Antibacterial Substances from Brown Algae II. Efficiency of Solvents in the Evaluation of Antibacterial Substances from Sargassum johnstonii Setchell et Gardner

Abstract

Four different solvente viz., acetone, diethylether, methanol and ethanol have been used to obtain crude extracts from S. johnstonü and the efficiency of the solvente is tested using gram-positive and gram-negative bacteria. The diethyl-ether extract exhibited Optimum antibacterial activity äs compared with the rest. Six differently preserved samples viz., frozen, shade dried, sun dried, oven dried, fresh and semi-fresh, were extracted with diethyl-ether and the extracts tested against gram-positive and gram-negative bacteria. Shade dried samples exhibited Optimum activity when compared with other seaweed samples.In another experiment, lipids from samples preserved äs listed above were extracted into Chloroform: methanol (2: l v/v) and the extract divided into two fractions. These two fractions were tested for their antibacterial acitivity against gram-positive and gram-negative bacteria. The fraction from a shade dried sample obtained using diethyl-ether äs the solvent exhibited a higher antimicrobial activity than the fraction extracted by solvent benzene.Botanica Marina / Vol. XXIX / 1986 / Fase. 6 Copyright © 1986 Walter de Gruyter · Berlin · New York and suitable solvent and to determine which type of preserved algal sample is best for achieving Optimum antibacterial activity against gram-positive and gramnegative test-bacteria. Material and MethodsThe seaweed samples were collected during low water of spring tides. Only healthy, fully grown plants still submerged under water during low tides were collected. The seaweed samples were cleaned with many changes of fresh seawater to remove epiphytes, Shells etc. attached to the algae and then dried under shade. The dried samples were brought to the laboratory and thoroughly washed first with sterile seawater Brought to you by | University of Arizona Authenticated Download Date | 6/1/15 6:18 AM

Antimicrobial, antioxidant properties and chemical composition of seaweeds collected from Saudi Arabia (Red Sea and Arabian Gulf)

“…This high inhibition gives a promising indication of developing a potent drug from marine natural sources used in treating human pathogens. Furthermore, the method of extraction, time and place of collecting algal samples, all together, play a critical role in determining the effectiveness of the seaweed extracts in study (Padmini Sreenivasa Rao et al, 1986). Higher antimicrobial activity was revealed with dried seaweeds compared to fresh extracts; lyophilization of algal samples, gives a greater compound extraction; whereas in fresh seaweeds where higher water content is present, produces diluted extracts with lower or even negligible inhibitory activity (Campos-Takaki et al, 1988, Padmini Sreenivasa Rao et al, 1986).…”

“…Moreover, higher medicinal effect was obtained from dry seaweeds samples than from fresh samples as indicated by many studies which reported that extracts prepared from fresh seaweeds showed negligible antimicrobial activity compared to that obtained from dried seaweeds (Padmini Sreenivasa Rao et al, 1986, Campos-Takaki et al, 1988, Manivannan et al, 2011). In addition, Salvador et al (2007) revealed that algal sample preparation method greatly affect the bioactivity of tested algae (e.g.…”

Antiplasmodial activity of two marine polyherbal preparations from Chaetomorpha antennina and Aegiceras corniculatum against Plasmodium falciparum

“…Marine plants are already known for the antibacterial Raja 2009;Sivaperumal 2009;Muthuraja 2009;Ramanathan and Raju 2000;Naqvi et al 1981;Padmini Sreenivasa Rao et al 1986a), antifungal Naqvi et al 1981;Rao and Shelat 1982;Padmini Sreenivasa Rao et al 1986b), antiviral (Padmakumar and Ayyakkannu 1997;Premanathan et al 1996;Rollet 1981, Balasooriya et al 1982Premanathan et al 1992;Premanathan et al 1993;Naqvi et al 1981), antioxidant (Larson 1988, Masuda et al 1999, antitumor (Hirazumi and Furusawa 1999), anticancer (Jongsuvat 1981), cytotoxicity (Manilal et al 2009;Shehnaz 2003), nematicidal (Manilal et al 2009;Baqar Naqvi et al 1992), antifeedant (Manilal et al 2009), larvicidal (Manilal et al 2009), phytotoxic (Shehnaz 2003), anticoagulant (Anand Ganesh et al 2009) and spermicidal (Prakash 2004) activities, but until recently, no effort has been made to find out the antiplasmodial activity of marine plants.…”

Antimicrobial activity of Iberian macroalgae

“…Previous studies that compared different treatments are scarce and were carried out on only a few taxa. Campos-Takaki et al (1988) and Padmini Sreenivasa Rao et al (1986) compared fresh and dried algal material; their results also showed lower activity in extracts from fresh tissue than in extracts from dried material. This is probably due to a higher dilution of the bioactive metabolites in the fresh material because of the higher water content.…”