Iron(III) reducing and antiradical activities of three Sideritis from Turkey

Context: Sideritis species (Lamiaceae) are widely used as herbal tea and have been used in folk medicine for their anti-inflammatory, anti-rheumatic, digestive, and antimicrobial activities in Turkey. Sideritis dichotoma Huter., Sideritis erythrantha Boiss. var. cedrotorum, and Sideritis vuralii H. Duman et Ba?er are available as commercial products in Turkey.

Objective: The antiradical activities of the various solvent extracts of Sideritis species are investigated here for the first time.

Materials and methods: Plant samples were sequentially extracted with n-hexane, dichloromethane, methanol, and aqueous methanol (50%, v/v) in Soxhlet apparatus. The extracts of Camellia sinensis (L.) Kuntze (Theaceae) were also prepared for use as a positive control. Total phenolics, iron(III) reductive effects, and 1,1-diphenyl-2-picrylhydrazyl (DPPH^?) radical scavenging activities of the all extracts were measured colorimetrically.

Results: The aqueous MeOH and MeOH extracts contained the highest amount of total phenols, whereas the n-hexane extract contained the lowest amounts. The polar extracts of C. sinensis showed higher antiradical activity and also iron(III) reductive effects than the Sideritis species; however, the non-polar extracts of Sideritis species were found to be more active than those from C. sinensis in the iron(III) reductive assay and in the DPPH^? assay as well. But none of the extracts was found to be as active as with positive controls, viz., ascorbic acid, butylated hydroxyanisole (BHA), and Trolox.

Discussion and conclusion: These results can be shown to have antioxidant activities of these Sideritis species and support the ethnopharmacological use of these Sideritis plants.     

Inhibition of angiotensin converting enzyme activity by five Senecio species

In our continuous search of biological properties of Senecio species (Compositae), we investigated S. ambiguus subsp. ambiguus (Biv.) DC, S. gibbosus subsp. gibbosus DC, S. leucanthemifolius Poiret, S. inaequidens DC, and S. vulgaris L. for their angiotensin converting enzyme (ACE) inhibitory activity through an in vitro bioassay based on the enzymatic cleavage of the chromophore-fluorophore labelled substrate dansyltriglycine into dansylglycine, which is quantitatively measured by HPLC. Among analyzed extracts, ethyl acetate demonstrated the highest activity with IC₅₀ values of 192.1 and 219.1?μg/mL for S. ambiguus subsp. ambiguus and S. inaequidens, respectively. Flavonoids were detected in these extracts on TLC sprayed with Natural Products reagent - polyethylene glycal reagent (NP/PEG).     

Antibacterial Activity of Silphium perfoliatum. Extracts

Abstract

Methanol and hexane extracts obtained from above-and below-ground organs of the cup plant Silphium perfoliatum. L. (Asteraceae) were analyzed by gas chromatography–mass spectrometry (GC-MS). Eighty-five components were identified in the extracts. Moreover, evaluation of the content of total secondary metabolites (flavonoids, o.-dihydroxyphenols, and glycoside-bonded oleanolic acid) was made in the methanol extract. It was found that leaf, inflorescence, and rhizome extracts of S. perfoliatum. were characterized by antibacterial action toward Gram-positive (Enterococcus faecalis., Staphylococcus aureus.) and Gram-negative (Escherichia coli., Pseudomonas aeruginosa. bacteria). All the extracts showed extremely high activity toward Staphylococcus aureus. FDA 209P strains (MIC values: 1.00 mg/mL for rhizome alcohol and hexane extracts; 2.50 mg/mL for leaf and inflorescence alcohol extracts and for leaf hexane extracts; 5.00 mg/mL for inflorescence hexane extracts). In general, alcohol extracts had slightly stronger antibacterial properties compared with lipophilic ones. Among the alcohol extracts, those made of S. perfoliatum. rhizomes had the highest activity compared with the leaf and inflorescence extracts.     

