Leishmanicidal activity of Maytenus illicifolia roots

In vitro evaluation of leishmanicidal activity of aqueous and ethanolic extracts of Maytenus illicifolia against three species of Leishmania. The root extracts showed differential activity against parasites, whereas the aerial part of the extracts was inactive.     

Anti-leishmanial and immunomodulatory activities of extracts from Portulaca hirsutissima and Portulaca werdermannii

Ethyl acetate and chloroform extracts from aerial parts of Portulaca werdermannii and P. hirsutissima were tested in lymphoproliferation assays and axenic cultures of Leishmania amazonensis and Trypanosoma cruzi. Both extracts of P. werdermannii and P. hirsutissima had a potent inhibitory activity on lymphocyte proliferation. On the contrary, only the chloroformic extract of both plants inhibited L. amazonensis growth, without effect on T. cruzi cultures. These results indicate these Portulaca species as potential sources of new active molecules for the treatment of leishmaniasis and immune-mediated pathologies.     

Mitogenic effect of Carthamus lanatus extracts, fractions and constituents

Extracts, fractions and constituents of Carthamus lanatus were tested for their mitogenic effect on bone marrow cells in mice. Most of the studied samples inhibited cell proliferation and only the flavonoid glycoside rutin caused increasing of mitotic activity.     

Antifeedant activity of Momordica dioica fruit pulp extracts on Spodoptera litura

The hexane extract and ethyl acetate soluble fraction of methanolic extract of the fruit pulp of Momordica dioica exhibited moderate and concentration dependent antifeedant activity against Spodoptera litura.     

CNS activity of Alstonia macrophylla leaf extracts: an ethnomedicine of Onge of Bay Islands

Methanol extract at 100-200 mg/kg p.o. and major nonpolar fraction B at 50 mg/kg of Alstonia macrophylla leaves caused a significant reduction in spontaneous activity, remarkable decrease in exploratory behavioural pattern, a reduction in muscle relaxant activity and also significantly potentiated phenobarbitone sodium-induced sleeping time. The phytochemical study of crude leaf extract revealed the presence of tannin, triterpenoid, flavonoid, sterol, alkaloid and reducing sugars. Further fractionation and purification of the n-butanol part of methanol extract yielded fraction A, fraction B and fraction C along with some minor fatty acids as the major compounds.     

Antimicrobial activity and cytotoxicity of Trapa bispinosa

The extracts of Trapa bispinosa showed interesting antimicrobial activity against Gram-positive and Gram-negative test organisms and significant cytotoxic activity.     

Antileishmanial polyphenols from Garcinia vieillardii

Seven xanthones, the new vieillardiixanthones B and C (1) and (7), pancixanthones A (2), B (3), 1,6-dihydroxyxanthone (6), pyranojacareubin and 5,6-O-dimethyl-2-deprenylrheediaxanthone together with two benzophenones, clusiachromene (4) and 3-geranyl-2,4,6-trihydroxybenzophenone (5) were isolated from the stem bark of the neocaledonian Garcinia vieillardii. 2, 5 and 6 showed a significant antileishmanial activity against the promastigote forms of Leishmania mexicana and L. infantum and against the amastigote forms of L. infantum.     

Antimicrobial activity of aqueous extracts and of berberine isolated from Berberis heterophylla

The antimicrobial activity of Berberis heterophylla leaves, stems and root aqueous extracts was studied in vitro on Gram-positive and Gram-negative bacteria and fungi. The in vitro antifungal activity of berberine isolated from the same source against different Candida species was also investigated.     

Antimicrobial activities and cytotoxicity of the brown alga Cystoseira tamariscifolia

The hexane, ethyl ether and dichloromethane fractions of the brown alga Cystoseira tamariscifolia extract showed interesting antimicrobial activities and cytotoxicity.     

Antibacterial and cytotoxic compounds from the bark of Cananga odorata

O-Methylmoschatoline, liriodenine and 3,4-dihydroxybenzoic acid isolated from the barks of Cananga odorata showed antibacterial activities against a number of Gram (+) and Gram (-) bacteria. The compounds also showed antifungal and cytotoxic activities.     

Analgesic properties of Capraria biflora leaves aqueous extract

The analgesic properties of dried leaves of Capraria biflora were investigated. The aqueous extract (50-200 mg kg(-1)) produced moderate inhibition of acetic acid-induced writhing in mice. At the same doses, a better analgesic effect was observed on the hot plate test.     

