Investigation of the effects of Chlorella vulgaris as an adjunctive therapy for dyslipidemia: Results of a randomised open-label clinical trial

New insights into Chlorella vulgaris applications

Environmental pollution is a big challenge that has been faced by humans in contemporary life. In this context, fossil fuel, cement production, and plastic waste pose a direct threat to the environment and biodiversity. One of the prominent solutions is the use of renewable sources, and different organisms to valorize wastes into green energy and bioplastics such as polylactic acid. Chlorella vulgaris, a microalgae, is a promising candidate to resolve these issues due to its ease of cultivation, fast growth, carbon dioxide uptake, and oxygen production during its growth on wastewater along with biofuels, and other productions. Thus, in this article, we focused on the potential of Chlorella vulgaris to be used in wastewater treatment, biohydrogen, biocement, biopolymer, food additives, and preservation, biodiesel which is seen to be the most promising for industrial scale, and related biorefineries with the most recent applications with a brief review of Chlorella and polylactic acid market size to realize the technical/nontechnical reasons behind the cost and obstacles that hinder the industrial production for the mentioned applications. We believe that our findings are important for those who are interested in scientific/financial research about microalgae.

Microalgae as an Alternative Mineral Source in Poultry Nutrition

This review explores the potential of microalgae as a sustainable and nutritionally rich alternative for mineral supplementation in poultry diets, addressing both the opportunities and challenges in this emerging field. Poultry nutrition, pivotal to the health and productivity of birds, traditionally relies on inorganic and organic mineral sources which, while effective, raise environmental and economic concerns. Microalgae offer a promising solution with their high contents of essential minerals, proteins, vitamins, and bioactive compounds. This review delves into the nutritional profiles of various microalgae, highlighting their rich contents of minerals which are crucial for physiological processes in poultry. It examines the bioavailability of these minerals and their impact on poultry health and productivity. Furthermore, it evaluates the environmental sustainability of microalgae cultivation and acknowledges the challenges in using microalgae in poultry diets, particularly in terms of the economic viability of large-scale production and the consistency of nutrient composition. It discusses the importance of rigorous safety assessments and regulatory compliance, given the potential risks of toxins and heavy metals. Overall, this analysis aims to provide a clear understanding of the role microalgae could play in poultry nutrition and address sustainability challenges in animal agriculture while also considering future perspectives and advancements needed in this field.

The effects of Chlorella vulgaris on cardiovascular risk factors: A comprehensive review on putative molecular mechanisms

High incidence rate of cardiovascular disease (CVD) make this condition as an important public health concern. The use of natural products in treating this chronic condition has increased in recent years one of which is the single-celled green alga Chlorella. Chlorella vulgaris (CV) has been studied for its potential benefits to human health due to its biological and pharmacological features. CV contains a variety of macro and micronutrients, including proteins, omega-3, polysaccharides, vitamins, and minerals. Some studies have indicated that taking CV as a dietary supplement can help reduce inflammation and oxidative stress. In some studies, cardiovascular risk factors that are based on hematological indices did not show these benefits, and no molecular mechanisms have been identified. This comprehensive review summarized the research on the cardio-protective benefits of chlorella supplementation and the underlying molecular processes.

White and honey Chlorella vulgaris: Sustainable ingredients with the potential to improve nutritional value of pork frankfurters without compromising quality

This study aimed to evaluate the effect of the chlorophyll-deficient microalgae mutants, honey (yellow) and white Chlorella vulgaris, (3%) on the nutritional, physicochemical, microbiological, and sensory characteristics of frankfurters. The presence of microalgae resulted in increased PUFA content and higher PUFA/SFA ratio, but lower n-6/n-3 ratio and lipid indices (P < 0.05). C. vulgaris inclusion in frankfurters increased (P < 0.05) Na, K, Ca, P, and Zn and improved the Na/K ratio, but lowered Mn, and in the case of white C. vulgaris, Cu content, compared to the control. The higher protein content decreased water release from emulsions elaborated with microalgae. White C. vulgaris inclusion decreased cohesiveness and springiness of the frankfurters. Due to the presence of pigment, microalgae inclusion led to a decrease in redness and an increase in yellowness of frankfurters. The presence of microalgae resulted in lower (P < 0.05) bacterial counts and did not affect TBARs during storage. The addition of microalgae in frankfurters produced acceptable sensory characteristics but resulted in lower scores compared to reference products.

