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.     

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.     

Extracts of Bolivian plants,Copaifera reticulata and Heisteria pallida inhibit in vitro free radical-mediated DNA damage

The presence of different extracts of antiinflammatory plants Copaifera reticulata and Heisteria pallida in a reaction medium containing calf thymus DNA in a free radical generating system protected DNA against oxidative damage in terms of deoxyribose oxidation. The highest antioxidant activity was obtained using the methanol extract of C. reticulata (IC₅₀=3 μg/mL), followed by the aqueous extracts of H. pallida (IC₅₀=257 μg/mL) and C. reticulata (IC₅₀=380 μg/mL). Both dichloromethane extracts and the methanol extract of H. pallida showed a decreased antioxidant activity at higher concentrations. These results suggest that these extracts are capable of suppressing the in vitro oxidative degradation of DNA. © 1997 John Wiley & Sons, Ltd.     

Cytotoxic Activities of Colombian Plant Extracts on Chinese Hamster Lung Fibroblasts

Fifty-one crude extracts from 31 Colombian plants used in traditional medicine have been screened for cytotoxicity in a MTT assay with V79 cells. Eleven extracts (21%) were active, showing a survival percentage below 20% with respect to the controls. The most active were ethanol and dichloromethane extracts from Acnistus arborescens leaves. The IC₅₀ values obtained (6 and 11 μg/mL) encourage a more in depth investigation.     

Compounds with tyrosinase inhibition, elastase inhibition and DPPH radical scavenging activities from the branches of Distylium racemosum Sieb. et Zucc

Twenty compounds were isolated from the ethanol extract of Distylium racemosum branches and their inhibitory activities on tyrosinase, elastase and free radicals evaluated. The isolated compounds were identified as dibenzofurans (1–4), abscisic acid (5), 6′‐O‐galloylsalidroside (6), catechin derivatives (7–11), gallic acid derivatives (12–14), tyrosol (15), flavonoids (16–18), lupeol (19) and 1,2,3,6‐tetragalloylglucose (20). For study of tyrosinase inhibition activities, when compared with arbutin (IC₅₀ 48.8 μg/mL), four compounds (8, 11, 13, 17) showed higher activities, with IC₅₀ values of 4.8, 30.2, 40.5 and 37.7 μg/mL, respectively. For the elastase inhibition test, dibenzofuran 1 showed greater activity than the positive control, oleanolic acid (IC₅₀ 9.7 μg/mL), with an IC₅₀ of 7.7 μg/mL. In the studies on DPPH radical scavenging activities, five compounds (11, 12, 13, 14, 15) showed higher activities than ascorbic acid (IC₅₀ 5.0 μg/mL), with IC₅₀ values of 4.6, 3.9, 2.9, 3.8 and 4.7 μg/mL, respectively. Copyright © 2011 John Wiley & Sons, Ltd.     

Anti-oxidative Activities of Ethanol Extracts from Both Wild Plant and Suspension Cell Cultures of Rheum franzenbachii

Objective To evaluate the content of rhaponticin and anti-oxidative activities of theethanol extracts from both the wild plants and suspension cell cultures of Rheum franzenbachii.Methods Quantitative analysis of rhaponticin was performed by HPLC.The anti-oxidative activities of the ethanol extracts were evaluated using 2,2-diphenyl-1-picrylhydrazyl(DPPH)scavenging assays.Results The content of rhaponticin in the roots of the wild plant was 4.36 mg/g,while the content was only 1.59 mg/g in the leaves.The content of rhaponticin in suspension cells cultured on Murashige and Skoog(MS)medium supplemented with 1.0 mg/L 6-benzylaminopurine(6-BAP)and 2.0 mg/L 2,4-dicholorophenoxy acetic acid(2,4-D)was 17.64 mg/g,which increased by 4.05 times compared with the content in the roots of the wild plants.The roots of wild plants displayed the strongest anti-oxidative activity,followed by thesuspension cells 5 and 6,and the scavenging percent was 91.96%,91.23%,and 89.27%,respectively,at the concentration of 100μg/mL.The IC50 values were 2.477,15.644,and 31.415μg/mL,respectively.In particular,the DPPH scavenging activity of the ethanol extracts from the roots of the wild plant was generally comparable to the control of ascorbic acid(VC),and the IC50 value of the extracts was lower than that of VC(2.502μg/mL).Conclusion Rhaponticin production in the cell culture can be modulated and the accumulation can be increased.The roots of the wild plant display the strongest anti-oxidative activity.These results suggest that R.franzenbachii could hold a good potential source for human health.     

