Dietary chitosan supplementation attenuates isoprenaline-induced oxidative stress in rat myocardium

Unveiling the Cardioprotective Power: Liquid Chromatography-Mass Spectrometry (LC-MS)-Analyzed Neolamarckia cadamba (Roxb.) Bosser Leaf Ethanolic Extract against Myocardial Infarction in Rats and In Silico Support Analysis

Neolamarckia cadamba (Roxb.) Bosser, a member of the Rubiaceae family, is a botanical species with recognized therapeutic properties. It is commonly used in traditional medicine to treat cardiac ailments and other disorders. However, the precise active constituents and the potential mechanisms by which they manage cardiovascular disorders remain unclear. Therefore, this study aimed to ascertain the bioactive components and investigate their underlying mechanisms of action. N. cadamba is used to treat cardiovascular disorders using the integrated metabolomic methodology. An HPLC-QTOF-MS/MS analysis determined the potential chemicals in the N. cadamba leaf ethanol extract (NCEE). A thorough investigation of the NCEE samples used in this study led to the identification of 32 phytoconstituents. Of the 32 compounds, 19 obeyed Lipinski's rule of five (RO5). A molecular docking study directed towards HMG-CoA reductase used 19 molecules. The reference drug atorvastatin indicated a binding energy of -3.9 kcal/mol, while the other substances, Cinchonain Ib and Dukunolide B, revealed binding energies of -5.7 and -5.3 kcal/mol, respectively. Both phytocompounds showed no toxicity and exhibited favorable pharmacokinetic properties. In vivo study results concluded that treatment with NCEE significantly reduced the cardiac myocardial infarction (MI) marker CK-MB and atherogenic risk indices, such as the atherogenic index plasma (AIP), cardiac risk ratio (CRR), and atherogenic coefficient (AC) in isoproterenol-induced MI rats. In MI rats, NCEE therapy significantly improved the antioxidant system of the heart tissue, as evidenced by the increased levels of GSH and SOD, lower levels of the oxidative stress marker MDA, and significantly decreased HMG-CoA activity. Additionally, electrocardiogram (ECG) signals from rats treated with NCEE resembled those treated with traditional atorvastatin to treat myocardial infarction. This study used H&E staining to show that administering NCEE before treatment reduced cardiac myocyte degeneration in rats with myocardial infarction, increased the presence of intact nuclei, and increased myocardial fiber strength. The potential cardioprotective effect observed in myocardial infarction (MI) rats treated with NCEE can be extrapolated from computational data to be caused by Cinchonain Ib.

Attenuation of isoprenaline-induced myocardial infarction by Rheum turkestanicum

BACKGROUND

Oxidative stress plays a major role in the pathogenesis of myocardial infarction. This study evaluated the cardioprotective effects of the hydroalcoholic extract of Rheum turkestanicum on isoprenaline-induced myocardial infarction (MI) in Wistar rats.

METHODS

In this study, we used liquid chromatography-mass spectrometry to determine the active compounds present in the extract. Thirty rats were divided to 5 groups (6 rats in each group). The extract was administered orally at the doses of 100 and 300 mg/kg body weight and then a subcutaneous injection of isoprenaline (85 mg/kg) was administered on the 8th and 9th days. Serum levels of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), and creatinine kinase (CPK) were measured using standard commercial kits. Serum activities of superoxide dismutase, catalase, and cardiac levels of thiol and lipid peroxidation were also determined. Hematoxylin and eosin were used for histopathological staining.

RESULTS

Phytochemical analysis revealed the presence of 24 compounds in the hydro-ethanolic extract of R. turkestanicum. Isoprenaline increased malondialdehyde (4.002 ± 0178, P < 0.001) while decreased thiol content (101.7 ± 6.186, P < 0.001). Moreover, reduced activities of superoxide dismutase (139 ± 10.88, P < 0.001) and catalase (2.812 ± 0.215, P < 0.001), and elevated levels of LDH (1245 ± 62.28, P < 0.001), CPK (898 ± 23.06, P < 0.001) and CK-MB (697 ± 50.22, P < 0.001) were observed. Pretreatment with the R. turkestanicum extract significantly reduced cardiac markers and increased thiol content as well as the activity of antioxidant enzymes. The extract attenuated the histopathological changes induced by isoprenaline.

