virgatum being the most potent (IC₅₀ values 4.8 and 5.4 μg/ml), whilst none of the algal extracts inhibited the growth of T. cruzi. Except for Porphyra leucosticta, extracts from all seaweeds also showed leishmanicidal activity with IC₅₀ values ranging from 16.5 to 85.6 μg/ml. Only the crude extract of Calliblepharis jubata showed some weak activity against Mycobacterium tuberculosis (MIC value 256 μg/ml), while the others were inactive at this concentration. Corallina officinalis was the only seaweed that displayed some marginal cytotoxicity (IC₅₀ value 88.6 μg/ml), and all remaining extracts were non‐toxic towards L6 cells at 90 μg/ml concentration. To our knowledge, this is the first study reporting antiprotozoal and antimycobacterial activity of British and Irish red algae. Copyright © 2010 John Wiley & Sons, Ltd.     

Antiprotozoal,antimycobacterial and cytotoxic potential of some british green algae

In the continuation of our search for natural sources for antiprotozoal and antitubercular molecules, we have screened the crude extracts of four green marine algae (Cladophora rupestris, Codium fragile ssp. tomentosoides, Ulva intestinalis and Ulva lactuca) collected from the Dorset area of England. Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani and Mycobacterium tuberculosis were used as test organisms in the in vitro assays. The selective toxicity of the extracts was also determined toward mammalian skeletal myoblast (L6) cells. The crude seaweed extracts had no activity against M. tuberculosis, but showed antiprotozoal activity against at least two protozoan species. All algal extracts were active against T. brucei rhodesiense, with C. rupestris being the most potent one (IC₅₀ value 3.7 μg/ml), whilst only C. rupestris and U. lactuca had moderate trypanocidal activity against T. cruzi (IC₅₀ values 80.8 and 34.9 μg/ml). Again, all four extracts showed leishmanicidal activity with IC₅₀ values ranging between 12.0 and 20.2 μg/ml. None of the extracts showed cytotoxicity toward L6 cells, indicating that their antiprotozoal activity is specific. This is the first study reporting antiprotozoal and antimycobacterial activity of British marine algae. Copyright © 2009 John Wiley & Sons, Ltd.     

Antiprotozoal activity of drimane and coloratane sesquiterpenes towards Trypanosoma brucei rhodesiense and Plasmodium falciparum in vitro

The extracts and 12 sesquiterpenes obtained from the East African medicinal plant Warburgia ugandensis Sprague (Canellaceae) were assessed for their antiplasmodial activity against the chloroquine‐sensitive (3D7) and chloroquine‐resistant (K1) strains of Plasmodium falciparum and antitrypanosomal activity against Trypanosoma brucei rhodesiense. The dichloromethane extract displayed strong antiplasmodial and antitrypanosomal activities with IC₅₀ values of 8.10 and 1.10 µg/mL against K1 strain of the malaria parasite and STlB900 strain of T. b. rhodesiense, respectively. Among the compounds evaluated for inhibition of trypomastigotes, both drimane and coloratane sesquiterpenes possessing aldehyde groups at positions 8 and 9 were found to show most antitrypanosomal activity with IC₅₀ values in the range 0.56–6.4 µM. The antiplasmodial assays also revealed that the six coloratane and six drimane sesquiterpenes isolated from this extract exhibited significant antitrypanosomal activity with IC₅₀ values ranged from 0.45 to ?114 µM. Among the compounds tested against the malarial parasite P. falciparum 11?‐hydroxymuzigadiolide (3) was most active with an IC₅₀ value of 6.40 µM. Copyright © 2010 John Wiley & Sons, Ltd.     

In Vitro activities of plant extracts from Saudi Arabia against malaria,leishmaniasis, sleeping sickness and Chagas disease