Enhancing Digestibility of Chlorella vulgaris Biomass in Monogastric Diets: Strategies and Insights

Microalgae, such as Chlorella vulgaris (CV), have been identified as promising animal feed sources due to their high content of essential nutrients, including proteins, total lipids, n-3 polyunsaturated fatty acids, and pigments. This study aimed to review the digestibility, bioaccessibility, and bioavailability of nutrients from CV biomass, and to analyse strategies to enhance their digestibility in monogastric animal diets. The study conducted a systematic review of the literature from databases such as PubMed, Scopus, Google Scholar, and Web of Science, up until the end of January 2023. The results of adding CV to poultry and swine diets were diverse and depended on a number of variables. However, pre-treatments applied to CV biomass improved nutrient digestibility and accessibility. CV biomass, produced in a cost-effective manner, has the potential to serve as a supplement or substitute for expensive feed ingredients and improve animal health, physiology, and immune status. Variations in results may be due to differences in microalgal strain, cultivation conditions, and dietary inclusion levels, among other factors. This study provides new insights and perspectives into the utilization of CV biomass in animal diets, highlighting its potential as a valuable ingredient to improve nutrient utilization.

Iron Bioaccessibility and Speciation in Microalgae Used as a Dog Nutrition Supplement

Chlorella vulgaris, Arthrospira platensis, Haematoccocus pluvialis, and Phaeodactylum tricornutum are species of interest for commercial purposes due to their valuable nutritional profile. The aim of this study was to investigate the iron content in these four microalgae, with emphasis on their iron bioaccessibility assessed using an in vitro digestion system to simulate the process which takes place in the stomach and small intestine of dogs, followed by iron quantification using atomic absorption spectrometry. Furthermore, the extraction of soluble proteins was carried out and size exclusion chromatography was applied to investigate iron speciation. Significant differences (p < 0.004) in iron content were found between C. vulgaris, which had the highest (1347 ± 93 μg g^-1), and H. pluvialis, which had the lowest (216 ± 59 μg g^-1) iron content. C. vulgaris, A. platensis, and H. pluvialis showed an iron bioaccessibility of 30, 31, and 30%, respectively, while P. tricornutum showed the lowest bioaccessibility (11%). The four species analysed presented soluble iron mainly bound to proteins with high molecular mass ranging from >75 to 40 kDa. C. vulgaris showed the highest iron content associated with good bioaccessibility; therefore, it could be considered to be an interesting natural source of organic iron in dog nutrition.

The effect of Chlorella vulgaris on obesity related metabolic disorders: a systematic review of randomized controlled trials

OBJECTIVES

Chlorella vulgaris (CV) as a unicellular algae is a dietary supplement with beneficial nutritious content, used for decades in some countries. Positive effects for CV supplementation on metabolic parameters has been established in animal and human studies. However there is a gap for this results summary for a definite conclusion announce. This systematic review aimed to summarize the effects of CV on body weight, lipid profile, and blood glucose.

CONTENT

PRISMA guidelines were charted in this review. Subject search was performed in MEDLINE, ProQuest, PubMed, ISI web of sciences, Google scholar, Cochrane and Scopus databases for randomized clinical trials published in English languages, until December 2020, which assessed the effects of CV on metabolic syndrome related symptoms in clinical trials.

SUMMARY

Out of 4,821 records screened, after duplicate and irrelevant exclusion by title and abstract, 20 articles remained for full text screening. Finally a total of 12 articles met the study inclusion criteria and were assessed for study method and results.

OUTLOOK

The findings showed controversies in anthropometric, glycemic and lipid profile effects. CV may have beneficial effects on obesity-related metabolic disorders; however, collected studies lacked statistical power to reach a definite conclusion. More well-designed studies are required.

High-intensity interval training with or without chlorella vulgaris supplementation in obese and overweight women: effects on mitochondrial biogenesis, performance and body composition

