Antitumor Activity of Extracts from Peperomia elongata.

Abstract

The cytotoxic potential of ethanol extracts from Peperomia elongata. H. B. & K. (Piperaceae) were evaluated against human cancer cell lines by the MTT method. The samples considered cytotoxic were tested for antimitotic activity with the sea urchin egg development test and for hemolytic activity using mice erythrocytes. The extracts from leaves (hexane), stems (ethanol, hexane, hexane:AcOEt, AcOEt, and MeOH:H₂O insoluble), and roots (R4) presented potential cytotoxic action. The stems extracts showed the highest toxicity in all tumor cell lines tested, with an IC₅₀ ≤ 9.0 µg/mL for ethanol extract, IC₅₀ ≤ 11.6 µg/mL for MeOH:H₂O insoluble, IC₅₀ ≤ 7.3 µg/mL for hexane extract, IC₅₀ ≤ 11.4 µg/mL for hexane: AcOEt, and IC₅₀ ≤ 16.2 µg/mL for AcOEt extract. All extracts considered cytotoxic for tumoral cell lines presented antimitotic activity. The samples from roots (R4) and stems (ethanol, MeOH:H₂O insoluble, and hexane extract from leaves) were found to possess lytic activity in mice erythrocytes but in higher doses (> 125 µg/mL). Further studies for the isolation and identification of the active principles of these extracts should be undertaken.     

Cytotoxicity Evaluation and Isolation of a Chroman Derivative from Phyllanthus amarus. Aerial Part Extract

Abstract

Chemical and cytotoxicity examinations of the crude methanol extract of the aerial parts of Phyllanthus amarus. Schum. et Thonn. (Euphorbiaceae) were investigated. The cytotoxicity property of the P. amarus. was evaluated in vitro., using the human ovarian A2780 cancer cell. Bioassay-guided fraction of the crude extract (IC₅₀ value of 31.2 µg/mL) showed that the dichloromethane fraction was most toxic with an IC₅₀ value of 22.7 µg/mL, whereas the polar methanol fraction was least cytotoxic with an IC₅₀ value of 31.2 µg/mL. This led to the isolation of a new chroman derivative from the dichloromethane fraction. On the basis of nuclear magnetic resonance and mass spectral data, the structure of the chroman was established as 4,4,8-trimethoxy chroman. The compound exhibited very little or no in vitro. cytotoxicity with an IC₅₀ of 16.2 µg/mL, relative to actinomycin, the reference compound, with an IC₅₀ of 2.0 ng/mL. It can therefore be concluded that the aerial parts of P. amarus., an extensively used plant remedy in various African and Asian Pacific ethnomedicines, is relatively nontoxic.     

Antioxidant and cytotoxic potential of a new thienyl derivative from Tagetes erecta roots

Context: The search for newer compounds against pathogenic species continues unabated due to drug resistance. Traditionally, Tagetes erecta Linn. (Compositae) has been used for the treatment of various parasitic and microbial diseases.

Objective: To evaluate the antioxidant activity of the ethanol extract of Tagetes erecta roots and its cytotoxicity against prostate and HeLa cancer cell lines followed by activity-guided isolation.

Materials and Methods: The antioxidant screening was carried out using diphenylpicrylhydrazyl (DPPH) radical scavenging assay with serial concentrations ranging from 2 to 100 µg/mL, and cytotoxicity was evaluated against prostate (PC-3) and HeLa cell lines using microculture tetrazolium test (MTT) assay with concentrations ranging from 500 to 1.89 µg/mL. Isolation of the ethanol extract was carried out using column chromatography whereby 21 isolates were obtained (T₁-T₂₁), and the most active isolate was subjected for characterization using ultraviolet (UV), infrared (IR), nuclear magnetic resonance (NMR), and mass spectroscopic techniques.

Results: The ethanol extract scavenged DPPH free radicals thereby exhibiting antioxidant activity with an IC₅₀ of 35.9 µg/mL. In addition, the extract conferred noticeable cytotoxicity against the HeLa (LD₅₀ of 164.28 µg/mL) and PC-3 cell lines (LD₅₀ of 407.3 µg/mL). Among all the isolates, T₃ showed antioxidant activity with IC₅₀ of 11.56 µg/mL and cytotoxicity with LD₅₀ of 12.5 µg/mL against HeLa and 30.25 µg/mL against PC-3 cell lines and was characterized as 2-ethynyl-5-(thiophen-2-yl) thiophene.

