Polyphenols Extracted from Shanxi-Aged Vinegar Inhibit Inflammation in LPS-Induced RAW264.7 Macrophages and ICR Mice via the Suppression of MAPK/NF-κB Pathway Activation

Natural product/diet-based regulation of macrophage polarization: Implications in treatment of inflammatory-related diseases and cancer

Macrophages are phagocytic cells with important physiological functions, including the digestion of cellular debris, foreign substances, and microbes, as well as tissue development and homeostasis. The tumor microenvironment (TME) shapes the aggressiveness of cancer, and the biological and cellular interactions in this complicated space can determine carcinogenesis. TME can determine the progression, biological behavior, and therapy resistance of human cancers. The macrophages are among the most abundant cells in the TME, and their functions and secretions can determine tumor progression. The education of macrophages to M2 polarization can accelerate cancer progression, and therefore, the re-education and reprogramming of these cells is promising. Moreover, macrophages can cause inflammation in aggravating pathological events, including cardiovascular diseases, diabetes, and neurological disorders. The natural products are pleiotropic and broad-spectrum functional compounds that have been deployed as ideal alternatives to conventional drugs in the treatment of cancer. The biological and cellular interactions in the TME can be regulated by natural products, and for this purpose, they enhance the M1 polarization of macrophages, and in addition to inhibiting proliferation and invasion, they impair the chemoresistance. Moreover, since macrophages and changes in the molecular pathways in these cells can cause inflammation, the natural products impair the pro-inflammatory function of macrophages to prevent the pathogenesis and progression of diseases. Even a reduction in macrophage-mediated inflammation can prevent organ fibrosis. Therefore, natural product-mediated macrophage targeting can alleviate both cancerous and non-cancerous diseases.

Chemopreventive and immunomodulatory effects of phenolic-rich extract of Commiphora leptophloeos against inflammatory bowel disease: Preclinical evidence

ETHNOPHARMACOLOGY RELEVANCE

Commiphora leptophloeos (Mart.) J.B. Gillet (Burseraceae) is a medicinal plant native to Brazil, popularly known as "imburana". Homemade leaf decoction and maceration were used to treat general inflammatory problems in the Brazilian Northeast population. Our previous research confirmed the anti-inflammatory activity of the C. leptophloeos hydroalcoholic leaf extract.

AIM OF THE STUDY

Inflammatory bowel disease (IBD) is a chronic and relapsing inflammatory disorder of the gut with no ideal treatment to maintain the remissive status. This work aimed to characterize the phytochemical composition and physicochemical properties of the C. leptophloeos hydroalcoholic leaf extract and its efficacy in chemopreventive and immunomodulatory responses in inflammatory bowel disease in non-clinical models.

MATERIALS AND METHODS

Mass spectrometry and physicochemical tests determined the phytochemical profile and physicochemical characteristics of the Commiphora leptophloeos (CL) extract. The chemopreventive and immunomodulatory effects of CL extract (50 and 125 μg/mL) were evaluated in vitro in the RAW 264.7 lipopolysaccharide (LPS) induced cell assay and in vivo in the model of intestinal inflammation induced by 2,4-Dinitrobenzenesulfonic acid (DNBS) in mice when they were treated with CL extract by intragastric gavage (i.g.) at doses of 300, 400 and 500 mg/kg.

RESULTS

Phytochemical annotation of CL extract showed a complex phenolic composition, characterized as phenolic acids and flavonoids, and satisfactory physicochemical characteristics. In addition, CL extract maintained the viability of RAW macrophages, reduced ROS and NO production, and negatively regulated COX-2, iNOS, TNF-α, IL-1β, IL-6, and IL-17 (p < 0.05). In the intestinal inflammation model, CL extract was able to downregulate NF-κB p65/COX-2, mTOR, iNOS, IL-17, decrease levels of malondialdehyde and myeloperoxidase and cytokines TNF-α, IL-1β and IL-6 (p < 0.05).

CONCLUSION

Based on these findings, CL extract reduced inflammatory responses by down-regulating pro-inflammatory markers in macrophages induced by LPS and DNBS-induced colitis in mice through NF-κB p65/COX-2 signaling. CL leaf extract requires further investigation as a candidate for treating inflammatory bowel disease.

