Extraction of Bioactive Compounds from Wine Lees: A Systematic and Bibliometric Review

The extraction of bioactive compounds from wine lees involves a variety of methods, the selection of which is crucial to ensure optimal yields. This systematic review, following PRISMA guidelines and utilizing the Web of Science database, aimed to examine the current state of this field, providing insights for future investigations. The search employed strategies with truncation techniques and Boolean operators, followed by a three-step screening using well-defined eligibility criteria. A bibliometric analysis was conducted to identify authors, affiliations, countries/regions, and research trends. Thirty references were selected for analysis, with Spain standing out as the main source of research on the topic. The majority of studies (66%) focused on the extraction of bioactive compounds from alcoholic fermentation lees, while 33% were directed towards malolactic fermentation lees. Binary mixtures (ethanol-water) were the predominant solvents, with ultrasound being the most used extraction method (31.3%), providing the highest average yields (288.6%) for the various evaluated compounds, especially flavonoids. The potential of wine lees as a source of bioactive compounds is highlighted, along with the need for further research exploring alternative extraction technologies and the combination of methods. Additionally, the importance of "in vitro" and "in vivo" tests to assess the bioactive potential of lees, as well as the use of computational tools to optimize extraction and identify the molecules responsible for bioactive activity, is emphasized.

Exploring the hypolipidemic effects of bergenin from Saxifraga melanocentra Franch: mechanistic insights and potential for hyperlipidemia treatment

OBJECTIVE

The goal of this study was to explore the hypolipidemic effects of bergenin extracted from Saxifraga melanocentra Franch (S. melanocentra), which is a frequently utilized Tibetan medicinal plant known for its diverse bioactivities. Establishing a quality control system for black stem saxifrage is crucial to ensure the rational utilization of its medicinal resources.

METHODS

A one-step polyamide medium-pressure liquid chromatography technique was applied to isolate and prepare bergenin from a methanol extract of S. melanocentra. A zebrafish model of hyperlipidemia was used to investigate the potential hypolipidemic effects of bergenin.

RESULTS

The results revealed that bergenin exhibited substantial hypo efficacy in vivo. Specifically, bergenin significantly reduced the levels of triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-c) while simultaneously increasing high-density lipoprotein cholesterol (HDL-c) levels. At the molecular level, bergenin exerted its effects by inhibiting the expression of FASN, SREBF1, HMGCRα, RORα, LDLRα, IL-1β, and TNF while promoting the expression of IL-4 at the transcriptional level. Molecular docking analysis further demonstrated the strong binding affinity of bergenin to proteins such as FASN, SREBF1, HMGCRα, RORα, LDLRα, IL-4, IL-1β, and TNF.

CONCLUSIONS

Findings indicate that bergenin modulates lipid metabolism by regulating lipid and cholesterol synthesis as well as inflammatory responses through signaling pathways associated with FASN, SREBF1, and RORα. These results position bergenin as a potential candidate for the treatment of hyperlipidemia.

Zebrafish Model Insights into Mediterranean Diet Liquids: Olive Oil and Wine

In this review, we explored the potential of a zebrafish model to investigate the antioxidant effects of key components of the Mediterranean diet, namely, olive oil and wine, in the context of preventing age-related diseases, particularly cardiovascular conditions. This paper explores the spectrum of observational studies to preclinical investigations and ultimately converges toward potential translational insights derived from animal experimentation. This review highlights the potential and underutilization of zebrafish as an experimental model in this domain. We highlighted the genetic proximity of zebrafish to humans, offering a unique opportunity for translational insights into the health benefits of olive oil and wine. Indeed, we wanted to focus on the potential of zebrafish to elucidate the health benefits of olive oil and wine while calling for continued exploration to unlock its full potential to advance our knowledge of age-related disease prevention within the Mediterranean diet framework.