Discussion: The new thienyl compound (T₃) exhibited profound antioxidant activity and cytotoxicity at relatively lower concentrations than the extract.

Conclusion: The observations provide support for the ethnobotanical use of the plant.     

Antimalarial Ethnobotany: In Vitro. Antiplasmodial Activity of Seven Plants Identified in the Nigerian Middle Belt

Abstract

Seven methanol extracts of seven plants from seven plant families were screened for antimalarial properties. The plants were identified and selected from Gboko and Kastina-Ala local government areas in the Tivland ethnobotany in the Middle Belt Zone of Nigeria. Methanol plant extracts were evaluated for in vitro. antimalarial properties using the lactate dehydrogenase technique, with a multiresistant strain of Plasmodium falciparum. K1. Quantification of activity was by estimation of the concentration of extracts that inhibited 50% growth of parasite (IC₅₀) in µg/ml. Of the seven plants screened, Erythrina senegalensis. DC (Leguminosae), Pericopsis elata. Harms (Papilionaceae), and Bridelia micrantha. Benth (Fabaceae) had IC₅₀ values of 99.7, 124.8, and 158.7?µg/ml, respectively. Nauclea latifolia. SM (Rubiaceae) extract exhibited the least activity in the assay with an IC₅₀ value of 478.9?µg/ml.     

Evaluation of the antimutagenic,antigenotoxic, and antioxidant activities of Eriobotrya japonica leaves

Abstract

Context: The leaves of Eriobotrya japonica (Thunb.) Lindl. (Rosaceae) are used in traditional medicine to treat inflammatory diseases. However, information about the antigenotoxic and antioxidant properties of its leaves remains to be elucidated.

Objective: The objective of this work was to evaluate the mutagenic/antimutagenic, genotoxic/antigenotoxic, and antioxidant potentials of aqueous and total oligomers flavonoid (TOF) extracts from E. japonica.

Materials and methods: The mutagenic/antimutagenic and genotoxic/antigenotoxic potentials of extracts (50, 250, and 500?µg/plate) were evaluated, respectively, by the Ames test with 48?h incubation and the SOS chromotest test with 2?h incubation. The antioxidant capacity of these extracts (ranging from 50 to 700?µg/mL) was tested using xanthine/xanthine oxidase and the deoxyribose assays.

Results: Eriobotrya japonica extracts showed neither mutagenic nor genotoxic effect. The highest protective effect against methyl methanesulfonate and 2-aminoanthracene was obtained in the presence of aqueous extract, with IC₅₀ values of 80 and 140?µg/plate, respectively, against S. typhimurium TA104. Moreover, this extract (500?µg/plate) was also able to reduce significantly the genotoxicity induced by nitrofurantoin and aflatoxin B1 with IC₅₀ values of 140 and 240?µg/assay, respectively. Likewise, aqueous and TOF extracts inhibited xanthine oxidase and superoxide anion formation with IC₅₀ values ranging from 45 to 95 and from 70 to 90?µg/mL, respectively. However, TOF extract is more efficient in inhibiting hydroxyl radical and chelating iron ion with IC₅₀ values of 140 and 400?µg/mL, respectively, when compared with the aqueous extract.

Conclusion: Eriobotrya japonica prevents the genotoxicity of some carcinogenic substances probably thanks to its antioxidant capacities.     

Cytotoxic and antiproliferative constituents from Dictyota ciliolata,Padina sanctae-crucis and Turbinaria tricostata

Context: The hexane extracts of Dictyota ciliolata Sonder ex Kützing (Dictyotaceae), Padina sanctae-crucis Børgesen (Dictyotaceae), and Turbinaria tricostata E.S. Barton (Sargassaceae) were found to exhibit cytotoxic and antiproliferative activities in vitro. Bioactive compounds responsible for these activities have not been studied in detail for these species and phytochemical studies are very limited.

Objective: Isolate, evaluate, and elucidate the bioactive constituents of D. ciliolata, P. sanctae-crucis, and T. tricostata.

