Seaweed as a functional feed supplement in animal diet–A review

Seaweeds or marine macro-algae are multicellular organisms that grow abundantly along the coastal line. The use of seaweeds as animal feed is a very common practice in coastal areas since ancient times. Generally, seaweeds are categorized into green, brown, and red seaweeds, based on their colouring pigments. Commercially, seaweeds are used as a source of phycocolloids, fertilizer, livestock feed, and for direct human consumption. The use of seaweeds as livestock feed gained much importance in recent years, as they have good nutritive value and also contain a variety of bioactive compounds that are responsible for many health related benefits. The bioactive compounds of seaweeds exhibit prebiotic, antimicrobial, antioxidant, anti-inflammatory, anticancer and immunomodulatory effects. Over the years, the beneficial effects of using seaweed in animal diets have been studied and reported by many researchers to promote the health and productive performance of livestock. In particular, the brown seaweeds were explored extensively as livestock feed because of their large size. The nutrient value and bioactive compounds concentration in seaweed varies with the species, growing conditions, habitat, environmental changes, season, harvesting procedure, and time. While including seaweed in animal diets all these factors should be taken into consideration. In this review, all the studies related to seaweed supplementation in animal diets will be discussed with a special focus on the potential health benefits

High toxicity and specificity of the saponin 3-GlcA-28-AraRhaxyl-medicagenate, from Medicago truncatula seeds, for Sitophilus oryzae

<p>Abstract</p> <p>Background</p> <p>Because of the increasingly concern of consumers and public policy about problems for environment and for public health due to chemical pesticides, the search for molecules more safe is currently of great importance. Particularly, plants are able to fight the pathogens as insects, bacteria or fungi; so that plants could represent a valuable source of new molecules.</p> <p>Results</p> <p>It was observed that <it>Medicago truncatul</it>a seed flour displayed a strong toxic activity towards the adults of the rice weevil <it>Sitophilus oryzae</it> (Coleoptera), a major pest of stored cereals. The molecule responsible for toxicity was purified, by solvent extraction and HPLC, and identified as a saponin, namely 3-GlcA-28-AraRhaxyl-medicagenate. Saponins are detergents, and the CMC of this molecule was found to be 0.65 mg per mL. Neither the worm <it>Caenorhabditis elegans</it> nor the bacteria <it>E. coli</it> were found to be sensitive to this saponin, but growth of the yeast <it>Saccharomyces cerevisiae</it> was inhibited at concentrations higher than 100 μg per mL. The purified molecule is toxic for the adults of the rice weevils at concentrations down to 100 μg per g of food, but this does not apply to the others insects tested, including the coleopteran <it>Tribolium castaneum</it> and the Sf9 insect cultured cells.</p> <p>Conclusions</p> <p>This specificity for the weevil led us to investigate this saponin potential for pest control and to propose the hypothesis that this saponin has a specific mode of action, rather than acting <it>via</it> its non-specific detergent properties.</p

Larvicidal effects of endophytic and basidiomycete fungus extracts on Aedes and Anopheles larvae (Diptera, Culicidae)

Introduction In vitro bioassays were performed to access the larvicidal activity of crude extracts from the endophytic fungus Pestalotiopsis virgulata (Melanconiales, Amphisphaeriaceae) and the saprophytic fungus Pycnoporus sanguineus (Basidiomycetes, Polyporaceae) against the mosquitoes Aedes aegypti and Anopheles nuneztovari. Methods The extracts were tested at concentrations of 100, 200, 300, 400 and 500ppm. Ethyl acetate mycelia (EAM) extracts and liquid culture media (LCM) from Pe. virgulata and Py. sanguineus were tested against third instar larvae of Ae. aegypti and An. nuneztovari. Results The larvicidal activity of the EAM extracts from Pe. virgulata against Ae. aegypti had an LC50=101.8ppm, and the extract from the basidiomycete fungus Py. sanguineus had an LC50=156.8ppm against the Ae. aegypti larvae. The Pe. virgulata extract had an LC50=16.3ppm against the An. nuneztovari larvae, and the Py. sanguineus extract had an LC50=87.2ppm against these larvae. Conclusions These results highlight the larvicidal effect of EAM extracts from the endophyte Pe. virgulata against the two larval mosquitoes tested. Thus, Pe. virgulata and Py. sanguineus have the potential for the production of bioactive substances against larvae of these two tropical disease vectors, with An. nuneztovari being more susceptible to these extracts