Screening of medicinal plants from Iranian traditional medicine for acetylcholinesterase inhibition

To find new herbal compounds with an acetylcholinesterase (AChE) inhibitory effect, this study focused on herbal drugs and resins which have been used in Iranian traditional medicine for the treatment of cognitive disorders. Forty drugs were selected from authoritative written documents of Iranian traditional medicine. Each drug was extracted by accelerated solvent extraction using dichloromethane followed by methanol. The 80 extracts were screened for AChE inhibitory activity by a TLC bioautography method. The inhibiting effect of the 32 most active extracts was measured by a microplate colorimetric assay. Due to the best activity, the seeds of Peganum harmala L. were investigated in detail. From the TLC bioautography assay the alkaloids harmaline and harmine were identified as active compounds. This result was confirmed by means of HPLC‐DAD. The IC₅₀ values were 41.2 μg/mL for the methanol extract, 95.5 μg/mL for the dichloromethane extract, 8.4 μg/mL for harmaline and 10.9 μg/mL for harmine. The concentrations of active compounds in the extracts were determined by a fast and precise HPLC method. As the amounts of harmaline and harmine in the extracts were correlated with the IC₅₀ values of the extracts, it can be concluded that these two alkaloids are responsible for the AChE inhibitory activity of P. harmala. Copyright © 2011 John Wiley & Sons, Ltd.     

Evaluation of Turkish seaweeds for antiprotozoal, antimycobacterial and cytotoxic activities

As part of our continuing research on seaweeds, crude MeOH extracts of two green, three brown and six red algae collected from Marmara, Black, Aegean and Mediterranean Seas were screened. Four parasitic protozoa, i.e. Plasmodium falciparum, Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani and the tubercle bacillus Mycobacterium tuberculosis were used as test organisms for the in vitro assays. The selective toxicity of the extracts was also determined against mammalian L6 cells. All seaweed extracts were active against T. brucei rhodesiense; the Dasya pedicellata extract was the most potent (IC₅₀ value 0.37 µg/mL). The same extract also weakly inhibited the growth of T. cruzi (IC₅₀ 62.02 µg/mL). All seaweed extracts also showed leishmanicidal activity (IC₅₀ values 16.76–69.98 µg/mL). The majority of the extracts also exhibited antiplasmodial potential and the most potent extracts were those from D. pedicellata (IC₅₀ 0.38 µg/mL), Codium bursa (IC₅₀ 1.38 µg/mL) and Caulerpa rasemosa (IC₅₀ 3.12 µg/mL). One brown and two red algal extracts showed some weak activity against Mycobacterium tuberculosis (MIC values 125–256 µg/mL). Except for the extract of Dasya pedicellata, none of the extracts displayed any cytotoxicity. This is the second study investigating the antiprotozoal activities of Turkish marine algae and identifies Dasya pedicellata, an understudied algal species, as a candidate for further studies. 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.     

