Fisetin and telmisartan each alone or in low-dose combination alleviate OVA-induced food allergy in mice

Therapeutic effects of candesartan in inflammatory skin disorders by suppressing Th17 differentiation

As angiotensin II is associated with inflammation, type I angiotensin II receptor blockers (ARBs) exibit anti-inflammatory effects in patients with hypertension as well as inflammatory disease animal models including arthritis models. The present study aimed to investigate whether ARBs exert anti-inflammatory effects in vivo in skin disorders. We tested effects of ARBs on 1-chloro-2,4-dinitrobenzene(CDNB)-induced atopic dermatitis-like and imiquimod-induced psoriasis-like skin models. CDNB-induced atopic dermatitis-like skin lesions were suppressed by administration of candesartan or telmisartan. The suppressive effect of telmisartan was blocked by the presence of GW9662, a selective PPARγ inhibitor, but not that of candesartan. Both ARBs suppressed increases in pro-inflammatory cytokine (IL-4, IL-13, IFN-γ, and IL-17A) levels, and GW9662 inhibited telmisartan-induced suppression but not candesartan. Candesartan significantly inhibited in vitro differentiation of naïve T cells into Th17 cells to a greater extent than telmisartan. In the imiquimod-induced psoriasis model, whose primary etiology is activation of IL-23/IL-17 axis, candesartan significantly suppressed psoriasis-like skin lesions and Th17 cell populations in both lymph nodes and spleens to a greater extent than telmisartan. Overall, certain ARBs may have anti-inflammatory effects in skin diseases. Candesartan may have therapeutic implications in inflammatory skin disorders by suppressing Th17 differentiation, while telmisartan might have therapeutic potential by activating PPARγ.

Intermittent fasting protects against food allergy in a murine model via regulating gut microbiota

Background

The prevalence of food allergy (FA) is increasing. Decreases in the diversity of gut microbiota may contribute to the pathogenesis of FA by regulating IgE production of B cells. Intermittent fasting (IF) is a popular diet with the potential to regulate glucose metabolism, boosting immune memory and optimizing gut microbiota. The potential effect of long-term IF on the prevention and treatment of FA is still unknown.

Methods

Two IF protocols (16 h fasting/8 h feeding and 24 h fasting/24 h feeding) were conducted on mice for 56 days, while the control mice were free to intake food (free diet group, FrD). To construct the FA model, all mice were sensitized and intragastrical challenged with ovalbumin (OVA) during the second half of IF (day 28 to day 56). Rectal temperature reduction and diarrhea were recorded to evaluate the symptoms of FA. Levels of serum IgE, IgG1, Th1/Th2 cytokines, mRNA expression of spleen T cell related transcriptional factors, and cytokines were examined. H&E, immunofluorescence, and toluidine blue staining were used to assess the structural changes of ileum villi. The composition and abundance of gut microbiota were analyzed by 16srRNA sequencing in cecum feces.

Results

The diarrhea score and rectal temperature reduction were lower in the two fasting groups compared to the FrD groups. Fasting was associated with lower levels of serum OVA-sIgE, OVA-sIgG1, interleukin (IL)-4 and IL-5, and mRNA expression of IL-4, IL-5, and IL-10 in the spleen. While no significant association was observed in interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-6, IL-2 levels. Less mast cell infiltration in ileum was observed in the 16h/8h fasting group compared to the FrD group. ZO-1 expression in the ileum of the two fasting groups was higher in IF mice. The 24h/24h fasting reshaped the gut microbiota, with a higher abundance of Alistipes and Rikenellaceae strains compared to the other groups.

Conclusion

In an OVA-induced mice FA model, long-term IF may attenuate FA by reducing Th2 inflammation, maintaining the integrity of the intestinal epithelial barrier, and preventing gut dysbiosis.

Potential Allergenicity Response to Moringa oleifera Leaf Proteins in BALB/c Mice

The reported association of Moringa oleifera seeds and allergic disease clinically resembling occupational asthma in cosmetic manufacturing workers has resultedin the need to identify such components in the manufacturing process. However, Moringa oleifera leaves from the same plant, an important food ingredient, have limited immunotoxicity data. This study aimed to determine if Moringa oleifera leafproteins (MLP) can elicit allergic responses in BALB/c mice. The BALB/c mice were sensitized twice and challenged 10 times to evaluate the potential allergenicityof MLP in vivo. The results showed increased levels of mast cells, total and specific IgE and IgG, severe signs of systemic anaphylaxis, and reduced body temperature compared with controls. The sensitized mice serum observed enhanced levels of histamine and Th-related cytokine release. Compared with the control group, increased levels of interleukins IL-4, IL-9, and IL-17A and enhanced expression and secretion of normal T cells were found in the culture supernatant of splenocytes treated with MLP.This study suggeststhat MLPcanelicit allergic responses; this providesmore comprehensive guidance for identifying new allergen candidates and developing hypoallergenic MLP products.

Resveratrol Treatment Prevents Increase of Mast Cells in Both Murine OVA Enteritis and IL-10-/- Colitis

Mast cells are involved in allergic and other inflammatory diseases. The polyphenol resveratrol is known for its anti-inflammatory properties and may be used as nutraceutical in mast cell associated diseases. We analyzed the effect of resveratrol on mast cells in vivo in ovalbumin-induced allergic enteritis as well as experimental colitis in IL-10^−/− mice which received resveratrol via drinking water. Treatment with resveratrol prevented the increase in mast cells in both allergic enteritis and chronic colitis in duodenum as well as in colon. Further, it delayed the onset of diseases symptoms and ameliorated diseases associated parameters such as tissue damage as well as inflammatory cell infiltration in affected colon sections. In addition to the findings in vivo, resveratrol inhibited IgE-dependent degranulation and expression of pro-inflammatory cytokines such as TNF-α in IgE/DNP-activated as well as in LPS-activated bone marrow-derived mast cells. These results indicate that resveratrol may be considered as an anti-allergic and anti-inflammatory plant-derived component for the prevention or treatment of mast cell-associated disorders of the gastrointestinal tract.