The Chelating Ability of Plant Polyphenols Can Affect Iron Homeostasis and Gut Microbiota

In the past decades, many studies have widely examined the effects of dietary polyphenols on human health. Polyphenols are well known for their antioxidant properties and for their chelating abilities, by which they can be potentially employed in cases of pathological conditions, such as iron overload. In this review, we have highlighted the chelating abilities of polyphenols, which are due to their structural specific sites, and the differences for each class of polyphenols. We have also explored how the dietary polyphenols and their iron-binding abilities can be important in inflammatory/immunomodulatory responses, with a special focus on the involvement of macrophages and dendritic cells, and how they might contribute to reshape the gut microbiota into a healthy profile. This review also provides evidence that the axes “polyphenol–iron metabolism–inflammatory responses” and “polyphenol–iron availability–gut microbiota” have not been very well explored so far, and the need for further investigation to exploit such a potential to prevent or counteract pathological conditions.

Flavonoid-Conjugated Gadolinium Complexes as Anti-Inflammatory Theranostic Agents

In this study, we designed, synthesized, and evaluated gadolinium compounds conjugated with flavonoids as potential theranostic agents for the treatment of inflammation. These novel theranostic agents combine a molecular imaging agent and one of three flavonoids (galangin, chrysin, and 7-hydroxyflavone) as anti-inflammatory drugs as a single integrated platform. Using these agents, MR imaging showed contrast enhancement (>10 in CNR) at inflamed sites in an animal inflammation model, and subsequent MR imaging used to monitor the therapeutic efficacy of these integrated agents revealed changes in inflamed regions. The anti-inflammatory effects of these agents were demonstrated both in vitro and in vivo. Furthermore, the antioxidant efficacy of the agents was evaluated by measuring their reactive oxygen species scavenging properties. For example, Gd-galangin at 30 μM showed a three-fold higher ROS scavenging of DPPH. Taken together, our findings provide convincing evidence to indicate that flavonoid-conjugated gadolinium compounds can be used as potentially efficient theranostic agents for the treatment of inflammation.

The Role of Diet in Regulation of Macrophages Functioning

The great importance of diet for health and high life-expectancy is established. The impact of nutrients on immune system is a point of growing research interest. Recent studies have found pro- and anti-inflammatory properties of some diet patterns and nutrients that can be used from the bench to the bedside for chronic low-grade inflammatory status correction. In this regard, the assessment of potential effects of nutrition on macrophage differentiation, proliferation, and functioning in health and disease is highly demanded. In this review, we present current data on the effects of nutrients on the macrophage functioning.

Gondoic acid alleviates LPS‑induced Kupffer cells inflammation by inhibiting ROS production and PKCθ/ERK/STAT3 signaling pathway

Kupffer cells (KCs) is the main macrophage in liver, and its inflammation is related to liver diseases. It has been shown that inflammatory macrophages are accompanied by changes in monounsaturated fatty acid (MUFA) content. However, the effect of gondoic acid (GA) on inflammation and its underlying mechanism have not been described. In the current study, we demonstrated that GA significantly inhibited the expression of pro-inflammatory factors in LPS-exposed KCs. Further research found that GA reduced lipopolysaccharide (LPS)-stimulated reactive oxygen species (ROS) levels and enhanced the expression of antioxidant genes. Meanwhile, GA obviously blocked the LPS-stimulated PKCθ/ERK/STAT3 signaling pathways to alleviate the inflammatory responses. These results demonstrated for the first time that GA improves KCs inflammation through the inhibition of ROS production and PKCθ/ERK/STAT3 signaling pathway, the results assist in the potential development of functional foods or prodrugs based on the GA rich plant oils.

Polyphenols extracted from Shanxi-aged vinegar exert hypolipidemic effects on OA-induced HepG2 cells via the PPARα-LXRα-ABCA1 pathway

Hyperlipidemia is one of the key risk factors causing many chronic diseases, and lowering blood lipid levels can prevent many diseases. In this paper, a hyperlipidemic cell model of oleic acid (OA) induced hepatocellular carcinoma cells (HepG2) was established using polyphenols extracted from Shanxi-aged vinegar (SAVEP). The effects of SAVEP on nuclear damage, mitochondrial membrane potential, apoptosis, cellular lipid deposition, and lipid metabolism protein expression in HepG2 hyperlipidemic cells were examined to investigate the lipid-lowering mechanism of SAVEP at the cellular level. The results showed that SAVEP could reduce the content of TC/TG index, repair the nuclear damage, reduce lipid accumulation and finally decrease the rate of apoptosis by up-regulating the expression of key proteins such as PPARα, LXRα, and ABCA1 in the process of lipid metabolism. PRACTICAL APPLICATIONS: In this thesis, the hypolipidemic activity of polyphenol extracts from Shanxi-aged vinegar was analyzed on the level of HepG2 cells. The hypolipidemic mechanism of oxidative stress, lipid metabolism and inflammatory stress was also elucidated. It provided a theoretical basis for the in-depth understanding of the hypolipidemic health effects of Shanxi-aged vinegar.