Paramylon from Euglena gracilis Prevents Lipopolysaccharide-Induced Acute Liver Injury

Microalgae in health care and functional foods: β-glucan applications, innovations in drug delivery and synthetic biology

Microalgae are emerging as a key player in healthcare, functional foods, and sustainable biotech due to their capacity to produce bioactive compounds like β-glucans, omega-3 fatty acids, and antioxidants in an eco-friendly manner. This review comprehensively discusses the role of microalgae in healthcare and functional foods, focusing particularly on β-glucan therapeutics, drug delivery innovations, and synthetic biology applications. In healthcare, microalgae-derived compounds show immense promise for treating diseases, boosting immunity, and tackling oxidative stress. Euglena-derived paramylon, a type of β-glucan, has shown potential in various medical applications, including immunomodulation and anticancer therapy. Synthetic biology and bioprocess engineering are enhancing microalgae's therapeutic and nutritional value, with applications in drug delivery and personalized medicine. To maximize the potential of microalgae, further research and development are needed to address scalability, regulatory alignment, and consumer acceptance, with a focus on interdisciplinary collaboration and sustainable practices to align healthcare innovation with environmental conservation.

Euglena gracilis-derived β-glucan ameliorates particulate matter (PM2.5)-induced airway inflammation by modulating nuclear factor kappa B, mitogen-activated protein kinase, and nuclear factor erythroid 2-related factor 2 signaling pathways in A549 cells and BALB/c mice

This study aimed to investigate the effects of β-glucan derived from Euglena gracilis (EGB), an edible microalga, on particulate matter (PM2.5)-induced airway inflammation in A549 cells and BALB/c mice. EGB effectively suppressed the mRNA and protein levels of inflammatory cytokines (IL-6, IL-1β, TNF-α, IL-8) and mediators (iNOS, COX-2), while inhibiting the NF-κB and MAPK signaling pathways triggered by PM2.5 exposure and reducing nuclear NF-κB levels. Additionally, EGB decreased PM2.5-induced ROS production and increased the protein levels of NRF2 and HO-1, along with genes encoding antioxidant enzymes (catalase, GPx, SOD1), associated with elevated nuclear NRF2 levels. EGB reduced immune cell infiltration and inflammatory cytokine levels in BALF and serum, both of which increased by PM2.5 exposure. EGB also significantly increased alveolar numbers while decreasing the gene expression of MMP1/9/13. Furthermore, EGB suppressed PM2.5-induced bronchial thickening and collagen-1 deposition by downregulating TGF-β1 expression, and alleviated goblet cell hyperplasia and mucin production in lung tissues. These results suggest that EGB effectively reduces PM2.5-induced airway inflammation by suppressing NF-κB and MAPK signaling pathways, lowering pro-inflammatory cytokines, and activating the NRF2-HO-1 signaling pathway to enhance antioxidant enzyme expression. This study highlights the potential of EGB as an edible functional agent for controlling PM-related airway inflammation.

Untapping the potential of algae for β-glucan production: A review of biological properties, strategies for enhanced production and future perspectives

β-Glucan, a naturally occurring polymer of glucose, is found in bacteria, algae, fungi, and higher plants (barley, oats, cereal seeds). Recently, β-glucan has gained attention due to its multiple biological roles, like anticancer, anti-inflammatory, and immunomodulatory effects. Globally, bacteria, mushrooms, yeast and cereals are used as conventional sources of β-glucan. However, obtaining it from these sources is challenging due to low quantity, complex branched structure, and costly extraction process. Algae have emerged as a potential sustainable alternative source of β-glucan to conventional sources due to several advantages including unique structural and functional advantages, higher yields, faster growth rates, and large-scale production in a controlled environment. Additionally, extracting β-glucan from microalgal sources is relatively easy and can be done without altering the structure of β-glucan. Some algal species, such as Euglena spp., are reported to contain higher β-glucan content than conventional β-glucan sources. This review highlights the current research and opportunities associated with algae-derived β-glucan and their biological roles. The challenges, research gaps and strategies to enhance algae-based β-glucan production and the need for further research in this promising area are also discussed. Future research can be extended to comprehend the cellular and molecular mechanisms via which β-glucan functions.

β-1,3-glucan from Euglena gracilis: a promising epidrug targeting epigenetic regulators PRMTs and SIRTs for therapeutic applications in ovarian cancer

Natural products serve as a valuable resource in drug discovery and the identification of bioactive molecules in the field of epimedicine, which targets epigenetic regulator enzymes through epidrugs. In this study, β-1,3-glucan (BG), a natural storage polysaccharide in Euglena gracilis, a well-known immunostimulatory agent, is propounded as a promising epidrug. To elucidate the therapeutic efficacy of BG against ovarian cancer, the molecular interactions between BG and epigenetic regulators, Protein Arginine Methyltransferases (PRMTs) and Sirtuins (SIRTs) were investigated using computational methods followed by in vitro gene expression studies in SKOV-3 ovarian cancer cell line. The binding energies of PRMT5 and SIRT5 against BG were observed as -65.5 and -68.2 kcal/mol, respectively. The in vitro cytotoxic effects of BG against human ovarian cancer cell line, SKOV-3 showed an IC50 of 150 µg/mL at 48 h. Significant epigenetic modifications were observed to be influenced by BG which increased the gene expression of PRMT5, SIRT5 and Nrf2 to 0.3, 0.5, and 0.7 fold-change respectively, while the Nrf1/2 plasmid showed reduced reporter activity by 29%. Collectively, both in silico and in vitro studies provided valuable insights into the epigenetic regulation of PRMT5 and SIRT5 by BG via Nrf1/2. Nonetheless, further preclinical and clinical investigations are essential to validate the therapeutic properties of BG as an epidrug against ovarian cancer.

