Evaluation of Antimycotic Activity of Extracts of Marine Algae Collected from Red Sea Coast, Jeddah, Saudi Arabia

In the present study, fifteen species of the dominant marine algae were collected during summer 2013 from four selected sites on Red sea coast, Jeddah, Saudi Arabia. The collected species belonged to Chlorophyta, Phaeophyta and Rhodophyta. Crude algal extracts were prepared by successive extractions using different solvents (acetone, ethanol, diethyl ether, ethyl acetate, methanol and petroleum ether). The crude algal extracts were examined for their antifungal efficacy against Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Candida albicans and Candida tropicalis using agar well diffusion method. The algal extracts evoked different patterns of antifungal activities. Results reveal that acetone was the best solvent suited for extraction of bioactive compounds from tested seaweeds with inhibition activity (19.3%) followed by ethyl acetate (17.1%), ethanol (16.4%), petroleum ether (15.9%), diethyl ether (15.85%), and finally methanol (15.4%). Chlorophyta exhibited the highest antimycotic effect followed by Rhodophyta and Phaeophyta. In Chlorophyta, the extracts of Ulva intestinalis were the most potent followed by U. lactuca, C. racemosa, U. linza and U. reticulate. Acanthophora spicifera showed the highest activity in Rhodophyta, followed by J. rubens, D. simplex, L. obtusa, G. gracilis, G. vermicuphylla and G. multipartita. Whereas, T. triquetra was the most effective species in Phaeophyta followed by P. pavonica and D. dichotoma. The minimal inhibitory concentrations (MICs) of the most potent algal extracts were in the range of 0.5 to 4 mg/ml. The results confirmed the antimycotic potentiality of seaweed extracts.

SCREENING FOR ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES IN SOME MARINE ALGAE FROM THE FUJIAN COAST OF CHINA WITH THREE DIFFERENT SOLVENTS

Three different solvents viz ethanol, acetone and methanol toluene (3:1) were used to extract antibiotics from 23 species of marine algae belonging to the Chlorophyta, Phaeophyta and Rhodophyta. Their crude extracts were tested for antibacterial and antifungal activities. Among them, the ethanol extract showed the strongest activity against the bacteria and fungi tested. Four species of the Rhodophyta ( Laurencia okamurai, Dasya scoparia, Grateloupia filicina and plocamium telfairiae ) showed a wide spectrum of antibacterial activity. Every solvent extract from the four species was active against all the bacteria tested. The test bacterium Pseudomonas solancearum and the fungus Penicilium citrinum were most sensitive to the extracts of marine algae. In general, the extracts of seaweeds inhibited bacteria more strongly than fungi and species of the Rhodophyta showed the greatest activity against the bacteria and fungi tested.

Ultrasonic-Assisted Extraction of Fucoxanthin from Marine Macroalga Padina australis:Optimization,Bioactivity,and Structural Characterization

Macroalgae serve as a potential feedstock for fucoxanthin extraction.Fucoxanthin,a bioactive pigment found in the chloroplasts of marine algae,exhibits significant pharmacological properties.As a member of the carotenoid family,fucoxanthin plays a crucial role in both the food and pharmaceutical industries.This research explores the effects of ultrasonics on the extraction of fucoxanthin from the marine macroalga Padina australis.In addition,various extraction techniques and the influence of solvents on the efficient separation of fucoxanthin from algae have been studied and compared.Using methanol,chloroform,and a combination of methanol and chloroform(1:1,v/v),conventional fucoxanthin extraction from Padina australis yielded 8.12 mg of fucoxanthin per gram of biomass.However,the ultrasonic-assisted extraction resulted in a significantly higher yield of 16.9 mg of fucoxanthin per gram of biomass,demonstrating that the use of ultrasonics enhances the extraction rate compared to conventional methods.Therefore,the efficient separation of fucoxanthin from Padina australis is highly dependent on ultrasonic-assisted extraction.The process conditions for the extraction were optimized to maximize the yield of fucoxanthin from seaweeds.The following parameters were selected for optimization studies:moisture content,particle size,mixing speed,extraction temperature,extraction duration,and solid-to-solvent ratio.The extracted fucoxanthin exhibited various biological activities,including antimicrobial and antioxidant properties,and its structure was elucidated through FTIR and NMR spectroscopy.Additionally,thin-layer chromatography of the crude algae extracts confirmed the presence of fucoxanthin in the marine algae.Given these findings,the optimized extraction process holds the potential for scaling up to large-scale fucoxanthin production.Fucoxanthin,as a potent pharmacological agent,offers promising applications in the treatment of various ailments.

In vitro antimicrobial activities of methanolic extract from marine alga Enteromorpha intestinalis

Objective:To extract the bioactive compound from Enteromorpha intestinalis(E. intestinalis) and determine its in vitro antimicrobial activity. Methods: E. intestinalis was extracted by methanol and subjected to antimicrobial screening. The antimicrobial activity was studied by using disc diffusion and broth dilution method. The effect of the extract on the growth profile of the bacterial was also examined via time-kill assay. Microscopy observations using SEM was done to determine the major alterations in the microstructure of methicillin-resistant Staphylococcus aureus(MRSA). Results: The results showed methanolic extract of E. intestinalis exhibited a favourable antimicrobial activity against tested bacteria with produced inhibition zone ranging from 8.0-19.0 mm. However, all the tested fungi and yeast were resistant to the extract treatment. Time kill assay suggested that methanolic extract of E. intestinalis had completely inhibited MRSA growth and also exhibited prolonged antibacterial activity. The main abnormalities noted from the microscopic observations were the structural deterioration in the normal morphology and complete collapsed of the bacteria cells after 36 h of treatment. Conclusions: The significant antibacterial activity shown by crude extract suggested its potential against MRSA infection. The extract may have potential to develop as antibacterial agent in pharmaceutical use.

