Cytotoxicity and antibacterial activity of extractives from Wedelia calendulacea

The cytotoxicity and antibacterial activity of petroleum ether, chloroform and methanol extracts of Wedelia calendulacea were assayed by brine shrimp lethality bioassay and standardized disk diffusion method against 19 bacterial strains. Three diterpenes isolated from the plant were also evaluated for in vitro antibacterial activities. The LC50 for the crude extracts against the brine shrimp nauplii were found to be 4.59 microg/ml, 7.99 microg/ml and 14.88 microg/ml, respectively, whereas the positive control, vincristine sulfate showed an LC50 of 0.58 microg/ml. Among the crude extracts and pure compounds tested, (-)-kaur-16-en-19-oic acid isolated from the chloroform extract showed the highest inhibitory activity against most of the bacterial strains with mean zone of inhibition of 10-21 mm at 200 microg/disc.     

Molluscicidal activity of Solanum species of the Northeast of Brazil on Biomphalaria glabrata

Seven species of Solanum were screened for their molluscicidal properties against Biomphalaria glabrata, the intermediated host of Schistosoma mansoni, Solanum agrarium, S. jabrense, S. melissarum, S. megalonyx, S. paludosum, S. paraibanum and S. stipulaceum. Four extracts showed molluscicidal activity with LC(50) from 22 to 56 microg/ml.     

Molluscicidal activity of Aglaia duperreana and the constituents of its twigs and leaves

The methanol (MeOH) extract of the twigs and leaves of Aglaia duperreana was investigated for its molluscicidal activity against Pomacea canaliculata. The extract was found to exhibit significant molluscicidal activity. The ethyl acetate soluble fraction of the extract showed the most potent molluscicidal activity among different solvent fractions. The bioactivity-guided chemical investigation of the ethyl acetate soluble fraction led to a new triterpenoid along with 15 known compounds. Their structures were elucidated by spectroscopic methods, including one- and two-dimensional nuclear magnetic resonance techniques as well as mass spectroscopic analysis. The molluscicidal activities of compounds 2-16 against P. canaliculata were also investigated. Naringenin trimethyl ether showed significant molluscicidal activity with a median lethal concentration (LC(50)) of 3.9 μg/mL, which was indicated higher potency than the positive control, tea saponin (LC(50)=4.5 μg/mL).     

Molluscicidal and radical scavenging activity of quinones from the root bark of Caryopteris x clandonensis

In the search for new molluscicidal natural products, the activity of the chloroform extract of the root barks of Caryopteris x clandonensis was tested. The LC(100) was <5 ppm. The fractionation and purification of the extract afforded 15-deoxyfuerstione, fuerstione and alpha-caryopterone as the main compounds. These compounds were tested against the snail Bulinus truncatus, an intermediate host snail of a schistosomiasis parasite and showed strong molluscicidal activity with LC(100)<4 ppm. In addition, they were found to have potent radical scavenging properties on superoxide radical.     

Insecticidal action of the polyphenolic rich fractions from the stem bark of Streblus asper on Dysdercus cingulatus

Extracts from the stem bark of Streblus asper possess insecticidal activity against the fifth instar of Dysdercus cingulatus. Methanolic extract showed an LC(50) value of 5.56 microg/insect. Partition with chloroform increased the insecticidal activity (LC(50) 2.01 microg/insect). Three polyphenolic rich fractions were obtained from silica-gel column chromatography of the chloroform fraction and found to have noteworthy insecticidal activity (LC(50): 1.82 microg, 2.70 microg, 2.26 microg/insect) by topical application. This may provide a useful beginning for the development of biopesticides.     

Antibacterial spectrum of Hypericum hookerianum.

The antibacterial activity of the chloroform, acetone and methanol extracts of Hypericum hookerianum leaves and stems was evaluated. All extracts showed antibacterial activity against six different gram-positive and gram-negative bacteria, the methanol extracts exhibiting the maximum inhibitory activity at 400 microg/ml.     

Screening of Indonesian medicinal plants for inhibitor activity on nitric oxide production of RAW264.7 cells and antioxidant activity

Traditional Indonesian medicinal plants were screened for their inhibitory effects on the nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and for the antioxidant activity through the evaluation of free radical scavenging effect and reducing power. The results of screening indicated that 50 methanolic extracts inhibited (>50%) lipopolysaccharides (LPS)-induced NO release from RAW264.7 cells at 50 microg/ml, with 18 having greater than 100% inhibition. At 200 microg/ml, 61 methanol extracts exhibited inhibitory activity (>50%), with 45 showing greater than 100% inhibition. In addition, the free radical scavenging effects of 6 methanolic extracts were found to be more than 50% for extract concentration of 0.5 mug/ml. The results indicate that the extracts contain active compounds that inhibit NO release and scavenge free radical.     

