Brown Algae Extract Research Articles

Antibacterial effects of brown algae extract against tilapia spoilage bacteria Pseudomonas fluorescens and Shewanella putrefaciens

Inhibitory effects were evaluated for the extract from edible brown algae Ascophyllum nodosum vs. Pseudomonas fluorescens and Shewanella putrefaciens, which are tilapia spoilage organisms. Modified Gompertz and Logistic models were used to describe the inhibition effect of the extract, and both models indicated that the extract could inhibit bacteria growth by extending lag time and reducing maximum growth rate. The Lambert-Pearson model was applied to calculate the minimum inhibitory concentration (MIC) and non-inhibitory concentration (NIC) of the extract. The best-fit MIC and NIC values for P. fluorescens were 1.145 and 0.036 mg/mL, and 0.947 and 0.106 mg/mL for S. putrefaciens, respectively. Bacteriostatic assays on agar plates showed that the extract applied at concentrations higher than the MIC caused significant bacteriostatic effects, especially in S. putrefaciens. Algae extract (42 μg/disc) had inhibition zones against both P. fluorescens (1.72 cm) and S. putrefaciens (1.58 cm) in a disc diffusion assay. Treating tilapia fillets with the extract significantly reduced the total viable counts of both bacterial strains and postponed spoilage odor occurrence time (day 2 for the control group vs. day 9 for the extract treated group) during storage at 4 °C. These findings suggest that the extract could be used as a natural anti-bacterial and preservation agent to extend the shelf life of cold storage tilapia.

Antibacterial, Antifungal and Algicidal Activity of Phlorotannins, as Principal Biologically Active Components of Ten Species of Brown Algae.

Marine seaweeds synthesize a plethora of bioactive metabolites, of which phlorotannins of brown algae currently attract special attention due to their high antibiotic and cytotoxic capacities. Here we measured the minimum inhibitory concentrations (MICs) of several semi-purified phlorotannin preparations of different origins and molecular composition using a set of model unicellular organisms, such as Escherichia coli, Saccharomyces cerevisiae, Chlamydomonas reinhardtii, etc. For the first time, MIC values were evaluated for phlorotannin-enriched extracts of brown algae of the orders Ectocarpales and Desmarestiales. Phlorotannin extracts of Desmarestia aculeata, Fucus vesiculosus, and Ectocarpus siliculosus showed the lowest MIC values against most of the treated organisms (4-25 μg/mL for bacteria and yeast). Analysis of the survival curves of E. coli showed that massive loss of cells started after 3-4 h of exposure. Microalgae were less susceptible to activity of phlorotannin extracts, with the highest MIC values (≥200 µg/mL) measured for Chlorella vulgaris cells. D. aculeata, E. siliculosus, and three fucalean algae accumulate considerable amounts (4-16% of dry weight) of phlorotannins with MIC values similar to those widely used antibiotics. As these species grow abundantly in polar and temperate seas and have considerable biomass, they may be regarded as promising sources of phlorotannins.

Effect of Brown Algae and Lichen Extracts on the SCOBY Microbiome and Kombucha Properties

Kombucha tea was made by the fermentation of SCOBY culture of green tea broth with the addition of Fucus vesiculosus algae extract, Cetraria islandica lichen extract and their mixture. Kombucha was also made without the herbal supplements as a control. After 11 days of fermentation, in addition to the yeast Brettanomyces bruxellensis and the bacteria Komagataeibacter rhaeticus and Komagataeibacter hansenii contained in all of the samples, the yeast Zygosaccharomyces bailii and bacteria Komagataeibacter cocois were detected in the samples with the herbal extracts. In all of the kombucha with herbal additives, the total fraction of yeast was decreased as compared to the control. The total content of polyphenols and the antioxidant activity of the beverages with and without the addition of herbal extracts were comparable. The kombucha made with the algae extract showed an increased content of sucrose and organic acids, while the fructose and glucose content in the samples with algae and the mixture of extracts were lower than in the other samples. The samples with the algae extract had the highest organoleptic indicators "aroma", "clarity" and "acidity", while the control samples had slightly higher indicators of "taste" and "aftertaste". The results of this study indicate the potential of algae and lichens as functional supplements for obtaining non-alcoholic fermented beverages with additional nutraceutical value.