Antibacterial activity of selected marine macro algae against vancomycin resistant Enterococcus faecalis

Objective:To evaluate the antibacterial activity of different extracts of Caulerpa chemnitzia(Epser)J.V.Lamououx,Caulerpa racemosa(Frosk.)Weber-van-Bosse(C.racemosa),Caulerpa scalpelliformis(R.Br.)Weber-van-Bosse,Ulva lactuca Lin,Ulva fasciata Dellie,Ulva reticulata Forsk,Stoechospermum marginatum(Ag.)Kutz(S.marginatum),Sargassum wightii Grev,Gracilaria verrucosa(Huds.)Papenfuss and Gracilaria edulis(S.G.Gemelin)P.C.Silva against Enterococcus faecalis(MTCC 439)(E.faecalis)and one clinical isolate of vancomycin resistant E.faecalis.Methods:The selected marine macro algae were extracted with different solvents viz.,hexane,chloroform,ethyl acetate,acetone and methanol.Antibacterial assay was carried out by using disc diffusion method,determination of minimum inhibitory concentration and minimum bactericidal concentration.Results:The maximum antibacterial activity was recorded in the ethyl acetate extracts of S.marginatum and C.racemosa than the other extracts.The mean zone of inhibition produced by the extracts in agar diffusion assays against the tested bacterial strains ranged from 7.1 to 14.5 mm.The minimum inhibitory concentration was between 250 and 500μg/mL,while the minimum bactericidal concentration was from 500 to 1000μg/mL.The ethyl acetate extracts of the seaweeds showed the presence of strong terpenoids,tannins and phenolic compounds compared with the other solvent extracts.Conclusions:These findings suggest that ethyl acetate extracts of S.marginatum and C.racemosa can be used as an antibacterial substance for the treatment of infection caused by E.faecalis.

中国经济海藻提取物生物活性

分别采用MTT法、双碟法、酶标法、光度法和增重法测定了广西涠洲岛、广东硇洲岛、山东青岛和威海沿岸具有代表性的大型海藻提取物的抗肿瘤、抗菌、免疫、抗炎、抑制α 葡萄糖苷酶和抗氧化的活性。结果表明 ,鸭毛藻、松节藻、小粘膜藻和点叶藻的甲醇提取物具有选择性细胞毒活性 ;酸藻水相、鸭毛藻的乙酸乙酯相有较强的抗菌活性 ;金膜藻、网地藻、石莼和萱藻的甲醇提取物有较好的免疫抑制活性 ;三叉仙菜、龙须菜、海萝、绳藻和小粘膜藻的甲醇提取物有较好的免疫增强活性 ;细枝软骨藻、粗枝软骨藻和绳藻的甲醇提取物有显著的抗炎活性 ;松节藻、肠浒苔和扁江蓠的脂溶性提取物能有效地抑制α 葡萄糖苷酶的活性 ;

福建30种海藻抗细菌活性的筛选

1991年5月从福建东山岛采集30种潮间带海藻(绿藻门、红藻门和褐藻门),采用甲醇∶甲苯(3∶1)混合提取溶剂,进行抗枯草杆菌和大肠杆菌活性的筛选。抑菌试验采用纸片法。结果表明:30种筛选的海藻中,27种海藻提取物对1种或2种受试菌显示了不同程度的抑菌活性,3种(褐藻门)无抗菌活性。受试的2种细菌均可被提取物所抑制,它们之间没有明显的差别。

大型海藻多糖的制备及应用研究

海藻多糖是大型海藻重要的组成成分,其生物活性是近年来研究的热点和重点。本文综述了近年来海藻多糖的水提、醇提、酸碱提、酶提、超声波辅助提取和微波辅助提取等6种方法,比较了不同制备方法的适用性及优缺点,详述了海藻多糖的免疫调节、抗肿瘤、抗病毒、降血糖、降血脂和抗氧化等生物活性及作用机理,介绍了海藻多糖在生物医药、食品以及化妆品领域的应用情况,展望了海藻多糖未来的研究重点,以期为海藻高值化开发利用研究提供一定的参考。

海洋藻类提取物的护肝功效研究进展

海藻是海洋植物中数量和种类最多的一类,经现代海洋生物技术从海藻中提取的主要活性物质有多糖、蛋白质及其水解物、多酚、光合色素等,具有多种生物活性,如抗氧化、抗炎、抗肿瘤、抗肥胖、抗糖尿病、降血脂、护肝护肾等作用。肝是体内重要的代谢器官,过度饮酒、肥胖、炎症、药物等多种原因均导致肝病的发生率不断升高,从而影响肝脏的代谢机能。本文综述近年来海洋藻类提取物的护肝功效研究进展,并对海洋藻类护肝功能食品的研发进行了展望,旨在为开发海洋藻类护肝食品提供理论依据。