CONCLUSION

According to the obtained results, R. turkestanicum may be an appropriate candidate to reduce isoprenaline-induced MI through modulation of oxidative stress. Administration of the extract attenuated cardiac enzymes following isoprenaline administration. The cardioprotective action of the extract can be attributed to the bioactive antioxidant ingredients of R. turkestanicum. To identify the precise mechanisms, further investigations are required.

Chitosan Displays a Potent Caloric Restriction Mimetic Effect in Senescent Rats

Chitosan is a polysaccharide made up of β1,4-linked d-glucosamine (GlcN) and N-acetyl-GlcN. In this study, we evaluated the possible caloric restriction mimetic (CRM) effect of dietary chitosan on systemic redox status, inflammatory biomarkers, and lipid profile in plasma and erythrocyte samples of d-galactose-induced mimetically aged rats. We found a significant increase (p < 0.05) in the reactive oxygen species, protein carbonyl, fasting glucose, body weight, cholesterol, triglyceride, inflammatory markers-interleukin-6 and tumor necrosis factor-alpha in an accelerated senescent rat model. There was also a significant decrease (p < 0.05) in glutathione, advanced glycation end product in senescent rats. Chitosan treatment increased ferric-reducing antioxidant potential, glutathione, plasma membrane-reduced system in accelerated senescent model of rats. Our finding suggests that chitosan has properties similar to a CRM and can effectively maintain the redox homeostasis during the aging process in rat erythrocytes.

Functional dynamics of myocardial injury biomarkers production during acute isoprenaline treatment in rats

Introduction: Isoprenaline or isoproterenol (1-(3,4-dihydroxyphenyl)-2-isopropylaminoethanolhydrochloride; ISO), a synthetic b-adrenergic agonist, can be used to establish myocardial ischemia, cardiotoxicity, necrosis and/or an experimental model of infarction in rats. Aim: Determination of the dynamics of myocardial injury biomarkers production of aspartate transaminase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), and high-sensitive troponin T (hsTnT), with changes on electrocardiogram (ECG) parameters during the subcutaneous aplication of ISO in male Wistar rats. Material and methods: All animals (n = 23) were divided into two groups: control group (n = 11) treated with a saline solution, during two consecutive days (0,2 ml/kg b.m. daily, sc); and the ISO group (n = 12) treated with isoprenaline, during two consecutive days (85 mg/kg b.m. daily, sc). Blood was drawn from the rat tail vein in both groups, in order to determine serum activity levels of myocardial injury biomarkers, and an ECG (n = 6) was registered prior to the application, as well as 48h following the first dose of of saline solution or isoprenaline. Results: In comparison to the control group, in which no significant enzyme activities elevation (p > 0.05) nor ECG changes were registered, ISO group presented a significant rise of two clinically significant biomarkers of acute myocardial injury/myocardial infarction (AMI), CK (p = 0.05) and hsTnT (p < 0.01), as well as an ST segment elevation, with a patognomonic ECG change. Conclusion: Obtained results support previous studies, proving that isoprenaline represents an adequate experimental model for myocardial injury/AMI induction, and a "golden standard" for evaluating potential cardioprotective effects of pharmacological and non-pharmacological therapeutic modalities, with the ultimate goal of lowering the degree of lesions and improving post-infarction myocardium function.

Antioxidative and Cardioprotective Effects of Schisandra chinensis Bee Pollen Extract on Isoprenaline-Induced Myocardial Infarction in Rats

