Characterization of nutritionally important lipophilic constituents from brown kelp Ecklonia radiata (C. Ag.) J. Agardh

Biosynthesis of silver nanoparticles from macroalgae Hormophysa triquetra and investigation of its antibacterial activity and mechanism against pathogenic bacteria

In this study, brown macroalgae Hormophysta triquetra (HT) collected from the Qatari coast is used to biosynthesize silver nanoparticles (AgNPs) from its aqueous (AQ), chloroform: methanol (MCF), and ethanolic extracts (ET). The NPs are characterized using Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Gas chromatography/Mass spectrometry (GC/MS) and X-ray photoelectron spectroscopy (XPS). The NPs were evaluated for their antibacterial activities by disc-diffusion method and their minimum inhibitory concentrations (MIC) were assessed. The NPs synthesized through biological process exhibited significant antibacterial efficacy against Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Pseudomonas stutzeri, and Pseudomonas fragi for all the three NPs. AQ-AgNP and ET-AgNP showed higher zones of inhibition for P. fragi with inhibitory zones of 22.5 mm and 25 mm respectively. On the other hand, MCF-AgNP showed a higher zone of inhibition for E. coli with an inhibition zone of 23.5 mm. The NPs inhibited the growth of bacterial strains by deforming their structure and forming pits. The results revealed that macroalgae HT could be used as a potential candidate to produce AgNPs and have efficient antibacterial activities against both types of bacteria i.e., Gram-positive (B. subtilis and S. aureus) and Gram-negative (E. coli, P. stutzeri, and P. fragi).

Effects of Dietary Components on Mast Cells: Possible Use as Nutraceuticals for Allergies?

Allergic diseases affect an estimated 30 percent of the world's population. Mast cells (MC) are the key effector cells of allergic reactions by releasing pro-inflammatory mediators such as histamine, lipid mediators, and cytokines/chemokines. Components of the daily diet, including certain fatty acids, amino acids, and vitamins, as well as secondary plant components, may have effects on MC and thus may be of interest as nutraceuticals for the prevention and treatment of allergies. This review summarizes the anti-inflammatory effects of dietary components on MC, including the signaling pathways involved, in in vitro and in vivo models. Butyrate, calcitriol, kaempferol, quercetin, luteolin, resveratrol, curcumin, and cinnamon extract were the most effective in suppressing the release of preformed and de novo synthesized mediators from MC or in animal models. In randomized controlled trials (RCT), vitamin D, quercetin, O-methylated epigallocatechin gallate (EGCG), resveratrol, curcumin, and cinnamon extract improved symptoms of allergic rhinitis (AR) and reduced the number of inflammatory cells in patients. However, strategies to overcome the poor bioavailability of these nutrients are an important part of current research.

Bioactivities of the Popular Edible Brown Seaweed Sargassum fusiforme: A Review

Sargassum fusiforme has a wide range of active constituents (such as polysaccharides, sterols, polyphenols, terpenes, amino acids, trace elements, etc.) and is an economically important brown algae with a long history. In recent years, S. fusiforme has been intensively studied and has attracted wide attention in the fields of agriculture, environment, medicine, and functional food. In this review, we reviewed the current research status of S. fusiforme at home and abroad over the past decade by searching Web of science, Google Scholar, and other databases, and structurally analyzed the active components of S. fusiforme, and on this basis, we focused on summarizing the cutting-edge research and scientific issues on the role of various active substances in S. fusiforme in exerting antioxidant, anti-inflammatory, antitumor, antidiabetic, immunomodulatory, antiviral antibacterial, and anticoagulant effects. The mechanisms by which different substances exert active effects were further summarized by exploring different experimental models and are shown visually. It provides a reference to promote further development and comprehensive utilization of S. fusiforme resources.