In vitro studies to assess the antidiabetic,antiperoxidative, and radical scavenging potential of Stereospermum colais

Context: Stereospermum colais (Buch.-Ham. ex Dillw.) Mabberley (Bignoniaceae), which has traditional medicinal properties, is distributed all over deciduous forests. In spite of its many uses, the antidiabetic, antiperoxidative and radical scavenging activities of this species have not been assessed, and its chemical composition is scarcely known.

Objective: Antidiabetic, antiperoxidation, xanthine oxidase (XO) inhibition, and radical scavenging activities of acetone and methanol extracts of Stereospermum colais roots were investigated. Protective effects of Stereospermum colais root extract in stabilizing sunflower oil was also examined.

Materials and methods: The protective effect of acetone (ASC) and methanol (MSC) extracts of Stereospermum colais root for the potential inhibition of α-glucosidase and α-amylase enzymes were studied by in vitro method. Glycation inhibitory activity was also studied to inhibit the production of glycated end products.

Results: Compared with acarbose, ASC showed a strong inhibitory activity against α-glucosidase (IC₅₀ 61.21 µg/mL) and a moderate inhibitory activity against α-amylase (IC₅₀ 681.08 µg/mL). Glycation inhibitory activity of Stereospermum colais root extracts by using an in vitro glucose-bovine serum albumin (BSA) assay was also done and compared with standard gallic acid. ASC also shows high XO inhibition potential, free radical scavenging activities, and low p-anisidine value indicates the high medicinal potency of Stereospermum colais root.

Discussion and conclusion: These results suggest that the extract of Stereospermum colais may be interesting for incorporation in pharmaceutical preparations for human health, since it can suppress hyperglycaemia, and or as food additives due to its antiradical efficiency.     

Antioxidant Activity Studies on Selected Sideritis. Species Native to Turkey

ABSTRACT

Sideritis. L. species are widely used as medicinal plants and as herbal teas in Turkey, in which 45 species of the genus are naturally found. The aim of this study was to determine the antioxidant activity of Sideritis. species found in the Mediterranean region. In this study, the antioxidant activities of the lyophilized extracts obtained from aerial parts of 17 species (18 taxa) of Sideritis. were compared, of which 15 taxa were endemic. The antioxidant activities of aqueous extracts were studied by two different techniques: qualitative DPPH (1,1-diphenyl-2-picrylhydrazyl radical) assay to detect the free radical scavenging activity and the TBA assay to detect liposome lipid peroxidation. All the extracts (except S. erithrantha. subsp. erithrantha., S. dichotoma., S. syriaca. subsp. nusariensis., S. tmolea.) showed a strong antioxidant activity with the DPPH test. High activity was observed in the S. brevibracteata. (IC₅₀ mg/ml = 0.16), S. condensata. (IC₅₀ mg/ml = 0.33), S. serratifolia. (IC₅₀ mg/ml = 0.31) extracts with the lipid peroxidation assay method.     

Screening of Spanish Medicinal Plants for Antioxidant and Antifungal Activities

Abstract

Dichloromethane, ethyl acetate, methanol, and aqueous extracts obtained from 16 Spanish medicinal plants were screened for their antioxidant and antifungal activities. The radical scavenging capacity was evaluated by the DPPH method using a rapid screening by TLC and a spectrophotometric assay. Polar extracts obtained from Jasonia glutinosa L. (Lamiaceae), Tanacetum parthenium (L.) Schultz (Lamiaceae), Equisetum telmateia Ehrh. (Equisetaceae), Verbena officinalis L. (Verbenaceae), and Lythrum salicaria L. (Lythraceae) showed high antioxidant properties. Among them, the methanol extract of Lythrum salicaria showed the strongest antiradical capacity with an IC₅₀ value similar to the positive control ascorbic acid. On the contrary, the best antifungal properties against Rhizopus stolonifer were produced by ethyl acetate or dichloromethane extracts from Anthemis arvensis L. subsp. arvensis (Asteraceae), Tanacetum parthenium, Santolina chamaecyparissus L. subsp. squarrosa Nyman (Asteraceae), Anagallis arvensis L. (Primulaceae) and the methanol extract of Anagallis foemina Miller (Primulaceae). The dichloromethane extract of Anthemis arvensis subsp. arvensis was the best inhibitor of fungus growth.     