Oxidative stress plays an important role in the pathogenesis of myocardial infarction (MI). Schisandra chinensis bee pollen extract (SCBPE) possesses powerful antioxidant capacity. This study aimed to further explore the antioxidative and cardioprotective effects of SCBPE on acute MI induced by isoprenaline (ISO) in rats. The rats were intragastrically administrated with SCBPE (600, 1200, or 1800 mg/kg/day) and Compound Danshen dropping pills (270 mg/kg/day) for 30 days, then subcutaneously injected with ISO (65 mg/kg/day) on the 29th and 30th day. Compared with the model group, pretreatment with middle and high doses of SCBPE significantly reduced serum aspartate transaminase, lactate dehydrogenase, and creatine kinase activities and increased myocardial superoxide dismutase, glutathione peroxidase, and catalase activities. The histopathologic aspects showed that pathological heart change was found in the model group and reduced to varying degrees in the SCBPE groups. Moreover, the protein expression of nuclear factor-erythroid 2-related factor 2 (Nrf-2), heme oxygenase-1 (HO-1), and Bcl2 in the heart increased in the SCBPE groups, while that of Bax decreased compared to the model group. Besides this, uridine was isolated from S. chinensis bee pollen for the first time. This study could provide a scientific basis for using Schisandra chinensis bee pollen as a functional food for the prevention of MI.

Chitosan oligosaccharides alleviate PM2.5-induced lung inflammation in rats

Air pollution of particulate matter (PM), especially PM_2.5, has become a major public health problem in China. Exploration of therapeutic and preventive measures against PM_2.5 toxicity is of practical significance. The aim of this study was to examine the inhibitory effects of chitosan oligosaccharides (COS) on PM_2.5-induced lung inflammation in rats. Forty SPF (specific pathogen-free) male Wistar rats weighing 200-220 g were randomly divided into four groups: control group, COS group, PM_2.5 group, and PM_2.5+COS group. COS was pre-administered to rats by gavage at a single dose of 500 mg/kg 2 h before intratracheal instillation of PM_2.5 at a single dose of 1.2 mg/kg daily for 3 consecutive days. Normal saline (NS) was used as negative control. Twenty-four hours after the last instillation of PM_2.5, rats were sacrificed and subjected to bronchoalveolar lavage (BAL). The BAL fluids (BALF) were collected for measurement of levels of total proteins, lactate dehydrogenase (LDH), interleukin-1 (IL-1β), IL-8, and tumor necrosis factor-ɑ (TNF-ɑ) using colorimetric or ELISA kits. Levels of total proteins, LDH activities, and pro-inflammatory mediators including IL-1β, IL-8, and TNF-ɑ in BALF of rats in PM_2.5 group significantly increased in comparison with those of the control group. Pre-treatment of rats with COS markedly blocked PM_2.5-induced increase in LDH, IL-8, and TNF-ɑ levels in BALF. In conclusion, PM_2.5 exposure induces rat lung inflammation, which could be ameliorated by the pre-treatment of COS.

Hypolipidemic activities of partially deacetylated α-chitin nanofibers/nanowhiskers in mice

Partially deacetylated α-chitin nanofibers/nanowhiskers mixtures (DEChNs) were prepared by 35% sodium hydroxide (NaOH) treatment followed by disintegration in water at pH 3-4. The aim of this study was to investigate the hypolipidemic effects of DEChNs at different dosage levels in male Kunming mice. The male mice were randomly separated into five groups, that is, a normal diet group, a high-fat diet group, and three DEChN groups that were treated with different doses of DEChN dispersions (L: low dose, M: medium dose, H: high dose). Primarily, the DEChNs significantly decreased body weight (BW) gain and adipose tissue weight (ATW) gain of mice. Meanwhile, the decreasing extent of weight ratios between ATW and BW was dependent on the dose of DEChNs. Moreover, the DEChNs prevented an increase in plasma lipids (cholesterol and triacylglycerol) in mice when they were fed a high-fat diet. Histopathological examination of hepatocytes revealed that the DEChNs were effective in decreasing the accumulation of lipids in the liver and preventing the development of a fatty liver. The results suggested that the DEChNs reduced the absorption of dietary fat and cholesterol in vivo and could effectively reduce hypercholesterolemia in mice.

Effects of low-molecular-weight chitosan on the growth performance, intestinal morphology, barrier function, cytokine expression and antioxidant system of weaned piglets

Background

Chitosan was used as an alternative to promote the growth of weaned piglets. And low-molecular-weight chitosan (LC) is one of chitosan derivatives and maintain beneficial biological properties of chitoson. The present experiment was carried out to examine the effects of LC on the growth performance, intestinal morphology, barrier function, cytokine expression, and antioxidant system of weaned piglets.

