RESUMEN
CONTEXT: Thais savignyi Deshayes (Muricidae) is widely distributed in the Red Sea. Its abundance and the history of Muricidae in traditional medicine make it a tempting target for investigation. OBJECTIVE: To investigate the chemical profile and biological activities of T. savignyi tissue extracts. MATERIALS AND METHODS: Methanol, ethanol, acetone, and ethyl acetate extracts from T. savignyi tissue were compared in their antioxidant by total antioxidant capacity, DPPH free radical scavenging, and total phenolic content. In addition, the antimicrobial, and antibiofilm properties (at 250 µg/mL) of the extracts were tested against Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Klebsiella pneumoniae, Staphylococcus aureus, and Candida albicans. The antioxidant extract with greatest activity was assessed for cytotoxicity (range 0.4-100 µg/mL) against 3 human cancer cell lines (UO-31, A549 and A431), and its chemical composition was investigated using GC-MS. Moreover, docking simulation was performed to predict its constituents' binding modes/scores to the active sites of thymidylate kinase. RESULTS: The ethyl acetate extract (Ts-EtOAc) showed the highest total antioxidant capacity (551.33 mg AAE/g dry weight), total phenolics (254.46 mg GAE/g dry weight), and DPPH scavenging (IC50= 24.0 µg/mL). Ts-EtOAc exhibited strong antibacterial (MIC: 3.9 µg/mL against K. pneumoniae), antibiofilm (MIC: 7.81 µg/mL against S. aureus), and antifungal (MIC: 3.9 µg/mL against C. albicans) activities and considerable cytotoxicity against cancer cells (UO-31: IC50= 19.96 ± 0.93, A549: IC50= 25.04 ± 1.15 µg/mL). GC-MS identified multiple bioactive metabolites in Ts-EtOAc extract belonging to miscellaneous chemical classes. Molecular docking studies revealed that the constituents of Ts-EtOAc have antibacterial potential. DISCUSSION AND CONCLUSIONS: T. savignyi extract has considerable antimicrobial and cytotoxic activities. Further studies are needed to isolate the active constituents of this snail for comprehensive drug discovery tests.
Asunto(s)
Antiinfecciosos , Antioxidantes , Acetatos , Acetona , Antibacterianos , Antiinfecciosos/farmacología , Antifúngicos/química , Antifúngicos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Etanol , Radicales Libres , Humanos , Metanol , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Fenoles/farmacología , Extractos Vegetales , Staphylococcus aureus , Tailandia , Extractos de TejidosRESUMEN
A wide range of endocrine disruptor compounds are routinely discharged to the ecosystem. Water contaminated with these compounds has a potential effect on the reproductive physiology of aquatic organisms as well as humans. In the present study, we tested the effect of the steroid estrogen, 17ß-estradiol, on Biomphalaria alexandrina, a snail species that is widely distributed in Egypt and that acts as an intermediate host for the human blood fluke, Schistosoma mansoni. The effects of exposure to 0.3 mg/L and 1 mg/L 17ß-estradiol on fecundity (MX) and reproductive rate (R0) of B. alexandrina were recorded. In addition, levels of steroid sex hormones and antioxidants in the hemolymph and ovotestis (OT) of exposed snails were measured. Histopathological changes in the OT of B. alexandrina were also investigated. Exposure to 0.3 mg/L and 1 mg/L 17ß-estradiol caused a significant increase in the number of egg masses per snail after 3 weeks and 1 week of exposure for the two tested concentrations compared with unexposed controls. An increase in the levels of progesterone hormone was recorded in the hemolymph of exposed snails in comparison with unexposed controls. Additionally, levels of the antioxidant enzyme glutathione (GSH) were increased in the hemolymph and OT tissues of snails after 2 and 4 weeks of exposure. Histopathological sections in the OT revealed an increase in the oocyte and a decrease in the sperm densities after 2 weeks and this effect was restored to normal conditions after 4 weeks of exposure to both tested concentrations. The current results indicate that B. alexandrina is sensitive to 17ß-estradiol and can therefore be used as bioindicator and model organism for the assessment of water pollution with endocrine disruptor compounds.