Investigation of biological activity of polar extracts isolated from Phlomis crinita Cav ssp. mauritanica Munby

The lyophilized infusion, the methanol, the ethyl acetate, and the total oligomer flavonoid (TOF)-enriched extracts prepared from the dried leaves of Phlomis crinita Cav. ssp. mauritanica Munby were investigated for the contents of flavonoids, tannins, coumarines and steroids. Antibacterial activity was investigated toward five bacterial strains. An inhibitory effect was observed against Staphyllococcus aureus and Enterococcus feacalis, and the minimal inhibitory concentrations ranged from 2.5 to 5 mg/mL of extract. The tested extracts exhibit an important free radical scavenging activity toward the 1,1-diphenyl 2-picrylhydrazyl (DPPH) free radical; with IC₅₀ values of 30.5, 6, 32, and 31.5 μg/mL, respectively, in the presence of lyophilized infusion, the TOF, the methanol, and the ethyl acetate extracts. Genotoxic and antigenotoxic properties of the different extracts were studied by using the SOS chromotest with Escherichia coli PQ37. The lyophilized infusion and TOF extracts obtained from P. crinita ssp. mauritanica showed no genotoxicity, whereas methanol and ethyl acetate extracts are considered as marginally genotoxic. On the other hand, we showed that each extract inhibited the mutagenicity induced by aflatoxin B1 (AFB1) (10 μg/assay) and nifuroxazide (NF) (10 μg/assay). The ethyl acetate extract showed the strongest level of protection toward the genotoxicity induced by both directly and indirectly genotoxic NF and AFB1. These tests proved that the lyophilized infusion possesses an antiradical activity likewise, it showed no genotoxic effect; that is why we choose this extract to assess its antiulcerogenic activity by using an ethanol-induced ulcerogenesis model in the rat. This test demonstrates that 300 mg/kg of a P. crinita ssp. mauritanica lyophilized infusion was more effective than the reference compound, cimetidine.     

In vitro evaluation of the antibacterial activity of extracts from 34 species of North American lichens

Context: The emergence of antibiotic resistant pathogens is a serious global health threat. Hence, the search for new antibiotic drugs from various natural sources should be given high priority. Lichens produce a variety of low molecular weight metabolic compounds and many cultures have utilized these compounds in traditional medicine for centuries.

Objective: Report the antibiotic properties of extracts from 34 North American lichens screened against four pathogenic bacteria.

Materials and methods: The micro-well dilution method was used to determine the minimum inhibitory concentration (MIC) of acetone and methanol extracts of 34 lichen species against four bacterial strains. Major chemical compounds in each species were identified using thin layer chromatography (TLC).

Results: Most of the lichen extracts demonstrated inhibitory effects against Staphylococcus aureus, Pseudomonas aeruginosa, and methicillin-resistant S. aureus (MRSA) with MIC values ranging from 3.9 to 500?µg/ml. In addition, extracts from three species, Letharia columbiana (Nutt.) J. W. Thomson (Parmeliaceae), Letharia vulpina (L.) Hue (Parmeliaceae), and Vulpicida canadensis (Räsänen) J.-E. Mattsson &; M. J. Lai (Parmeliaceae) (MIC?=?125–500?µg/ml) were also effective against Escherichia coli. Generally, acetone extractions were found to be more effective than methanol extractions.

Discussion and conclusion: Results of this study show that lichen extracts provide significant antimicrobial activity against both Gram-positive and Gram-negative bacteria. These results suggest that lichens may be an important potential source of antibacterial drugs.     

Methanol extracts from Cystoseira tamariscifolia and Cystoseira nodicaulis are able to inhibit cholinesterases and protect a human dopaminergic cell line from hydrogen peroxide-induced cytotoxicity

Context Marine macroalgae contain several bioactive molecules that may be developed as functional foods, but information about their neuroprotective potential is scarce.

