Zerumbone exhibits anti-inflammatory effects by suppressing eicosanoid signaling: Evidence from LPS-induced peripheral blood leukocytes

Zerumbone, a sesquiterpene isolated from Zingiber zerumbet, has many bioactivities, exhibiting anti-inflammatory properties. However, the effect of zerumbone on the eicosanoid signaling pathway has yet to be examined. Here, we deciphered the anti-eicosanoid properties of zerumbone isolated from ginger. The molecular interaction between zerumbone and eicosanoid metabolizing enzymes (COX-2, 5-LOX, FLAP, and LTA4-hydrolase) and receptors (EP-4, BLT-1, and ICAM-1) along with NOS-2 were assessed using Auto-Dock 4.2 and visualized by chimera and Liggplot+ software. Further, the leukocytes were treated with zerumbone (1-20 μM) and activated using bacterial lipopolysaccharide (LPS-10 nM). The oxidative stress (OS) markers, antioxidant enzymes, and the eicosanoid pathway mediators such as COX-2, 5-LOX, BLT-1, and EP-4 were assessed. The molecular interaction of zerumbone with eicosanoids showed a higher binding affinity with mPGES-1, followed by NOS-2, FLAP, COX-2, LTA-4-hydrolase, and BLT-1. The concentration of 5 μM zerumbone effectively prevented the generation of reactive oxygen species (ROS) and nitric oxide (NO). Likewise, zerumbone significantly (p<0.05) inhibited COX-2, 5-LOX, NOS-2, EP-4, BLT-1, and ICAM-1 expression in LPS-induced peripheral blood leukocytes from rats. Further, the zerumbone treatment on the human PBMCs activated with LPS showed significant inhibition in the expression of ICAM1, COX-2, 5-LOX, and the generation of inflammatory cytokines compared to the control. Overall, the data presented infers that zerumbone positively modulates critical enzymes and receptors of eicosanoids in leukocytes activated with lipopolysaccharides. Thus, zerumbone can be a potential anti-eicosanoid drug in managing inflammation.

Polysaccharide from Spirulina platensis Evokes Antitumor Activity in Gastric Cancer Cells via Modulation of Galectin-3 and Exhibited Cyto/DNA Protection: Structure-Function Study

Polysaccharides play significant role in the management of different cancer types including gastric cancer. Here, we report the effect of spirulina polysaccharide (Sp) on galectin-3 modulatory activity in gastric cancer cells (AGS). The isolated Sp possessed an average molecular weight of 1457 kDa and galactose (42%) as a major sugar consisting of (β1-4d) units with a galactoarabinorhamnoglycan backbone. The Sp inhibited the proliferation of AGS cells by 48% without affecting normal NIH/3T3 cells as compared to doxorubicin, a known anticancer drug. Also, Sp exhibited significant (p < 0.05) galectin-3 mediated hemeagglutination inhibition with MIC of 9.37 μg/mL compared to galactose (6.25 μg/mL), a sugar specific to galectin-3. Galactose showed the highest molecular interaction with galectin-3 in the in silico study. In addition, Sp exhibited the cytoprotection in RBCs, buccal cells, and DNA exposed to oxidants. These findings suggest that Sp offers a promising therapeutic tool in the management of gastric cancer.

Ginger and turmeric lipid-solubles attenuate heated oil-induced oxidative stress in the brain via the upregulation of NRF2 and improve cognitive function in rats

