Anthelmintic coumarin from Ethulia conyzoides var. gracilis Asch. & Schweinf

The alcoholic extract of aerial parts of Ethulia conyzoides var. gracilis Asch. & Schweinf. exhibits a significant anthelmintic activity when tested in vitro against Ascaris lumbricoides using santonin as a reference. Four coumarins were isolated and identified; ethuliacoumarin A was found to be responsible for the anthelmintic activity.     

Screening of Panamanian Plants for Molluscicidal Activity

A total of 153 crude extracts of Panamanian plants (28 species from 21 families) have been screened for molluscicidal activity against Biomphalaria glabrata, one of the intermediate hosts of schistosomiasis. When tested at 400 ppm, 15 extracts were active. The most potent of these came from Cyperus luzulae (Cyperaceae) and Hymenaea courbaril (Leguminosae).     

Study of the Molluscicidal Activity of Some Phenolic Compounds: Structure-Activity Relationship

The relationship between the structure of 14 phenolic compounds and their molluscicidal activity against the molluscan intermediate host of urinary schistosomiasis, Bulinus truncatus, is discussed. It was found that among flavonoids tested, unhydroxylated flavone compound and flavanone hesperidin were the most active (LC₅₀ = 5.47 and 8.91 ppm, respectively), whereas gallic acid compound with para-methoxy group was the most effective among phenolic acids tested (LC₅₀ = 3.60 ppm). These results are encouraging and prove other biological application of these compounds.     

On the molluscicidal activity of tannin containing plants

The aqueous and methanolic extracts of a series of typical tannin containing plants exhibit strong molluscicidal properties against the freshwater snail biomphalaria glabrata, which is the intermediate host of schistosomiasis. The crude extracts of Krameria triandra (Krameriaceae) and Arctostaphylos uvaursi (Ericaceae) were active at concentrations of 50 ppm. Hydrolyzable and condensed tannins are responsable for the molluscicidal activity. This report indicates a new class of plant derived compounds which may have important practical application for the control of schistosomiasis in endemic areas.     

Molluscicidal and antischistosomal activities of Zingiber officinale

Experiments were conducted to study the major constituents of Zingiber officinale responsible for its molluscicidal activity and the effect of the active component on different stages of Schistosoma mansoni. Gingerol and shogaol exhibited potent molluscicidal activity on Biomphalaria glabrata. Gingerol (5.0 ppm) completely abolished the infectivity of Schistosoma mansoni miracidia and cercariae in B. glabrata and mice, respectively, indicating that the molluscicide is capable of interrupting schistosome transmission at a concentration lower than its molluscicidal concentrations.     

Antiviral, haemolytic and molluscicidal activities of triterpenoid saponins from Maesa lanceolata: establishment of structure-activity relationships

Ten saponins isolated from the leaves of Maesa lanceolata were tested for their antiviral, haemolytic and molluscicidal activities. The influence of the substitution pattern of these acylated triterpenoid saponins on their biological activities was investigated and structure-activity relationships were established. Maesasaponin VI(2) (3 beta-O-[[alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-galactopyranosyl-(1 --> 3)]-[beta-D-galactopyranosyl-(1 --> 2)]-beta-D-glucopyranuronyl]-21 beta,22 alpha-diangeloyloxy-13 beta,28-epoxyolean-16 alpha,28 alpha-diol), the most potent molluscicidal compound (LC(50) 0.5 ppm), also showed virucidal and haemolytic activity. In general, 21,22-diacylation appeared to be associated with a virucidal (reduction factor of the viral titer > or = 10(3) at 50 microg/ml) and haemolytic activity (HC(50) < or = 1 microg/ml).     

The toxic activities of Arisaema erubescens and Nerium indicum mixed with Streptomycete against snails

The comparative molluscicidal activities of Arisaema erubescens tuber extracts and Nerium indicum leaf extracts mixed with Streptomycete violacerruber dilution (SD) against the snail Oncomlania hupensis and the responses of the isozymes, esterase (EST) and superoxide dismutase (SOD) to the A. erubescens extracts and the mixtures were investigated. The molluscicidal activity of A. erubescens water extracts mixed with S. violacerruber dilution was 4-5 times higher than a single A. erubescens or S. violacerruber dilution after 24-h exposure, and is also higher than that of N. indicum leaf water extracts mixed with S. violacerruber dilution. At the end of exposure to the N-butanol extracts of A. erubescens tubers (NEAT), the EST activity in snail liver decreased and some enzyme bands (EST 1 and EST 3 in exposure to NEAT) disappeared but the activities of SOD 1 increased. The effect was more obvious in mixture treatment than in single NEAT or SD treatment. The results indicated that molluscicidal activities of plant and microorganism could be more effective than single plant. The decline of the detoxic ability in snail liver cells could be the reason of the snail dying.     