Objective The objective of this study is to determine the in vitro antioxidant and neuroprotective features of marine algae from the southern coast of Portugal and to assess the total content of different types of bioactives.

Materials and methods Methanol extracts from 21 macroalgal species from the southern Portugal were evaluated for in vitro antioxidant and acetylcholinesterase (AChE) inhibition. Active extracts were further evaluated for inhibitory activity against butyrylcholinesterase (BuChE) and tyrosinase (TYRO), and for their ability to attenuate hydrogen peroxide (H₂O₂)-induced toxicity in SH-SY5Y cells. The total contents of different phenolic groups were determined for the most active extracts.

Results Cystoseira tamariscifolia (Hudson) Papenfuss (Sargassaceae) had the highest antiradical activity (92%, 1?mg/mL). Cystoseira nodicaulis (Withering) M. Roberts (Sargassaceae) (75%) and Cystoseira humilis Schousboe ex Kützing (Sargassaceae) (70%) had the highest iron-chelating activity at 10?mg/mL. Cystoseira baccata (S.G. Gmelin) P.C. Silva (Sargassaceae) was more active towards copper (66%, 10?mg/mL). Cystoseira tamariscifolia had the highest AChE inhibitory capacity (85%, 10?mg/mL). Cystoseira tamariscifolia and C. nodicaulis were also active against BuChE and TYRO, and were able to protect SH-SY5Y cells against oxidative stress induced by H₂O₂. Cystoseira tamariscifolia had the highest content of all the groups of phenolics, and was particularly enriched in hydroxycinnamic acids (106?mg CAE/g DW).

Discussion and conclusion Results indicate that C. tamariscifolia and C. nodicaulis are important sources of nutraceutical compounds and may be considered functional foods that could improve cognitive functions.     

Mutagenicity of Hypericum lysimachioides extracts

Hypericum (Hypericaceae) species are extensively used in several fields such as traditional medicine, food and crop protection. Despite its usage in many fields, the identification of the genotoxic potential of this herb is still incomplete. In this study, we evaluated genotoxic effects of the petroleum ether, hexane, ethyl acetate, and methanol extract of Hypericum lysimachioides Boiss. var. lysimachioides by Ames Salmonella/microsome test and SOS chromotest. The mutagenic activity of Hypericum lysimachioides var. lysimachioides extracts was investigated by using Salmonella typhimurium strains TA98 and TA100 and also the SOS chromotest with Escherichia coli PQ37 strain, with or without S9 metabolic activation. In this initial report we demonstrated that all extracts of H. lysimachioides var. lysimachioides showed significant mutagenic activity on both strains of Salmonella either with or without S9 mixture. No mutagenicity was found in the SOS chromotest either with or without S9 mixture. These results indicate a significant mutagenicity of the petroleum ether, hexane, ethyl acetate and methanol extracts of Hypericum lysimachioides var. lysimachioides in vitro. It can be suggested that quercetin and flavonol or their synergistic effects may be main mutagenic agents in the photopharmaceuticals Hypericum lysimachioides var. lysimachioides extract.     

Cytotoxic effects of four Caryophyllaceae species extracts on macrophage cell lines

Context: Saponins have been reported to possess antitumor properties, to inhibit angiogenesis and to induce tumor apoptosis.

Objective: To test the possible cytotoxic effect of crude extracts from four Caryophyllaceae species including Gypsophila paniculata L., Gypsophila trichotoma Wend., Saponaria officinalis L., and Dianthus sylvestris Wulffen on cultured monocyte/macrophage cell lines.

Materials and methods: After acid hydrolysis of the methanol-aqueous extracts, two representative prosaponins of the Caryophyllaceae, gypsogenin 3-O-glucuronide and quillaic acid 3-O-glucuronide were purified using solid-phase extraction (SPE), then identified by ultra-performance liquid chromatography–electrospray/mass spectrometry (UPLC-ESI/MS). Cytotoxic activity of the crude extracts at concentrations ranging from 0.1 to 200?µg/ml was evaluated on rat alveolar macrophage NR8383 and human monocytic THP-1 cell lines. Apoptosis was determined by measuring caspase-3 activity.