The potential antileishmanial activity of some Sudanese medicinal plants

A preliminary examination of the crude methanol extracts of eight plant species collected from Sudan, revealed that only three plant species had a considerable in vitro antileishmanial activity on Leishmania major promastigotes at a concentration < 0.5 µg/mL. The plants Azadirchta indica, Maytenus senegalensis and Eucalyptus globulus gave IC₅₀ values of 11.5, 55 and 78 µg/mL, respectively. Extracts of Pseudocedrela kotscifye and Balanites aegyptiaca had a moderate biological activity, whereas extracts of Sonchous cornatus, Khaya senegalensis and Tamarindus indica failed to exhibit any significant antileishmanial activity against L. major at concentrations <100 µg/mL. Liquid–liquid partitioning of the methanol extracts indicated that fractions of M. senegalensis in dichloromethane and ethyl acetate had the highest antileishmanial activity at 5 µg/mL; IC₅₀ values were 5.01 and 29.7 µg/mL, respectively. Preliminary phytochemical analysis of the dichloromethane fraction revealed terpenoids and traces of phenolic principles but no alkaloid, tannins or flavonoids were detected. As lymphocyte proliferation was inhibited by P. kotscifye and A. indica at higher concentrations (<50 µg/mL) in the presence of phytohaemagglutinin (PHA), M. senegalensis had no significant toxic effect whereas S. cornatus, T. indica and K. senegalensis had a stimulatory impact on lymphocyte cells. Copyright © 1998 John Wiley & Sons, Ltd.     

Antioxidant activity of yellow dock (Rumex crispus L., Polygonaceae) fruit extract

The methanol extract of ripe Rumex crispus L. fruits was evaluated for its antioxidant potential by assays for ferric‐reducing antioxidant power (FRAP), DPPH‐free radical scavenging activity (DPPH) and the influence on lipid peroxidation in liposomes (LP). Considerable activity was observed in all test systems (FRAP: 9.9 mmol Fe²⁺/g; DPPH IC₅₀: 3.7 μg/mL; LP IC₅₀: 4.9 μg/mL), comparable to that of BHT (FRAP: 8.0 μg/mL; DPPH IC₅₀: 19.4 μg/mL; LP IC₅₀: 3.5 μg/mL), but lower than the activity of ascorbic acid, rutin and quercetin, used as positive control substances. The in vivo effects were evaluated in several hepatic antioxidant systems (activities of LPx, GSH‐Px, Px, CAT and XOD, as well as GSH content), after treatment with the studied yellow dock extract in different doses, or in combination with carbon tetrachloride (CCl₄). Pretreatment with the R. crispus extract inhibited CCl₄‐induced oxidative stress by decreasing LPx and increasing GSH content in a dose dependent manner, bringing the levels of antioxidant enzymes to near control values. Copyright © 2010 John Wiley & Sons, Ltd.     

Screening of New Zealand Plant Extracts for Inhibitory Activity Against HIV-1 Protease

231 Ethanol/aqueous extracts from New Zealand plants were screened for inhibitory activity against HIV-1 protease using fluorogenic and HPLC assays. Among the examined extracts, Pseudotsuga menziesii , Elaeocarpus hookerianus , Pernettya macrostigma and Cassinia leptophylla showed significant inhibition at a concentration of 50 μg/mL in the HPLC confirmation assay. The IC₅₀ values of these extracts to HIV-1 protease on its synthetic peptide substrate were 9.63, 9.74, 27.62 and 60.73 μg/mL, respectively. The derivatives of dihydroquercetin and [5′5′]-bisdihydroquercetin from Pseudotsuga menziesii could be the causative compounds for the inhibition.     

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.     

Antihyperlipidemic Components of Cassia auriculata Aerial Parts: Identification Through In Vitro Studies

Cassia auriculata (Caesalpiniaceae) is a common Asian beverage and medicinal plant widely used in tradition medicine for diabetes, hyperlipidemia and various other disease conditions. Previous studies on crude extracts of C. auriculata have documented the scientific basis for some of its traditional medicinal uses. The present study investigates the antilipase activity of the ethanol extract of the aerial parts along with the previously isolated compounds (kaempferol‐3‐O‐rutinoside, rutin, kaempferol, quercetin and luteolin). The crude extract displayed inhibitory activity against pancreatic lipase with IC₅₀ of 6.0 ± 1.0 µg/mL. The most active antilipase compound was kaempferol‐3‐O‐rutinoside with IC₅₀ value (2.9 ± 0.50 μM) only about twice weaker than the standard antilipase drug, orlistat (IC₅₀ = 1.45 ± 0.26 μM). Luteolin, quercetin and rutin were found to be weak pancreatic lipase inhibitors (IC₅₀ over 100 μM), whereas kaempferol showed no activity up to 250 μM. The antihyperlipidemic effect of C. auriculata could be attributed to direct lipase inhibitory effect of the plant constituents. Copyright © 2012 John Wiley & Sons, Ltd.     

