Low dietary n-6/n-3 polyunsaturated fatty acid ratio prevents induced oral carcinoma in a hamster pouch model

CD36: The Bridge between Lipids and Tumors

It has been found that the development of some cancers can be attributed to obesity, which is associated with the excessive intake of lipids. Cancer cells undergo metabolic reprogramming, shifting from utilizing glucose to fatty acids (FAs) for energy. CD36, a lipid transporter, is highly expressed in certain kinds of cancer cells. High expressions of CD36 in tumor cells triggers FA uptake and lipid accumulation, promoting rapid tumor growth and initiating metastasis. Meanwhile, immune cells in the tumor microenvironment overexpress CD36 and undergo metabolic reprogramming. CD36-mediated FA uptake leads to lipid accumulation and has immunosuppressive effects. This paper reviews the types of FAs associated with cancer, high expressions of CD36 that promote cancer development and progression, effects of CD36 on different immune cells in the tumor microenvironment, and the current status of CD36 as a therapeutic target for the treatment of tumors with high CD36 expression.

Sustainable pig diets: partial grain replacement with former food products and its impact on meat quality

This study investigated the effects of salty and sugary former foodstuff products (FFPs) on the quality traits and meat composition of 36 male castrated pigs (Swiss Large White breed) as well as sensory characteristics of the loins. The animals were fed three different diets for both the growing (G) and finishing (F) phases: (1) a standard diet (ST), 0% FFPs; (2) a diet with 30% of sugary FFPs (e.g., chocolate, biscuits, cakes) as a replacement for traditional ingredients (SU); and (3) a diet with 30% of salty FFPs (e.g., bread, pasta, and breadsticks) as a replacement for traditional ingredients (SA). For a comprehensive assessment of meat quality, protein and fat content in the LD were analyzed. AA and FA profile were determined both in the LD and backfat. Meat quality traits such as pH and temperature, thawing, cooking and drip losses, and shear force have been evaluated. Then, pork loins have been assessed for sensory attributes by a trained sensory panel. The SA diet decreased 20:5 n-3 levels (P < 0.001) in the muscle and 22:5 n-3 levels (P < 0.05) in both muscle and backfat but increased (P < 0.05) the ratio of mono-unsaturated to saturated fatty acids compared to the ST group. Both the SU and SA diets elevated (P < 0.001) the n-6:n-3 fatty acids ratio compared to the ST diet. Dietary treatments did not affect other meat quality traits. Regarding sensory attributes, the loin from pigs fed with SU and SA diets were sweeter (P < 0.001). Loins of SA pigs were more tender (P < 0.001), had a more intense pork aroma (P < 0.001) and had more flavor (P < 0.01) compared to ST loins. Overall, the use of FFPs affected the fatty acid profile of pork while improving the sensory quality of the loins, with no negative effects observed on the technological and nutritional quality of the meat.

Effects of Pig Dietary n-6/n-3 Polyunsaturated Fatty Acids Ratio and Gender on Carcass Traits, Fatty Acid Profiles, Nutritional Indices of Lipid Depots and Oxidative Stability of Meat in Medium-Heavy Pigs

The effects of different dietary n-6/n-3 polyunsaturated fatty acids (PUFA) ratios and gender on key carcass traits, as well as the nutritional and technological quality of lipids in medium-heavy pig tissues have been poorly studied. To investigate the subject, 24 Large White, barrows and gilts, evenly divided into two groups of 12, were fed from 80 kg of live-weight (LW) until slaughter at 150 kg LW, either a high (9.7:1) (HPR) or low (1.4:1) (LPR) dietary n-6/n-3 PUFA ratio. On individual samples of longissimus thoracis muscle (LTM), subcutaneous (SF) and perirenal (PF) adipose tissues (ATs), the fatty acid (FA) composition was determined by gas chromatography, and lipid nutritional indices (LNIs) were calculated. The oxidative stability of meat was evaluated by determining the malondialdehyde content on raw and cooked (24 h postmortem) and refrigerated (8 days postmortem) LTM samples. The carcass traits did not vary between genders and diets. The LPR group showed a higher n-3 PUFA level and a lower n-6/n-3 PUFA ratio in all the tissues examined and better LNI, especially in the ATs. Diet did not affect the oxidative stability of meat. Gender did not influence the n-6/n-3 PUFA ratio, while barrows showed improvements in some LNI in ATs. Reducing the n-6/n-3 ratio in the diet of growing-finishing medium-heavy pigs improved the FA profile in all tissues and most LNI in ATs without impairing the oxidative stability of meat.