Materials and methods: Bioassay-guided cytotoxicity fractionations using the Hep-2 cell line of the hexane extracts from these brown algae were analyzed using various chromatographic techniques. Cytotoxic and antiproliferative activities of all isolated compounds were also evaluated on a panel of cell lines (KB, Hep-2, MCF-7, and SiHa). Furthermore, their selectivity index, the ratio of cytotoxicity on normal cells to cancer cells, was evaluated using the HEK-293 cell line.

Results: Four compounds were isolated from studied species: two sterol, fucosterol (1) and 24ξ-hydroperoxy-24-vinylcholesterol (2); and two diterpenes, pachydictyol A (3) and dictyol B acetate (4). The major bioactive components of the hexane extracts of T. tricostata and P. sanctae-crucis were compounds 1 and 2 (with CC₅₀ varying around 3.1–25.6?µg/mL) on cell lines tested. Whereas compounds 1, 3, and 4 showed cytotoxic activity against cancer cell lines (CC₅₀ varying between 14.8 and 41.2?µg/mL) and were major bioactive constituents of hexane extract of D. ciliolata. Compounds 1 and 4 showed antiproliferative activity on MCF-7 (IC₅₀?=?43.3?µg/mL for compound 1 and 38.3?µg/mL for compound 2) and SiHa (IC₅₀?=?43.3?µg/mL for compound 1 and 38.3?µg/mL for compound 2) cell lines.

Conclusion: This study is the first investigation on the bioactive components of D. ciliolata, P. sanctae-crucis, and T. tricostata. Although compounds 1–3 were described previously, the pharmacological activity of compound 4 is presented here for the first time.     

Study of cytotoxic activity,podophyllotoxin, and deoxypodophyllotoxin content in selected Juniperus species cultivated in Poland

Abstract

Context: The demand for podophyllotoxin and deoxypodophyllotoxin is still increasing and commercially exploitable sources are few and one of them, Podophyllum hexandrum Royle (Berberidaceae), is a “critically endangered” species.

Objective: The first aim was to quantify the amount of podophyllotoxin and deoxypodophyllotoxin in 61 Juniperus (Cupressaceae) samples. Cytotoxic activity of podophyllotoxin and ethanolic leaf extracts of Juniperus scopulorum Sarg. “Blue Pacific” and Juniperus communis L. “Depressa Aurea” was examined against different leukemia cell lines.

Materials and methods: Ultra-performance liquid chromatography (UPLC) analysis was performed with the use of a Waters ACQUITY UPLC^TM system (Waters Corp., Milford, MA). The peaks of podophyllotoxin and deoxypodophyllotoxin were assigned on the basis of their retention data and mass-to-charge ratio (m/z). Trypan blue assay was performed to obtain IC₅₀ cytotoxicity values against selected leukemia cell lines.

Results: Juniperus scopulorum was characterized with the highest level of podophyllotoxin (486.7?mg/100?g DW) while Juniperus davurica Pall. contained the highest amount of deoxypodophyllotoxin (726.8?mg/100?g DW). Podophyllotoxin IC₅₀ cytotoxicity values against J45.01 and CEM/C1 leukemia cell lines were 0.0040 and 0.0286?µg/mL, respectively. Juniperus scopulorum extract examined against J45.01 and HL-60/MX2 leukemia cell lines gave the respective IC₅₀ values: 0.369–9.225?µg/mL. Juniperus communis extract was characterized with the following IC₅₀ cytotoxity values against J45.01 and U-266B1 cell lines: 3.310–24.825?µg/mL.

Conclusions: Juniperus sp. can be considered as an alternative source of podophyllotoxin and deoxypodophyllotoxin. Cytotoxic activity of podophyllotoxin and selected leaf extracts of Juniperus sp. against a set of leukemia cell lines was demonstrated.     

Bioassay-Guided Isolation of Antimalarial Triterpenoid Acids from the Leaves of Morinda lucida.

Abstract

The EtOH, CH₂Cl₂, and petroleum ether extracts from Morinda lucida. Benth. leaves have been shown to exhibit an in vitro. antiplasmodial activity against a chloroquine-sensitive Plasmodium falciparum. strain with IC₅₀ values 5.7 ± 1.3, 5.2 ± 0.8, and 3.9 ± 0.3 µg/mL, respectively. In vivo., at a daily oral dose of 200 mg/kg body weight, they produced at least 62.5%, 67.5%, and 72.2% reduction of parasitemia in mice infected with Plasmodium berghei berghei., respectively. A bioassay-guided fraction of the most active petroleum ether extract resulted in the isolation of two known triterpenic acids as ursolic acid 1 and oleanolic acid 2. In vitro., 1 and 2 exhibited an antiplasmodial activity with IC₅₀ values of 3.1 ± 1.3 and 15.2 ± 3.4 µg/mL, respectively. In vivo., at a daily dose of 200 mg/kg body weight, they produced 97.7% and 37.4% chemosuppression, respectively. However, all tested samples were inactive in vitro. against chloroquine-resistant Plasmodium falciparum. (K1) at the highest tested concentration of 25 µg/mL.     