Results

A total of 40 piglets weaned at 21 d of age, with average body weight 6.37 ± 0.08 kg, were randomly assigned (5 pens/diet; 4 pigs/pen) to 2 treatments (a basal diet and the basal diet supplemented with 50 mg/kg LC) and were fed for 28 d. Compared with the control group, average daily feed intake (ADFI), and the expression of intestinal barrier protein ZO-1 was increased (P < 0.05) when the piglets fed the diet supplemented with LC. No significant differences were found in average daily gain (ADG, P > 0.05), gain-to-feed ratio (G:F, P > 0.05), the incidence of diarrhea (P > 0.05), or the antioxidant capacity (P > 0.05) between two groups. The expression of IL-1β and TNF-α in jejunal mucosa were significantly decreased (P < 0.05) in piglets fed the LC-supplemented diet in comparison to the control.

Conclusion

The results of this study indicate that dietary supplementation with LC at 50 mg/kg was effective for enhancing the growth performance in weaned piglets, improving intestinal barrier function and alleviating intestinal inflammation.

Pre-protective effects of dietary chitosan supplementation against oxidative stress induced by diquat in weaned piglets

The protective effects of chitosan (CS) supplementations on oxidative stress induced by diquat in weaned piglets were investigated. A total of 36 crossbreed piglets with an average live body weight (BW) of 8.80 ± 0.53 kg were weaned at 28 ± 2 days and randomly divided into six dietary treatments (n = 6): control (basal diet), negative control (10 mg diquat/kg BW injected to piglets fed with basal diet), and basal diet treatments containing either 250, 500, 1000, or 2000 mg/kg of CS administered to piglets injected with 10 mg diquat/kg BW. The experiment conducted for 21 days which consisted of pre-starter period (14 days) and starter period (7 days). BW, feed intake, and fecal consistency were monitored. Blood samples were collected to determine antioxidative and immune parameters. CS supplementation improved the growth performance and decreased fecal score of piglets from days 1 to 14. Diquat also induced oxidative stress and inflammatory responses by decreasing the activities of antioxidant and regulating cytokines. But dietary CS alleviated these negative effects induced by diquat that showed decreasing serum concentrations of pro-inflammatory cytokines but increasing activities of antioxidant enzymes and anti-inflammatory cytokines. Results indicated that CS attenuated the oxidative stress of piglets caused by diquat injection.

Dietary supplementation of thiamine and pyridoxine-loaded vanillic acid-grafted chitosan microspheres enhances growth performance, metabolic and immune responses in experimental rats

In the present investigation, the effect of dietary supplementation of thiamine and pyridoxine loaded vanillic acid-grafted chitosan microspheres (TPVGC) on growth, metabolic and immune responses in Wistar strain albino rats was studied. Eight experimental groups, namely four groups each for male and female rats were fed with 0, 0.4, 0.8 and 1.6% of TPVGC in the diet. At the end of 45days feeding trials, both male and female rats supplemented with TPVGC had higher weight gain% and specific growth rate than the control groups. Significantly (p<0.05) lower blood glucose level and higher respiratory burst activity were recorded in the treatment groups than the control groups of both male and female rats. Activity of metabolic enzymes (aspartate amino transferase, alanine aminotransferase, alkaline phosphatase and acid phosphatase) and antioxidant enzymes (superoxide dismutase, catalase and glutathione S-transferase) were significantly higher (p<0.05) in the control groups and a decreasing trend in the same was observed with a gradual increase in the inclusion level of TPVGC in the diet of the treatment groups. However, a reverse trend was observed for acetylcholine esterase. It was inferred that dietary supplementation of thiamine and pyridoxine loaded vanillic acid-grafted chitosan enhanced the growth performance, metabolic and immune responses in the animal-model.