The beneficial effects of high-intensity interval training (HIIT) and chlorella vulgaris (CV) on body composition and mitochondrial biogenesis have been shown in some mechanistic studies. This study aimed to determine the effects of CV and/or HIIT on mitochondrial biogenesis, performance and body composition among overweight/obese women. There was a significant reduction in the fat mass (FM) of the CV + HIIT group, as compared with the placebo group (P = 0·005). A marginal significant increase in body water (P = 0·050) and PPAR-γ coactivator-1α (P = 0·050) was also found only in the CV + HIIT group, as compared with the placebo. Relative (P < 0·001) and absolute (P < 0·001) VO_2max, as well as Bruce MET (P < 0·001), were significantly increased in the HIIT and HIIT + CV groups. Besides, the synergistic effect of CV and HIIT on the Bruce MET increment was found (interaction P-value = 0·029). No significant changes were observed in BMI, fat-free mass, visceral fat, silent information regulator 1 and fibroblast growth factor-21. In this randomised clinical trial, forty-six overweight/obese women were assigned to four groups including CV + HIIT and HIIT + placebo groups that received three capsules of CV (300 mg capsules, three times a day) or corn starch, in combination with three sessions/week of HIIT. CV and placebo groups only received 900 mg of CV or corn starch, daily, for 8 weeks. Biochemical assessments, performance assessment and body composition were obtained at the beginning and end of the intervention. HIIT may be, therefore, effective in improving mitochondrial biogenesis, performance and body composition in overweight/obese women.

Digestibility of Meat Mineral and Proteins from Broilers Fed with Graded Levels of Chlorella vulgaris

The incorporation of sustainable protein sources in animal feeding is a growing trend. So far, no study has investigated in vitro digestion of meat, from broilers fed microalgae, in a human model. This research aimed to evaluate the effect of incorporating Chlorella vulgaris in the broilers diet on human protein digestibility, and mineral bioaccessibility. The study used 240 male Ross 308 broilers randomly allocated to groups fed a control diet or a diet where soybean meal was replaced with 10% (CV10%), 15% (CV15%), or 20% (CV15%) of C. vulgaris for 40 days. The microalga supplementation increased the protein and lowered the fat content in the muscle. Results on the percentages of amino acids highlighted that arginine and threonine proportions increased and lysine and cysteine proportions decreased with microalga inclusion. CV15% and CV20% meat had higher amount of K, Ca, Mg, P, and Fe in raw breasts, improving the nutrient composition of the meat. Cooking caused a decrease in Na and K and an increase in other minerals. CV20% had higher bioaccessibility of K, Ca, Mg, P, and Mg, compared to the control. Replacing soybean meal in broiler feed with higher concentrations of C. vugaris could improve the digestibility of meat protein and minerals.

Effect of supplementation with Chlorella vulgaris on lipid profile in adults: A systematic review and dose-response meta-analysis of randomized controlled trials

OBJECTIVE

To summarize available findings on the effect of Chlorella vulgaris supplementation on lipid profile in adults.

DESIGN

Systematic review and meta-analysis of randomized controlled trials (RCTs).

SETTING

This study followed 2020 PRISMA guideline. We performed a systematic search in the online databases to identify relevant articles and then, extracted required data from each paper for the meta-analysis. Random-effects models were used to obtain overall mean difference (MD) comparing Chlorella vulgaris supplementation with a control group.

MAIN OUTCOME MEASURES

Blood lipids including triglyceride (TG), total cholesterol (TC), LDL-C, and HDL-C.

RESULTS

In total, 10 RCTs with a total sample size of 539 adults (264 in the Chlorella vulgaris group and 275 in the control group) were included. Of the 10 RCTs, four had a low risk of bias for all aspects of the Cochrane risk of bias tool. Also, only two studies determined the chlorella content, purity, potency, and contamination of the supplements used in the intervention. Combining results from these studies showed a summary MD of -2.11 mg/dL (95% CI: -7.28 to 3.06) for TG, -7.47 mg/dL (95% CI: -12.98 to -1.96) for TC, -7.71 mg/dL (95% CI: -14.05 to -1.37) for LDL-C, and -0.45 mg/dL (95% CI: -0.67 to 1.57) for HDL-C, indicating a beneficial effect of Chlorella vulgaris supplementation on TC and LDL-C levels. Based on the dose-response analysis, the reducing effect of Chlorella vulgaris supplementation on LDL-C levels was seen at the dosages between zero and 1500 mg/d (P for non-linearity= 0.01), whereas in higher amounts, this effect was not significant.

CONCLUSION

We found that Chlorella vulgaris supplementation had a beneficial effect on TC and LDL-C levels with no significant effect on TG and HDL-C levels.

