High-fat diet intake from senescence inhibits the attenuation of cell functions and the degeneration of villi with aging in the small intestine, and inhibits the attenuation of lipid absorption ability in SAMP8 mice

Senolytic Treatment Improve Small Intestine Regeneration in Aging

Aging induces a series of alterations, specifically a decline in the stature and number of villi and crypts in the small intestine, thus compromising the absorbent capability of the villi. This investigation employed a senolytic combination of dasatinib and quercetin (D+Q) to examine its impact on the intestinal tract of elderly mice. Our findings demonstrate that D+Q treatment leads to a decrease in the expression of p21, p16, and Ki67, while concurrently triggering removal of apoptotic cells within the villi. Additionally, D+Q treatment exhibits the ability to promote growth in both the height and quantity of villi and crypts, along with stimulating nitric oxide (NO) production in aged mice. The study presented a model to assess strategies to alleviate age-related senescence in the intestinal tract of elderly mice. Importantly, D+Q showcases promising potential in enhancing intestinal functionality within the aging.

Bazi Bushen capsule improves the deterioration of the intestinal barrier function by inhibiting NLRP3 inflammasome-mediated pyroptosis through microbiota-gut-brain axis

Purpose

The senescence-accelerated prone mouse 8 (SAMP8) is a widely used model for accelerating aging, especially in central aging. Mounting evidence indicates that the microbiota-gut-brain axis may be involved in the pathogenesis and progression of central aging-related diseases. This study aims to investigate whether Bazi Bushen capsule (BZBS) attenuates the deterioration of the intestinal function in the central aging animal model.

Methods

In our study, the SAMP8 mice were randomly divided into the model group, the BZ-low group (0.5 g/kg/d BZBS), the BZ-high group (1 g/kg/d BZBS) and the RAPA group (2 mg/kg/d rapamycin). Age-matched SAMR1 mice were used as the control group. Next, cognitive function was detected through Nissl staining and two-photon microscopy. The gut microbiota composition of fecal samples was analyzed by 16S rRNA gene sequencing. The Ileum tissue morphology was observed by hematoxylin and eosin staining, and the intestinal barrier function was observed by immunofluorescence. The expression of senescence-associated secretory phenotype (SASP) factors, including P53, TNF-α, NF-κB, IL-4, IL-6, and IL-10 was measured by real-time quantitative PCR. Macrophage infiltration and the proliferation and differentiation of intestinal cells were assessed by immunohistochemistry. We also detected the inflammasome and pyroptosis levels in ileum tissue by western blotting.

Results

BZBS improved the cognitive function and neuronal density of SAMP8 mice. BZBS also restored the intestinal villus structure and barrier function, which were damaged in SAMP8 mice. BZBS reduced the expression of SASP factors and the infiltration of macrophages in the ileum tissues, indicating a lower level of inflammation. BZBS enhanced the proliferation and differentiation of intestinal cells, which are essential for maintaining intestinal homeostasis. BZBS modulated the gut microbiota composition, by which BZBS inhibited the activation of inflammasomes and pyroptosis in the intestine.

Conclusion

BZBS could restore the dysbiosis of the gut microbiota and prevent the deterioration of intestinal barrier function by inhibiting NLRP3 inflammasome-mediated pyroptosis. These results suggested that BZBS attenuated the cognitive aging of SAMP8 mice, at least partially, by targeting the microbiota-gut-brain axis.

The Roles of Lipid Metabolism in the Pathogenesis of Chronic Diseases in the Elderly

Lipid metabolism plays crucial roles in cellular processes such as hormone synthesis, energy production, and fat storage. Older adults are at risk of the dysregulation of lipid metabolism, which is associated with progressive declines in the physiological function of various organs. With advancing age, digestion and absorption commonly change, thereby resulting in decreased nutrient uptake. However, in the elderly population, the accumulation of excess fat becomes more pronounced due to a decline in the body's capacity to utilize lipids effectively. This is characterized by enhanced adipocyte synthesis and reduced breakdown, along with diminished peripheral tissue utilization capacity. Excessive lipid accumulation in the body, which manifests as hyperlipidemia and accumulated visceral fat, is linked to several chronic lipid-related diseases, including cardiovascular disease, type 2 diabetes, obesity, and nonalcoholic fatty liver disease. This review provides a summary of the altered lipid metabolism during aging, including lipid digestion, absorption, anabolism, and catabolism, as well as their associations with age-related chronic diseases, which aids in developing nutritional interventions for older adults to prevent or alleviate age-related chronic diseases.