Tanzanian medicinal plants used traditionally for the treatment of malaria: In vivo antimalarial and in vitro cytotoxic activities

Seventeen fractions of extracts obtained from 11 Tanzanian medicinal plants, which had previously been shown to possess a high antimalarial activity in vitro were submitted to the 4-day suppressive test in Plasmodium berghei-infected mice, and were investigated for cytotoxic activity in human carcinoma cell lines in vitro. Several fractions administered orally to the mice (500 mg/kg body weight/day) produced a significant reduction of parasitaemia. The most effective plant fractions investigated were those of the root and stem bark of Maytenus senegalensis (90% and 63% suppression of parasitaemia, respectively) and of the roots of Cissampelos mucronata (59% suppression). Highest cytotoxic activities were found with all fractions of Maytenus senegalensis (IC₅₀ 1 μg/mL) and with the PE fraction of the roots of Salacia madagascariensis (median IC₅₀=1.2 μg/mL for HT 29 and 2.3 μg/mL for KB).     

Toxicological studies on Globularia alypum and Zygophyllum gaetulum in rats

This work examines the toxicological effects of Globularia alypum leaves and Zygophyllum gaetulum aerial parts used in the traditional treatment of diabetes mellitus in Morocco. The LD₅₀ after oral administration of the plant infusions was higher than 10 g/kg body weight. Chronic toxicity was evaluated by analysis of biochemical and haematological parameters and by anatomo-histopathological studies. It is suggested that these plants have no toxicological effects in rats. Copyright © 1998 John Wiley & Sons, Ltd.     

Antiviral activity in vitro of Cupressus sempervirens on two human retroviruses HIV and HTLV

A proanthocyanidin polymer fraction (MW 1500–2000 daltons) from Cupressus sempervirens L. (Cupressaceae) exhibited true antiviral activity in vitro against two retroviruses, HIV and HTLV III B. In comparison with AZT no toxicity was observed with PPC at concentrations of 50 μg/mL which exceeded the IC₅₀ values (1.5 to 15 μg/mL for HIV and 5 to 25 μg/mL for HTLV). © 1998 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.     

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 Jatrogrossidione from Jatropha grossidentata and Jatrophone from Jatropha isabellii

The activity of jatrogrossidione, the main diterpene of Jatropha grossidentata and jatrophone from Jatropha isabellii was determined against Leishmania and Trypanosoma cruzi strains in vitro as well as against Leishmania amazonensis in vivo. Jatrogrossidione showed a strong in vitro leishmanicidal and trypanocidal activity with IC₁₀₀ of 0.75 and 1.5–5.0 μg/mL, respectively. Under similar conditions, the IC₁₀₀ of glucantime, ketoconazole and pentamidine towards Leishmania strains were >100, 50–100 and 1 μg/mL, respectively. The IC₅₀ of jatrogrossidione was <0.25 μg/mL against amastigote forms of Leishmania infecting macrophages, with toxicity at concentrations higher than 0.5 μg/mL. BALB/c mice infected with L. amazonensis strain PH 8 were treated 24 h after infection with jatrogrossidione and jatrophone for 13 consecutive days. Jatrophone at 25 mg/kg/day subcutaneously administered was significantly active ( p <0.05) against the virulent strain PH 8 of L. amazonesis ; it was more active than Glucantime at 112 mg Sb^v per kg/day. Subcutaneous administration of jatrophone, however, proved to be too toxic under our assay conditions. Assays of single local treatment on the footpad infection 2 weeks after inoculation of L. amazonensis indicated that jatrogrossidione and jatrophone were inactive at the selected doses.