Results: Quantitative analysis by reversed-phase high-performance liquid chromatography (RP-HPLC) revealed a high content of gypsogenin 3-O-glucuronide in Gypsophila species roots (0.52–1.13% dry weight). At a concentration ≥10?µg/ml of crude extracts, a significant reduction of NR8383 and THP-1 cell lines viability was evidenced using the Trypan blue exclusion test. D. sylvestris extract exhibited the highest toxicity against THP-1 cells. Caspase-3 activation was evidenced after 4 and 24?h incubation of macrophages with 100?µg/ml of S. officinalis and G. trichotoma extracts, indicating apoptosis induction.

Discussion and conclusion: Crude extracts from the assayed species revealed cytotoxic effects toward macrophage cell lines. In Gypsophila species, gypsogenin 3-O-glucuronide derivatives could be responsible for the observed cytotoxicity. Therefore, crude extract of Caryophyllaceae is worth investigating for the potential development of agents against cancer cells.     

Chemical composition,antioxidant and antibacterial activities of two Spondias species from Northeastern Brazil

Context: The leaves of Spondias tuberosa Arr. Cam. (Anacardiaceae) and Spondias mombin L. have been traditionally used for medicinal purposes. Some studies reveal their antibacterial, antimicrobial, and antiviral properties.

Objective: Determine the chemical composition, antioxidant, and antimicrobial activities of Spondias species to justify its ethnopharmacological use.

Materials and methods: Spondias species extracts were prepared with methanol:water 80:20 and analyzed by silica gel column chromatography and reversed phase liquid chromatography (HPLC). The antioxidant activity was evaluated by scavenging the radicals 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS?+) and measuring antimicrobial activity (agar well diffusion method, minimum inhibitory concentration and minimum bactericidal concentrations).

Results: The HPLC analysis of Spondias extracts demonstrated the occurrence of high yield of flavonoids. Found in S. mombin were quercetin (2.36?±?0.01?mg/g) and ellagic acid (41.56?±?0.01?mg/g) and in S. tuberosa species rutin (53.38?±?1.71?mg/g), quercetin (24.46?±?0.87?mg/g), and ellagic acid (169.76?±?0.17?mg/g). The antibacterial activity of the extracts against the various bacteria strains varied from 8.8 to 20.1?mm. MIC values from 62.5 to 125 µg/mL were satisfactory when compared with other plant products. Medium DPPH scavenging activity IC₅₀ for Spondias extracts varied from 0.042 to 0.558?mg/mL and for ABTS from 0.089 to 0.465?mg/mL. DPPH scavenging activity for constituent ellagic acid IC₅₀?=?0.042?mg/mL and for quercetin IC₅₀?=?0.081?mg/mL.

Discussion and conclusion: The chemical study of Spondias leaf extracts showed the occurrence of quercetin, rutin and ellagic acid, substances with relevant antioxidant and antimicrobial activities.     

Antioxidant and antiradical properties of new amino-acid derivatives of aminoalcohols

The antioxidant, antiradical, and membranotropic properties of newly synthesized compounds of the group of N-[3-hydroxy-3-(p-substituted phenyl)-1-propyl] amino acids were studied on model systems in vitro.According to the results, amino-acid derivatives of aminopropanols did not exhibit any significant antioxidant or antiradical activity as evidenced by Fe(II)-stimulated ascorbate-dependent peroxidation, by spectrophotometric monitoring of a decrease in the concentration of stable 2,2-diphenyl-1-picrylhydrazyl radical, or by photochemiluminescence techniques. However, these compounds revealed a membrane-stabilizing effect preventing hemolytic destruction of cells under conditions of H₂O₂-stimulated oxidative stress of erythrocytes. In this respect, derivatives of glycine, leucine, and methionine were most interesting.     