The in vitro activity of the methanol extracts of 51 plants randomly collected from the Kingdom of Saudi Arabia and some of their fractions (petroleum ether, chloroform, ethyl acetate and aqueous) were evaluated against Plasmodium falciparum, Trypanosoma brucei brucei, T. cruzi and Leishmania infantum, as well as toxicity against MRC‐5 fibroblast cells. Ten crude methanolic extracts that demonstrated potent and adequately selective antiprotozoal activity were subjected to solvent fractionation using petroleum ether, ethyl acetate and chloroform. Only three samples showed promising antiprotozoal activity. Argemone ochroleuca (CHCl₃ fraction) showed pronounced activity against P. falciparum_GHA (IC₅₀ 0.32 μg/mL) and T. cruzi (IC₅₀ 0.30 μg/mL) with low cytotoxicity against MRC‐5 cells (CC₅₀ 11.6 μg/mL). Capparis spinosa (EtOAc fraction) showed pronounced activity against P. falciparum_GHA with an IC₅₀ 0.50 μg/mL in the absence of toxicity against MRC‐5 cell line (CC₅₀ > 30 μg/mL). Heliotropium curassavicum (CHCl₃ fraction) showed similar activity against P. falciparum (IC₅₀ 0.65 μg/mL; MRC‐5 CC₅₀ > 30 μg /mL). These three extracts will be subjected for further extensive studies to isolate and identify their active constituents. Copyright © 2010 John Wiley & Sons, Ltd.     

Cyclooxygenase‐2 inhibitory and antioxidant compounds from the truffle Elaphomyces granulatus

The ethanol extract of fruiting bodies of Elaphomyces granulatus, a truffle‐like fungus, was evaluated for cyclooxygenase‐2 (COX‐2) enzyme inhibitory and antioxidant activities. Inhibition of COX‐2 activity was evaluated in mouse macrophages (RAW 264.7). The extract of E. granulatus caused a 68% inhibition of COX‐2 activity at 50 µg/mL. Bioassay‐guided investigation led to the isolation and identification of two active compounds, syringaldehyde and syringic acid. Syringaldehyde moderately inhibited COX‐2 activity with an IC₅₀ of 3.5 µg/mL, while syringic acid strongly inhibited COX‐2 activity with an IC₅₀ of 0.4 µg/mL. The antioxidant activity of the extract and isolated compounds was evaluated in HL‐60 cells by the DCFH‐DA method. The extract of E. granulatus showed a potent antioxidant effect, with an IC₅₀ of 41 µg/mL. Of the pure compounds, syringic acid displayed a strong antioxidant activity, with an IC₅₀ of 0.7 µg/mL, while syringaldehyde showed no activity in the assay. Copyright © 2008 John Wiley & Sons, Ltd.     

Medicinal Plants Traditionally Used for Treatment of Obesity and Diabetes Mellitus – Screening for Pancreatic Lipase and α‐Amylase Inhibition

In order to find new pancreatic lipase (PL) and α‐amylase inhibitors from natural sources for the treatment of obesity and related diseases as diabetes mellitus II, 23 medicinal plants with weight‐reducing, serum glucose‐reducing or related potential were investigated. Methanolic and water extracts of the plants were evaluated by using two in vitro test systems. Our findings have shown that the methanolic extract of Hibiscus sabdariffa L. (Malvaceae) showed high inhibitory activities to PL (IC₅₀: 35.8 ± 0.8 µg/mL) and α‐amylase (IC₅₀: 29.3 ± 0.5 µg/mL). Furthermore, the methanolic extract of Tamarindus indica L. (Leguminosae) showed a high anti‐lipase (IC₅₀: 152.0 ± 7.0 µg/mL) and the aqueous extract a high anti‐amylase (IC₅₀: 139.4 ± 9.0 µg/mL) activity. This work provides a priority list of interesting plants for further study with respect to the treatment of obesity and associated diseases. Copyright © 2015 John Wiley & Sons, Ltd.     

Xanthine Oxidase Inhibitory Activity of Hungarian Wild‐Growing Mushrooms

Mushrooms represent a remarkable and yet largely unexplored source of new, biologically active natural products. In this work, we report on the xanthine oxidase (XO) inhibitory activity of 47 wild‐growing mushrooms native to Hungary. Aqueous and organic (n‐hexane, chloroform, and 50% methanol) extracts of selected mushrooms from different families were screened for their XO inhibitory activities. Among the 188 extracts investigated, the chloroform and 50% methanol fractions proved to be the most effective. Some species exhibited high inhibitory activity, e.g., Hypholoma fasciculare (IC₅₀ = 67.76 ± 11.05 µg/mL), Suillus grevillei (IC₅₀ = 13.28 ± 1.58 µg/mL), and Tricholoma populinum (IC₅₀ = 85.08 ± 15.02 µg/mL); others demonstrated moderate or weak activity. Additional studies are warranted to characterize the compounds responsible for the XO inhibitory activity of mushroom extracts. Copyright © 2014 John Wiley & Sons, Ltd.     