Leishmanicidal and cytotoxic activities of Nigella sativa and its active principle,thymoquinone

Abstract

Context: Leishmaniasis is a complex disease with a broad spectrum of clinical presentations.

Objective: We evaluated the anti-leishmanial effects of Nigella sativa L. (Ranunculaceae) against Leishmania tropica and Leishmania infantum with an in vitro model.

Materials and methods: Antileishmanial effects of essential oil and methanolic extract of N. sativa (0–200?µg/mL) and thymoquinone (0–25?µg/mL) on promastigotes of both species and their cytotoxicity activities against murine macrophages were evaluated using the MTT assay at 24, 48, and 72?h. Moreover, their leishmanicidal effects against amastigotes were investigated in a macrophage model, for 48 and 72?h.

Results: The findings showed that essential oil (L. tropica IC₅₀ 9.3?μg/mL and L. infantum IC₅₀ 11.7?μg/mL) and methanolic extract (L. tropica IC₅₀ 14.8?μg/mL and L. infantum IC₅₀ 15.7?μg/mL) of N. sativa, particularly thymoquinone (L. tropica IC₅₀ 1.16?μg/mL and L. infantum IC₅₀ 1.47?μg/mL), had potent antileishmanial activity on promastigotes of both species after 72?h. In addition, essential oil (L. tropica IC₅₀ 21.4?μg/mL and L. infantum IC₅₀ 26.3?μg/mL), methanolic extract (L. tropica IC₅₀ 30.8?μg/mL and L. infantum IC₅₀ 34.6?μg/mL), and thymoquinone (L. tropica IC₅₀ 2.1?μg/mL and L. infantum IC₅₀ 2.6?μg/mL) mediated a significant decrease in the growth rate of amastigote forms of both species. Thymoquinone (CC₅₀ 38.8?μg/mL) exhibited higher cytotoxic effects against murine macrophages than the other extracts.

Conclusion: N. sativa, especially its active principle, thymoquinone, showed a potent leishmanicidal activity against L. tropica and L.infantum with an in vitro model.     

Antidiabetic and antioxidant potency evaluation of different fractions obtained from Cucumis prophetarum fruit

Abstract

Context: Cucumis prophetarum Linn. (Cucurbitaceae) fruit is used for inflammatory-related problems and is proved to be possessing anticancer and hepatoprotective effects.

Objective: The present investigation was to study the effect of different fractions of C. prophetarum on antidiabetic and antioxidant activity.

Materials and methods: Aqueous crude extract (CE) of C. prophetarum fruits was fractionated into water soluble fraction 1 (F1), chloroform fraction 2 (F2), basic fraction 3 (F3), and neutral fraction 4 (F4) by acid–base extraction. CE and its fractions at different doses (0.02–0.1?mg/mL) were subjected to antidiabetic (α-amylase and α-glucosidase inhibition assays) and antioxidant (DPPH, superoxide radical scavenging (SO) and metal chelation) evaluation.

Results: F1 exhibited effective antidiabetic activity (p?<?0.05) with an IC₅₀ value of 20.6 and 59.9?µg/mL. The activity decreased in the order of CE?>?F4?>F3?>?F2, according to α-amylase assay, which were the same, with the exception of the rank order of F4 and CE, as the α-glucosidase assay. Furthermore, F1 (IC₅₀?=?73?µg/mL) showed better reducing ability than CE?>F4?>F2?>?F3 (IC₅₀?=?78–272?µg/mL), according to the DPPH assay. In SO and metal chelation assays, F1 showed the highest activity (IC₅₀?=?101 and 147?µg/mL), respectively; the activity decreased in the order of CE?>F4?>F3?>?F2 (IC₅₀?=?126–469?µg/mL) for SO and 194–944?µg/mL for metal chelation assay.

