The effects of Nigella sativa extract on hypothyroidism-associated learning and memory impairment during neonatal and juvenile growth in rats.

OBJECTIVES: It has been shown that hypothyroidism-induced oxidative damage in brain tissue is involved in its adverse effects on learning and memory. Nigella sativa (N. sativa) has been suggested to have antioxidant and neuroprotective effects. The objective of this study was to investigate the effects of hydroalcoholic extract of N. sativa on hypothyroidism-associated learning and memory impairment during neonatal and juvenile growth in rats. METHODS: Thirty pregnant rats were kept in separate cages. After delivery, the mothers and their offspring were randomly divided into six groups including: (1) control, (2) PTU (propylthiouracil), (3) PTU-NS 100, (4) PTU-NS 200, (5) PTU-NS 400, and (6) PTU-Vit C (vitamin C). All dams except the control group received 0.005% PTU in their drinking water during lactation. Besides PTU, dams in groups 3, 4, 5, and 6 received 100, 200, and 400 mg/kg N. sativa extract, or 100 mg/kg Vit C, respectively. After lactation period, pups continued to receive same experimental treatment for the first 8 weeks of their life. Then, 10 male offspring of each group were randomly selected and assessed for the learning and memory abilities by using Morris water maze (MWM) and passive avoidance (PA) tests. Blood samples were collected for thyroxine assessment, animals were euthanized, and the brain tissues were removed and analyzed for total thiol groups and malondialdehyde (MDA) concentrations. RESULTS: PTU exposure significantly increased the time latency in MWM test, while reduced the time spent in target quadrant, and decreased the latency for entering the dark compartment in PA test. These effects were associated with significant reduction in serum thyroxine levels and brain levels of thiol groups, and significant elevation in hippocampal MDA. Administration of 400 mg/kg N. sativa extract and 100 mg/kg Vit C reduced the time latency, while increased the time spent in target quadrant compared to the PTU group in MWM test. Treatment by 100-400 mg/kg of N. sativa extract and also Vit C significantly increased the time latency for entering the dark compartment in PA test. The serum thyroxine concentrations of the animals treated by all doses of the N. sativa extract as well as by Vit C were higher than that of the PTU group. Two hundred and four hundred milligrams/kilogram of NS extract and 100 mg/kg Vit C decreased the MDA concentration in hippocampal tissues, while increased thiol contents compared to the PTU group. DISCUSSION: The results of this study demonstrate that the hydroalcoholic extract of N. sativa have protective effects on hypothyroidism-associated learning and memory impairment during neonatal and juvenile growth in rats. The effects were comparable to Vit C and might be due to the protective effects of N. sativa extract against brain tissues' oxidative damage.

Dietary flaxseed modulates the colonic microenvironment in healthy C57Bl/6 male mice which may alter susceptibility to gut-associated diseases.

Understanding how dietary components alter the healthy baseline colonic microenvironment is important in determining their roles in influencing gut health and gut-associated diseases. Dietary flaxseed (FS) has demonstrated anti-colon cancer effects in numerous rodent models, however, exacerbated acute colonic mucosal injury and inflammation in a colitis model. This study investigates whether FS alters critical aspects of gut health in healthy unchallenged mice, which may help explain some of the divergent effects observed following different gut-associated disease challenges. Four-week-old C57Bl/6 male mice were fed an AIN-93G basal diet (BD) or an isocaloric BD+10% ground FS diet for 3 weeks. FS enhanced colon goblet cell density, mucus production, MUC2 mRNA expression, and cecal short chain fatty acid levels, indicative of beneficial intestinal barrier integrity responses. Additionally, FS enhanced colonic regenerating islet-derived protein 3 gamma (RegIIIγ) and reduced MUC1 and resistin-like molecule beta (RELMß) mRNA expression which may indicate altered responses in regulating microbial defense and injury repair responses. FS diet altered the fecal microbial community structure (16S rRNA gene profiling), including a 20-fold increase in Prevotella spp. and a 30-fold reduction in Akkermansia muciniphila abundance. A 10-fold reduction in A. muciniphila abundance by FS was also demonstrated in the colon tissue-associated microbiota (quantitative PCR). Furthermore, fecal branched chain fatty acids were increased by FS, indicative of increased microbial-derived putrefactive compounds. In conclusion, consumption of a FS-supplemented diet alters the baseline colonic microenvironment of healthy mice which may modify subsequent mucosal microbial defense and injury-repair responses leading to altered susceptibility to different gut-associated diseases.