Protective effects of neohesperidin and poncirin isolated from the fruits of Poncirus trifoliata on potential gastric disease

The effects of Poncirus trifoliata (P. trifoliata) (Ponciri Fructus, PF) extract and its constituents such as neohesperidin and poncirin on gastritis in rats and human gastric cancer cells were investigated. The PF 70% ethanol extracts (1 g) showed approximately 11.38% of acid‐neutralizing capacities and cytotoxicity (IC₅₀ = 85.39 µg/mL) against human AGS gastric cancer cells. In addition, neohesperidin exhibited antioxidant activity (IC₅₀ = 22.31 µg/mL) in the 1,1‐diphenyl‐2‐picryldydrazyl (DPPH) radical‐scavenging assay. Neohesperidin (50 mg/kg) and poncirin (100 mg/kg) significantly inhibited 55.0% and 60.0% of HCl/ethanol‐induced gastric lesions, respectively, and increased the mucus content. In pylorus ligated rats, neohesperidin (50 mg/kg) significantly decreased the volume of gastric secretion and gastric acid output, and increased the pH. From these results, it could be suggested that neohesperidin and poncirin isolated from PF may be useful for the treatment and/or protection of gastritis. Copyright © 2009 John Wiley & Sons, Ltd.     

Modulation of Cox‐1, 5‐, 12‐ and 15‐Lox by Popular Herbal Remedies Used in Southern Italy Against Psoriasis and Other Skin Diseases

Acanthus mollis (Acanthaceae), Achillea ligustica, Artemisia arborescens and Inula viscosa (Asteraceae) are used in Southern Italy against psoriasis and other skin diseases that occur with an imbalanced production of eicosanoids. We here assessed their in vitro effects upon 5‐, 12‐, 15‐LOX and COX‐1 enzymes as well as NFκB activation in intact cells as their possible therapeutic targets. All methanol crude extracts inhibited both 5‐LOX and COX‐1 activities under 200 µg/mL, without significant effects on the 12‐LOX pathway or any relevant in vitro free radical scavenging activity. NFκB activation was prevented by all extracts but A. mollis. Interestingly, A. ligustica, A. arborescens and A. mollis increased the biosynthesis of 15(S)‐HETE, an anti‐inflammatory eicosanoid. A. ligustica (IC₅₀ = 49.5 µg/mL) was superior to Silybum marianum (IC₅₀ = 147.8 µg/mL), which we used as antipsoriatic herbal medicine of reference. Its n‐hexane, dichloromethane and ethyl acetate fractions had also inhibitory effects on the LTB₄ biosynthesis (IC₅₀s = 9.6, 20.3 and 68 µg/mL, respectively) evidencing that the apolar extracts of A. ligustica are promising active herbal ingredients for future phytotherapeutical products targeting psoriasis. © 2014 The Authors. Phytotherapy Research published by John Wiley & Sons Ltd.     

Biological activities of xanthatin from Xanthium strumarium leaves

The objective of the present work was to evaluate the biological activities of the major bioactive compound, xanthatin, and other compounds from Xanthium strumarium (Asteraceae) leaves. Inhibition of bloodstream forms of Trypanosoma brucei brucei and leukaemia HL‐60 cell proliferation was assessed using resazurin as a vital stain. Xanthatin was found to be the major and most active compound against T. b. brucei with an IC₅₀ value of 2.63 µg/mL and a selectivity index of 20. The possible mode of action of xanthatin was further evaluated. Xanthatin showed antiinflammatory activity by inhibiting both PGE₂ synthesis (24% inhibition) and 5‐lipoxygenase activity (92% inhibition) at concentrations of 100 µg/mL and 97 µg/mL, respectively. Xanthatin exhibited weak irreversible inhibition of parasite specific trypanothione reductase. Unlike xanthatin, diminazene aceturate and ethidium bromide showed strong DNA intercalation with IC₅₀ values of 26.04 µg/mL and 44.70 µg/mL, respectively. Substantial induction of caspase 3/7 activity in MIA PaCa‐2 cells was observed after 6 h of treatment with 100 µg/mL of xanthatin. All these data taken together suggest that xanthatin exerts its biological activity by inducing apoptosis and inhibiting both PGE₂ synthesis and 5‐lipoxygenase activity thereby avoiding unwanted inflammation commonly observed in diseases such as trypanosomiasis. Copyright © 2011 John Wiley & Sons, Ltd.     