Molluscicidal properties of Acacia nilotica

The acetone, alcohol and aqueous extracts of fruits of Acacia nilotica (L) Willd. ex Del. (Mimosaceae) showed molluscicidal activity against Bulinus truncatus and Biomphalaria pfeifferi, the two snail species which transmit schistosomiasis in the Sudan (S. haematobium and S. mansonii). TAN, a new vegetable molluscicide prepared from the aqueous extract of the fruits of A. nilotica was produced on a pilot scale by using the spray drying procedure. Due to the high content of tannins in the powder (more than 56%), the molluscicidal properties of this plant may well be due to these compounds.     

Molluscicidal Properties of Acacia nilotica.

The acetone, alcohol and aqueous extracts of fruits of ACACIA NILOTICA (L) W ILLD. ex D EL. (Mimosaceae) showed molluscicidal activity against BULINUS TRUNCATUS and BIOMPHALARIA PFEIFFERI, the two snail species which transmit schistosomiasis in the Sudan (S. haematobium and S. mansonii). TAN, a new vegetable molluscicide prepared from the aqueous extract of the fruits of A. NILOTICA was produced on a pilot scale by using the spray drying procedure. Due to the high content of tannins in the powder (more than 56%), the molluscicidal properties of this plant may well be due to these compounds.     

Glaucolide B, A Molluscicidal Sesquiterpene Lactone, and Other Constituents of Vernonia eremophila

The sesquiterpene lactone glaucolide B was isolated from the molluscicidal extract of VERNONIA EREMOPHILA Mart, and shown to be responsible for the molluscicidal activity. Hydrogenolysis of glaucolide B resulted in the disappearance of the activity. Other inactive constituents of the extract were 3,7-dimethoxy-5,3',4'-trihydroxyflavone and two transformation products, possibly artefacts, of glaucolide B. Glaucolide B exhibited strong antimicrobial activity against B, CEREUS and moderate activity against S. AURENS, but was inactive in several other systems.     

Toxicity and mutagenicity of the molluscicidal plant Ambrosia maritima L.

The acute and subchronic toxicity of the molluscicidal plant, Ambrosia maritima L., has been tested on rats. No toxic signs could be detected neither after oral administration of 5 g/kg of dried leaves of the plant as a powder or as a methanolic extract, nor after the incorporation of 50,000 ppm powdered leaves in the feed during 4 weeks. Using an aqueous extract of the plant material of A. maritima or using ambrosin, one of the active molluscicidal components of the plant, no mutagenic activity could be detected in the S. typhimurium strains TA97, TA 98, TA1538, TA100 and TA1535.     

Molluscicides from some common medicinal plants of eastern Uttar Pradesh,India

Many aquatic snails act as intermediate hosts for the larvae of trematodes, Fasciola hepatica and Fasciola gigantica, which cause the diseases fascioliasis and schistosomiasis. The WHO has tested several thousands of synthetic compounds for the control of the snail host. Although effective, these molluscicides have so far not proved themselves to be entirely satisfactory. With a growing awareness of environmental pollution, efforts are being made to discover molluscicidal products of plant origin. Being products of biosynthesis, these are potentially biodegradable in nature. Several groups of compounds present in various plants have been found to be toxic to target organisms at acceptable doses ranging from <1 to 100 ppm. Common medicinal plants, i.e. Thevetia peruviana, Alstonia scholaris (Family; Apocynaceae), Euphorbia pulcherima and Euphorbia hirta (Family; Euphorbiaceae), have potent molluscicidal activity against freshwater snails. The toxicological actions of Thevetia peruviana may be due to the presence of apigenin‐5‐methyl ether (flavonoid) and triterpenoid glycosides, while a number of alkaloids (pseudo‐akuammigine in addition to betulin, ursolic acid and β‐sitosterol), steroids and triterpenoids are present in Alstonia scholaris and the diterpenoids, pulcherrol, β‐sitosterol, hentriacontane, ellagic acid and β‐amyrin are present in Euphorbia hirta and in Euphorbia pulcherima. Although, at present very little literature is available on the control of vector snails through plant origin pesticides, an attempt has been made in this review to assemble all the known information on molluscicidal properties of common medicinal plants of eastern Uttar Pradesh, India, which might be useful for the control of harmful snails. Copyright © 2009 John Wiley & Sons, Ltd.     

Molluscicidal properties of various saponins

A series of 24 different saponins isolated from various medicinal plants have been tested against BIOMPHALARIA GLABRATA, one of the snail vectors of schistosomiasis (bilharziasis). In general, monodesmosidic triterpenoid saponins exhibit strong molluscicidal activity whereas bidesmosidic saponins as well as the aglycones are fully inactive. Some dammarane glycosides and alkaloidal saponins have also been tested.     