Extraction and Quantitation of Phytosterols from Edible Brown Seaweeds: Optimization, Validation, and Application

Brown seaweeds are known as important marine food sources, from which phytosterols have been recognized as functional food components with multiple health-beneficial effects. However, studies on phytosterol extraction and quantitation from edible brown seaweeds are limited. In the present work, extraction methods for seaweed phytosterols were compared and optimized by one-factor-at-one-time method and response surface methodology. Moreover, the quantitation method of total sterols and major sterol components, including fucosterol, saringosterol, and ostreasterol, was established and validated using 1H NMR. Furthermore, the developed extraction and determination methods were applied to investigate three common edible seaweeds from Japan (Hijiki, Wakame, and Kombu). As a result, the finally optimized conditions were ultrasound-assisted extraction with CHCl3-MeOH 2:3 for 15 min followed by saponification with 1.65 mL of 1.85 M KOH for 14.5 h. Based on the developed methods, phytosterols in three seaweeds were compared, and Hijiki showed an abundant total sterol amount (2.601 ± 0.171 mg/g DW), significantly higher than Wakame (1.845 ± 0.137 mg/g DW) and Kombu (1.171 ± 0.243 mg/g DW). Notably, the composition of the sterol components varied in different seaweeds. These findings might help the nutritional investigation and functional food development concerning phytosterols from seaweeds.

Carotenoids: Dietary Sources, Extraction, Encapsulation, Bioavailability, and Health Benefits-A Review of Recent Advancements

Natural carotenoids (CARs), viz. β-carotene, lutein, astaxanthin, bixin, norbixin, capsanthin, lycopene, canthaxanthin, β-Apo-8-carotenal, zeaxanthin, and β-apo-8-carotenal-ester, are being studied as potential candidates in fields such as food, feed, nutraceuticals, and cosmeceuticals. CAR research is advancing in the following three major fields: (1) CAR production from natural sources and optimization of its downstream processing; (2) encapsulation for enhanced physical and chemical properties; and (3) preclinical, clinical, and epidemiological studies of CARs' health benefits. This review critically discusses the recent developments in studies of the chemistry and antioxidant activity, marketing trends, dietary sources, extraction, bioaccessibility and bioavailability, encapsulation methods, dietary intake, and health benefits of CARs. Preclinical, clinical, and epidemiological studies on cancer, obesity, type 2 diabetes (T2D), cardiovascular diseases (CVD), osteoporosis, neurodegenerative disease, mental health, eye, and skin health are also discussed.

Advances in Lipid Extraction Methods-A Review

Extraction of lipids from biological tissues is a crucial step in lipid analysis. The selection of appropriate solvent is the most critical factor in the efficient extraction of lipids. A mixture of polar (to disrupt the protein-lipid complexes) and nonpolar (to dissolve the neutral lipids) solvents are precisely selected to extract lipids efficiently. In addition, the disintegration of complex and rigid cell-wall of plants, fungi, and microalgal cells by various mechanical, chemical, and enzymatic treatments facilitate the solvent penetration and extraction of lipids. This review discusses the chloroform/methanol-based classical lipid extraction methods and modern modifications of these methods in terms of using healthy and environmentally safe solvents and rapid single-step extraction. At the same time, some adaptations were made to recover the specific lipids. In addition, the high throughput lipid extraction methodologies used for liquid chromatography-mass spectrometry (LC-MS)-based plant and animal lipidomics were discussed. The advantages and disadvantages of various pretreatments and extraction methods were also illustrated. Moreover, the emerging green solvents-based lipid extraction method, including supercritical CO2 extraction (SCE), is also discussed.

Phytosterols in Seaweeds: An Overview on Biosynthesis to Biomedical Applications

Seaweed extracts are considered effective therapeutic alternatives to synthetic anticancer, antioxidant, and antimicrobial agents, owing to their availability, low cost, greater efficacy, eco-friendliness, and non-toxic nature. Since the bioactive constituents of seaweed, in particular, phytosterols, possess plenty of medicinal benefits over other conventional pharmaceutical agents, they have been extensively evaluated for many years. Fortunately, recent advances in phytosterol-based research have begun to unravel the evidence concerning these important processes and to endow the field with the understanding and identification of the potential contributions of seaweed-steroidal molecules that can be used as chemotherapeutic drugs. Despite the myriad of research interests in phytosterols, there is an immense need to fill the void with an up-to-date literature survey elucidating their biosynthesis, pharmacological effects, and other biomedical applications. Hence, in the present review, we summarize studies dealing with several types of seaweed to provide a comprehensive overview of the structural determination of several phytosterol molecules, their properties, biosynthetic pathways, and mechanisms of action, along with their health benefits, which could significantly contribute to the development of novel drugs and functional foods.