Antiprotozoal activity of Khaya anthotheca, (Welv.) C.D.C. a plant used by chimpanzees for self-medication

Ethnopharmacological relevance

Khaya species, endemic to Africa and Madagascar, continues to be valuable in indigenous traditional medicine. Their bitter tasting barks are decocted to treat fevers, several febrile conditions, microbial infections and worm infestations. In the Budongo rain forest of Western Uganda, non-human primates, especially chimpanzees and baboons, have been observed to eat the bitter non-nutritious bark and occasionally the seed.

Materials and methods

Extracts were prepared by sequential fractionation with solvents of increasing polarities and assayed using standard procedures. Bioassay guided purification of the petroleum ether extract by column chromatography yielded three pure limonoids, Grandifolione (1), 7-deacetylkhivorin (2) and 1,3-deacetyldeoxyhavenensin (3). The antitrypanosomal, antileishmanial and antiplasmodial activities of pure compounds (1) and (2) were evaluated in vitro against Plasmodium falciparum K1, Trypanosoma brucei rhodesiense STIB 900, Trypanosoma cruzi trypomastigotes (Tulahuen C4), and axenic Leishmania donovani MHOMET-67/L82 and for cytotoxicity against L6 rat skeletal myoblast cells, in parallel with standard drugs.

Results

Of the four extracts tested, the petroleum ether extract showed activity against Plasmodium falciparum (IC₅₀ 0.955 μg/ml) and Trypanosoma brucei rhodesiense (IC₅₀ 5.72 μg/ml). The pure compounds (1) and (2) demonstrated activity against Plasmodium falciparum (KI strain) and marginal activities against Trypanosoma brucei brucei, Trypanosoma brucei rhodesiense, Trypanosoma cruzi and Leishmania donovani.

Conclusion

The present study provides evidence justifying the use of Khaya preparations in traditional medicine to treat fevers and microbial infections. The observed antiprotozoal activity of grandifolione and 7-deacetylkhivorin from the seed of Khaya anthotheca further confirms the ethnomedicinal potential of this plant and supports the hypothesis that non-human hominids (chimpanzees and baboons) too, eat the bitter bark and seeds for self-medication and in general, the use of Khaya plant material for medication by humans in disease endemic tropical areas. The antiprotozoal activity of gradifolione, and, the antitrypanosomal and antileishmanial activities of 7-deacetylkhivorin are reported here for the first time.     

Antiviral activity of chilean medicinal plant extracts

Chilean flora is a potential source of bioactive compounds, including some with antiviral activity. Ninety aqueous and hydroaloholic extracts from 36 native and introduced plant species were screened for antiviral activity on herpes (HSV-1 and HSV-2) and HIV viruses. Furthermore, the samples were assayed for antimicrobial effect on pathogenic bacteria and a yeast. Plants were selected according to their indication of use for treating symptomatology of possible viral aetiology in Chilean folk medicine. The hydroaloholic extracts of Cassia stipulacea and Escallonia illintia exhibited detectable antiviral effects towards HSV-1 with IC₅₀ values of 80 and 40 μg crude extract/mL, respectively. Samples belonging to Aristotelia chilensis (IC₅₀ of 40 μg/mL), Drymis winteri (IC₅₀ values of 35 and 80μg/mL), Elytropus chilensis and Luma apiculata, with an IC₅₀ value of 100 μg/mL showed activity against HSV-2. None of the extracts showed activity against HIV at extract concentrations which were nontoxic for cells.     

Trypanocidal activity of ergosterol peroxide from Pleurotus ostreatus

Chagas' disease, which is caused by the protozoan parasite Trypanosoma cruzi, is a public health problem in South America affecting millions of people, and more recently several thousands in countries where the disease is not endemic. Due to the magnitude of the problem, finding a cure for this disease remains a major challenge. The aim of this study is to evaluate the trypanocidal activity of ergosterol peroxide (5α, 8α‐epidioxy‐22E‐ergosta‐6, 22‐dien‐3β‐ol) isolated from Pleurotus ostreatus (Jacq.) P. Kumm. f. sp. Florida. The ergosterol peroxide showed strong trypanocidal activity on the intracellular form of T. cruzi. Ergosterol peroxide had an inhibitory concentration (IC₅₀) of 6.74 µg/mL on T. cruzi, but showed no lytic action on erythrocytes and no cytotoxic effect on mammalian cells at concentrations higher than 1600 µg/mL. The interaction of Trypanosoma cruzi with ergosterol peroxide in vitro resulted in a strong lytic activity possibly due to the disruption of the parasite membrane. This is the first report of trypanocidal activity, a new biological property of ergosterol peroxide isolated from Pleurotus ostreatus (Jacq.) P. Kumm. f. sp. Florida. Copyright © 2011 John Wiley & Sons, Ltd.     