Lipid metabolism reprogramming in head and neck cancer

Lipid metabolism reprogramming is one of the most prominent metabolic anomalies in cancer, wherein cancer cells undergo dysregulation of lipid metabolism to acquire adequate energy, cell membrane building blocks, as well as signaling molecules essential for cell proliferation, survival, invasion, and metastasis. These adaptations enable cancer cells to effectively respond to challenges posed by the tumor microenvironment, leading to cancer therapy resistance and poor cancer prognosis. Head and neck cancer, ranking as the seventh most prevalent cancer, exhibits numerous abnormalities in lipid metabolism. Nevertheless, the precise role of lipid metabolic rewiring in head and neck cancer remains unclear. In line with the LIPID MAPS Lipid Classification System and cancer risk factors, the present review delves into the dysregulated molecules and pathways participating in the process of lipid uptake, biosynthesis, transportation, and catabolism. We also present an overview of the latest advancements in understanding alterations in lipid metabolism and how they intersect with the carcinogenesis, development, treatment, and prognosis of head and neck cancer. By shedding light on the significance of metabolic therapy, we aspire to improve the overall prognosis and treatment outcomes of head and neck cancer patients.

Recent insights into dietary ω-6 fatty acid health implications using a systematic review

The American Heart Association suggests that consuming ω-6 fatty acids (5-10% of total energy) can prevent cardiovascular disease by improving lipoprotein profiles. However, some studies warn of deleterious effects of these due to eicosanoid biosynthesis. We explored the five years for clinical evidence of ω-6 fatty acids on several diseases including inflammation, cancer, cardiovascular disease, and metabolic syndrome. Predefined criteria identified a total of 21 articles in 5 databases. Some studies indicated that dietary arachidonic acid was not related to increase of pro-inflammatory cytokines. In cohort studies, ω-6 fatty acids prevented the onset of digestive and lung cancer. ω-6 Fatty acids improved blood lipoprotein profiles. Moreover, consuming ω-6 fatty acids delayed diabetes mellitus and chronic renal disease and had positive effects on muscle recovery and glaucoma. In conclusion, ω-6 fatty acids have beneficial effects on cancers, blood lipoprotein profiles, diabetes, renal disease, muscle function, and glaucoma without inflammation response.

Changes in Serum Fatty Acid Composition and Metabolome-Microbiome Responses of Heigai Pigs Induced by Dietary N-6/n-3 Polyunsaturated Fatty Acid Ratio

Changing fatty acid composition is a potential nutritional strategy to shape microbial communities in pigs. However, the effect of different n-6/n-3 polyunsaturated fatty acid (PUFA) ratios on serum fatty acid composition, microbiota, and their metabolites in the intestine of pigs remains unclear. Our study investigated the changes in serum fatty acid composition and metabolome–microbiome responses induced by dietary n-6/n-3 PUFA ratio based on a Heigai-pig model. A total of 54 Heigai finishing pigs (body weight: 71.59 ± 2.16 kg) fed with 3 types of diets (n-6/n-3 PUFA ratios are 8:1, 5:1, and 3:1) were randomly divided into 3 treatments with 6 replications (3 pigs per replication) for 75 days. Results showed that dietary n-6/n-3 PUFA ratio significantly affected biochemical immune indexes including glucose (Glu), triglycerides (TG), total cholesterol (TChol), non-esterified fatty acid (NEFA), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and total thyroxine (TT4), and medium- and long-chain fatty acid composition, especially n-3 PUFA and n-6/n-3 PUFA ratio in the serum. However, no significant effects were found in the SCFAs composition and overall composition of the gut microbiota community. In the low dietary n-6/n-3 PUFA ratio group, the relative abundance of Cellulosilyticum, Bacteroides, and Alloprevotella decreased, Slackia and Sporobacter increased. Based on the metabolomic analysis, dietary n-6/n-3 PUFA ratio altered the metabolome profiles in the colon. Moreover, Pearson’s correlation analysis indicated that differential microbial genera and metabolites induced by different n-6/n-3 PUFA ratio had tight correlations and were correlated with the n-6 PUFA and n-3 PUFA content in longissimus dorsi muscle (LDM) and subcutaneous adipose tissue (SAT). Taken together, these results showed that lower dietary n-6/n-3 PUFA ratio improved serum fatty acid composition and metabolome–microbiome responses of Heigai pigs and may provide a new insight into regulating the metabolism of pigs and further better understanding the crosstalk with host and microbes in pigs.