The effects of Chlorella supplementation on glycemic control, lipid profile and anthropometric measures on patients with type 2 diabetes mellitus

BACKGROUND

Diabetes is a chronic disease and the prevalence of it is rapidly increasing. Recently, the use of natural products in chronic diseases such as diabetes has gained more attention. Chlorella, a single-celled green alga, is one of them. There have been some studies on the effects of chlorella supplementation in chronic diseases such as NAFLD, prediabetes, and diabetic mice, but none of them examined the effects of chlorella in patients with T2DM. The present study was designed to evaluate the effects of chlorella supplementation on glycemic control, lipid profile, and anthropometric indices in type 2 diabetic patients.

METHODS

This study is a double-blind, randomized controlled trial. 84 patients with T2DM assigned into two groups, receiving 1500 mg/day C. vulgaris or placebo for 8 weeks. Anthropometric information, blood pressure, 24-h food intake recall, and blood samples were collected at the beginning and end of the study to determine the changes of FBS, HbA1c, insulin concentration, insulin resistance, and lipid profile.

RESULTS

None of the variables investigated in this study showed a significant change after 8 weeks of intervention with C. vulgaris.

CONCLUSION

According to the findings of this study, supplementation with C. vulgaris with a dosage of 1500 mg/day for 8 weeks, does not improve the anthropometric measurements, glycemic status, and lipid profile as well. Thus, it cannot be considered as a complementary therapeutic approach to common medications at this dosage and duration. However, future studies with a higher dosage of C. vulgaris and more prolonged than 8 weeks are needed to be done.

Chlorella vulgaris is an effective supplement in counteracting non-alcoholic fatty liver disease-related complications through modulation of dyslipidemia, insulin resistance, and inflammatory pathways

This study was aimed to investigate the effect of microalgae Chlorella vulgaris (C. vulgaris) on nonalcoholic fatty liver disease (NAFLD)-related complications induced by high-fat diet (HFD). Fifty adult male rats were divided into six groups. Control group and HFD group treated with or without C. vulgaris 5% and 10%. Biochemical parameters in serum were measured by spectrophotometric and enzyme-linked immunosorbent assay (ELISA) methods. The relative gene expression levels of Tumor Necrosis Factor-alpha (TNF-α), NF-kappa B (NF-ƙB), and p38 Mitogen-Activated Protein Kinases (p38 MAPK) in the liver were assessed by using quantitative real-time PCR, while the protein levels of NF-ƙB and TNF-α in the liver homogenate were determined by ELISA. The effects of HFD significantly were reversed by C. vulgaris, especially at a 10% dose. Therefore, it can be concluded that C. vulgaris therapeutically could be useful to improve NAFLD and its complications. PRACTICAL APPLICATIONS: It is established that NAFLD is associated with the resistance to insulin, dyslipidemia, and inflammation. Accordingly, modulating of these conditions may be useful in the management of NAFLD. Our results showed the effectiveness of C. vulgaris against NAFLD-related complication through the alleviating insulin resistance, dyslipidemia and also down-regulation of inflammatory genes in p38 MAPK/TNF-α/NF-ƙB pathway. The results of our study may be useful for scientist to prepare an effective supplement from C. vulgaris to overcoming NAFLD-related complications.

Chlorella vulgaris microalgae in Ruminant Nutrition: a Review of the Chemical Composition and Nutritive Value

Recently, microalgae, natural marine resources, have gained increasing interests as a feed for animals. Chlorella vulgaris microalgae are single-cell microorganisms that have been used to provide nutrition to humans and animals for centuries. In the present review, we unveil the composition and nutritive value of C. vulgaris microalgae as a feed for ruminants. Research has shown that inclusion of C. vulgaris microalgae in diets improved feed utilization, milk production and quality, growth performance, and meat quality in ruminants, as a result of improved diet nutritive value. Very low doses of C. vulgaris in feed enhance growth and lactational performance of ruminants. Additionally, C. vulgaris showed very promising results as an alternative to corn and soybean meal; however, it is an expensive protein feed. Therefore, the main constraint to use of C. vulgaris as a feedstuff is its high cost of production, making improvement of cultivation technology to reduce the production costs a critical issue in the near future.