Evaluation of larvicidal activity of medicinal plant extracts against three mosquito vectors

AbstractObjectiveTo evaluate the mosquito larvicidal activity of plant extracts.MethodsThe hexane, chloroform, ethyl acetate, acetone, and methanol leaf, flower and seed extracts of Abrus precatorius (A. precatorius), Croton bonplandianum (C. bonplandianum), Cynodon dactylon (C. dactylon), Musa paradisiaca (M. paradisiaca) and Syzygium aromaticum (S. aromaticum) were tested against fourth instar larvae of Anopheles vagus (An. vagus), Armigeres subalbatus (Ar. subalbatus) and Culex vishnui (Cx. vishnui).ResultsThe highest larval mortality was found in seed ethyl acetate extracts of A. precatorius and leaf extracts of C. bonplandianum, flower chloroform and methanol extracts of M. paradisiaca, and flower bud hexane extract of S. aromaticum against An. vagus with LC50 values of 19.31, 39.96, 35.18, 79.90 and 85.90 μg/mL; leaf ethyl acetate and methanol extracts of C. dactylon, flower methanol extract of M. paradisiaca, flower bud methanol extract of S. aromaticum against Ar. subalbatus with LC50 values of 21.67, 32.62, 48.90 and 78.28 μg/mL, and seed methanol of A. precatorius, flower methanol extract of M. paradisiaca, flower bud hexane extract of S. aromaticum against Cx. vishnui with LC50 values of 136.84, 103.36 and 149.56 μg/mL, respectively.ConclusionsThese results suggest that the effective plant crude extracts have the potential to be used as an ideal ecofriendly approach for the control of disease vectors. This study provides the first report on the larvicidal activity of crude solvent extracts of different mosquitoes

Adult emergence inhibition and adulticidal activity of leaf crude extracts against Japanese encephalitis vector, Culex tritaeniorhynchus

AbstractMosquitoes have developed resistance to various synthetic insecticides, making its control increasingly difficult. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. The aim of this study was to evaluate the adult emergence inhibition (EI) and adulticidal activity of the leaf hexane, chloroform, ethyl acetate, acetone, and methanol extracts of Aegle marmelos (Linn.) Correa ex Roxb, Andrographis lineata Wallich ex Nees., Andrographis paniculata (Burm.f.) Wall. ex Nees., Cocculus hirsutus L. Diels, Eclipta prostrata L. and Tagetes erecta L. were tested against japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae). All plant extracts showed moderate EI and adulticidal activity effects after 24h of exposure at 1,000ppm; however, the highest EI activity was found in leaf methanol extracts of A. marmelos, A. paniculata, T. erecta, and chloroform extract of E. prostrata (EI50=141.94, 214.17, 166.43, and 184.58ppm; EI90=590.26, 882.34, 532.00 and 571.81ppm); and the effective adulticidal activity was observed in acetone extract of A.marmelos, hexane of A.lineata, ethlyl acetate of A.paniculata, methanol extracts of C.hirsutus, E.prostrata, and T.erecta (LD50=139.05, 251.24, 205.06, 222.10, 166.73, and 232.74ppm; LD90=426.19, 837.09, 813.59, 794.42, 579.43 and 807.41ppm), respectively against C. tritaeniorhynchus. These results suggest that the leaf methanol extract of C. hirsutus, E. prostrata, and T. erecta have the potential to be used as an ideal eco-friendly approach for the control of the C. tritaeniorhynchus. Therefore, this study provides first report on the mosquito EI and adulticidal activity of plant extracts against a vector