[6]-Gingerol impedes 7,12-dimethylbenz(a)anthracene-induced inflammation and cell proliferation-associated hamster buccal pouch carcinogenesis through modulating Nrf2 signaling events

The present study examines the chemopreventive role of [6]-gingerol, an active component of ginger, on 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis models. The HBP has been developed with an addition of 0.5% of DMBA to the HBP area three times per week, up to the end of the 16th experimental week. At the end of the experiment, we noticed 100% tumor incidence and precancerous lesions, such as dysplasia, hyperplasia, keratosis, and well-differentiated squamous cell carcinoma, in DMBA-induced HBP. Furthermore, we observed that [6]-gingerol inhibited the increased thiobarbituric acid-reactive substances and decreased antioxidant levels in DMBA-induced hamsters. Moreover, [6]-gingerol inhibits DMBA-exposed over expression of inflammatory markers (inducible nitric oxide synthase, interleukin [IL]-1β, IL-6, cyclooxygenase-2, and tumor necrosis factor-α) and cell proliferation markers (cyclin D1, proliferating cell nuclear antigen); induces proapoptotic markers in HBP. Nuclear factor erythroid-2-related factor-2 (Nrf2) is a major antioxidant transcription factor, which regulates the antioxidant gene-dependent scavenge of tumor proliferation and apoptosis. Overexpression of Nrf2 signaling plays a pivotal role and can be a novel target in preventing carcinogenesis. In this study, [6]-gingerol restores the DMBA-induced depletion of Nrf2 signaling and thereby prevents buccal pouch carcinogenesis in hamsters. These results point out that [6]-gingerol impedes the responses of inflammatory and cell proliferation-associated progression of cancer through the action of Nrf2 signaling.

Low Dietary n-6/n-3 PUFA Ratio Regulates Meat Quality, Reduces Triglyceride Content, and Improves Fatty Acid Composition of Meat in Heigai Pigs

The objective of this study was to investigate the effects of dietary supplementation with different n-6/n-3 polyunsaturated fatty acid (PUFA) ratios on growth performance, meat quality, and fatty acid profile in Heigai pigs. A total of 54 Heigai finishing pigs (body weight: 71.59 ± 2.16 kg) were randomly divided into three treatments with six replications (three pigs per replication) and fed diets containing different n-6/n-3 PUFA ratios: 8:1, 5:1, and 3:1. Pigs fed the dietary n-6/n-3 PUFA ratio of 8:1 had the highest feed to gain ratio (p < 0.01), carcass weight (p < 0.05), redness a* (p < 0.01), and yellowness b* (p < 0.01). Fatty acid compositions in longissimus dorsi muscle (LDM) and subcutaneous adipose tissue (SAT) were significantly changed (p < 0.01). Notably, the meat from the pigs fed with the low dietary n-6/n-3 PUFA ratio had higher n-3 PUFA contents (p < 0.01) and lower n-6/n-3 PUFA ratio (p < 0.01). The triglyceride and total cholesterol contents were significantly decreased in SAT from the pigs fed with dietary n-6/n-3 PUFA ratios of 5:1 (p < 0.05) and 3:1 (p < 0.01). Reducing n-6/n-3 PUFA ratio upregulated the expression of HSL (p < 0.05), CPT1 (p < 0.01), and FABP4 (p < 0.01) but downregulated ATGL (p < 0.01) expression. These results demonstrate that the lower n-6/n-3 PUFA ratio regulates meat quality and enhances the deposition of n-3 PUFA in Heigai pigs.