Conclusion: The results indicate that F1 possesses potent in vitro antidiabetic and antioxidant activities.     

Screening of Latin American plants for antiparasitic activities against malaria,Chagas disease,and leishmaniasis

In order to explore rationally the medical potential of the plant biodiversity of the Central and South American region as a source of novel antiparasitic molecules, a multinational Organization of American States (OAS) project, which included the participation of multidisciplinary research centers from Argentina, Bolivia, Colombia, Costa Rica, Guatemala, Nicaragua and Panama, was carried out during the period 2001-2004. This project aimed at screening organic plant extracts for antitrypanosomal, antileishmanial and antimalarial activities and subsequently isolating and characterizing bioactive molecules. Plants for antiparasitic screening were selected from a database of ethnomedical uses of Latin American plants (PlanMedia) based on the amount of biological and chemical information available in the literature. We report here the evaluation of 452 extracts from 311 plant species in vitro screens against Plasmodium falciparum, Leishmania mexicana, and Trypanosoma cruzi. Out of 311 species tested, 17 plants (5.4%) showed antiparasitic activities at IC₅₀ values?≤?10?µg/mL. The most active plants were Acnistus arborescens (L.) Schltdl. (Solanaceae) (leaf, EtOH, IC₅₀: 4?µg/mL) Monochaetum myrtoideum Naudin (Melastomataceae) (leaf, MeOH, IC₅₀: 5?µg/mL) and Bourreria huanita (Lex.) Hemsl. (Boraginaceae) (branch, EtOH, IC₅₀: 6?µg/mL). These were selectively active against P. falciparum, L. mexicana and T. cruzi, respectively.     

In vivo and in vitro toxicological evaluations of aqueous extract from Cecropia pachystachya leaves

ABSTRACT

Cecropia pachystachya

leaves are popularly used to treat asthma and diabetes. Despite the widespread consumption of this plant, there are few scientific studies regarding its toxicological potential. In order to conduct a thorough study concerning the potential adverse effects, the aim of this study was to assess acute and subacute toxicity tests of crude aqueous extract from C. pachystachya leaves (CAE-Cp) using in vivomodel, as well as in vitro cytotoxicity, genotoxicity and antioxidant activity. In addition, genotoxicity, and cytotoxicity of chlorogenic acid (CGA) and cytotoxicity of isoorientin (ISOO) were also evaluated. The antioxidant activity was verified by DPPH, cytotoxicity using sulforhodamine B (SRB) assay and genotoxicity by comet assay on V79 cells. The phytochemical analysis of CAE-Cp detected flavonoids and tannins, CGA and ISOO as the major compounds utilizing HPLC. The total flavonoid content (6.52 mg/g EQ) and antioxidant activity (EC₅₀ = 62.15 µg/ml) of CAE-Cp were determined. In vitro evaluations with CAE-Cp showed genotoxic effects at 0.31 to 2.5 mg/ml and an expressive cytotoxicity on HT-29 (IC₅₀ = 4.43 µg/ml) cells. CGA was genotoxic against V79 cells at 0.07 mg/ml and cytotoxic against to HT-29 (IC₅₀ = 71.70 µg/ml), OVCAR-3 (IC₅₀ = 80.07 µg/ml), MCF-7 (IC₅₀ = 45.58 µg/ml) and, NCI-H460 (IC₅₀ = 71.89 µg/ml) cancer cell lines. Wistar rats treated with a single dose (2,000 mg/kg) CAE-Cp decreased hemoglobin levels after 14 days, although no significant toxicity was observed in animals after 28 days. In view of the in vitro cytotoxicity and genotoxicity detected, further studies are necessary to establish the safe use of CAE-Cp.     

Antioxidant and anti-cholinesterase activity of Sargassum wightii

Abstract

Context. Sargassum has been used in traditional Chinese medicine since the eighth century AD to treat goiter. Sargassum wightii Greville (Sargassaceae) is a major source of alginic acid used widely in food and drug industries.

Objective: To evaluate the anti-Alzheimer potential of S. wightii through evaluation of antioxidant and cholinesterase inhibitory activities.