In this study, we elucidated the modulatory potentials of lipid-solubles from ginger and turmeric that may migrate to oils during heating on the brain antioxidant defense and cognitive response in rats. Male Wistar rats were fed with control diet [including native canola oil (N-CNO), and native sunflower oil (N-SFO)], or experimental diets [including heated canola oil (H-CNO), heated sunflower oil (H-SFO), heated canola oil with ginger (H-CNO + GI), heated canola oil with turmeric (H-CNO + TU), heated sunflower oil with ginger (H-SFO + GI), heated sunflower oil with turmeric (H-SFO + TU)] for 90 days. Memory parameters [Morris water maze, elevated plus maze, novel object recognition test, T-maze (spontaneous alteration)], locomotor skills (open field test and rotarod test), antioxidant defense enzymes, reactive oxygen species, NOS2, ICAM-1, and NRF-2 level in the brain were assessed. Compared to their respective controls, heated oil-fed rats, but not those fed oils heated with ginger or turmeric, showed significant (p < 0.05) reduction in the memory, motor coordination skills, antioxidant defense enzymes, and NRF-2 activation in the brain. Compared to their respective controls, the brain NOS-2 and ICAM-1 were significantly (p < 0.05) increased in heated oil-fed rats, but not those fed oils heated with ginger or turmeric. Chronic intake of repeatedly heated oil causes brain dysfunction by inducing oxidative stress through NRF-2 downregulation. Lipid-solubles from ginger and turmeric that may migrate to oil during heating prevent the oxidative stress and cognitive dysfunction triggered by heated oils in rats.

Role of n-3 Fatty Acids on Bile Acid Metabolism and Transport in Dyslipidemia: A Review

Dietary n-3 fatty acids, especially of marine origin, eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3), have always been lauded for their profound effects on regulating the risk factors for major metabolic disorders. Yet, their consumption rate is poor compared to n-6 fatty acids [linoleic acid (18:2n-6)], which are predominantly consumed. Hence, the skewed n-6 to n-3 fatty acid ratio may have a bearing on the risk factors of various diseases, including dyslipidemia. Dyslipidemia and other lifestyle diseases associated with it, such as diabetes, obesity, hypertension, are a growing concern in both developed and developing countries. A common strategy for addressing dyslipidemia involves bile acid (BA) sequestration, to interrupt the enterohepatic circulation of BA, resulting in the modulation of lipid absorption in the intestine, thereby normalizing the levels of circulating lipids. The BA homeostasis is under the tight control of hepatic and enteric BA transporters. Many investigations have reported the effects of dietary constituents, including certain fatty acids on the reabsorption and transport of BA. However, a critical review of the effects of n-3 fatty acids on BA metabolism and transport is not available. The present review attempts to explore certain unmapped facets of the n-3 fatty acids on BA metabolism and transport in dyslipidemia, and their interplay with biological processes involving lipid rafts and gut microbiome.

Hyperlipidemia Downregulate Brain Antioxidant Defense Enzymes and Neurotrophins in Rats: Assessment of the Modulatory Potential of EPA+DHA and Zerumbone

BACKGROUND

Oxidative stress (OS) plays a vital role in the pathogenesis of cognitive disorders. In this study, brain antioxidant defense dysregulation as a consequence of hyperlipidemia, and the efficacy of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA), and zerumbone (Z) in their modulation are assessed.

METHODS AND RESULTS

Male Wistar rats are fed control, high-fat (HF), HF + fish oil (HF+F), HF + zerumbone (HF+Z), and HF + fish oil + zerumbone (HF+F+Z) diet for 60 days. Markers of OS, antioxidant enzymes, monoamine oxidase, nuclear factor (erythroid-derived 2)-like 2 (NRF-2), nitric oxide-2 (NOS-2), inter cellular adhesion molecule-1 (ICAM-1), and neurotrophins are measured. Hyperlipidemia increases OS, decreases antioxidant enzyme activity, increases monoamine oxidase activity, increases NOS-2 and ICAM-1 expression, decreases NRF-2 activation, decreases nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF) levels in the brain compared to control. While EPA+DHA and zerumbone significantly (p < 0.05) restores the perturbations induced by hyperlipidemia.

CONCLUSION

It is concluded that hyperlipidemia cause OS by decreasing the activity of brain antioxidant enzymes via the downregulation of NRF-2. The reduced brain neurotrophins in hyperlipidemia indicate its potential risk on cognitive attributes. EPA+DHA, together with zerumbone, positively modulates hyperlipidemia induced brain dysfunction thereby offering promising therapeutic strategy.