Evaluation of antimicrobial properties of Achillea L. flower head extracts

Thirty-nine extracts obtained from flower heads of 13 Achillea species [A. multifida (DC.) Boiss., A teretifolia Waldst.&Kitt., A. schischkinii Sosn., A. setacea Waldst.&Kitt., A. crithmifolia Waldst.&Kitt., A. falcata L., A. biebersteinii Afan, A. coarctata Poir., A. millefolium L. subsp. pannonica (Scheele) Hayek., A. clypeolata Sm., A. kotschyi Boiss. subsp. kotschyi, A. phyrigia Boiss.&Bal,. and A. nobilis L. subsp. neilreichii (Kerner) Formánek] were evaluated for antimicrobial activity against Escherichia coli ATCC 29908, hemorrhagic E. coli (O157:H7) RSSK 232, E. coli ATCC 25922, Staphylococcus aureus ATCC 43300 (methicillin/oxacillin-resistant), S. aureus ATCC 6538/P, Streptococcus epidermidis ATCC 12228, Salmonella typhimurium CCM 5445, Bacillus cereus ATCC 7064, Bacillus subtilis ATCC 6633, Pseudomonas aeroginosa ATCC 27853, Enterococcus faecalis ATCC 29212, and Candida albicans ATCC 90028. The minimum inhibitory concentrations (MICs) were determined for all extracts against the tested organisms. Hexane extracts of A. coarctata and A. setacea showed antibacterial activity against E. faecalis (MIC=31.25 and 62.5 μg/mL, respectively). Chloroform extracts of a number of Achillea species showed selective activity against the tested bacteria isolates; MICs for the most active species (A. teretifolia, A. multifida) were found to range from 50 to 75 μg/mL against S. aureus, S. epidermidis, and S. typhymurium. All of the extracts were inactive against C. albicans at the tested concentrations. The study has shown that several Achillea species possess antibacterial activity, which may yield novel antibacterial compounds with potential use as phytotherapeutics.     

Sempervivum davisii: phytochemical composition,antioxidant and lipase-inhibitory activities

Context: Sempervivum davisii Muirhead (Crassulaceae) is a traditional medicinal herb from Eastern Anatolia. To date the composition of phytochemicals and physiological properties of this herb were not subjected to any research.

Objective: This study identifies compounds in S. davisii hydrophilic extracts and evaluates their potential biological properties.

Materials and methods: Ethanol-based lyophilized extracts were obtained from aerial parts of plant (10?g of ground dry plant material in 200?mL of acidified aqueous ethanol, shaken for 2?h at 22?°C with supernatant collected and freeze-dried under vacuum). Phytochemical composition was investigated by liquid chromatography mass spectrometry (LC-MS/MS, phenolics) and gas chromatography mass spectrometry (GC-MS, volatiles). Phenolic compounds were quantified by high-performance liquid chromatography (HPLC) and the Folin–Ciocalteu assay. Subsequently, antioxidant capacity [ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) assays] and enzyme inhibitory properties (isolated porcine pancreatic lipase) of the extracts were determined.

Results: Polyphenolic compounds were the main constituents of lyophilized extracts, among which kaempferol glycosides and quercetin hexoside dominated. The extracts exhibited potent antioxidant (FRAP values of 1925.2–5973.3?μM Fe²⁺/g DW; ORAC values of 1858.5–4208.7?μM Trolox Eq./g DW) and moderate lipase inhibitory (IC₅₀: 11.6–2.96?mg/mL) activities. Volatile compounds (nonanal, dehydroxylinalool oxide isomers, 2-decenal, 2-undecenal, 2,6-di-tetr-butylphenol) were also found.

Conclusions: Phenolic compounds with the dominating kaempferol and quercetin derivatives are the sources of potent antioxidant properties of S. davisii hydrophilic extracts. The extracts exhibit moderate inhibitory properties towards isolated pancreatic lipase.     