Materials and methods: Successive extraction was done using solvents of varying polarity. Solvent extracts (100–500?µg/mL) were employed for all the antioxidant assays. Free radical scavenging activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl, OH?, H₂O₂ radical scavenging assay. The reducing power of the seaweed was evaluated by ferric reducing antioxidant power and reducing power assay. Cholinesterase (ChE) inhibitory activity was evaluated and the Km, Vmax and Ki were calculated. Further, compound characterization was done by GC-MS analysis.

Results: The non-polar extracts were found to possess significant antioxidant activity. At 100?μg/mL, petroleum ether, hexane, benzene and dichloromethane extracts showed significant ChE inhibitory activity with IC₅₀ values of 19.33?±?0.56, 46.81?±?1.62, 27.24?±?0.90, 50.56?±?0.90?µg/mL, respectively, for AChE, and 17.91?±?0.65, 32.75?±?1.00, 12.98?±?0.31, 36.16?±?0.64?µg/mL, respectively, for BuChE. GC-MS reveals that 1,2-benzenedicarboxylic acid, diisooctyl ester is the major compound present in dichloromethane extract of S. wightii. The mode of inhibition exhibited by dichloromethane extract against the cholinesterases was found to be competitive type.

Discussion and conclusion: The presence of high amount of terpenoids could be the possible reason for its potential antioxidant and ChE inhibitory activity.     

Anti-HIV-1 integrase activity and molecular docking of compounds from Albizia procera bark

Abstract

Context: Albizia procera (Roxb.) Benth. (Mimosaceae) has been traditionally used in Thai longevity preparations. Thus, searching for HIV-1 integrase (HIV-1 IN) agents from natural sources is of interest.

Objective: The objective of this study is to examine the inhibitory activity against HIV-1 IN of compounds isolated from the stem bark of Albizia procera.

Materials and methods: The EtOH extract and isolated compounds of Albizia procera bark were examined for anti-HIV-1 IN activity at various concentrations (10–100?µg/mL and 10–100?µM) using the multiplate integration assay and molecular docking.

Results and discussions: The results showed that the ethanol extract had good anti-HIV-1 IN activity with an IC₅₀ value of 19.5?µg/mL, whereas ethyl acetate fraction exhibited the most potent with an IC₅₀ value of 19.1?µg/mL, followed by water fraction (IC₅₀ value?=?21.3?µg/mL), hexane and chloroform fractions (IC₅₀ value?>?100?µg/mL), respectively. From bioassay-guided isolation, the ethyl acetate fraction was further separated to give two compounds which are (+)-catechin (1) and protocatechuic acid (2), respectively. Of the tested samples, (+)-catechin (1) exhibited appreciable activity against HIV-1 IN with an IC₅₀ value of 46.3?µM, whereas protocatechuic acid (2) showed mild activity with 46.0% inhibition at concentration of 100?µM. (+)-Catechin (1) could interact with Thr66, Gly148, and Glu152 in the core domain of IN enzyme, whereas protocatechuic acid (2) could bind with Thr66, His67, Glu152, Asn155, and Lys159. This is the first report on anti-HIV-1 IN activity of Albizia procera bark. These results may suggest that Albizia procera bark has potential as anti-HIV-1 IN agent.     

Antiprotozoal Activity of Ethanol Extracts of Some Bomarea Species

Abstract

The antiprotozoal activity of 26 ethanol extracts derived from 13 species of the genus Bomarea (Alstroemeriaceae) were evaluated against the promastigote forms of three Leishmania species (L. amazonensis L., L. braziliensis Vianna, and L. donovani Laveran & Mesnil) and the epimastigote form of Trypanosoma cruzi Chagas. IC₅₀ values for leishmanicidal activities were between 4.9 and 98.6 μ g/mL, B. setacea extracts being the most active against the three species of Leishmania. Amphotericin B (IC₅₀ = 0.2 μ g/mL) and pentamidine (IC₅₀ = 10 μ g/mL) were used as control in this assay. IC₅₀ values for antitrypanosomal activities were between 65.2 and 92.7 μ g/mL, whereas the control benznidazole had an IC₅₀ value of 2 μ g/mL.     

Bioassay-guided isolation of Poliovirus-inhibiting constituents from Zephyranthes candida

Abstract

Context: Plants of the Zephyranthes genus are globally used in folk medicine. In a previous study, Zephyranthes candida Linn. (Amaryllidaceae) was identified as having antiviral properties; this led to anti-poliovirus assay-guided isolation of compounds from crude methanol extract of the plant.