Diets enriched with cranberry beans alter the microbiota and mitigate colitis severity and associated inflammation.

Common beans are rich in phenolic compounds and nondigestible fermentable components, which may help alleviate intestinal diseases. We assessed the gut health priming effect of a 20% cranberry bean flour diet from two bean varieties with differing profiles of phenolic compounds [darkening (DC) and nondarkening (NDC) cranberry beans vs. basal diet control (BD)] on critical aspects of gut health in unchallenged mice, and during dextran sodium sulfate (DSS)-induced colitis (2% DSS wt/vol, 7 days). In unchallenged mice, NDC and DC increased (i) cecal short-chain fatty acids, (ii) colon crypt height, (iii) crypt goblet cell number and mucus content and (iv) Muc1, Klf4, Relmß and Reg3γ gene expression vs. BD, indicative of enhanced microbial activity and gut barrier function. Fecal 16S rRNA sequencing determined that beans reduced abundance of the Lactobacillaceae (Ruminococcus gnavus), Clostridiaceae (Clostridium perfringens), Peptococcaceae, Peptostreptococcaceae, Rikenellaceae and Pophyromonadaceae families, and increased abundance of S24-7 and Prevotellaceae. During colitis, beans reduced (i) disease severity and colonic histological damage, (ii) increased gene expression of barrier function promoting genes (Muc1-3, Relmß, and Reg3γ) and (iii) reduced colonic and circulating inflammatory cytokines (IL-1ß, IL-6, IFNγ and TNFα). Therefore, prior to disease induction, bean supplementation enhanced multiple concurrent gut health promoting parameters that translated into reduced colitis severity. Moreover, both bean diets exerted similar effects, indicating that differing phenolic content did not influence the endpoints assessed. These data demonstrate a proof-of-concept regarding the gut-priming potential of beans in colitis, which could be extended to mitigate the severity of other gut barrier-associated pathologies.

Anti-inflammatory and anti-chemotactic effects of dietary flaxseed oil on CD8(+) T cell/adipocyte-mediated cross-talk.

SCOPE: CD8(+) T cell/adipocyte paracrine interactions represent a critical step in the development of the obese inflammatory phenotype that is disrupted by long-chain n-3 PUFA. Our objective was to determine the effect of flaxseed-derived n-3 PUFA (α-linolenic acid) on these paracrine interactions. METHODS AND RESULTS: C57BL/6 mice were fed 3.5% flaxseed oil (FX) + 3.5% corn oil diet w/w or an isocaloric 7% corn oil w/w control diet (CON) for 3 wk. 3T3-L1 adipocytes and purified primary splenic CD8(+) T cells were cocultured at an obese cellular ratio (10% CD8(+) T cells) and LPS-stimulated (10 ng/mL mimicking obese circulating endotoxin levels) for 24 h. FX cocultures reduced (i) secreted IL-6, tumor necrosis factor α (TNF-α), macrophage chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 1α (MIP-1α), and RANTES (regulated on activation, normal T cell expressed and secreted) levels; (ii) activation of inflammatory transcription factors NFκB (nuclear factor kappa-light-chain-enhancer of activated B cell) p65 and signal transducer and activator of transcription-3 (STAT3); and (iii) RAW264.7 macrophage chemotaxis versus CON (p ≤ 0.05). Coculture of pre-inflamed adipocytes (10 ng/mL LPS, 24 h prior to CD8(+) T-cell addition) resulted in reduced secretion of IL-6, IL-1ß, MCP-1, MCP-3, MIP-1ß, and RANTES in FX cocultures versus CON (p ≤ 0.05). CONCLUSION: FX exerts an anti-chemotactic and anti-inflammatory effect on CD8(+) T cell/adipocyte paracrine interactions (cross-talk), which has the potential to mitigate macrophage chemotaxis which drives components of the obese phenotype.