In-Vitro Efficacy Investigation and an Open-Label, Single-Arm Clinical Study of a Gentle Micropeeling Cream for Sensitive and Non-Sensitive Skin

Skin exfoliators, specifically alpha and beta hydroxy acids, have been shown to improve overall skin health and the clinical signs of aging. A micropeeling cream was developed with hydroxy acids and a brown algae extract and the efficacy and tolerability were evaluated in two parts. In the first part of the pre-clinical investigation, the micropeeling cream and the placebo control were evaluated by ELISA, immunostaining, qPCR and an activity assay using ex vivo and in vitro models. In the second part of the clinical efficacy study, 36 female subjects were enrolled for bioinstrumental measurements, visual imaging and clinical evaluation for 28 days. Fifty percent of subjects had sensitive skin. The ex-vivo study showed an increase in loricrin, superoxide dismutase 2, and extracellular matrix expression, without stimulating inflammatory biomarkers. The dermatologist observed a significant enhancement in all the parameters evaluated at day 28, and radiance, homogeneity, and roughness were significantly better after the first cream application. The homogeneity, desquamation and pore diameter showed significant improvement at day 7. The cream improved markers associated with skin aging and protection ex vivo. It was well tolerated, even on sensitive skin, and provided a significant improvement of fine lines, skin texture, and overall skin characteristics.

The Biostimulant Effect of Hydroalcoholic Extracts of Sargassum spp. in Tomato Seedlings under Salt Stress.

Currently, the use of biostimulants in agriculture is a tool for mitigating certain environmental stresses. Brown algae extracts have become one of the most important categories of biostimulants in agriculture, and are derived from the different uses and positive results obtained under optimal and stressful conditions. This study aimed to examine the efficacy of a foliar application of a hydroalcoholic extract of Sargassum spp. and two controls (a commercial product based on Ascophyllum nodosum and distilled water) with regard to growth, the antioxidant system, and the expression of defense genes in tomato seedlings grown in nonsaline (0 mM NaCl) and saline (100 mM NaCl) conditions. In general, the results show that the Sargassum extract increased the growth of the seedlings at the end of the experiment (7.80%) compared to the control; however, under saline conditions, it did not modify the growth. The Sargassum extract increased the diameter of the stem at the end of the experiment in unstressed conditions by 14.85% compared to its control and in stressful conditions by 16.04% compared to its control. Regarding the accumulation of total fresh biomass under unstressed conditions, the Sargassum extract increased it by 19.25% compared to its control, and the accumulation of total dry biomass increased it by 18.11% compared to its control. Under saline conditions, the total of fresh and dry biomass did not change. Enzymatic and nonenzymatic antioxidants increased with NaCl stress and the application of algal products (Sargassum and A. nodosum), which was positively related to the expression of the defense genes evaluated. Our results indicate that the use of the hydroalcoholic extract of Sargassum spp. modulated different physiological, metabolic, and molecular processes in tomato seedlings, with possible synergistic effects that increased tolerance to salinity.

Seaweed Cosmetics under the Spotlight of Sustainability

Seaweeds represent a diverse and valuable source of cosmetic compounds such as vitamins, minerals, trace elements, amino acids, antioxidants, etc., with moisturizing, anti-inflammatory, and regenerative effects. The so-called “blue cosmetics” represent a line of products related to the use of natural active ingredients and an important market share in major international cosmetic brands. To be recognised as environmentally sustainable, it is essential to ensure that algae-derived products comply with environmentally sound harvesting, production, and extraction practices. In this work, Life Cycle Assessment (LCA) methodology was used to carry out an environmental impact assessment of the processing of the brown algae extract from Fucus vesiculosus and its comparative profile with the most used antioxidants in cosmetics: vitamin C and green tea extracts. Considering an equivalent formulation in antioxidant content, the results showed that seaweed has the lowest environmental load while green tea extracts have the highest environmental impact. Furthermore, to further reduce emissions from seaweed processing, the use of renewable energy sources and the valorisation of biomass residues as fertilisers in a circular economy approach are proposed.