Inhibition of Trypanosoma cruzi by plant extracts used in Chinese medicine

In this work, we assessed the effect of extracts obtained from 17 plants used in traditional Chinese medicine. These extracts were tested in vitro with the epimastigote form of Trypanosoma cruzi, clone Bra C(15) C(2), at 27 degrees C in F-29 medium at a concentration of 100 microg/ml in axenic cultures. Allopurinol was used as reference drug. Seven plant extracts showed inhibitory activities lower than 25%. Pueraria lobata, Mahonia beaei, Dictamus dasycarpus, Kochia scoparia, Sophora flavescens and Ligustrum lucidum showed effects with inhibition values between 25% and 60%, whereas Lithospermum erythrorhizon, Saussurea lappa, Melia toosendan and Cinnamomum cassia showed the greatest inhibitory activity of 100%. The IC(50) of these extracts were: 0.4, 2.4, 1.8 and 3.9 microg/ml, respectively. The MTT assay was made and did not show cytotoxic activity. These results allowed us to suggest that L. erythrorhizon, S. lappa, M. toosendan and C. cassia could be a source of new compounds against T. cruzi.     

Comparison of bioactive compounds content, free radical scavenging and anti-acne inducing bacteria activities of extracts from the mangosteen fruit rind at two stages of maturity

Contents of bioactive components, free radical scavenging and anti-acne producing bacteria activities of young and mature fruit rind extracts of mangosteen were compared. The young fruit rind extract contained significantly higher contents of phenolics and tannins and promoted higher free radical scavenging activity than the mature fruit rind extract, while the later extract contained higher contents of flavonoids and α-mangostin xanthone and gave higher anti-acne producing bacteria activity than the young fruit rind extract. Thus, the young and mature stages of mangosteen fruit rind should be beneficial for further development of antioxidant and anti-acne pharmaceutical preparations, respectively.     

Antimicrobial properties of Uvaria chamae stem bark

The antimicrobial properties of the methanol extract of Uvaria chamae stembark (ME) were investigated. The more active ethylacetate-soluble fraction (EAS) was separated by PTLC into 18 sub-fractions. Following phytochemical and antimicrobial screening, several sub-fractions, testing positive for the presence of glycosides (8, 11–15) and tannins (18), exhibited activity against a number of microorganisms, being in some cases more active than penicillin G and chloramphenicol.     

Symbiotic properties and Rhizobium requirements for effective nodulation of five tropical dry zone acacias

Five tropical dry zone acacias were inoculated with three fast-growing Rhizobium strains and four slow-growing Bradyrhizobium strains. After two months of growth in the greenhouse, the plants were harvested and their shoot height and dry weight, nodule number and dry weight, acetylene reduction activity, and total shoot nitrogen were determined. The results showed that: (1) Acacia polyacantha (being evaluated for the first time) was promiscuous, nodulating indiscriminately with Rhizobium and Bradyrhizobium strains. (2) Faidherbia albida and Acacia holosericea (that were previously known to nodulate with Bradyhizobium strains only) nodulated with Rhizobium strains as well and (3) Acacia senegal and Acacia nilotica that were previously known to be nodulated exclusively by Rhizobium strains only were nodulated with both genera.

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Resumé Cinq espèces d'acacias de zone tropicale séche ont été inoculées avec trois souches de Rhizobium à croissance rapide et quatre souches de Bradyrhizobium à croissance lente. Aprés deux mois de croissance en serre, les plants ont été récoltés et lahauteur et le poids sec de parties aériennes, le nombre et le poids sec de nodules, l'activité réductrice de l'acétylène et la quantité d'azote total contenue dans les parties aériennes ont été déterminés. Les résultats ont montrés que: (1) Acacia polyacantha (étudié, pour la prémière fois) est une espèce qui nodule indifféremment avec des souches de Rhizobium et de Bradyrhizobium. (2) Faidherbia albida et Acacia holosericea nodulaient également indifféremment avec des souches de Rhizobium et de Bradyrhizobium, contrairement à des études antérieures qui montraient que ces espèces nodulaient exclusivement avec des souches de Bradyrhizobium. (3) De même, Acacia senegal et Acacia nilotica nodulent avec les deux types de souches alors qu'elles étaient connues pour être nodulées exclusivement par des souches de Rhizobium.