Effects of melatonin and theanine administration on pentylenetetrazole-induced seizures and brain tissue oxidative damage in ovariectomized rats.

BACKGROUND/AIM: The effects of coadministration of melatonin and theanine (Mel/Thea) on pentylenetetrazole (PTZ)-induced seizures and brain tissue oxidative damage were investigated in ovariectomized (OVX) and sham-operated rats. MATERIALS AND METHODS: The rats were divided into the following groups: 1) sham, 2) ovariectomized (OVX), 3) sham-PTZ, 4) OVX- PTZ, 5) sham-Mel/Thea-PTZ, and 6) OVX-Mel/Thea-PTZ. Groups 1-4 received saline, while groups 5 and 6 received a combination of Mel/Thea for 6 weeks. All animals except for those in groups 1 and 2 received a single injection of PTZ. RESULTS: The OVX-PTZ group had higher generalized tonic-clonic seizure (GTCS) latency compared to the sham-PTZ group. Administration of Mel/Thea increased minimal clonic seizure and GTCS latencies in both the sham-Mel/Thea-PTZ and OVX-Mel/Thea-PTZ groups compared to the controls. Additionally, PTZ exposure increased malondialdehyde levels and reduced thiol concentrations in brain tissues of both the sham-PTZ and OVX-PTZ groups. Mel/Thea pretreatment resulted in MDA reduction and thiol increase in brain tissues. CONCLUSION: The results of this study demonstrated the antioxidant and anticonvulsant activities of Mel/Thea despite the presence or absence of ovarian hormones.

White and dark kidney beans reduce colonic mucosal damage and inflammation in response to dextran sodium sulfate.

Common beans are a rich source of nondigestible fermentable components and phenolic compounds that have anti-inflammatory effects. We assessed the gut-health-promoting potential of kidney beans in healthy mice and their ability to attenuate colonic inflammation following dextran sodium sulphate (DSS) exposure (via drinking water, 2% DSS w/v, 7 days). C57BL/6 mice were fed one of three isocaloric diets: basal diet control (BD), or BD supplemented with 20% cooked white (WK) or dark red kidney (DK) bean flour for 3 weeks. In healthy mice, anti-inflammatory microbial-derived cecal short chain fatty acid (SCFA) levels (acetate, butyrate and propionate), colon crypt height and colonic Mucin 1 (MUC1) and Resistin-like Molecule beta (Relmß) mRNA expression all increased in WK- and DK-fed mice compared to BD, indicative of enhanced microbial activity, gut barrier integrity and antimicrobial defense response. During colitis, both bean diets reduced (a) disease severity, (b) colonic histological damage and (c) increased mRNA expression of antimicrobial and barrier integrity-promoting genes (Toll-like Receptor 4 (TLR4), MUC1-3, Relmß and Trefoil Factor 3 (TFF3)) and reduced proinflammatory mediator expression [interleukin (IL)-1ß, IL-6, interferon (IFN)γ, tumor necrosis factor (TNF)α and monocyte chemoattractant protein-1], which correlated with reduced colon tissue protein levels. Further, bean diets exerted a systemic anti-inflammatory effect during colitis by reducing serum levels of IL-17A, IFNγ, TNFα, IL-1ß and IL-6. In conclusion, both WK and DK bean-supplemented diets enhanced microbial-derived SCFA metabolite production, gut barrier integrity and the microbial defensive response in the healthy colon, which supported an anti-inflammatory phenotype during colitis. Collectively, these data demonstrate a beneficial colon-function priming effect of bean consumption that mitigates colitis severity.