A HPLC‐DAD method for identifying and estimating the content of fucoxanthin, β‐carotene and chlorophyll a in brown algal extracts

Seaweeds are photosynthetic organisms that have high contents of pigments. The coloration of each alga is defined by the content and combination of pigments synthesized, which varies among species and environmental conditions. The most abundant pigments in algae are chlorophylls and carotenoids, lipophilic molecules that can be used as natural colorants and have high acceptance by consumers. In this work, a simple and short hands-on time HPLC-DAD method for identifying and estimating the pigment content of algal extracts, specifically fucoxanthin, β-carotene and chlorophyll a was carried out. Using this optimized method, a pigment screening was performed on the ethanolic extracts obtained by ultrasound-assisted extraction from nine brown algal from the Atlantic coastline: Ascophyllum nodosum, Bifurcaria bifurcata, Fucus spiralis, Himanthalia elongata, Laminaria saccharina, Laminaria ochroleuca, Pelvetia canaliculata, Sargassum muticum and Undaria pinnatifida. HPLC results permitted to highlight L. saccharina and U. pinnatifida as promising sources of these three target pigments containing a total amount of 10.5 – 11.5 mg per gram of dry weight. Among them, the most abundant one was fucoxanthin, an added-value compound with a high potential to be commercially exploited by different industries, such as the food, cosmetic, and pharmaceutical sectors.

New Monocyclic Terpenoid Lactones from a Brown Algae Sargassum macrocarpum as Monoamine Oxidase Inhibitors.

Algae are unique natural products that can produce various types of biologically active compounds. The 70% ethanol extract of brown algae Sargassum macrocarpum collected from the East Sea of Korea inhibited human monoamine oxidases A and B enzymes (hMAO-A and hMAO-B) at a 50 μg/mL concentration. The bioassay-guided isolation was performed through solid-phase extraction and the Sepbox system followed by serial high-performance liquid chromatography on the reverse phase condition, resulting in the identification of two new monocyclic terpenoid lactones, sargassumins A and B (1 and 2). The planar structures of the compounds were determined by a combination of spectroscopic data. The absolute configurations were determined by the interpretation of circular dichroism data. Compound 1 exhibited mild hMAO-A inhibition (42.18 ± 2.68% at 200 μM) and docked computationally into the active site of hMAO-A (−8.48 kcal/mol). Although compound 2 could not be tested due to insufficient quantity, it docked better into hMAO-A (−9.72 kcal/mol). Therefore, the above results suggest that this type of monocyclic terpenoid lactone could be one of the potential lead compounds for the treatment of psychiatric or neurological diseases.

Antibacterial activity of four marine seaweeds collected from the coast of Gaza Strip, Palestine

Four commonly occurring marine seaweeds; Ulva lactuca, Enteromorpha compressa (Chlorophyta), Padina pavonica (Phaeophyta) and Jania rubens (Rhodophyta) were collected from the coast of Gaza strip, Palestine. Crude extracts were prepared using the solvent methanol and evaluated for antibacterial activity by well diffusion method against both Gram negative (Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris and Klebsiella pneumoniae) and Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis). The crude methanolic extract of U. lactuca inhibited the growth of all the test organisms except E. coli. Seaweed extract of E. compressa was found to be effective against two of the examined bacteria. Algae belonging to Chlorophyta showed higher antibacterial activity than other members of the algae tested in the present investigation. The methanol extracts of brown and red algae did not show any significant effect on the growth of tested bacteria. E. coli was resistant to all the extracts. Results of the present study confirmed the potential use of seaweed extracts as a source of antibacterial compounds.