Oxidative, epigenetic changes and fermentation processes in the intestine of rats fed high-fat diets supplemented with various chromium forms

The aim of the study was to determine how feeding rats a high-fat diet (F) supplemented with various forms of chromium affects the responses of the immune and redox systems, as well as epigenetic changes in the ileal tissue and the course of fermentation processes in the caecum. The rats received a pharmacologically relevant dose 0.3 mg Cr/kg body weight in form of chromium(III) picolinate (Cr-Pic), chromium (III)-methionine (Cr-Met), or chromium nanoparticles (Cr-NPs). The F increased DNA oxidation and raised the level of interleukin IL-6. The F was shown to reduce the intensity of fermentation processes in the caecum while increasing the activity of potentially harmful enzymes in the faeces. The addition of Cr in the form of Cr-NPs and Cr-Met in rats fed F beneficially increased mobilization of enzymes of the DNA repair pathway. All forms of Cr, but especially Cr-NPs, beneficially decreased the activity of caecal bacterial β-glucuronidase, faecal β-glucosidase and β-glucuronidase. However, due to the increase in level of cytokine IL-2 in small intestinal wall, induced by all tested forms of chromium, it is difficult to state conclusively that this element can mitigate unfavourable pro-inflammatory and oxidative changes induced by a F in the small intestinal wall.

Carbohydrate-restricted diet alters the gut microbiota, promotes senescence and shortens the life span in senescence-accelerated prone mice

This study examined the effects of a carbohydrate-restricted diet on aging, brain function, intestinal bacteria and the life span to determine long-term carbohydrate-restriction effects on the aging process in senescence-accelerated prone mice (SAMP8). Three-week-old male SAMP8 were divided into three groups after a week of preliminary feeding. One group was given a controlled diet, while the others fed on high-fat and carbohydrate-restricted diets, respectively. The mice in each group were further divided into two subgroups, of which one was the longevity measurement group. The other groups fed ad libitum until the mice were 50 weeks old. Before the test period termination, passive avoidance test evaluated the learning and memory abilities. Following the test period, serum and various mice organs were obtained and submitted for analysis. The carbohydrate-restricted diet group exhibited significant decrease in the survival rate as compared to the other two diet groups. The passive avoidance test revealed a remarkable decrease in the learning and memory ability of carbohydrate-restricted diet group as compared to the control-diet group. Measurement of lipid peroxide level in tissues displayed a marked increase in the brain and spleen of carbohydrate-restricted diet group than the control-diet and high-fat diet groups. Furthermore, notable serum IL-6 and IL-1β level (inflammation indicators) elevations, decrease in Enterobacteria (with anti-inflammatory action), increase in inflammation-inducing Enterobacteria and lowering of short-chain fatty acids levels in cecum were observed in the carbohydrate-restricted diet group. Hence, carbohydrate-restricted diet was revealed to promote aging and shortening of life in SAMP8.

Chronic high fat feeding paradoxically attenuates cerebral capillary dysfunction and neurovascular inflammation in Senescence-Accelerated-Murine-Prone Strain 8 mice

Background: A body of epidemiological, clinical and preclinical studies suggest increased risk for cerebro- and cardio-vascular disease associated with dietary ingestion of long-chain saturated fatty acids (LCSFA). In wild-type rodent models, chronic ingestion of LCSFA diets are associated with increased cerebral capillary permeability, heightened neurovascular inflammation and poorer cognitive performance. However, recent studies suggest that diets enriched in fat may paradoxically attenuate elements of the ageing phenotype via a caloric support axis.Objective: The purpose of this study was to explore the effects of dietary LCSFA on cerebral capillary integrity and neurovascular inflammation in an established model of accelerated ageing, Senescence-Accelerated-Murine-Prone Strain 8 (SAMP8) mice.Methods: From 6 weeks of age, SAMP8 mice and age-matched controls were randomised to either normal chow, or to an LCSFA-enriched diet, for either 12 or 34 weeks. An additional group of SAMP8 mice were provided the LCSFA-enriched diet for 12 weeks followed by the provision of ordinary low-fat chow for 22 weeks. Ex vivo measures of cerebrovascular integrity, neurovascular inflammation and astrocytic activation, were determined via 3-dimensional immunofluorescent confocal microscopy methodologies.Results: LCSFA-fed SAMP8 mice had markedly attenuated cerebral capillary dysfunction concomitant with reduced microglial activation. In SAMP8 mice transiently maintained on an LCSFA diet for 12 weeks, suppression of neurovascular inflammation persisted. Marked hippocampal astrogliosis was evident in LCSFA-fed mice when compared to SAMP8 mice maintained on ordinary chow.Conclusion: The findings from this study support the notion that high-fat, potentially ketogenic diets, may confer neuroprotection in SAMP8 mice through a vascular-support axis.