Chitosan oligosaccharide affects antioxidant defense capacity and placental amino acids transport of sows

BACKGROUND

Chitosan oligosaccharide (COS) is widely consumed as a functional food due to its multiple health effects, but few studies about COS supplement on placental antioxidant and nutrition transport capacity were reported. Taken pregnant sow as a model, we aimed to investigate the effects of dietary COS supplementation during late gestation on placental amino acids transport and antioxidant defense capacity of sows. From day (d) 85 of gestation to parturition, sixteen pregnant sows were divided into a control group (basal diet without COS supplementation) and a COS group (30 mg COS/kg basal diet). Plasma sample of sow was collected on d 110 of gestation, and placenta tissue was obtained during parturition. Then plasma antioxidant enzyme's activities, the relative level of oxidant stress related genes, amino acids transport related genes and mTOR pathway molecules in placenta were determined.

RESULTS

Results showed that maternal dietary supplementation with COS increased (P < 0.05) plasma total SOD, caused a downtrend in plasma MDA (0.05 < P < 0.10) on d 110 of gestation. Interestingly, the mRNA expression of some antioxidant genes in the placenta were increased (P < 0.05) and pro-inflammatory cytokines were reduced (P < 0.05) by COS supplement, whereas no significant difference was observed in the activities of placental total SOD and CAT between two groups. Additionally, further study demonstrated that COS feeding stimulated mTOR signaling pathway, increased amino acids transporters expression in placenta.

CONCLUSIONS

These observations suggested that COS supplement in sow's diet during late gestation enhanced antioxidant defense capacity of sows, promoted placental amino acids transport, which may contribute to the health of sows and development of fetus during gestation.

Nanofibers based on chitin: a new functional food

Chitin (β-(1-4)-poly-N-acetyl-D-glucosamine) is widely distributed in nature. A method for the preparation of chitin nanofibers (CNFs) is reported. CNFs are considered to have several potential applications because they have useful properties such as high specific surface area and porosity. More recently, beneficial effects of CNF as functional foods were reported. First, the anti-inflammatory effect of oral administration of chitin CNFs was demonstrated in a mouse model of inflammatory bowel disease (IBD). It was found that CNFs improved clinical symptoms and suppressed IBD. CNFs decreased the areas with nuclear factor-κB (NF-κB) staining in colon tissue. Second, the anti-obesity effects of surface-deacetylated chitin nanofibers (SDACNF) in a mouse model of high-fat diet-induced obesity was evaluated. SDACNFs suppressed the increase in body weight produced by the high-fat diet; however, CNFs did not suppress such weight gain. SDACNFs decreased serum levels of leptin. These results suggest that CNF and SDACNF are promising functional foods for patients with IBD or obesity.

Dietary Chitosan Supplementation Ameliorates Isoproterenol-Induced Aberrations in Membrane-Bound ATPases and Mineral Status of Rat Myocardium

Myocardial infarction is one of the major public concerns in both developed and developing countries. Recently, there is growing interest in potential healthcare applications of marine natural products in the field of cardiovascular research. In the present study, we have examined the membrane-stabilizing potential of marine mucopolysaccharide-chitosan in modulating the aberrations of thiol-dependent membrane-bound ATPases activities, mineral status, and cardiac diagnostic markers in isoproterenol-induced myocardial infarction condition in rats. Dietary intake of chitosan significantly (p < 0.05) counteracted the isoproterenol-induced lipid peroxidation and maintained the levels of thiol contents and cardiac biomarkers at concentrations analogous to that of normal controls in the rat myocardium. Chitosan administration also significantly mitigated isoproterenol-induced aberrations in the membrane-bound ATPase activities in the heart tissue and preserved the myocardial mineral status in serum and heart tissue of experimental rats at near normal value. The results of the present study have indicated that the salubrious effect of dietary chitosan supplementation in attenuating the experimentally induced myocardial infarction condition is probably ascribable to its antioxidant defense and membrane-stabilizing properties.

Lack of cardioprotection by single-dose magnesium prophylaxis on isoprenaline-induced myocardial infarction in adult Wistar rats

Aim

Magnesium (Mg²⁺) is effective in treating cardiovascular disorders such as arrhythmias and pre-eclampsia, but its role during myocardial infarction (MI) remains uncertain. In this study, we investigated the effects of Mg²⁺ pre-treatment on isoprenaline (ISO)-induced MI in vivo.