Separation of Mineral from Brown Algae Extract using Micro Filtration (MF) and Ultra Filtration (UF) Membrans – Review

Brown algae ( Phaeophyta ) contain active compounds such as carbohydrates, proteins, phenolics, fats, pigments, vitamins and minerals. The mineral content of brown algae is around 8% to 40% consisting of cations Na + , K + , Mg ++ , Fe ++ , Zn ++ , Mn ++ and heavy metals. Bioactive brown algae has many benefits, including Fucoidan as a cancer drug. The barrier of using Fucoidan as a medicine is its high mineral content. Therefore, the minerals must be separated. The extraction process of brown algae using various methods has been carried out with the aim of isolating the active component of Fucoidan that is free from minerals that will be an obstacle in utilizing the active component. This paper will describe some of the latest methods of extracting the active ingredients of brown algae and mineral separation processes using Micro Filtration (MF) and Ultra Filtration (UF) membrane. MF and UF membrane can separate small molecules such as cations (minerals) that can pass through the membrane so that macromolecules such as carbohydrates, fats, proteins, pigments, phenolics and vitamins can be separated from minerals and active ingredients in the absence of minerals can be obtained. The purpose of this paper is to provide research directions in the exploration of the active ingredients of brown algae for pharmaceutical and cosmetic applications without side effects caused by high metal or mineral content above the threshold value in brown algae extracts.

Alginate Oligosaccharide Alleviated Cisplatin-Induced Kidney Oxidative Stress via Lactobacillus Genus-FAHFAs-Nrf2 Axis in Mice.

Alginate oligosaccharide is the depolymerized product of alginate, a natural extract of brown algae, which is associated with beneficial health effects. Here, we aimed to investigate the mechanism via which alginate oligosaccharides improve kidney oxidative damage and liver inflammation induced by cisplatin chemotherapy via the gut microbiota. C57BL/6J mice were treated with cisplatin were administered alginate oligosaccharide via gavage for 3 weeks. Compared to that observed in the cisplatin chemotherapy group without intragastric administration of alginate oligosaccharide, liver inflammation improved in the alginate oligosaccharide group, indicated by reduction in lipopolysaccharide and interleukin-1β (IL-1β) levels. This was accompanied by improvement in the oxidative stress of mice kidneys, indicated by the increase in the levels of superoxide dismutase (SOD), catalase (CAT) and nuclear NF-E2-related factor 2 (Nrf2) in renal tissue, and reduction in the levels of malondialdehyde (MDA) in renal tissue and serum creatinine (Cr) to the levels of the normal control group. Alginate oligosaccharide intervention increased the concentration of fatty acid esters of hydroxy fatty acids (FAHFAs). Alginate oligosaccharide regulated the composition of the intestinal microbial community and promoted Lactobacillus stains, such as Lactobacillus johnsonii and Lactobacillus reuteri. Spearman analysis showed that 5 members of FAHFAs concentrations were positively correlated with Lactobacillus johnsonii and Lactobacillus reuteri abundance. We observed that alginate oligosaccharide increased FAHFAs producing-related bacterial abundance and FAHFAs levels, enhanced the levels of SOD and CAT in kidney tissue, and reduced the levels of MDA via activating Nrf2, thereby ameliorating the renal redox injury caused by cisplatin chemotherapy.

Antimicrobial Potential of Zinc Oxide Nanoparticles from Marine Macroalgae

Abstract: The current study evaluates the free antimicrobial and radical scavenging properties of zinc oxide nanoparticles(ZnONP’s) synthesized from an aqueous extract of Sargassum polycystum brown algae. The free radical scavenging potential of ZnO nanoparticles was evaluated through DPPH, Nitric oxide, Hydroxyl radical and Hydrogen peroxide scavenging assays. In addition to that, the antibacterial and antifungal activity of synthesized ZnO nanoparticles was examined against different species. The free radical scavenging and antimicrobial potential of these Sargassum polycystum ZnO nanoparticles were associated with their phenolic compounds. ZnO- NP’s DPPH radical reducing potential was found to be 12.45 ± 0.19μg/mL, Nitric oxide at 0.68±0.04 μg/ml, Hydrogen peroxide to be 0.39±0.01 μg/ml and Hydroxyl radical scavenging potential with 0.63±0.04 μg/ml. Furthermore, ZnO- NP’s antimicrobial efficacy showed significant results against Staphylococcus aureus, Escherichia coli, Salmonella typhi, Klebsiella pneumonia and fungal strains of A. niger Candida albicans. Further research is on purifying the selected phenolic compounds and developing their acuteness for specificity for ultimate pharmaceutical use. Keywords: Marine algae, ZnO nanoparticles, antioxidant and antimicrobial activity, Gulf of Mannar.