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Biomphalaria/efectos de los fármacos , Disruptores Endocrinos/toxicidad , Monitoreo del Ambiente/métodos , Estradiol/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Antioxidantes/metabolismo , Ecosistema , Egipto , Biomarcadores Ambientales/efectos de los fármacos , Fertilidad/efectos de los fármacos , Gónadas/efectos de los fármacos , Gónadas/patología , Hemolinfa/efectos de los fármacos , Hemolinfa/metabolismo , HumanosRESUMEN
CONTEXT: Praziquantel (PZQ) is a highly efficacious anthelmintic against many flatworms including schistosomes. PZQ has been in use for more than 25 years, and concern is increasing that resistance has emerged in human schistosomes in Egypt and other endemic countries. OBJECTIVE: The current study was designed to evaluate a recently described method for induction of PZQ resistance in Schistosoma mansoni. MATERIALS AND METHODS: Successive subcurative drug treatments of Biomphalaria alexandrina snails infected with an Egyptian strain of S. mansoni were undertaken. Cercariae shed from snails exposed and unexposed to PZQ were used to infect mice. Forty-five days after infection, mice were treated with a single oral dose of PZQ in 2% aqueous solution of Cremophor-EL®. The concentration of PZQ was 0, 200, 400, or 800 mg/kg. Thirty-three days after treatment, all groups of mice were dissected to collect the S. mansoni worms by the perfusion technique. In addition, the oogram pattern was examined to study the production, maturity, and death of S. mansoni eggs in the different groups of mice. RESULTS: The present study has shown that the sublethal dose for induction of PZQ resistance in the intra-molluscan S. mansoni stages was 500 mg/kg. The worm count and the percentage of immature eggs in different groups of mice were significantly affected by the intra-molluscan exposure to PZQ and the drug concentration used to treat infected mice. DISCUSSION AND CONCLUSION: The results obtained herein confirm the possibility of using successive drug treatments of infected B. alexandrina to induce PZO resistance in S. mansoni.
Asunto(s)
Antihelmínticos/farmacología , Praziquantel/farmacología , Schistosoma mansoni/efectos de los fármacos , Esquistosomiasis mansoni , Caracoles/efectos de los fármacos , Animales , Antihelmínticos/uso terapéutico , Evaluación Preclínica de Medicamentos/métodos , Resistencia a Medicamentos/efectos de los fármacos , Ratones , Praziquantel/uso terapéutico , Esquistosomiasis mansoni/tratamiento farmacológico , Esquistosomiasis mansoni/mortalidad , Caracoles/parasitologíaRESUMEN
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-ß-d-glucopyranoside (5) and benzyl alcohol 7-O-(3',4',6'-tri-O-galloyl)-ß-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.
Asunto(s)
Eucalyptus , Melaleuca , Metanol/farmacología , Extractos Vegetales/farmacología , Schistosoma mansoni/efectos de los fármacos , Esquistosomicidas/farmacología , Animales , Metanol/química , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta , Esquistosomicidas/química , Esquistosomicidas/aislamiento & purificaciónRESUMEN
A laboratory-based susceptibility study was carried out on snails Bulinus truncatus collected from highland Abha, Asser, Saudi Arabia to Egyptian Schistosoma haematobium to investigate the potential role of Saudi B. truncatus in the transmission of Egyptian S. haematobium and to know the possibility that the parasite might be able to spread into Saudi Arabia. The results revealed that, compared to Egyptian snails, survival of snails at day 25 post-exposure was significantly higher in Saudi B. truncatus ones. The infection rate was higher in Saudi snails as compared to Egyptian ones. The incubation period was shorter in Saudi snails but the duration of cercarial shedding was longer in the Egyptian than in the Saudi snails. The production of S. haematobium cercariae per snail was higher in Egyptian snails than in Saudi ones. These results suggest that Saudi B. truncatus can play a role in the transmission of Egyptian S. haematobium in Saudi Arabia and therefore this parasite might be able to spread into the Kingdom. In addition, electrophoretic analysis of tissue soluble proteins was done to determine the effects of the parasite on both the Egyptian and Saudi snails. The electrophoretic analysis revealed the occasional presence or absence of certain bands in infected snails in comparison with non-infected one.
Asunto(s)
Proteínas/química , Proteínas/metabolismo , Schistosoma haematobium/fisiología , Caracoles/metabolismo , Caracoles/parasitología , Animales , Electroforesis , Interacciones Huésped-Parásitos , Arabia SauditaRESUMEN
The mating system of B. alexandrina was studied under laboratory condition by allozyme analysis and SDS-PAGE protein analysis for parent snails and their progenies of two successive generations produced by self and cross fertilization. Allozyme analysis detected 11 genetic loci in 3 enzymes; ACP (3 loci), LDH (2 loci) and EST (6 loci). The mean number of Allele (A), average heterozygosity over loci (H) and dendrogram from cluster analysis based on genetic distances between snail groups showed a genetic heterogeneity in parents and 1st generation higher than that in the 2nd generation. Cross-fertilization and genetic heterogeneity among snails decreased through generations. Snails practiced self-fertilization showed genetic alterations and genetic heterogeneity was either decreased or increased. SDS-PAGE profile of tissue protein revealed that the mating system in B. alexandrina showed specific bands, 204 & 214 KDa, in snails bred by self-fertilization. D value based on shared protein bands number and estimated similarity between parents and progenies showed that parents were approximately similar with self and cross progenies in 1st generation and only with cross progenies in 2nd generation as self progenies showed increase or decrease in similarity. B. alexandrina susceptibility to S. mansoni was not affected when snails were bred by cross or self fertilization.