Fucosterol of Marine Macroalgae: Bioactivity, Safety and Toxicity on Organism

Fucosterol (24-ethylidene cholesterol) is a bioactive compound belonging to the sterol group that can be isolated from marine algae. Fucosterol of marine algae exhibits various biological activities including anti-osteoarthritic, anticancer, anti-inflammatory, anti-photoaging, immunomodulatory, hepatoprotective, anti-neurological, antioxidant, algicidal, anti-obesity, and antimicrobial. Numerous studies on fucosterol, mainly focusing on the quantification and characterization of the chemical structure, bioactivities, and health benefits of fucosterol, have been published. However, there is no comprehensive review on safety and toxicity levels of fucosterol of marine algae. This review aims to discuss the bioactivities, safety, and toxicity of fucosterol comprehensively, which is important for the application and development of fucosterol as a bioactive compound in nutraceutical and pharmaceutical industries. We used four online databases to search for literature on fucosterol published between 2002 and 2020. We identified, screened, selected, and analyzed the literature using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method and identified 43 studies for review. Despite the potential applications of fucosterol, we identified the need to fill certain related research gaps. Fucosterol exhibited low toxicity in animal cell lines, human cell lines, and animals. However, studies on the safety and toxicity of fucosterol at the clinical stage, which are required before fucosterol is developed for the industry, are lacking.

Combination of a multiplatform metabolite profiling approach and chemometrics as a powerful strategy to identify bioactive metabolites in Lepidium meyenii (Peruvian maca)

Lepidium meyenii is an edible plant that has been used as a nutritional supplement worldwide due to its medicinal properties. However, most of the studies have focused on the pharmacological activities of the extracts rather than their chemical composition. Herein, we used a combination of a multiplatform metabolite profiling approach and chemometrics to identify bioactive metabolites in L. meyenii. Extracts obtained with ethyl acetate and ethanol showed the promising antioxidant, anti-glioma and antibacterial activities. Sixty metabolites were identified by HPLC-MS, whereas fifteen were identified by GC-MS. Partial least squares discriminant analysis (PLS-DA), hierarchical cluster analysis (HCA), and Variable Importance in Projection (VIP) successfully discriminated extracts obtained in different organic solvents from in natura dry roots and commercial product samples of L. meyenii. Additionally, correlation analysis allowed us to pinpoint potential candidates responsible for each biological activity tested for the extracts, which could be extrapolate for other food-related species.

Spices in the Apiaceae Family Represent the Healthiest Fatty Acid Profile: A Systematic Comparison of 34 Widely Used Spices and Herbs

Spices and herbs are well-known for being rich in healthy bioactive metabolites. In recent years, interest in the fatty acid composition of different foods has greatly increased. Thus, the present study was designed to characterize the fatty acid composition of 34 widely used spices and herbs. Utilizing gas chromatography (GC) flame ionization detection (FID) and GC mass spectrometry (MS), we identified and quantified 18 fatty acids. This showed a significant variation among the studied spices and herbs. In general, oleic and linoleic acid dominate in seed spices, whereas palmitic, stearic, oleic, linoleic, and α-linolenic acids are the major constituents of herbs. Among the studied spices and herbs, the ratio of n-6/n-3 polyunsaturated fatty acids (PUFAs) was recorded to be in the range of 0.36 (oregano) to 85.99 (cumin), whereas the ratio of PUFAs/saturated fatty acids (SFAs) ranged from 0.17 (nutmeg) to 4.90 (cumin). Cumin, coriander, fennel, and dill seeds represent the healthiest fatty acid profile, based upon fat quality indices such as the ratio of hypocholesterolemic/hypercholesterolemic (h/H) fatty acids, the atherogenic index (AI), and the thrombogenic index (TI). All these seed spices belong to the Apiaceae family of plants, which are an exceptionally rich source of monounsaturated fatty acids (MUFAs) in the form of petroselinic acid (C18:1n12), with a very small amount of SFAs.