Brown and Red Marine Macroalgae as Novel Bioresources of Promising Medicinal Properties

ABSTRACT Bioactive compounds from marine macroalgae are gaining immense attention for their application as natural ingredients in various nutraceuticals and food supplements. The present study evaluated the medicinal properties of the organic extracts of four each of brown and red marine macroalgal species, using various in vitro assays. Organic extracts of brown algae of Fucophycidan subclass, such as Sargassum plagiophyllum, Turbinaria decurrens, and red alga Hydropuntia edulis, displayed potential inhibitory properties against antioxidants (IC50 0.2–0.8 mg/mL) and carbolytic enzymes (IC50 0.2–0.9 mg/mL) compared to those exhibited by other studied algae. Noticeably, organic extracts of red alga H. edulis and brown alga T. decurrens could effectively attenuate pro-inflammatory 5-lipoxygenase (IC50 0.4–0.6 mg/mL), thereby demonstrating their potential application to dissuade inflammatory pathogenesis. This study demonstrated the predominantly available brown and red macroalgae as potential marine bioresources to develop functional food candidates.

Chemical Composition, Phytochemical Constituent, and Toxicity of Methanol Extract of Brown Algae (Padina sp.) from Puntondo Coast, Takalar (Indonesia)

Background: Padina sp. is an algae that has potential as a functional food. This study aimed to explore the chemical and photochemical constituent in the methanolic exract of Padina sp. Methods: Brown algae of Padina sp. from Puntondo coast, Takalar, Indonesia was prepared. The algae characterization was carried out based on the standard procedure of Association of Official Agricultural Chemists (AOAC). Toxicity of Padina sp. was. determined with Brine Shrimp Lethality Test (BSLT). Results: Chemical contents were 13.46% water, 38.02% ash, 12.33% protein, 1.60% fat, 20.02% fiber, and 48.06% carbohydrate. The FTIR spectrum displayed the presence of hydroxyl, carboxylic acids, aldehydes, aliphatic hydrocarbons, fatty acids, and unsaturated hydrocarbons. Padina sp. extract consisted of phytol compound which had 70-96% similarity with steroids, fatty acids, carboxylic acids, terpenoid, and proteins. The result of toxicity was 6344.54 ppm indicating not toxic. Conclusion: Padina sp. can be used as a raw material source for functional food and pharmaceutical industry.

Instant drinks based on extracts of Japan sea brown algae and fruit and berry juices as functional products