Antimicrobial and cytotoxicity evaluation of Buchholzia coriacea stem bark

Fractions prepared from the methanol extract of Buchholzia coriacea stem bark exhibited a high concentration-dependent antibacterial and antifungal activity compared to the standard antibiotics, ampicillin and tioconazole. In the brine shrimp lethality (BSL) assay, the methanol extract was found to be non-toxic with an LC(50) of 1031 microg/ml. The two main compounds present in the most active fraction were isolated and identified as lupeol and beta-sitosterol.     

Trypanocidal activity of extracts and fractions of Bertholletia excelsa

Crude extracts and fractions of Bertholletia excelsa stem barks were tested for trypanocidal activity. Acetone and methanol extracts showed significant in vitro trypanocidal activity against trypomastigote form of Trypanosoma cruzi since in the concentration of 500 microg/ml, the parasites were reduced in 100% and 90.3% respectively, whereas the triterpene betulinic acid pure isolated from hexane extract presented 75.4%.     

Antimicrobial and cytotoxic activities of Achyranthes ferruginea

Chloroform extract (CE) of Achyranthes ferruginea and N-trans-feruloyl-4-methyldopamine (1) showed remarkable antimicrobial activities against a wide range of bacteria and fungi. Both crude extract (CE) and compound 1 showed significant cytotoxicity of LC(50) at 16.21 microg/ml and 11.70 microg/ml, respectively.     

Antioxidant activity of polyphenols from solid olive residues of c.v. Coratina

The antioxidant profile of extracts from solid olive residue (SOR) of c.v. Coratina, a cultivar widely diffused in the south of Italy, using both cell-free and cell-based experimental models, was investigated. A total hydroalcoholic extract (polyphenols content 19.7%) and a purified extract (Oleaselecttrade mark) (polyphenols content 35.1%) were tested for their ability to quench the stable free radical DPPH, the peroxyl radicals (ORAC assay), by monitoring the loss in fluorescence of R-phycoerythrin induced by the peroxyl radical generator AAPH and their ability to inhibit the cumene hydroperoxide-induced lysis of rat red blood cells (RBC). The total hydroalcoholic extract showed IC(50) 26.96+/-1.53 microg/ml in the DPPH assay, that 10 microg/ml were equivalent to 2.11+/-0.12 microg/ml Trolox (ORAC assay) and IC(50) 1.7+/-0.20 microg/ml in the RBC hemolysis. The Oleaselect extract was 4 to 5 folds more active than the hydroalcoholic extract in all the experimental models, with IC(50) values of 7.36+/-0.38 microg/ml in the DPPH test and of 0.38+/-0.03 microg/ml in RBC; the antioxidant activity in the ORAC assay was slightly greater than that of Trolox (10 microg/ml equivalent to 11.45+/-0.40 microg/ml). The scavenging effect of the extract in the ORAC assay was compared to that of verbascoside (the main polyphenol component) and of caffeic acid (the basic constituent of verbascoside): the results indicate that caffeic acid (10 microg/ml equivalent to 35.70+/-2.95 microg/ml Trolox) is more potent than verbascoside (10 microg/ml equivalent to 15.42+/-1.21 microg/ml Trolox) in entrapping peroxyl radicals. Finally the antioxidant activity of the Oleaselect extract was confirmed in human umbilical endothelial cells (EC) exposed to the site-specific peroxyl radical inducer AAPH, where a massive lipid peroxidation process (marker the fluorescence probe BODIPY) takes place, paralleled by a marked loss of cell viability (calcein assay). The purified extract (1-20 microg/ml) pre-incubated with EC for 1 h dose-dependently inhibited both the lipid-peroxidation damage and cell death. Taking into account the total polyphenol content, these results clearly indicate a greater antioxidant activity for the purified extract, due to a cooperative antioxidant interaction among its polyphenol constituents.     