Role of Microalgae as a Source for Biofuel Production in the Future: A Short Review

The continued burning of fossil fuels since the beginning of the last century led to higher emissions of greenhouse gases and thus leads to global warming. Microalgae are one of the most important sources of green hydrocarbons because this type of algae has a high percentage of lipids and has rapid growth, consumes the carbon dioxide in large quantities. Besides, the cultivation of these types of algae does not require arable land. This review aims to explain the suitability of microalgae as a biofuel source depending on the fat content, morphology, and other parameters and their effect on the conversion processes of microalgae oil into biofuels by different zeolite catalytic reactions. It also discusses in detail the major chemical processes that convert microalgae oil to chemical products. This review sheds light on one of the most important groups of microalgae (Chlorella vulgaris microalgae). This review includes a historical overview and a comprehensive description of the structure needed to develop this type of algae. The most important methods of production, their advantages and disadvantages are also deliberated in this work. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

Edible Microalgae and Their Bioactive Compounds in the Prevention and Treatment of Metabolic Alterations

Marine and freshwater algae and their products are in growing demand worldwide because of their nutritional and functional properties. Microalgae (unicellular algae) will constitute one of the major foods of the future for nutritional and environmental reasons. They are sources of high-quality protein and bioactive molecules with potential application in the modern epidemics of obesity and diabetes. They may also contribute decisively to sustainability through carbon dioxide fixation and minimization of agricultural land use. This paper reviews current knowledge of the effects of consuming edible microalgae on the metabolic alterations known as metabolic syndrome (MS). These microalgae include Chlorella, Spirulina (Arthrospira) and Tetraselmis as well as Isochrysis and Nannochloropsis as candidates for human consumption. Chlorella biomass has shown antioxidant, antidiabetic, immunomodulatory, antihypertensive, and antihyperlipidemic effects in humans and other mammals. The components of microalgae reviewed suggest that they may be effective against MS at two levels: in the early stages, to work against the development of insulin resistance (IR), and later, when pancreatic -cell function is already compromised. The active components at both stages are antioxidant scavengers and anti-inflammatory lipid mediators such as carotenoids and -3 PUFAs (eicosapentaenoic acid/docosahexaenoic acid; EPA/DHA), prebiotic polysaccharides, phenolics, antihypertensive peptides, several pigments such as phycobilins and phycocyanin, and some vitamins, such as folate. As a source of high-quality protein, including an array of bioactive molecules with potential activity against the modern epidemics of obesity and diabetes, microalgae are proposed as excellent foods for the future. Moreover, their incorporation into the human diet would decisively contribute to a more sustainable world because of their roles in carbon dioxide fixation and reducing the use of land for agricultural purposes.

Chlorella vulgaris ameliorates sodium nitrite-induced hepatotoxicity in rats

The current was conducted to evaluate the ameliorating effect of Chlorella vulgaris (CV) extract against sodium nitrite-induced hepatotoxicity in rats. Forty-five rats were allocated randomly into 5 groups (n = 9). Group I (GI), control group: orally gavaged with normal saline daily. Group II (GII): orally gavaged with CV extract (70 mg/kg BW) for 3 months. Group III (GIII): orally gavaged with sodium nitrite (80 mg/kg BW) for 3 months. Group IV (GIV): received sodium nitrite as GIII and CV extract as GII simultaneously for 3 months. Group V (GV): received CV extract as GII and then, sodium nitrite as in GIII from the end of first month until the end of the experiment. Sodium nitrite significantly increased the activities of serum alanine aminotransferase, aspartate aminotransferase, and serum concentrations of tumor interleukin 1-β and necrosis factor α. In addition, it increased concentrations of malondialdehyde and nitric oxide and expression level of caspase-3 in the hepatic tissue. However, it decreased activities of hepatic glutathione peroxidase, catalase, and superoxide dismutase and induced degenerative and necrotic changes in hepatic tissues. In contrast, CV extract administration modulated sodium nitrite-induced inflammation, oxidative stress, and alteration in hepatic tissue function and architecture. This study indicated that CV extract modulated sodium nitrite-induced hepatic toxicity through decreasing oxidative stress and inflammation and enhancing antioxidant enzyme activities in hepatic tissue of rats.

Effect of Chlorella vulgaris on Liver Function Biomarkers: a Systematic Review and Meta-Analysis