Association of Lifelong Intake of Barley Diet with Healthy Aging: Changes in Physical and Cognitive Functions and Intestinal Microbiome in Senescence-Accelerated Mouse-Prone 8 (SAMP8)

Barley intake reportedly reduces the risk of cardiovascular disease, but effects on the systemic phenotypes during healthy aging have not yet been examined. Therefore, we examined the effects of barley on the lifespan; behavioral phenotypes, such as locomotor activity, and cognitive functions, and intestinal microbiome in the senescence-accelerated mouse-prone 8 (SAMP8) mouse. We prepared two mild high-fat diets by adding lard, in which the starch components of AIN-93G were replaced by rice or barley "Motchiriboshi." SAMP8 (four weeks old, male) mice were fed AIN-93G until eight weeks old, and then rice (rice group) or barley diet (rice: barley = 1:4, barley group) until death. Changes in aging-related phenotypes, object and spatial recognition, locomotor and balancing activities, and the intestinal microbiome were recorded. Moreover, plasma cholesterol levels were analyzed at 16 weeks old. Barley intake prolonged the lifespan by approximately four weeks, delayed locomotor atrophy, and reduced balancing ability and spatial recognition. Barley intake significantly increased the medium and small particle sizes of high-density lipoprotein (HDL) cholesterol, which is associated with a reduced risk of total stroke. The Bacteroidetes to Firmicutes ratio in the barley group was significantly higher than that in the rice group during aging. Thus, lifelong barley intake may have positive effects on healthy aging.

Influence of long-term feeding of high-fat diet on quercetin and fat absorption from the small intestine in lymph duct-cannulated rats

This study aimed to investigate the effect of dietary lipids and a long-term high-fat diet on lymphatic triglyceride and quercetin absorption in rats with a surgically implanted thoracic lymph cannula. Quercetin-3-O-β-glucoside reduced the lymphatic triglyceride output from the intestines; this reduction was prominent among rats fed a high-fat diet.

Standardisation of the Japanese diet for use in animal experiments

The aim of this study was to develop a purified diet that mimics the characteristics of the Japanese diet using readily available materials with a simpler composition and a focus on quality, with the goal of facilitating performance of studies on the Japanese diet worldwide. The utility of the new diet was examined as a mimic of the standard Japanese diet for use in animal experiments. We examined whether a key characteristic of the Japanese diet of being less likely to cause obesity could be reproduced. The mimic diet had a balance of protein, fat and carbohydrate based on the 1975 Japanese diet, which is the least likely to cause obesity, and materials chosen with reference to the National Health and Nutrition Survey (NHNS). To examine similarities of the mimic diet with the model 1975 Japanese diet, we created a menu of the 1975 diet based on the NHNS and prepared the freeze-dried and powdered diet. The mimic diet, the 1975 Japanese diet, a control AIN-93G diet and a Western diet were fed to mice for 4 weeks. As a result, the mimic diet and the 1975 diet resulted in less accumulation of visceral fat and liver fat. Mice given these two diets showed similar effects. This indicates that the mimic diet used in this study has characteristics of the 1975 Japanese diet and could be used as a standard Japanese diet in animal experiments.

Gastrointestinal Motility, Mucosal Mast Cell, and Intestinal Histology in Rats: Effect of Prednisone

Our aim was to verify the effects of prednisone related to gastrointestinal motility, intestinal histology, and mucosal mast cells in rats. Two-month-old male Wistar rats were randomly assigned to control group (vehicle) animals receiving saline 0.9% (n = 7) or treated orally with 0.625 mg/kg/day of prednisone (n = 7) or 2.5 mg/kg/day of prednisone (n = 7) during 15 days. Mast cells and other histologic analyses were performed in order to correlate to gastric emptying, cecum arrival, and small intestine transit evaluated by Alternating Current Biosusceptometry. Results showed that prednisone in adult rats increased the frequency of gastric contractions, hastened gastric emptying, slowed small intestinal transit, and reduced mucosal mast cells. Histologically, the treatment with both doses of prednisone decreased villus height, whereas longitudinal and circular muscles and crypt depth were not affected. These findings indicate an impairment of intestinal absorption which may be linked to several GI dysfunctions and symptoms. The relationship between gastrointestinal motor disorders and cellular immunity needs to be clarified in experimental studies since prednisone is one of the most prescribed glucocorticoids worldwide.

Intake of mulberry 1-deoxynojirimycin prevents colorectal cancer in mice

The effect of 1-deoxynojirimycin, a caloric restriction mimetic, was examined in ICR mice with azoxymethane dextran sodium sulfate-induced colorectal cancer. Azoxymethane is a carcinogen (10 mg/kg body weight), and 2% dextran sodium sulfate (w/v) used as a colitis-inducing agent. Mice were separated into 5 groups: a group without colorectal cancer fed a normal diet (CO– group), and groups with colorectal cancer fed a normal diet (CO+ group), a calorie-restricted diet (caloric restriction group), and diets including 0.02% and 0.1% 1-deoxynojirimycin (l-1-deoxynojirimycin and H-1-deoxynojirimycin groups). The tumor incidence and number were reduced significantly in the caloric restriction group compared to the CO+ group, and were also suppressed in a dose-dependent manner by 1-deoxynojirimycin. mRNA for anti-apoptotic Bcl-2 was decreased and that for pro-apoptotic Bax was increased in the carcinoma tissue of CR, l-1-deoxynojirimycin and H-1-deoxynojirimycin groups. These results suggest that caloric restriction and 1-deoxynojirimycin inhibit growth of colorectal cancer by inducing apoptosis in an induced cancer model in mice.