Molluscicidal constituents of Calophyllum from Madagascar: activity of some natural and synthetic neoflavonoids and khellactones.

Crude extracts of seeds, leaves and barks of four Madagascan Calophyllum species: C. inophyllum, C. recedens, C. chapelieri, and C. verticullatum, have been tested for molluscicidal activity against Biomphalaria glabrata. All seed extracts showed significant activity. The major constituents of the most active Calophyllum species were examined. Some related coumarinic derivatives were synthesized in order to improve the biological activity. Among the compounds prepared, 5,7-dihydroxy-6-(2-methylbutyryl)-4-phenyl-coumarin presented an interesting molluscicidal activity.     

Anacardic acid: molluscicide in cashew nut shell liquid

The components of anacardic acid, (a mixture of 6-n-C (15) alkylsalicylic acids whose side chains vary in degrees of unsaturation) have been isolated by high pressure liquid chromatography from a crude extract of cashew nut shell, ANACARDIUM OCCIDENTALE, and tested for toxicity to fresh water snails, BIOMPHALARIA GLABRATA. The triene component is the most toxic form (LC (50) 0.35 ppm), the diene and monoene components are less toxic (LC (50) 0.9 and 1.4 ppm), and the saturated component is relatively nontoxic (LC (50) > 5 ppm). Since decarboxylated anacardic acid (cardanol) and salicylic acid do not kill snails at concentrations up to 5 ppm, it appears that both, carboxyl group and unsaturated side chain are absolutely required for molluscicidal activity. The mechanism of toxicity of anacardic acid to snails is unknown.     

O,O′-二烷基-O″-(5-取代-3-苯并噻吩乙腈肟)磷酸酯及硫代磷酸酯的合成

合成了18个O,O′-二烷基-O″-(5-取代-3-苯并噻吩乙腈肟)磷酸酯及硫代磷酸酯类化合物(Ⅰ_1～18)。初步杀螺试验结果表明,其中5个化合物,即Ⅰ_2,3,7,11,12有明显的杀螺增效作用。     

Molluscicidal and antischistosomal activities of methanol extracts and isolated compounds from Eucalyptus globulus and Melaleuca styphelioides

Context: Schistosomiasis is a parasitic disease that results in severe organ damage. Snail control is the best measure to control schistosomiasis. Plant-derived molluscicides have gained increasing attention for the control of schistosomiasis because they have low toxicity towards non-target organisms. Tannins are particularly suitable for snail control because they are less toxic than saponins to non-target organisms.

Objective: To identify the most toxic components of two plants belonging to the family Myrtaceae, namely Eucalyptus globulus Labill. and Melaleuca styphelioides Sm against the different developmental stages of Schistosoma mansoni and its snail host.

Materials and methods: The 80% MeOH leaf extracts of the tested plants and their isolated compounds were screened for their molluscicidal activity (expressed as LC₅₀ and LC₉₀ after 24?h exposure) against the snail Biomphalaria alexandrina. The anti-schistosomal activity of the tested samples was determined at 20?ppm (after 1 or 2?h exposure) against the different developmental stages of S. mansoni, including the miracidia, cercariae and worms. Biochemical parameters were measured to determine the toxicity mechanisms of the treated snails. The structures of the isolated compounds were elucidated based on NMR, UV and HRESI-MS/MS data.

Results: Potent molluscicidal activity was observed for the ellagitannin dimer eucalbanin B (12), with an LC₅₀ value of 55?ppm. Treatment of the snails with the LC₂₅ of eucalbanin B (30.8?ppm) resulted in a significant decrease in the protein level by 22.7% and 25.8% in the snail tissues and hemolymph, respectively. The decreased protein content was attributed to destruction of the snail tissue and impairment in protein synthesis under stress conditions of intoxication with eucalbanin B. Alterations in the activities of the transaminases and phosphatases in the treated snails indicated destruction and intoxication of the snail tissues. A significant increase in the levels of the transaminases alanine aminotransferase (ALT) (57.8%) and aspartate aminotransferase (AST) (113.2%) in the snail hemolymph and a significant decrease in their tissue levels to 7.4 and 48.6%, respectively, were attributed to their release from the damaged tissue into the hemolymph. Alkaline phosphatase (ALP) was significantly increased by 38.5 and 181.4% in the hemolymph and tissues, respectively. Acid phosphatase (ACP) was also significantly increased by 48.4 and 21.2% in the hemolymph and tissues, respectively. The 80% MeOH extract of E. globulus together with mallophenol B (3), 2,2,8-trimethyl-6-formyl-chrom-3-ene-7-O-β-d-glucopyranoside (5) and benzyl alcohol 7-O-(3′,4′,6′-tri-O-galloyl)-β-d-glucopyranoside (10) exhibited miracidicidal activity with almost 100% toxicity at 20?ppm for the three compounds and 80% toxicity for the extract. Moreover, E. globulus extract showed cercaricidal and schistosomicidal activity with 100 and 40% mortality, respectively.