Nowadays, there is a need to create functional drinks that not only normalize the water-electrolyte balance, but also correct and optimize the chemical structure of the diet. The basis for the production of dry drinks can be fruit and berry juices, extracts of herbal raw materials, including algae, etc. The aim of the study was to develop dry drinks based on dry extracts of brown algae (Costaria costata and Undaria pinnatifida) and concentrated fruit and berry juices and to evaluate the content of biologically active substances in them, as well as the antioxidant properties of the resulting drinks. Material and methods. Brown algae of the Far Eastern region Costaria costata and Undaria pinnatifida were used as objects, from which dry hydrothermal extracts were obtained, as well as dry drinks based on these extracts (21-26%) and concentrated fruit and berry juices of black currant and blueberry (31-37%). The content of iodine was determined by titrimetric method, fucoidan, the sum of phenolic compounds, flavonoids, catechins - by spectrophotometric method, vitamin C - titrimetrically, anthocyanins - by pH-differential spectrophotometry. Identification of phenolic compounds was carried out by HPLC. The antiradical properties of beverages were evaluated by the ability to interact with the stable 2.2-diphenyl-1-picrylhydrazyl free radical in vitro spectrophotometrically. Results. Dry hydrothermal extracts of C. costata and U. pinnatifida brown algae are characterized by a high content of bioactive substances, the main of which are fucoidan and iodine. The fucoidan content in C. costata extract was 1.7 g/100 g, in U. pinnatifida extract - 0.5 g/100 g; the iodine content was 0.0036 and 0.0028 g/100 g, respectively. The content of phenolic compounds was at least 205 mg of tannic acid per 1 g, the main compounds were syringic acid and epicatechin, salicylic and coumaric acids, as well as chlorogenic, caffeic, 2.5-dihydroxybenzoic, ferulic acid and gallates of epigallocatechin and epicatechin. The developed drinks based on dry extracts of C. costata and U. pinnatifida brown algae (21-26%) and concentrated blueberry and blackcurrant juices (31-37%) (the rest is powdered sugar) are a food system enriched with bioactive substances. The content per 1 serving of drinks (10 g per 200 ml) of iodine was high and amounted to 70-75 mcg, phenolic compounds - about 250 mg, vitamin C level was maximum in a drink with black currant (41-44 mg), fucoidan content ranged from 79 to 84 mg. The resulting dry drinks satisfy the daily physiological requirement in iodine by at least 40%, in vitamin C - by at least 30% when consuming 1 serving. The radical binding activity of all the studied beverages was quite high and amounted to 91.1-96.5%. The drink with blueberry juice and C. costata extract showed maximum antiradical properties. Conclusion. The developed dry soft drinks based on dry extracts of C. costata and U. pinnatifida brown algae and concentrated juices of black currant or blueberry contain a wide range of bioactive compounds. They can be attributed to functional products due to the high degree of satisfaction of the daily physiological requirement of the human body in vitamin C and iodine and are characterized by high antiradical properties.

Bioconjugation of Fluorescent Gold Nanoparticles Synthesized Using Marine Brown Algae Sargassum longifolium

In the present study, fluorescent gold nanoparticles (Flu Au‐NPs) were synthesized via simple and ecofriendly green route using extract of brown algae Sargassum longifolium (S. longifolium). Characterization of synthesized Au‐NPs was undertaken. The characteristic absorption peak of Au‐NPs was in range 530 nm in UV‐vis spectrum. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) allow the visualization of the morphological and structural character of Au‐NPs. The mean particle size was calculated to be 17‐50 nm. Energy dispersive X‐ray spectroscopy analysis (EDAX) confirmed the presence of pure gold in the synthesized Au‐NPs. The X‐ray diffraction (XRD) pattern showed the face‐centered cubic (FCC) nature of Au‐NPs. Fourier transform infrared spectrometer (FT‐IR) showed the characteristic peaks of different biocomponents in the brown algae S. longifolium extract which acted as stabilizing or capping agents of Au‐NPs.

Опыт применения ирригационной терапии при острой респираторной вирусной инфекции у детей

Objective of the Paper: To draw the attention of pediatricians, otorhinolaryngologists, general practitioners to the possibilities of irrigation therapy in the treatment of acute respiratory viral infections in children. Key points. Irrigation therapy is widely used for the prevention and treatment of acute infections of the upper respiratory tract in children, and is an effective and safe method. However, there are no indications in the clinical guidelines about the exact concentrations of saline solutions, the method of irrigation therapy, and its duration. For use in acute respiratory viral infections in children at different periods of the disease, it is preferable to use a slightly hypertonic solution of sea water in the form of a fine spray. In the acute period, irrigation therapy reduces the need for the use of decongestants and antibiotics. In the subacute and post-viral periods, it promotes the regeneration of the ciliary epithelium. Conclusion. The addition of Ascophyllum nodosum brown algae extract to solutions for irrigation therapy can increase the effectiveness of treatment, promote faster relief of inflammation in the nasal cavity, and restore the mucosa due to the anti-inflammatory, antimicrobial, and immunomodulatory properties of fucoidans. Keywords: acute respiratory viral infections, irrigation therapy, children, sea water, brown algae.