Objective: Isolation of anti-poliovirus constituents from Z. candida.

Material and methods: Active chloroform fraction from crude methanol extract of Z. candida (whole plant) was subjected to bioassay-guided fractionation; repeated column and preparative thin layer chromatography led to isolation of active compounds. Chemical structures were identified using spectroscopic techniques. Using serial two-fold dilution of maximum non-toxic concentration (MNTC) of each compound (0.0625–1?µg/mL for lycorine and 0.625–10?µg/mL for trisphaeridine and 7-hydroxy-3′,4′-methylenedioxyflavan), the ability of extracts to inhibit viral-induced cell death in tissue culture was evaluated 72?h post-infection by the colorimetric method using MTT (3-[4,5-dimethylthiazol–2-yl]-2,5-diphenyltetrazolium bromide) dye. Regression analysis was used to determine 50% inhibitory concentration (IC₅₀) and 50% cytotoxicity concentration (CC₅₀), from which selective index (SI) was calculated.

Results: From the chloroform fraction, three compounds were isolated and identified, namely lycorine (1), trisphaeridine (2), and 7-hydroxy-3′,4′-methylenedioxyflavan (3) as the anti-polioviral components. Lycorine was the most active, with an IC₅₀ value of 0.058?µg/mL followed by trisphaeridine (2) with an IC₅₀ of 0.1427?µg/mL, and 7-hydroxy-3′,4′-methylenedioxyflavan (3) with an IC₅₀ of 0.2384?µg/mL.

Discussions and conclusions: The antipoliovirus activity of trisphaeridine (2) and 7-hydroxy-3′,4′-methylenedioxyflavan (3) is established in this report; these compounds are of moderate toxicity and have very good SI. They could be a potential template for the development of a new antiviral agent.     

Antioxidant Potential of an Extract of Calendula officinalis. Flowers in Vitro. and in Vivo.

Abstract

An extract of Calendula officinalis. Linn. (Compositae) was evaluated for its antioxidant potential in vitro. and in vivo.. Calendula officinalis. extract was found to scavenge superoxide radicals generated by photoreduction of riboflavin and hydroxyl radicals generated by Fenton reaction and inhibited in vitro. lipid peroxidation. Concentrations needed for 50% inhibition (IC₅₀) were 500, 480, and 2000 µg/mL, respectively. Extract scavenged ABTS radicals and DPPH radicals and IC₅₀ were 6.5 and 100 µg/mL, respectively. IC₅₀ values were compared with that of ginger extract, which is a standard antioxidant extract. The drug also scavenged nitric oxide, and the IC₅₀ was found to be 575 µg/mL. Extract also produced dose-dependent scavenging of nitric oxide in culture. The oral administration of Calendula. extract inhibited superoxide generation in macrophages in vivo. by 12.6% and 38.7% at doses of 100 and 250 mg/kg b.wt. Oral administration of Calendula officinalis. to mice for 1 month significantly increased catalase activity. The extract produced significant increase in glutathione levels in blood and liver. Glutathione reductase was found to be increased, whereas glutathione peroxidase was found to be decreased after administration of Calendula. extract. These results indicated Calendula officinalis. has significant antioxidant activity in vitro. and in vivo..     

Evaluation of antihemolytic and antioxidant activities of Geranium tuberosum subsp. tuberosum with in vitro models

Context: There are 33 Geranium species growing in Turkey characterized by the presence of polyphenolic compounds. Some Geranium (Geraniaceae) species are used as antidiabetics, hemostatics, antihemorrhoidals, antidiarrheics and for the treatment of pain, fevers, and gastrointestinal ailments, or are consumed as food.

Objective: The in vitro antioxidant activity and antihemolytic effect of ethyl acetate (EtOAc), n-butanol (BuOH), methanol (MeOH) and water extracts of Geranium tuberosum L. subsp. tuberosum (Geraniaceae), a medicinal food plant, have been evaluated.

Materials and methods: The two antioxidant enzyme activities of human erythrocyte, namely superoxide dismutase (SOD) and catalase (CAT), after in vitro incubation with the extracts, were examined in order to see whether the observed effects are related to altered enzymatic efficiency. Reduced glutathione (GSH) levels were also measured as oxidative stress marker. Antihemolytic activity of extracts was shown by hemolysis assay in erythrocytes. Furthermore, total phenolic content of extracts was measured by Folin–Ciocalteu method.