Dietary Fat and Cancer-Which Is Good, Which Is Bad, and the Body of Evidence

A high-fat diet (HFD) induces changes in gut microbiota leading to activation of pro-inflammatory pathways, and obesity, as a consequence of overnutrition, exacerbates inflammation, a known risk factor not only for cancer. However, experimental data showed that the composition of dietary fat has a greater impact on the pathogenesis of cancer than the total fat content in isocaloric diets. Similarly, human studies did not prove that a decrease in total fat intake is an effective strategy to combat cancer. Saturated fat has long been considered as harmful, but the current consensus is that moderate intake of saturated fatty acids (SFAs), including palmitic acid (PA), does not pose a health risk within a balanced diet. In regard to monounsaturated fat, plant sources are recommended. The consumption of plant monounsaturated fatty acids (MUFAs), particularly from olive oil, has been associated with lower cancer risk. Similarly, the replacement of animal MUFAs with plant MUFAs decreased cancer mortality. The impact of polyunsaturated fatty acids (PUFAs) on cancer risk depends on the ratio between ω-6 and ω-3 PUFAs. In vivo data showed stimulatory effects of ω-6 PUFAs on tumour growth while ω-3 PUFAs were protective, but the results of human studies were not as promising as indicated in preclinical reports. As for trans FAs (TFAs), experimental data mostly showed opposite effects of industrially produced and natural TFAs, with the latter being protective against cancer progression, but human data are mixed, and no clear conclusion can be made. Further studies are warranted to establish the role of FAs in the control of cell growth in order to find an effective strategy for cancer prevention/treatment.

Obesity: An emerging driver of head and neck cancer

Obesity has become pandemic and emerged as one of the most critical global health care problems worldwide since last century. Recent studies have demonstrated that there may be a causal link between obesity and higher risks and mortality of cancers, including prostate, breast, colon, and thyroid cancers, head and neck cancer (HNC). This review focuses on the relationship between obesity and HNC, and the molecular mechanism of abnormal lipid metabolism in HNC. Elucidating the mechanism may open up new possibilities for strategies to reduce risk and mortality of HNC in an increasingly obese population.

Effects of Fish Oil on Lipid Metabolism and Its Molecular Biological Regulators in Chronic Ethanol-Fed Rats

The purpose of this study was to clarify the hepatoprotective mechanisms of fish oil in ethanol-fed rats based on lipid metabolism. Thirty eight-week-old male Wistar rats were divided into six groups: C (control), CF25 (control diet with 25% fish oil substitution), CF57 (control diet with 57% fish oil substitution), E (ethanol-containing diet) group, EF25 (ethanol-containing diet with 25% fish oil substitution), and EF57 (ethanol-containing diet with 57% fish oil substitution) groups. All of the groups were pair-fed an isoenergetic diet based on E group. Rats were sacrificed after eight weeks. When compared with C group, the plasma aspartate transaminase (AST) activity and hepatic steatosis and inflammatory cell infiltration were significantly higher, while plasma adiponectin level and hepatic AMP-activated protein kinase α (AMPKα) protein expression was significantly lower in the E group. However, the hepatic damage, including steatosis and inflammation were ameliorated in the EF25 and EF57 groups. Moreover, mRNA levels of fatty acid-oxidative enzymes, such as medium-chain acyl-coenzyme A dehydrogenase (MCAD) and carnitine palmitoyltransferase I (CPT-1) were significantly elevated in the EF57 group than those in E group. Partial replacement with fish oil might improve the fatty acid oxidation by raising mRNA levels of downstream transcription factors, finally inhibit the ethanol-induced hepatic steatosis in rats.