     

A new biphenyl and antimicrobial activity of extracts and compounds from Clusia burlemarxii

Phytochemical investigation on Clusia burlemarxii (Clusiaceae) led to isolation and identification of nine compounds. Were isolated from leaves 3-O-α-L- rhamnopyranosylquercetin, 3-O-α-L-rhamnopyranosylkaempferol, 4-hydroxy-5,5-dimethyldihydrofuran-2-one, 2Z-δ-tocotrienoloic acid and friedelin and were isolated from trunk betulinic acid, protocatechuic acid, lyoniresinol, and a new biphenyl 2,2-dimethyl-3,5-dihydroxy-7-(4-hydroxyphenyl)chromane. The structures were determined by ¹H, ¹³C-NMR, DEPT, HMBC, HMQC, HRESIMS. The Minimal Inhibitory Concentration against Streptococcus mutans, Staphylococcus aureus, Bacillus subtilis, Micrococcus luteus, Escherichia coli, Salmonella choleraesuis, Pseudomonas aeruginosa, Aspergillus niger and Cladosporium cladosporioides was also determined. Extracts and compounds showed significant activity against tested Gram-positive bacteria, none activity against tested Gram-negative bacteria and fungi.     

Antimutagenic, antioxidant and antimicrobial properties of Maytenus krukovii bark

The hydroalcoholic extract of Maytenus krukovii bark was investigated for its in vitro mutageno-protective activities by means of the Ames Salmonella/microsome assay. The extract showed an inhibitory effect in both T98 and T100 strains against the mutagenic activity of promutagen 2-aminoanthracene but was not protective against directly acting mutagens sodium azide and 2-nitrofluorene. When tested as a radical scavenger and antioxidant it produced a dose-dependent inhibition. The extract did not show significant antibacterial properties, and was weakly active against dermatophyte and phytopathogenic fungi, but inhibited the growth of phytopathogen Pithyum ultimum.     

Selective logging and fire as drivers of alien grass invasion in a Bolivian tropical dry forest

Logging is an integral component of most conceptual models that relate human land-use and climate change to tropical deforestation via positive-feedbacks involving fire. Given that grass invasions can substantially alter fire regimes, we studied grass distributions in a tropical dry forest 1–5 yr after selective logging, and experimentally tested the effect of forest fire on populations of invasive grasses. In unlogged forests and in microhabitats created by selective logging we found a total of four alien and 16 native grass species. Grasses covered 2% of unlogged and 4% of logged forest, with grass cover in logged forest concentrated in areas directly disturbed by logging; log landings and roads had relatively greater grass cover (37% and 17%, respectively) than did skid trails (10%) and felling gaps (8%). Total grass cover and grass species richness increased with canopy openness and were greatest in sites most severely disturbed by logging. The grass flora of these disturbed areas was composed mostly of native ruderal species (e.g., Digitaria insularis, Leptochloa virgata), a native bamboo (Guadua paniculata), and Urochloa (Panicum) maxima, a caespitose C₄ pasture grass introduced from Africa. Urochloa maxima formed monodominant stands (up to 91% cover and 2–3 m tall) and grew on 69% of log landings and 38% of roads. To better understand the potentially synergistic effects of logging and fire on the early stages of grass invasion, we tested the effect of a 12-ha experimental fire on U. maxima populations in a selectively logged forest. Three years after the fire, the area covered by alien grass in burned forest increased fourfold from 400 m² (pre-fire) to 1660 m²; over the same period in a logged but unburned (control) area, U. maxima cover decreased from 398 m² to 276 m². Increased canopy openness due to fire-induced tree mortality corresponded with the greater magnitude of grass invasion following fire. Selective logging of this dry forest on the southern edge of the Amazon Basin promotes alien grass invasion; when coupled with fire, the rate of invasion substantially increased. Recognition of the grass-promoting potential of selective logging is important for understanding the possible fates of tropical forests in fire-prone regions.     

Cytotoxic sesquiterpenoids from the fruits of Lindera communis

A new sesquiterpenoid, namely Linerenone (1), together with three known sesquiterpenoids (2–4), were isolated from the fruits of Lindera communis. Their structures were determined by extensive spectroscopic analysis including 1D, 2D-NMR and HR-MS spectra. Compound 1 showed significant cytotoxic activity against H460, ES2 and DU145 cancer cells with IC₅₀ of 2.1 μg/mL, 2.8 μg/mL and 3.0 μg/mL, respectively.     

Repellence and toxicity of Schinus molle extracts on Blattella germanica

The biological activities of ethanol and petroleum ether extracts from leaves and fruits of Schinus molle against adults of Blattella germanica were examined by repellence test and topical application. All extracts produced significant repellent effect and mortality.