Dietary flaxseed intake exacerbates acute colonic mucosal injury and inflammation induced by dextran sodium sulfate.

Flaxseed (FS), a dietary oilseed, contains a variety of anti-inflammatory bioactives, including fermentable fiber, phenolic compounds (lignans), and the n-3 polyunsaturated fatty acid (PUFA) α-linolenic acid. The objective of this study was to determine the effects of FS and its n-3 PUFA-rich kernel or lignan- and soluble fiber-rich hull on colitis severity in a mouse model of acute colonic inflammation. C57BL/6 male mice were fed a basal diet (negative control) or a basal diet supplemented with 10% FS, 6% kernel, or 4% hull for 3 wk prior to and during colitis induction via 5 days of 2% (wt/vol) dextran sodium sulfate (DSS) in their drinking water (n = 12/group). An increase in anti-inflammatory metabolites (hepatic n-3 PUFAs, serum mammalian lignans, and cecal short-chain fatty acids) was associated with consumption of all FS-based diets, but not with anti-inflammatory effects in DSS-exposed mice. Dietary FS exacerbated DSS-induced acute colitis, as indicated by a heightened disease activity index and an increase in colonic injury and inflammatory biomarkers [histological damage, apoptosis, myeloperoxidase, inflammatory cytokines (IL-6 and IL-1ß), and NF-κB signaling-related genes (Nfkb1, Ccl5, Bcl2a1a, Egfr, Relb, Birc3, and Atf1)]. Additionally, the adverse effect of the FS diet was extended systemically, as serum cytokines (IL-6, IFNγ, and IL-1ß) and hepatic cholesterol levels were increased. The adverse effects of FS were not associated with alterations in fecal microbial load or systemic bacterial translocation (endotoxemia). Collectively, this study demonstrates that although consumption of a 10% FS diet enhanced the levels of n-3 PUFAs, short-chain polyunsaturated fatty acids, and lignans in mice, it exacerbated DSS-induced colonic injury and inflammation.

Cooked navy and black bean diets improve biomarkers of colon health and reduce inflammation during colitis.

Common beans contain non-digestible fermentable components (SCFA precursors) and phenolic compounds (phenolic acids, flavonoids and anthocyanins) with demonstrated antioxidant and anti-inflammatory potential. The objective of the present study was to assess the in vivo effect of cooked whole-bean flours, with differing phenolic compound levels and profiles, in a mouse model of acute colitis. C57BL/6 mice were fed a 20 % navy bean or black bean flour-containing diet or an isoenergetic basal diet (BD) for 2 weeks before the induction of experimental colitis via 7 d dextran sodium sulphate (DSS, 2 % (w/v) in the drinking-water) exposure. Compared with the BD, both bean diets increased caecal SCFA and faecal phenolic compound concentrations (P< 0·05), which coincided with both beneficial and adverse effects on colonic and systemic inflammation. On the one hand, bean diets reduced mRNA expression of colonic inflammatory cytokines (IL-6, IL-9, IFN-γ and IL-17A) and increased anti-inflammatory IL-10 (P< 0·05), while systemically reduced circulating cytokines (IL-1ß, TNFα, IFNγ, and IL-17A, P< 0·05) and DSS-induced oxidative stress. On the other hand, bean diets enhanced DSS-induced colonic damage as indicated by an increased histological injury score and apoptosis (cleaved caspase-3 and FasL mRNA expression) (P< 0·05). In conclusion, bean-containing diets exerted both beneficial and adverse effects during experimental colitis by reducing inflammatory biomarkers both locally and systemically while aggravating colonic mucosal damage. Further research is required to understand the mechanisms through which beans exert their effects on colonic inflammation and the impact on colitis severity in human subjects.