Evaluation of the anti-glycation effect and skin protection effect by a supplement containing brown algae extract powder. (A randomized,Double-blind,Placebo-controlled, Parallel group study)

Glycation stress is a concept of biological stress caused by excess sugars, aldehyde and its subsequent reactions in the body. Especially, it is thought that accumulation of Advanced Glycation End products (AGEs) cause skin yellowing, deep wrinkles and a decrease in skin elasticity due to crosslinking to collagen or elastin in the dermis.

PENGARUH STRES AKUT TERHADAP KADAR GULA DARAH MENCIT (Mus Musculus) DENGAN PERLAKUAN EKSTRAK ETANOL ALGA COKELAT (Sargassum sp.)

Stress is a non-specific response in the body to conditions or conditions that occur as a result of exposure to stressors. High stress usually has a negative impact on the body, one of which is increasing blood sugar levels. Brown algae is one of the traditional marine plants and contains secondary metabolite compounds such as alkaloids, flavonoids, and steroids which are antidepressants so that they can prevent the increase in blood sugar levels. This study aims to determine the effect of acute stress on blood sugar levels of mice by giving ethanol extract of brown algae. This research is a true experimental research design with pre test and post test control group design. 30 mice were divided into normal control (KN), negative control (K-), positive control (K +) groups, ethanol extract of brown algae with a concentration of 2.5% (P1) and 5% (P2). The study was started by measuring the initial blood sugar levels in all groups, then groups K-, K +, P1, and P2 were given stress treatment with the FST method for 6 minutes for 7 days. Group K + was given alprazolam at a dose of 0.2 ml at 1 hour before treatment, while P1 and P2 were given brown algae at 30 minutes before treatment. After the treatment, it was followed by measurement of the final blood sugar level. The data from the observations were analyzed using the dependent T-test with a confidence level of 95%. The results showed that the post-test blood sugar levels in the P1 and P2 groups experienced an increase, but the increase was not significant. The results also showed that the significance values (2-tailed) in the P1 and P2 groups were 0.772 and 0.392 (sig> 0.05), meaning that it could be concluded that there was no effect of giving ethanol extract of brown algae on the prevention of increasing blood sugar levels after acute stress.

Effects of Nitrogen, Azoxystrobin and a Biostimulant Based on Brown Algae and Yeast on Wild Rocket Features at Harvest and During Storage

Recently, the use of biostimulant substances of different origins has been affirmed. They act differently on the physiological processes of the plant, helping to improve its productive response and resistance to biotic and abiotic stress. Therefore, the response of the wild rocket to two substances known to have biostimulating activity (Azoxystrobin, and a fluid extract of brown algae and yeast), was evaluated. Two experimental trials (Exp 1 and Exp 2) were carried out in the greenhouse. The collected product, in addition to being evaluated from a qualitative point of view, was used for evaluation of shelf life. Exp 1 involved the comparison of two N levels with two Azoxystrobin levels (treated–Azo+, and untreated control). Exp 2 involved the comparison of two N levels, and two biostimulating substances based on Azoxystrobin (Azo+) and on fluid extracts of yeast and brown algae (YBA+), in addition to untreated control. A split-plot experimental design with three replications was used. Azo+ increased marketable yield of wild rocket by 16.8% and enhanced some qualitative features at harvest as the increase in chlorophyll (+17.8%) and carotenoids (+13.5%), and decrease in nitrates (−10.6%), regardless of the nitrogen level. Furthermore, Azo+ increased the shelf life (+2.5 days) of wild rocket stored at 3.5 °C. In particular, Azo+ slowed the loss of chlorophyll (yellowing) and the worsening of odor and visual appearance. As Azoxystrobin is a fungicide effective for the control of some diseases of wild rocket, its use should be promoted as it would offer not only the benefit of disease control but also improved production and shelf life. YBA+ caused an increase in the chlorophyll content (+12.5%) at harvest of wild rocket, but reduced its antioxidant activity (−40%). YBA+ did not cause substantial variations in shelf life with the exception of a slowdown in the degradation of carotenoids. Further research is desirable to evaluate other variables such as the dose and time of application.