Protective efficacy of Psidium cattleianum and Myracrodruon urundeuva aqueous extracts against caries development in rats

This study evaluated the influence of Psidium cattleianum Sabine (Myrtaceae) and Myracrodruon urundeuva Allemão (Anacardiaceae) aqueous extracts on S. mutans counts and dental enamel micro-hardness of rats submitted to a cariogenic challenge. Sixty Wistar rats were distributed in three groups and received water (control) or aqueous extracts of Psidium cattleianum or Myracrodruon urundeuva as hydration solution. Initially the animals had their sublingual and submandibular salivary glands surgically removed and the parotid ducts ligated. Then the rats were inoculated with 10⁶ CFU of Streptococcus mutans ATCC 35668 and were fed with a cariogenic diet. To detect and quantify the presence of S. mutans, oral biofilms were sampled and microbial DNA was extracted and submitted to amplification by means of real-time PCR (Polymerase Chain Reaction). After seven weeks the animals were sacrificed and enamel demineralization was analyzed by cross-sectional micro-hardness. Both extracts produced a significant reduction on S. mutans counts and decreased the enamel demineralization. It can be concluded that the extracts tested had a significant effect on S. mutans in oral biofilm of the rats, decreasing S. mutans accumulation and enamel demineralization.     

Antimicrobial activity of four annual Papaver species growing in Turkey

The extracts obtained from aerial parts of four annual Papaver (Papaveraceae) species from sections Argemonidium (P. argemone L. subsp. davisii Kadereit) and Rhoeadium (P. clavatum Boiss. & Hausskn. ex Boiss., P. dubium L. subsp. lecoqii var. lecoqii (Lamotte) Syme Kadereit and P. rhoeas L.) have been investigated for antimicrobial activity using a microbroth dilution technique. The antimicrobial activity of these species is reported for the first time. The petroleum ether and diethyl ether extracts of P. dubium subsp. lecoqii showed antibacterial activity against Staphylococcus aureus (MIC: 9.76 and 19.52 μg/mL, respectively). The diethyl ether and chloroform extracts of P. argemone subsp. davisii and diethyl ether, chloroform and acetone extracts of P. rhoeas had activity against S. aureus with a MIC value of 39.06 μg/mL.     

Angiotensin-converting enzyme inhibitory activity of Viscum triflorum is host plant-dependent

Context: Viscum triflorum DC. (Viscaceae) is a hemiparasitic plant used in traditional medicine on Réunion Island as a remedy to treat hypertension.

Objective: The in vitro angiotensin-converting enzyme (ACE) inhibitory activity of extracts of V. triflorum and the corresponding host plant species were examined to evaluate the use as a remedy against hypertension, and to investigate whether the host plants have an influence on the activity.

Materials and methods: Aqueous, ethanol and acetone extracts of 24 leaf samples of V. triflorum and the corresponding host plants, representing 10 plant species, were prepared. The ACE inhibitory activities of the extracts were measured by HPLC using dansyltriglycine as substrate.

Results and conclusion: Water extracts of Viscum samples from only two of the 10 host plants, namely Acacia heterophylla Willd. (Fabaceae) and Sophora denudata Bory (Fabaceae), showed significant inhibitory activity, ≥50% inhibition in a concentration of 0.33?mg crude plant extract in 1?mL test solution. From the two mentioned host plant species activity was only detected in the water extract from one of the six samples of A. heterophylla. Three host species showed pronounced activity without any detection of activity in the samples of V. triflorum. The results support the traditional use provided that V. triflorum is collected from A. heterophylla or S. denudata.     

Screening of Southeastern Brazilian Mikania. Species on Trypanosoma cruzi.

Abstract

Southeastern Brazilian Mikania. (Asteraceae) species were evaluated for trypanocidal activity against the trypomastigote forms of Trypanosoma cruzi.at a concentration of 4000 µg/mL. Fourteen extracts were examined for in vitro. trypanocidal properties. Of total extracts, 92.9% (13 extracts) exhibited trypanocidal effects. The dichloromethane extract of Mikania camporum. B. Robinson and the methanol extract of Mikania micrantha. H. B. K. caused 100% lysis of the parasites.