Conclusion: E. globulus is a potential source for biocidal compounds against S. mansoni and its snail host. This is the first study to test the biocidal activity of the isolated compounds.     

Molluscicidal activity and clinico-pathological effect ofAgave lophantha

Dry powder and different extracts of Agave lophantha were tested against Biomphalaria alexandrina. The results showed that the butanol extract has high molluscicidal activity. The activity of the dry powder has been found to be stable under the effect of some simulated field conditions. Also the toxicological effect of the plant on mice was tested through determination of certain parameters such as total protein, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and acid phosphatase enzymes as well as histopathological study on liver and kidney.     

Renal enzyme activities in experimental ochratoxin A-induced porcine nephropathy: diagnostic potential of phosphoenolpyruvate carboxykinase and gamma-glutamyl transpeptidase activity

Enzyme activities have been measured in needle biopsies from kidneys of pigs fed 1 ppm or 0.2 ppm of ochratoxin A for 1-5 wks. After feeding 1 ppm toxin for 1 wk, the activity of cytosolic phosphoenolpyruvate carboxykinase (PEPCK) was decreased by 40% and remained inhibited until the termination of the experiment (5 wk). The activity of gamma-glutamyl transpeptidase, a brush-border enzyme found in the proximal tubules, was reduced to a similar degree and remained inhibited. The activities of hexokinase, a cytosolic enzyme of general distribution in the nephron, and phosphate-dependent glutaminase, a distal tubule enzyme, were not affected. The biopsy results were confirmed by measurements in renal slices taken at the termination of the experiment, except that biopsy samples showed more variation in enzyme activity and a lower PEPCK activity. A guinea pig antibody against the cytosolic form of PEPCK was used to demonstrate that the mitochondrial form of the enzyme, which accounts for a considerable part of the total cellular activity, was not affected by ochratoxin A. When mitochondrial PEPCK activity present in the cytosolic fraction was accounted for, ochratoxin A was found to reduce PEPCK activity by 70-80%. The increase of ochratoxin A exposure from zero through 0.2 ppm to 1 ppm, which resulted in dose-dependent activity decrease of PEPCK and gamma-glutamyl transpeptidase, was accompanied by dose-dependent decrease of renal function, as measured by a reduction of maximal tubular excretion of para-aminohippurate per clearance of inulin (TmPAH/CIn) and an increase in glucose excretion. This suggest that these enzymes are sensitive indicators of ochratoxin A-induced porcine nephropathy. Assuming that porcine nephropathy represents a valid model of endemic (Balkan) nephropathy in humans, the measurement of cytosolic PEPCK and gamma-glutamyl transpeptidase activity in the kidney could be a sensitive test for ochratoxin A-induced disease in humans.     

Molluscicidal and larvicidal activities and essential oil composition of Cymbopogon winterianus

Abstract

Context. Cymbopogon winterianus Jowitt ex Bor (Poaceae), known as citronella grass, is an aromatic herbaceous plant and the essential oil extracted from this grass is used in cosmetics, perfumes, hygiene and cleanliness products worldwide.

Objective: This study investigated the composition and molluscicidal and larvicidal activities of the essential oil of C. winterianus cultivated in North Brazil.

Materials and methods: The oil was obtained by hydrodistillation, analyzed by gas chromatography (GC) and GC-mass spectrometry and then its molluscicidal and larvicidal activities against snails (Biomphalaria glabrata) and hatched larvae of Artemia salina, respectively, were evaluated at concentrations from 10 to 1000?mg/L.

Results: The main constituents of oil were citronellal (26.5%), geraniol (16.2%), elemol (14.5%) and citronellol (7.3%). The molluscicidal test revealed significant lethal concentration (LC) values (LC₉₀?=?97.0?mg/L, LC₅₀?=?54.0?mg/L and LC₂₀?=?22.0?mg/L), indicating the presence of molluscicidal compounds in the oil. In addition, the oil showed moderate larvicidal activity (LC₅₀?=?181.0?mg/L) against the larvae of A. salina, which could justify its use in the aquatic environment without affecting other living organisms.

Discussion and conclusion: The results suggest that the oil of C. winterianus could be an effective alternative to control schistosomiasis, with an average margin of safety to other living organisms that coexist with snails.