Taxodione and Extracts from Salvia austriaca Roots as Human Cholinesterase Inhibitors

Taxodione, an abietane diterpenoid, was isolated from Salvia austriaca transformed roots grown in in vitro conditions. The compound is known to have antibacterial, cytotoxic and anti‐tumour properties. This study evaluates the ability of pure taxodione and extracts obtained from the S. austriaca hairy roots and roots from field‐grown plants to inhibit human acetylcholinesterase and butyrylcholinesterase. Both extracts were found to have similar actions against acetylcholinesterase. The IC₅₀ for extracts from transformed and untransformed roots were 142.5 and 139.5 µg ml^?1, respectively. The highest activity towards human acetylcholinesterase was demonstrated by taxodione (IC₅₀ = 54.84 µg ml^?1). With respect to BChE inhibition, the root extracts demonstrated stronger activity (IC₅₀ = 23.6 µg ml^?1: field‐grown plants and 41.6 µg ml^?1: transformed roots) than taxodione (IC₅₀ = 195.9 µg ml^?1). Taxodione showed significant cytotoxicity against A549 cell line (IC₅₀ = 9.1 µg ml^?1), whereas the activities for the extracts from S. austriaca roots of field‐grown plants (IC₅₀ = 75.7 µg ml^?1) and hairy roots (IC₅₀ = 86.2 µg ml^?1) were lower. Computer modelling suggests that taxodione should not demonstrate cardiotoxic or genotoxic activity. It also indicates that taxodione should demonstrate very rapid transport from the body with very good blood–brain barrier penetration, but with no cumulative effect on the human body. The obtained results indicate that taxodione is a safe compound and may be used for further investigations in pharmacological activities. Copyright © 2015 John Wiley & Sons, Ltd.     

Camellia sinensis Ameliorates the Efficacy of Last Line Antibiotics Against Carbapenem Resistant Escherichia coli

Aquo‐ethanolic extract of Camellia sinensis (PTRC‐31911‐A), standardized using Fourier transform infrared analysis, was found to have seven common functional groups in comparison with pre‐identified marker compound ‘quercetin’. Phyto‐chemical quantitation analysis revealed the presence of 10.65 µg/mg of flavonoids. The bioactivity fingerprint profile of PTRC‐31911‐A includes IC_{50 (Hydroxyl radical site specific scavenging)} = 11.36 ± 0.5 µg/mL, IC_{80 (Hydroxyl radical non‐site specific scavenging)} = 26.44 ± 0.5 µg/mL and IC_{50 (Superoxide ion scavenging)} = 10.141 ± 0.5 µg/mL. The drug combination analysis of PTRC‐31911‐A with five third‐line antibiotics was carried out against carbapenem‐resistant Escherichia coli. The analysis of combination of PTRC‐31911‐A (6.25–1000 µg/mL) and antibiotics (6.25–1000 µg/mL) revealed synergistic behaviour (fractional inhibitory concentration indices < 1) with tigecycline, ertapenem, meropenem, colistin and augmentin. The lead combination of PTRC‐31911‐A + ertapenem or meropenem showed maximum augmentative potential at 50 and 100 µg/mL, respectively, with nearly five‐fold decrease in minimum inhibitory concentrations as compared with respective antibiotics alone. The synergistic effects implied that the antibacterial combinations of PTRC‐31911‐A and ertapenem, meropenem, colistin, tigecycline or augmentin would be more effective than a single monotherapy with either of the antibacterial agent. Copyright © 2015 John Wiley & Sons, Ltd.     