Inflammation and Obesity: The Pharmacological Role of Flavonoids in the Zebrafish Model

A Mediterranean-style diet is highly encouraged thanks to its healthy food pattern, which includes valuable nutraceuticals such as polyphenols. Among these, flavonoids are associated with relevant biological properties through which they prevent or fight the onset of several human pathologies. Globally, the enhanced incidence of overweight and obese people has caused a dramatic increase in comorbidities, raising the need to provide better therapies. Therefore, the development of sophisticated animal models of metabolic dysregulation has allowed for a deepening of knowledge on this subject. Recent advances in using zebrafish (Danio rerio) as model for metabolic disease have yielded fundamental insights into the potential anti-obesity effects of flavonoids. Chronic low-grade inflammation and immune system activation seem to characterize the pathogenesis of obesity; thus, their reduction might improve the lipid profile of obese patients or prevent the development of associated metabolic illnesses. In this review, we highlight the beneficial role of flavonoids on obesity and related diseases linked to their anti-inflammatory properties. In light of the summarized studies, we suggest that anti-inflammatory therapies could have a relevant place in the prevention and treatment of obesity and metabolic disorders.

Recent development in zebrafish model for bioactivity and safety evaluation of natural products

The zebrafish is a species of freshwater fish, popular in aquariums and laboratories. Several advantageous features have facilitated zebrafish to be extensively utilized as a valuable vertebrate model in the lab. It has been well-recognized that natural products possess multiple health benefits for humans. With the increasing demand for natural products in the development of functional foods, nutraceuticals, and natural cosmetics, the zebrafish has emerged as an unprecedented tool for rapidly and economically screening and identifying safe and effective substances from natural products. This review first summarized the key factors for the management of zebrafish in the laboratory, followed by highlighting the current progress on the establishment and applications of zebrafish models in the bioactivity evaluation of natural products. In addition, the zebrafish models used for assessing the potential toxicity or health risks of natural products were involved as well. Overall, this review indicates that zebrafish are promising animal models for the bioactivity and safety evaluation of natural products, and zebrafish models can accelerate the discovery of novel natural products with potential health functions.

Pleiotropic effects of polyphenols on glucose and lipid metabolism: Focus on clinical trials

Epidemiological evidence from observational studies suggests that dietary polyphenols (PPs) - phytochemicals found in a variety of plant-based foods - can reduce the risk of developing type 2 diabetes mellitus (T2DM). Clinical trials have also indicated that PPs may help manage the two key features of T2DM, hyperglycemia and dyslipidemia. Since the incidence of T2DM is dramatically increasing worldwide, identifying food-based approaches that can reduce the risk of developing it and help manage its main risk factors in early-stage disease has clinical and socioeconomic relevance. After a brief overview of current epidemiological data on the incidence of T2DM in individuals consuming PP-rich diets, we review the evidence from clinical trials investigating PP-enriched foods and/or PP-based nutraceutical compounds, report their main results, and highlight the knowledge gaps that should be bridged to enhance our understanding of the role of PPs in T2DM development and management.

The Marine Seagrass Halophila stipulacea as a Source of Bioactive Metabolites against Obesity and Biofouling