Hydroxytyrosol attenuates ethanol-induced liver injury by ameliorating steatosis, oxidative stress and hepatic inflammation by interfering STAT3/iNOS pathway

Objective: Hydroxytyrosol (HT) is a polyphenol with a wide range of biological activities. Excessive drinking can lead to oxidative stress and inflammation in the liver, which usually develop into alcohol liver disease (ALD). At present, there is no specific drug to treat ALD. In this paper, the protection effect of HT on ALD and the underline mechanism were studied.Methods: HepG2 cells were exposed to ethanol in vitro and C57BL/6J mice were fed with a Lieber-DeCarli ethanol liquid diet in vivo.Results: triglyceride (TG) level in serum and the expression of fatty acid synthase (FASN) were reduced significantly by the treatment with HT The acetaldehyde dehydrogenase (ALDH) activity was increased, the serum level of malondialdehyde (MDA) was decreased, catalase (CAT) and glutathione (GSH) were increased, suggesting that HT may reduce its oxidative damage to the body by promoting alcohol metabolism. Furthermore, according to the mRNA levels of tnf-α, il-6 and il-1β, HT inhibited ethanol-induced inflammation significantly. The anti-inflammatory mechanism of HT may be related to suppress the STAT3/iNOS pathway.Dissussion: Our study showed that HT could ameliorate ethanol-induced hepatic steatosis, oxidative stress and inflammation and provide a new candidate for the prevention and treatment of ALD.

Potential of algae-derived alginate oligosaccharides and β-glucan to counter inflammation in adult zebrafish intestine

Alginate oligosaccharides (AOS) are natural bioactive compounds with anti-inflammatory properties. We performed a feeding trial employing a zebrafish (Danio rerio) model of soybean-induced intestinal inflammation. Five groups of fish were fed different diets: a control (CT) diet, a soybean meal (SBM) diet, a soybean meal+β-glucan (BG) diet and 2 soybean meal+AOS diets (alginate products differing in the content of low molecular weight fractions - AL, with 31% < 3kDa and AH, with 3% < 3kDa). We analyzed the intestinal transcriptomic and plasma metabolomic profiles of the study groups. In addition, we assessed the expression of inflammatory marker genes and histological alterations in the intestine. Dietary algal β-(1, 3)-glucan and AOS were able to bring the expression of certain inflammatory genes altered by dietary SBM to a level similar to that in the control group. Intestinal transcriptomic analysis indicated that dietary SBM changed the expression of genes linked to inflammation, endoplasmic reticulum, reproduction and cell motility. The AL diet suppressed the expression of genes related to complement activation, inflammatory and humoral response, which can likely have an inflammation alleviation effect. On the other hand, the AH diet reduced the expression of genes, causing an enrichment of negative regulation of immune system process. The BG diet suppressed several immune genes linked to the endopeptidase activity and proteolysis. The plasma metabolomic profile further revealed that dietary SBM can alter inflammation-linked metabolites such as itaconic acid, taurochenodeoxycholic acid and enriched the arginine biosynthesis pathway. The diet AL helped in elevating one of the short chain fatty acids, namely 2-hydroxybutyric acid while the BG diet increased the abundance of a vitamin, pantothenic acid. Histological evaluation revealed the advantage of the AL diet: it increased the goblet cell number and length of villi of the intestinal mucosa. Overall, our results indicate that dietary AOS with an appropriate amount of < 3kDa can stall the inflammatory responses in zebrafish.

Euglena gracilis Promotes Lactobacillus Growth and Antioxidants Accumulation as a Potential Next-Generation Prebiotic

Euglena gracilis, a single-celled microalga with various trophic growth styles under different cultivation conditions, contains nutrients, such as ß-1,3-glucans, essential amino acids, fatty acids, vitamins, and minerals. It has recently attracted attention as a new health food. Among them, ß-1,3-glucans, paramylon of Euglena, is an insoluble dietary fiber and is well known as an immune booster, attenuator of obesity and diabetes, reducer of acute liver injury, and suppressor of atopic dermatitis, and other chronic inflammatory disorders. Recently, evidence has appeared for the positive health effects of foods, food ingredients, or biochemical compounds derived from several other microalgae, such as Chlorella, Spirulina, Dunaliella, Phaeodactylum, and Pavlova. Until most recently, the prebiotic activity of Euglena and paramylon was reported. Emerging prospects of microalgae as prebiotics were well summarized, but the mechanisms behind the bacterial growth promotion by microalgae are not elucidated yet. Thus, we evaluated the prebiotic prospects of both autotrophic and heterotrophic Euglena on six different Lactobacillus. What’s more, the stimulated mechanism was revealed by bacterial culture medium metabolomic analysis. This study could widen the knowledge about the prebiotic activity of Euglena as a next-generation prebiotic and other microalgae-derived compounds as potential health foods.