Anti-plasmodial activity of Ailanthus excelsa

The anti-plasmodial activity of Ailanthus excelsa stem bark was investigated. The methanolic extract inhibited in vitro growth of chloroquine-sensitive (D10) and resistant strains (W2) of Plasmodium falciparum (IC50 4.6 and 2.8 microg/ml, respectively). The effect was retained in the chloroform fraction (3.1 and 2.1 microg/ml, respectively). The anti-plasmodial activity could be ascribed to the impairment of haemoglobin degradation through the inhibition of plasmepsin II activity (IC50 of 13.43+/-1.74 microg/ml) and of the haem detoxification to haemozoin.     

Antiinflammatory and analgesic activities of Zizyphus lotus root barks

The root barks of Zizyphus lotus were extracted with water, chloroform, ethyl acetate and methanol to determine their antiinflammatory and analgesic activities. Aqueous extract (50, 100 and 200 mg/kg) given intraperitoneally (i.p.) showed a significant and dose-dependent antiinflammatory and analgesic activity.     

Molluscicidal activity of some Moroccan medicinal plants

Among 14 plants of Moroccan folk medicine tested for molluscicidal activity, ethyl acetate extract from Origanum compactum and hexane extracts from both Chenopodium ambrosioides and Ruta chalepensis were the most active (LC(90)=2.00, 2.23 and 2.23 mg l(-1), respectively) against the schistosomiasis-transmitting snail Bulinus truncatus.     

Molluscicidal activity against Oncomelania hupensis of Ginkgo biloba

In search for molluscicidal active components, petroleum ether, ethyl acetate, ethanol, and water extracts from Ginkgo sarcotesta were evaluated against the snail Oncomelania hupensis. The bioassay-oriented showed that the activity concentrates in the petroleum ether extract (LD(50) 7.81 ppm). Ginkgolic acids, isolated from the petroleum ether extract, exhibited strong molluscicidal activity (LD(50) 1.49 ppm), gingkgolic acid C15:1 having the strongest molluscicidal activity.     

Larvicidal activity of Cybistax antisyphilitica against Aedes aegypti larvae

The larvicidal activity against Aedes aegypti larvae of a stem wood hexane extract of Cybistax antisyphilitica was evaluated. Bioassay-guided fractionation of the crude extract, monitored by larvicidal assay, led to the isolation of a natural quinone identified as 2-hydroxy-3-(3-methyl-2-butenyl)-1.4-naphthoquinone (lapachol). This compound was quite potent against A. aegypti larvae (LC50 26.3 microg/ml).     

浅谈紫穗槐4种提取液对大皱鳃金龟子的活性分析

以甲醇、乙醇、氯仿和蒸馏水为溶剂获得的4种紫穗槐提取液,对沙地害虫大皱鳃金龟子进行了活性测定。结果表明：乙醇提取液（100mg/mL ）对大皱鳃金龟子毒杀活性最强,氯仿提取液次之,蒸馏水和甲醇提取液在4种提取液中活性最差;紫穗槐4种溶剂提取液对大皱鳃金龟子均有一定的触杀作用,但是活性均不高。     

Antibacterial activity and cytotoxicity of extractives from Ravenia spectabilis

A methanolic extract of Ravenia spectabilis, an isolated alkaloid, arborinine plus a fraction comprising arborinine and gamma-fagarine (VLC), showed mild to significant in vitro antibacterial activity. In a brine shrimp lethality bioassay, the extract and the fraction were found to exhibit moderate cytotoxicity having LC50 of 76.26 microg/ml and 14.98 microg/ml, respectively.     

Anxiolytic activity of aerial and underground parts of Passiflora incarnata

The petroleum ether, chloroform, methanol, and water extracts of Passiflora incarnata whole plant and sorted out plant parts have been evaluated for their anxiolytic activity using the elevated plus-maze model in mice. The methanol extracts of leaves, stems, flowers, and whole plant exhibited anxiolytic effects at 100, 125, 200 and 300 mg/kg, respectively. The roots were practically devoid of anxiolytic effects. These results show that roots and flowers of P. incarnata act as natural adulterants by causing a significant increase in the anxiolytic dose. Therefore, separation of these parts is recommended prior to any pharmacological, phytochemical and standardization studies on P. incarnata.     

Antibacterial activity of Jatropha multifida roots.

Hexane, ethyl acetate, chloroform and methanol successive extracts of Jatropha multifida yellow rootbark, red rootbark and rootwood effectively inhibited the growth of B. subtilis and S. aureus at concentration of 200 microg/disk.