Marine organisms, including seagrasses, are important sources of biologically active molecules for the treatment of human diseases. In this study, organic extracts of the marine seagrass Halophila stipulacea obtained by different polarities from leaves (L) and stems (S) (hexane [HL, HS], ethyl acetate [EL, ES], and methanol [ML, MS]) were tested for different bioactivities. The screening comprehended the cytotoxicity activity against cancer cell lines grown as a monolayer culture or as multicellular spheroids (cancer), glucose uptake in cells (diabetes), reduction of lipid content in fatty acid-overloaded liver cells (steatosis), and lipid-reducing activity in zebrafish larvae (obesity), as well as the antifouling activity against marine bacteria (microfouling) and mussel larval settlement (macrofouling). HL, EL, HS, and ES extracts showed statistically significant cytotoxicity against cancer cell lines. The extracts did not have any significant effect on glucose uptake and on the reduction of lipids in liver cells. The EL and ML extracts reduced neutral lipid contents on the larvae of zebrafish with EC₅₀ values of 2.2 µg/mL for EL and 1.2 µg/mL for ML. For the antifouling activity, the HS and ML extracts showed a significant inhibitory effect (p < 0.05) against the settlement of Mytilus galloprovincialis plantigrade larvae. The metabolite profiling using HR-LC-MS/MS and GNPS (The Global Natural Product Social Molecular Networking) analyses identified a variety of known primary and secondary metabolites in the extracts, along with some unreported molecules. Various compounds were detected with known activities on cancer (polyphenols: Luteolin, apeginin, matairesinol), on metabolic diseases (polyphenols: cirsimarin, spiraeoside, 2,4-dihydroxyheptadec-16-ynyl acetate; amino acids: N-acetyl-L-tyrosine), or on antifouling (fatty acids: 13-decosenamide; cinnamic acids: 3-hydroxy-4-methoxycinnamic acid, alpha-cyano-4-hydroxycinnamic), which could be, in part, responsible for the observed bioactivities. In summary, this study revealed that Halophila stipulacea is a rich source of metabolites with promising activities against obesity and biofouling and suggests that this seagrass could be useful for drug discovery in the future.

Wine Lees as a Source of Antioxidant Compounds

The winemaking industry produces large amount of byproducts, including grape pomace, stalks, and lees. Wine lees are a natural source of phenolic compounds, which have important antioxidant and biological properties. Due to the high quantities produced worldwide, this byproduct can be an ideal raw material for obtaining phenolic compounds that could be of interest in the food and pharmaceutical industries. In this mini review, the main characteristics of wine lees as well as their phenolic composition and antioxidant activity have been summarized from the information in the literature.

Effects of resveratrol and genistein on growth, nutrient utilization and fatty acid composition of rainbow trout

The replacement of the finite and costly resource fish oil is an important task for aquaculture nutrition. A promising approach could be the use of plant bioactives that may have the potential to influence the metabolism and the synthesis of n-3 long chain polyunsaturated fatty acids, especially EPA (20:5n-3) and DHA (22:6n-3). In this study, the two phytochemicals resveratrol (RV) and genistein (G) were investigated for their effects on fish growth, nutrient utilization and body nutrient composition alongside their effects on whole body fatty acid (FA) composition. In a feeding trial lasting 8 weeks, rainbow trout (initial BW: 81.4±0.5 g) were held in a recirculating aquaculture system and fed six experimental diets with varying fish oil levels as plain variants or supplemented with 0.3% of dry matter (DM) of either RV or G. The six diets were as follows: diet F4 had 4% DM fish oil, diet F0 had 0% DM fish oil, diets F4+RV, F4+G, F0+RV and F0+G were equal to the diets F4 and F0, respectively, and supplemented with the phytochemicals RV and G. The feeding of the F0+RV diet resulted in reduced feed intake, growth rate and slightly reduced whole body lipid levels. At the same time, the amount of polyunsaturated FA and the n-3/n-6 ratio were significantly increased in whole body homogenates of rainbow trout fed diet F0+RV in comparison to the F0 control. The feeding of the F0+G diet led to reduced feed intake, slightly increased protein utilization but did not significantly affect the whole body FA composition. Overall, feeding the fish oil-free diet supplemented with the phytochemicals resulted in more pronounced effects on fish performance and FA composition than the single factors per se (dietary fish oil level or phytochemical). Present data indicate that G might not be of profitable use for trout nutrition. In terms of FA composition, RV could be a potentially useful complement for fish oil. However, the impairment of growth and performance parameters as observed in the present study discourages its use in trout diets.