Results: All extracts enhanced GSH levels, and the activity of SOD and CAT. The EtOAc extracts seems to be the most potent antioxidant at 100 µg/mL (SOD activity 173.736?±?8.33, CAT activity 133.218?±?3.31, GSH level 2.264?±?2.21). However, apart from the MeOH extracts at 100 µg/mL (68.699?±?3.93), they didn’t increase the resistance of erythrocytes to H₂O₂ induced cytotoxicity. Therefore, while a significant antioxidant effect was observed in these samples, antihemolytic effect was not determined.

Discussion and conclusion: The title plant has shown high antioxidant activity without cytotoxicity up to 100 µg/mL, thus could be a potent source as natural antioxidant.     

Antitumor and antioxidant activity of Polyalthia longifolia stem bark ethanol extract

In the present study, the ethanol extract of stem bark of Polyalthia longifolia Benth. and Hook (Annonaceae) was screened for its in vitro and in vivo antitumor activity. In vitro cytotoxicity of P. longifolia extract was assessed in murine cancer cells and in human cancer cells by Trypan blue exclusion assay and MTT assay, respectively. P. longifolia extract showed concentration-dependent cytotoxicity in Ehrlich’s ascites carcinoma (EAC) and Dalton’s ascites lymphoma (DLA) cells with IC₅₀ values of 45.77 and 52.52?µg/mL, respectively. In the MTT assay, the IC₅₀ values of P. longifolia extract against HeLa and MCF-7 cells were 25.24 and 50.49 µg/mL, respectively. In vivo antitumor activity against Ehrlich’s ascites tumor and Dalton’s solid tumor models was assessed by administering 50 and 100?mg/kg of P. longifolia extract, i.p., for 7 consecutive days. P. longifolia extract, at a dose of 100?mg/kg, significantly enhanced mean survival time (MST) and marginally improved hematological parameters when compared to EAC control mice. And the same dose significantly reduced the tumor volume as compared to control DLA inoculated mice. Positive control, cisplatin (3.5?mg/kg, i.p., single dose), significantly enhanced MST and improved hematological parameters when compared to EAC and significantly reduced the tumor volume when compared to DLA control. In vitro antioxidant potential of P. longifolia extract was also determined owing to the role of reactive oxygen species in tumor initiation and progression. P. longifolia extract scavenged DPPH radicals, reduced ferric ions and inhibited lipid peroxidation with IC₅₀ values of 18.14, 155.41 and 73.33 µg/mL, respectively.     

Bioassay-guided isolation of antioxidant agents with analgesic properties from flowers of Tagetes patula

Context: Tagetes patula L. is one of the French marigold group of the Asteraceae family. It is recognized in folklore for its medicinal and pesticidal properties.

Objective: In search of more effective, but non-toxic compounds with antioxidative potential led to the bioassay guided isolation studies on the extracts of T. patula.

Materials and methods: The bioassay on Tagetes patula flowers were carried out guided by in vitro antioxidant activity using DPPH assay. A minor but proven plant constituent methyl protocatechuate (1) was isolated by column chromatography, while patuletin (2) and patulitrin (3) obtained in bulk by employing solvent partition of methanol extract. Derivatization of patuletin into benzoyl, cinnamoyl and methyl was conducted to establish the structure activity relationship (SAR). Analgesic activity of compound 2 was evaluated using acetic acid-induced writhing test and hot-plate test in mice. The toxicity of methanol extract and compound 2 were also determined.

Results: Polar extracts, fractions and phases demonstrated better antioxidant activity. The synthetic methyl protocatechuate (1) showed IC₅₀ value of 2.8?±?0.2?μg/mL, whereas patuletin (2) (IC₅₀?=?4.3?±?0.25 µg/mL) was comparable to quercetin and rutin but significantly better than patulitrin (3) (IC₅₀?=?10.17?±?1.16 µg/mL). Toxicity test for the methanol extract and compound 2 did not elicit any behavioral changes or cause mortality in mice. Compound 2 also demonstrated mild analgesic property.

Discussion and conclusion: These findings demonstrate that the plant polar extracts and fractions possess significant antioxidant property with non-toxic effect. Compound 1 is a genuine plant constituent of T. patula.