Methods

Rats divided into four groups were each pre-treated with either MgSO₄ (270 mg/kg intraperitoneally) or an equivalent volume of physiological saline, prior to the ISO (67 mg/kg subcutaneously) or saline treatments. One day post-treatment, the electrocardiogram and left ventricular blood pressures were recorded. Infarcts were determined using 2,3,5-triphenyltetrazolium chloride staining, and serum markers of lipid peroxidation were measured with spectrophotometric assays.

Results

Mg²⁺ pre-treatment neither altered the ISO-induced infarct size compared with ISO treatment alone (^p > 0.05), nor reversed the low-voltage electrocardiogram or the prominent Q waves induced by ISO, despite a trend to decreased Q waves. Similarly, Mg²⁺ did not prevent the ISO-induced decrease in peak left ventricular blood pressure or the decrease in minimal rate of pressure change. Mg²⁺ did not reverse the ISO-induced gain in heart weight or loss of body weight. Neither ISO nor Mg²⁺ altered the concentrations of lipid peroxidation markers 24 hours post MI induction.

Conclusion

Although Mg²⁺ had no detrimental effects on electrical or haemodynamic activity in ISO-induced MI, the lack of infarct prevention may detract from its utility in MI therapy.

The potential of chitosan and its derivatives in prevention and treatment of age-related diseases

Age-related, diet-related and protein conformational diseases, such as atherosclerosis, diabetes mellitus, cancer, hypercholesterolemia, cardiovascular and neurodegenerative diseases are common in the elderly population. The potential of chitosan, chitooligosaccharides and their derivatives in prevention and treatment of age-related dysfunctions is reviewed and discussed in this paper. The influence of oxidative stress, low density lipoprotein oxidation, increase of tissue stiffness, protein conformational changes, aging-associated chronic inflammation and their pathobiological significance have been considered. The chitosan-based functional food also has been reviewed.

Effect of media milling on lipid-lowering and antioxidant activities of chitosan

The effect of media milling on lipid-lowering and antioxidant activities of chitosan was studied in rats fed high-fat diets. Results showed that media-milled chitosan was more effective than chitosan in reducing body weight gain and liver fat accumulation of rats. Compared with chitosan, the reducing effects of media-milled chitosan on serum triacylglycerol (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were increased by 10.1, 7.5 and 10.2%, and liver TG and TC-reducing effects were increased by 16.2 and 14.6%, respectively. Rats fed media-milled chitosan showed decreased levels of free fatty acid (FFA) and thiobarbituric acid-reactive substances (TBARS) and increased superoxide dismutase (SOD) activity. The cholesterol and fat in feces of rats fed media-milled chitosan were higher than those of rats fed chitosan. These results suggested media milling enhanced the lipid-lowering and antioxidant activities of chitosan, and the reason might be partly due to its effect on strengthening the ability of chitosan in promoting fecal lipid excretions.

Effects of chitosan on intestinal inflammation in weaned pigs challenged by enterotoxigenic Escherichia coli

The aim of this study was to investigate whether supplementation with chitosan (COS) could reduce diarrhea and to explore how COS alleviates intestinal inflammation in weaned pigs. Thirty pigs (Duroc×Landrace×Yorkshire, initial BW of 5.65±0.27) weaned at age 21 d were challenged with enterotoxigenic Escherichia coli during a preliminary trial period, and then divided into three treatment groups. Pigs in individual pens were fed a corn-soybean meal diet, that contained either 0 (control), 50 mg/kg chlortetracycline, or 300 mg/kg COS for 21 days. The post-weaning diarrhea frequency, calprotectin levels and TLR4 protein expression were decreased (P<0.05) in both the COS and chlortetracycline groups compared with control. Simultaneously, supplemental COS and chlortetracycline had no effect on the mRNA expression of TNF-α in the jejunal mucosa, or on the concentrations of IL-1β, IL-6 and TNF-α in serum. However, COS supplementation improved (P<0.05) the mRNA expression of IL-1β and IL-6 in the jejunal mucosa. The results indicate that supplementation with COS at 300 mg/kg was effective for alleviating intestinal inflammation and enhancing the cell-mediated immune response. As feed additives, chitosan and chlortetracycline may influence different mechanisms for alleviating inflammation in piglets.