Fatty Acid Composition and Fatty Acid Associated Gene-Expression in Gilthead Sea Bream (Sparus aurata) are Affected by Low-Fish Oil Diets, Dietary Resveratrol, and Holding Temperature

To sustainably produce marine fish with a high lipid quality rich in omega-3 fatty acids, alternative sources of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are being identified. Moreover, the use of bioactive compounds that would stimulate the in vivo fatty acid synthesis, such as resveratrol (RV), would reduce the dependence on fish oil in aquafeeds. Gilthead sea bream (Sparus aurata) were fed four experimental diets combining two fish oil levels (6% dry matter (DM); 2% DM) with or without 0.15% DM resveratrol supplementation (F6, F2, F6 + RV, F2 + RV) for two months. Additionally, the fish were challenged either at 19 °C or 23 °C. A higher water temperature promoted their feed intake and growth, resulting in an increased crude lipid content irrespective of dietary treatment. The fatty acid composition of different tissues was significantly affected by the holding temperature and dietary fish oil level. The dietary RV significantly affected the hepatic EPA and DHA content of fish held at 19 °C. The observed effect of RV may be partly explained by alterations of the mRNA steady-state levels of ∆6-desaturase and β-oxidation-related genes. Besides the relevant results concerning RV-mediated regulation of fatty acid synthesis in marine fish, further studies need to be conducted to clarify the potential value of RV to enhance fillet lipid quality.

Dietary resveratrol impairs body weight gain due to reduction of feed intake without affecting fatty acid composition in Atlantic salmon

Recent studies suggest that the use of vegetable oils at expense of fish oil in aquaculture feeds might have potential negative effects on fish redox homeostasis and adiposity. Resveratrol (RESV) is a lipid-soluble phytoalexin present in fruits and vegetables with proven in vivo antioxidant function in animals. The present study aims to assess the potential use of RESV in Atlantic salmon feeds. To this end, post-smolt salmons with an initial BW of 148±3 g were fed four experimental diets for 15 weeks. A diet low in fish oil served as a control and was supplemented with 0, 0.5, 1.5 and 2.5 g/kg of RESV, respectively. The effect of the experimental diets on animal performance, tissue fatty acid composition, and the expression of genes encoding proteins involved in antioxidant signalling, lipid peroxidation, and metabolism were studied. Resveratrol significantly reduced feed intake and final BW of the salmon. Feeding RESV did not affect the sum of saturated and monounsaturated fatty acids or total lipids in the fillet. While the content of total polyunsaturated fatty acids was not affected, the percentages of some fatty acids in the liver and fillet were changed by RESV. Furthermore, in liver, the relative expression of glutathione peroxidase 4b, nuclear factor-like 2, and arachidonate 5-lipoxygenase remained unchanged across treatment groups. In conclusion, the negative impact of dietary RESV on FI and hence reduction of the BW discourages its inclusion in low fish oil diets for Atlantic salmon.

Fatty Acid Profile Is Modulated by Dietary Resveratrol in Rainbow Trout (Oncorhynchus mykiss)

To produce fish of a high quality that are rich in omega-3 fatty acids (n-3 FA) and simultaneously generate more sustainable aquaculture, the combined use of phytochemicals and vegetable oils in fish feed seems to be a promising approach. Resveratrol (RV) potentially induces endogenous fatty acid synthesis, resulting in elevated n-3 FA levels in fish. RV putatively influences ∆6-desaturase, the key enzyme in FA metabolism, and serves as a ligand for PPARα, a transcription factor regulating β-oxidation. Rainbow trout (36.35 ± 0.03 g) were randomly allocated into six groups and fed diets with reduced fish oil levels (F4 = 4%, F2 = 2% and F0 = 0% of dry matter) supplemented with 0.3% (w/w) RV (F4 + RV, F2 + RV and F0 + RV). RV significantly affected FA composition in liver tissue and whole fish homogenates. 20:5n-3 (EPA) and 22:6n-3 (DHA) were significantly increased whereas precursor FA were diminished in fish fed the F2 + RV and F0 + RV diets when compared to F4 + RV and F0. RV significantly elevated ∆6-desaturase protein levels in the livers of F0 + RV fed animals. Hepatic mRNA expression of ∆6-desaturase, PPARα, and its target genes were affected by the dietary fish oil level and not by dietary RV. The results of this study indicated a potential benefit of supplementing RV in fish oil deprived diets elevating n-3 FA levels in rainbow trout.