Activity of Scottish Plant,Lichen and Fungal Endophyte Extracts against Mycobacterium aurum and Mycobacterium tuberculosis

With tuberculosis the leading bacterial killer worldwide and other mycobacterial diseases on the increase, the search for new antimycobacterial agents is timely. In this study, extracts from plants, lichens and fungal endophytes of Scottish provenance were screened for activity against Mycobacterium aurum and M. tuberculosis H₃₇Rv. The best activity against M. aurum was observed for extracts of Juniperus communis roots and Cladonia arbuscula (MIC = 4 µg/mL), and a fungal endophyte isolated from Vaccinium myrtillus (MIC = 8 µg/mL). The best activity against M. tuberculosis was observed for extracts of C. arbuscula, Empetrum nigrum, J. communis roots, Calluna vulgaris aerial parts, Myrica gale roots and stems (93 to 99% inhibition at 100 µg/mL). Potent antitubercular activity (90 to 96% inhibition at 100 µg/mL) was also observed for the ethanol extracts of Xerocomus badius, Chalciporus piperatus, Suillus luteus and of endophytes isolated from C. vulgaris, E. nigrum, Vaccinium vitis‐idaea and V. myrtillus. The results obtained this study provide, in part, some scientific basis for the traditional use of some of the selected plants in the treatment of tuberculosis. They also indicate that fungal endophytes recovered from Scottish plants are a source of antimycobacterial agents worthy of further investigation. Copyright © 2009 John Wiley & Sons, Ltd.     

Damnacanthal from the Congolese Medicinal Plant Garcinia huillensis has a Potent Preferential Cytotoxicity against Human Pancreatic Cancer PANC‐1 Cells

Screening of eight Congolese medicinal plants showed that the CHCl₃ and MeOH extracts of Aframomum melegueta (PC₅₀ = 47.8 µg/mL and 13.8 µg/mL, respectively) and CHCl₃ extracts of Garcinia huillensis (PC₅₀ = 17.8 µg/mL) and Securidaca longepedunculata (PC₅₀ = 23.4 µg/mL) had preferential cytotoxicity against human pancreatic cancer PANC‐1 cells under nutrient‐deprived conditions. The active constituents of the CHCl₃ extract of G. huillensis were examined and 12 known anthraquinones were identified. Among them, damnacanthal (1) caused preferential necrotic cell death of PANC‐1 and PSN‐1 cells under nutrient‐deprived and serum‐sensitive conditions (PC₅₀ = 4.46 µm and 3.77 µm , respectively). Copyright © 2012 John Wiley & Sons, Ltd.     

HPLC Analysis of Stephania rotunda Extracts and Correlation with Antiplasmodial Activity

Stephania rotunda (Menispermaceae), a creeper commonly found in the mountainous areas of Cambodia, has been mainly used for the treatment of fever and malaria. Thus, the aim of this study is to investigate the chemical composition and antiplasmodial activity of different samples of S. rotunda and compare their antiplasmodial activity with their alkaloid content. Sixteen samples from different parts (roots, stem, and tuber) of S. rotunda were collected from four regions of Cambodia (Battambang, Pailin, Siem Reap, and Kampot). Reversed‐phase HPLC was used to determine the content of three bioactive alkaloids (cepharanthine, tetrahydropalmatine, and xylopinine). These three alkaloids have been found in all samples from Battambang and Pailin (samples I–IX), whereas only tetrahydropalmatine was present in samples from Siem Reap and Kampot (samples X–XVI). The analyzed extracts were evaluated for their antiplasmodial activity on W2 strain of Plasmodium falciparum. Among them, 13 extracts were significantly active with inhibitory concentration 50 (IC₅₀) from 1.2 to 3.7 µg/mL and 2 extracts were moderately active (IC₅₀ = 6.1 and 10 µg/mL, respectively), whereas sample XI was not active (IC₅₀ = 19.6 µg/mL). A comparison between antiplasmodial activity and concentration of the three bioactive alkaloids in S. rotunda extracts has been realized. Copyright © 2012 John Wiley & Sons, Ltd.     

Antioxidant and antiinflammatory effect of Epilobium parviflorum Schreb.

Epilobium parviflorum Schreb. (Onagraceae) is used for the treatment of benign prostatic hyperplasia (BPH), but its biological action is not entirely identified. This paper aims to report data on E. parviflorum with respect to its antioxidant and antiinflammatory effects. The aqueous acetone extract of E. parviflorum showed higher antioxidant effect in the DPPH assay than well known antioxidants and inhibited the lipid peroxidation determined by the TBA assay (IC₅₀ = 2.37 ± 0.12 mg/mL). In concentrations of 0.2–15.0 µg/mL the extract possessed a protective effect, comparable to catalase (250 IU/mL), against oxidative damage, generated in fibroblast cells. In the COX inhibition assay E. parviflorum decreased the PGE₂ release, so showing inhibition of the COX‐enzyme (IC₅₀ = 1.4 ± 0.1 µg/mL). Copyright © 2008 John Wiley & Sons, Ltd.