Effect of δ-Tocopherol on Mice Adipose Tissues and Mice Adipocytes Induced Inflammation

Suppression of Inflammation in Adipocyte-Macrophage Coculture by Passion Fruit Seed Extract: Insights into the p38 and NF-ҡB Pathway

Obesity, which is characterized by chronic low-grade inflammation, involves the infiltration of immune cells into adipose tissue, leading to the secretion of inflammatory cytokines and subsequent inflammation. Therefore, the aim of this study was to examine the potential of passion fruit seed extract (PSEE) in mitigating lipopolysaccharide (LPS)-induced inflammation in a coculture system comprising macrophages and adipocytes. PSEE demonstrated significant reductions in reactive oxygen species (ROS) and nitric oxide (NO) levels, primarily achieved through the downregulation of inducible nitric oxide synthase (iNOS) protein expression in LPS-induced adipocyte-macrophage cocultures. Furthermore, PSEE effectively suppressed the secretion of TNF-α and IL-1β by attenuating the gene expression of these cytokines, as well as other inflammation-related genes such as MMP-2, IL-6, and MCP-1. Notably, PSEE exhibited potent inhibitory effects on the p38 and NF-κB signaling pathways, thus alleviating inflammation in the LPS-induced adipocyte-macrophage cocultures. Additionally, PSEE led to a decrease in the expression of ACC, HSL, and FaSN, while aP2 and ATGL showed increased expression in LPS-induced cocultured macrophages and adipocytes. These findings suggest that passion fruit seed extract effectively combats inflammation by suppressing the p38 and NF-κB signaling pathways, resulting in reduced levels of proinflammatory cytokines, NO, and ROS production.

Selected Seeds as Sources of Bioactive Compounds with Diverse Biological Activities

Seeds contain a variety of phytochemicals that exhibit a wide range of biological activities. Plant-derived compounds are often investigated for their antioxidant, anti-inflammatory, immunomodulatory, hypoglycemic, anti-hypercholesterolemic, anti-hypertensive, anti-platelet, anti-apoptotic, anti-nociceptive, antibacterial, antiviral, anticancer, hepatoprotective, or neuroprotective properties. In this review, we have described the chemical content and biological activity of seeds from eight selected plant species-blackberry (Rubus fruticosus L.), black raspberry (Rubus coreanus Miq.), grape (Vitis vinifera L.), Moringa oleifera Lam., sea buckthorn (Hippophae rhamnoides L.), Gac (Momordica cochinchinensis Sprenger), hemp (Cannabis sativa L.), and sacha inchi (Plukenetia volubilis L). This review is based on studies identified in electronic databases, including PubMed, ScienceDirect, and SCOPUS. Numerous preclinical, and some clinical studies have found that extracts, fractions, oil, flour, proteins, polysaccharides, or purified chemical compounds isolated from the seeds of these plants display promising, health-promoting effects, and could be utilized in drug development, or to make nutraceuticals and functional foods. Despite that, many of these properties have been studied only in vitro, and it's unsure if their effects would be relevant in vivo as well, so there is a need for more animal studies and clinical trials that would help determine if they could be applied in disease prevention or treatment.

Comparison of delta-tocotrienol and alpha-tocopherol effects on hepatic steatosis and inflammatory biomarkers in patients with non-alcoholic fatty liver disease: A randomized double-blind active-controlled trial

OBJECTIVE

We aimed to compare the efficacy of δ-tocotrienol with α-tocopherol in the treatment of patients with non-alcoholic fatty liver disease (NAFLD).

DESIGN AND INTERVENTIONS

This study was a double-blinded, active-controlled trial. The patients with NAFLD were randomly assigned to receive either δ-tocotrienol 300 mg or α-tocopherol 268 mg twice daily for 48 weeks.

ENDPOINTS

The primary endpoints were change from baseline in fatty liver index (FLI), liver-to-spleen attenuation ratio (L/S ratio), and homeostatic model assessment for insulin resistance (HOMA-IR) at 48 weeks. Key secondary endpoints were change in markers of inflammation, oxidative stress, and hepatocyte apoptosis. Clinical assessment, biochemical analysis, and computed tomography scan of the liver were conducted at baseline, 24 and 48 weeks.

RESULTS

A total of 100 patients (δ-tocotrienol = 50, α-tocopherol = 50) were randomized and included in the intention to treat analysis. Compared with baseline, there was a significant improvement (p < .001) in FLI, L/S ratio, HOMA-IR, and serum malondialdehyde in both groups at 48 weeks that was not significant between the two groups. However, there was a significantly greater decrease in body weight, serum interleukin-6, tumor necrosis factor-alpha, leptin, cytokeratin-18, and increase in adiponectin in the δ-tocotrienol group compared to the α-tocopherol group at 48 weeks (p < .05). No adverse events were reported.

CONCLUSION

δ-tocotrienol and α-tocopherol exerted equally beneficial effects in terms of improvement in hepatic steatosis, oxidative stress, and insulin resistance in patients with NAFLD. However, δ-tocotrienol was more potent than α-tocopherol in reducing body weight, inflammation, and apoptosis associated with NAFLD. TRIAL REGISTRATION: Sri Lankan Clinical Trials Registry (https://slctr.lk/SLCTR/2019/038).

Delta-Tocopherol Suppresses the Dysfunction of Thermogenesis due to Inflammatory Stimulation in Brown Adipocytes

Brown adipose tissue (BAT) functions as a radiator for thermogenesis and helps maintain body temperature and regulate metabolism. Inflammatory signals have been reported to inhibit PGC-1α activation and UCP1-mediated thermogenesis in brown adipocytes. Inflammation is mainly caused by cell hypertrophy and macrophage invasion due to obesity, and invading macrophages secrete inflammatory cytokines, including TNF-α, IL1β, and IL6, which suppress the thermogenesis in BAT. Tocopherol is a lipid-soluble vitamin with anti-inflammatory effects is expected to contribute to the suppression of inflammation in adipose tissue. In this study, we investigated the protective effect of tocopherols, α-tocopherol (α-toc) and δ-tocopherol (δ-toc), against brown adipocyte inflammation and thermogenesis dysfunction.Inflammatory stimulation by TNF-α, a major inflammatory cytokine, significantly decreased the protein expression levels of UCP1 and PGC-1α in rat primary brown adipocytes. The pre-incubation of α-toc or δ-toc significantly suppressed the decrease in UCP1 and PGC-1α expression and lipid accumulation. Additionally, α-toc and δ-toc suppress the induction of ERK1/2 gene expression, implying that an antiinflammatory effect is involved in this protective effect. We fed mice a high-fat diet for 16 weeks and investigated the effects of α-toc and δ-toc in the diet. Intake of α-toc and δ-toc significantly suppressed weight gain and hypertrophy of brown adipocytes. Our results suggest that α-toc and δ-toc suppress the dysfunction of thermogenesis in brown adipocytes due to inflammation and contribute to the treatment of obesity and obesity-related metabolic diseases.