This study presents a comprehensive systematic review and meta-analysis of randomized controlled trials (RCTs) on Chlorella vulgaris (C. vulgaris) supplementation and liver function biomarkers. Pertinent studies were identified using Scopus, ISI Web of Science, PubMed, and Cochrane library databases up to August 2020. Mean differences were pooled using a random-effects model. Pooling 7 RCTs together showed that C. vulgaris supplementation led to a significant reduction of serum aspartate aminotransferase (AST) levels (weighted mean difference [WMD], −9.15 U/L; 95% confidence interval [CI], −16.09, −2.21), but not alanine aminotransferase (ALT) or alkaline phosphatase (ALP) levels compared to the placebo consumption. Subgroup-analysis indicated that C. vulgaris supplementation had more effect on AST decreasing among non-alcoholic fatty liver disease patients (WMD, −16.42 U/L; 95% CI, −29.75, −3.09) than others. Furthermore, subgroup analysis based on kind of compression showed that C. vulgaris supplementation significantly decreased ALT levels (WMD, −4.65 U/L; 95% CI, −8.88, −0.42) compared with the placebo, but not metformin consumption. It seems that C. vulgaris supplementation mainly affects AST levels rather than ALT and ALP levels, however, as mentioned the effect of C. vulgaris on those enzymes might be context-dependent. Therefore, further investigations with a large number of patients as well as on different disorders are necessary and can provide more definitive evidence.

Supplementing wastewater with NPK fertilizer as a cheap source of nutrients in cultivating live food (Chlorella vulgaris)

Introduction

The decline in fishery resources from the wild has led to an ever increasing focus on aquaculture in recent years. With increasing aquaculture of animal species, there is an increasing need for suitable microalgae in the production of these animals. However, cultivation of microalgae in expensive pure chemical media is one of the major challenges facing large-scale cultivation of microalgae.

Purpose

The present study investigated the suitability of aquaculture wastewater (AWW) supplemented with NPK (nitrogen:phosphorus:potassium) fertilizer as a cheap source of nutrient to cultivate a microalga Chlorella vulgaris (C. vulgaris).

Methods

C. vulgaris with an initial cell density of 0.8 × 106 cells/mL was batch cultured in AWW supplemented with NPK at 0.1, 0.5, 1.0 g/L and BBM for 20 days under laboratory conditions using 2000 mL Erlenmeyer flasks. The proximate composition, chlorophyll, minerals, and vitamins analysis of C. vulgaris biomass were done using standard analytical methods.

Results

The highest values in optical density (4.872 ± 0.025), dry cell weight (2.858 ± 0.015 g/L), specific growth rate (0.2097 ± 0.0038 day–1), and biomass productivity (0.1701 ± 0.0007 g/L/day) were obtained in C. vulgaris grown in AWW + 1.0 NPK medium. The total chlorophyll, protein, lipid, and carbohydrate content of the microalgae biomass were in the range of 0.05–0.862%, 44.062–57.089%, 17.064–23.260%, and 15.217–21.896%, respectively. Furthermore, microalgae grown in AWW + 1.0 NPK showed good vitamin and mineral content compared to BBM grown alga.

Conclusion

These findings indicated that the AWW + 0.1 NPK, AWW + 0.5 NPK, and AWW + 1.0 NPK are potential growth media for C. vulgaris cultivation and can replace the BBM medium, which is very expensive and less accessible to users.

Chlorella vulgaris Ameliorates Oxidative Stress and Improves the Muscle Regenerative Capacity of Young and Old Sprague-Dawley Rats

Muscle atrophy in ageing is a multifactorial degenerative process impacted by cellular ageing biology, which includes oxidative stress. Chlorella vulgaris is a coccoid green eukaryotic microalga rich in antioxidants. The aim of this study was to determine the effect of C. vulgaris in ameliorating oxidative stress, thus elucidating its mechanism in improving muscle mass, strength and function in young and old rats. Fifty-six male Sprague-Dawley (SD) rats aged 3 months (young) and 21 months (old) were divided into three groups: Group 1 (control) was given distilled water; Group 2 was treated with 150 mg/kg body weight (BW) of C. vulgaris; and Group 3 was treated with 300 mg/kg BW of C. vulgaris for three months. Grip and muscle strength and muscle integrity were determined on days 0, 30, 60, and 90 of treatment. Urine and blood were collected on days 0 and 90 of treatment for oxidative stress marker determination, while the gastrocnemius muscles were collected for muscle oxidative stress analysis. Increased grip strength of the front and hind paws was observed in young C. vulgaris-treated rats on days 30, 60, and 90 compared to the untreated control on the same days (p < 0.05). There was a significant increase in lean bone mineral content (BMC) in young rats treated with 300 mg/kg BW C. vulgaris compared to untreated rats on days 30 and 60. The fat mass was significantly decreased in young and old C. vulgaris-treated rats on day 90 compared to the untreated control. The total path was significantly increased for old rats treated with 300 mg/kg BW C. vulgaris on days 60 and 90 compared to day 0. Young and old C. vulgaris-treated rats demonstrated a significant decrease in urinary isoprostane F_2t and plasma creatine kinase-MM (CKMM) compared to the control on day 90. A significant decrease in malondialdehyde (MDA) and 4-hydroxyalkenal (HAE) levels were observed in young and old rats treated with C. vulgaris. C. vulgaris improved the muscle mass, strength, and function in young and old rats. This effect could be due to its potency in ameliorating oxidative stress in the skeletal muscle of young and old rats.

Quantifying the Effect of Supplementation with Algae and Its Extracts on Glycolipid Metabolism: A Meta-Analysis of Randomized Controlled Trials

AIMS

The effect of algae and its extract supplementation on glycolipid metabolism has not been finalized. Therefore, the purpose of the meta-analyses was to assess the effects of its supplementation on glycolipid metabolism concentration.

METHODS

We have systematically searched PubMed, Web of Science, the Cochrane Library and Embase to identify randomized controlled trials (RCTs) that investigated the impact of algae and its extracts supplementation on glycolipid metabolism. Effect size analysis was performed using weighted mean difference (WMD) and 95% CI between the methods of the experiment group and the control group. Subgroup analyses were performed to explore the possible influences of study characteristics. Publication bias and sensitivity analysis were also performed.

RESULTS

A total of 27 RCTs (31 trials) with 1221 participants were finally selected for the meta-analysis. The algae and its extract intervention significantly decreased glycosylated hemoglobin (HbA1c, WMD = -0.18%; 95% CI: -0.27 to -0.10; p < 0.001), high-density lipoprotein cholesterol (HDL-C, WMD = -0.22 mmol/L; 95% CI: -0.38 to -0.06; p = 0.008), and triglycerides (TC, WMD = -0.31 mmol/L; 95% CI: -0.37 to -0.25; p < 0.001) levels and increased insulin (WMD = 6.05 pmol/mL; 95% CI: 4.01 to 8.09; p < 0.001) levels. It did not significantly change the blood glucose, homeostasis model assessment-insulin resistance index (HOMA-IR), 2-h post-meal blood glucose (2hPBG) and other lipid profiles. Subgroup analyses based on the duration of intervention and subjects demonstrated that the intervention of algae and its extracts for 10 weeks or fewer and more than 40 subjects decreased TC levels (p < 0.05). Moreover, the intervention reduced TC and 2hPBG concentrations for East Asians (p < 0.05).

CONCLUSIONS

Our findings provided evidence that algae and its extract interventions were beneficial for the regulation of human glycolipid metabolism. More precise RCTs on subjects are recommended to further clarify the effect of algae, seaweed polysaccharide, seaweed polypeptide, algae polyphenol and its products intervention on glycolipid metabolism.

Chlorella vulgaris Modulates Genes and Muscle-Specific microRNAs Expression to Promote Myoblast Differentiation in Culture

Background

Loss of skeletal muscle mass, strength, and function due to gradual decline in the regeneration of skeletal muscle fibers was observed with advancing age. This condition is known as sarcopenia. Myogenic regulatory factors (MRFs) are essential in muscle regeneration as its activation leads to the differentiation of myoblasts to myofibers. Chlorella vulgaris is a coccoid green eukaryotic microalga that contains highly nutritious substances and has been reported for its pharmaceutical effects. The aim of this study was to determine the effect of C. vulgaris on the regulation of MRFs and myomiRs expression in young and senescent myoblasts during differentiation in vitro.

Methods

Human skeletal muscle myoblast (HSMM) cells were cultured and serial passaging was carried out to obtain young and senescent cells. The cells were then treated with C. vulgaris followed by differentiation induction. The expression of Pax7, MyoD1, Myf5, MEF2C, IGF1R, MYOG, TNNT1, PTEN, and MYH2 genes and miR-133b, miR-206, and miR-486 was determined in untreated and C. vulgaris-treated myoblasts on Days 0, 1, 3, 5, and 7 of differentiation.

Results

The expression of Pax7, MyoD1, Myf5, MEF2C, IGF1R, MYOG, TNNT1, and PTEN in control senescent myoblasts was significantly decreased on Day 0 of differentiation (p<0.05). Treatment with C. vulgaris upregulated Pax7, Myf5, MEF2C, IGF1R, MYOG, and PTEN in senescent myoblasts (p<0.05) and upregulated Pax7 and MYOG in young myoblasts (p<0.05). The expression of MyoD1 and Myf5 in young myoblasts however was significantly decreased on Day 0 of differentiation (p<0.05). During differentiation, the expression of these genes was increased with C. vulgaris treatment. Further analysis on myomiRs expression showed that miR-133b, miR-206, and miR-486 were significantly downregulated in senescent myoblasts on Day 0 of differentiation which was upregulated by C. vulgaris treatment (p<0.05). During differentiation, the expression of miR-133b and miR-206 was significantly increased with C. vulgaris treatment in both young and senescent myoblasts (p<0.05). However, no significant change was observed on the expression of miR-486 with C. vulgaris treatment.

Conclusions

C. vulgaris demonstrated the modulatory effects on the expression of MRFs and myomiRs during proliferation and differentiation of myoblasts in culture. These findings may indicate the beneficial effect of C. vulgaris in muscle regeneration during ageing thus may prevent sarcopenia in the elderly.

Chlorella vulgaris Improves the Regenerative Capacity of Young and Senescent Myoblasts and Promotes Muscle Regeneration

Sarcopenia is characterized by the loss of muscle mass, strength, and function with ageing. With increasing life expectancy, greater attention has been given to counteracting the effects of sarcopenia on the growing elderly population. Chlorella vulgaris, a microscopic, unicellular, green alga with the potential for various pharmaceutical uses, has been widely studied in this context. This study is aimed at determining the effects of C. vulgaris on promoting muscle regeneration by evaluating myoblast regenerative capacity in vitro. Human skeletal myoblast cells were cultured and underwent serial passaging into young and senescent phases and were then treated with C. vulgaris, followed by the induction of differentiation. The ability of C. vulgaris to promote myoblast differentiation was analysed through cellular morphology, real-time monitoring, cell proliferation, senescence-associated β-galactosidase (SA-β-gal) expression, myogenic differentiation, myogenin expression, and cell cycle profiling. The results obtained showed that senescent myoblasts exhibited an enlarged and flattened morphology, with increased SA-β-gal expression, reduced myogenic differentiation, decreased expression of myogenin, and an increased percentage of cells in the G ₀/G ₁ phase. Treatment with C. vulgaris resulted in decreased SA-β-gal expression and promotion of myogenic differentiation, as observed via an increased fusion index, maturation index, myotube size, and surface area and an increased percentage of cells that stained positive for myogenin. In conclusion, C. vulgaris improves the regenerative capacity of young and senescent myoblasts and promotes myoblast differentiation, indicating its potential to promote muscle regeneration.

Characteristics of the home food environment that mediate immediate and sustained increases in child fruit and vegetable consumption: mediation analysis from the Healthy Habits cluster randomised controlled trial

Background

The home food environment can influence the development of dietary behaviours in children, and interventions that modify characteristics of the home food environment have been shown to increase children’s fruit and vegetable consumption. However to date, interventions to increase children’s fruit and vegetable consumption have generally produced only modest effects. Mediation analysis can help in the design of more efficient and effective interventions by identifying the mechanisms through which interventions have an effect. This study aimed to identify characteristics of the home food environment that mediated immediate and sustained increases in children’s fruit and vegetable consumption following the 4-week Healthy Habits telephone-based parent intervention.

Method

Analysis was conducted using 2-month (immediate) and 12-month (sustained) follow-up data from a cluster randomised control trial of a home food environment intervention to increase the fruit and vegetable consumption of preschool children. Using recursive path analysis, a series of mediation models were created to investigate the direct and indirect effects of immediate and sustained changes to characteristics of the home food environment (fruit and vegetable availability, accessibility, parent intake, parent providing behaviour, role-modelling, mealtime eating practices, child feeding strategies, and pressure to eat), on the change in children’s fruit and vegetable consumption.

Results

Of the 394 participants in the randomised trial, 357 and 329 completed the 2- and 12-month follow-up respectively. The final mediation model suggests that the effect of the intervention on the children’s fruit and vegetable consumption was mediated by parent fruit and vegetable intake and parent provision of these foods at both 2- and 12-month follow-up.

Conclusion

Analysis of data from the Healthy Habits trial suggests that two environmental variables (parental intake and parent providing) mediate the immediate and sustained effect of the intervention, and it is recommended these variables be targeted in subsequent home food environment interventions to bring about immediate and sustained changes in child fruit and vegetable intake.

Trial registration

ACTRN12609000820202.