Encapsulation of Satureja khuzistanica extract in alginate hydrogel accelerate wound healing in adult male rats

BACKGROUND

Finding the best dressing for a specific wound had continued from the past to present. The aim of this study was to evaluate the effect of encapsulated extract of Satureja khuzistanica in hydrogel alginate at wound healing.

METHODS

Thirty-two male Wistar rats with a puncture wound in the back of the neck skin were divided randomly into four groups including a control group, Satureja khuzistanica-treated group, hydrogel alginate-treated group, and Satureja khuzistanica encapsulated in hydrogel alginate-treated group. Rats were treated for 22 days. The skin samples were taken on 3rd, 7th, 14th, and 22nd days after treatment for light microscopy. Results were analyzed in accordance with Kruskal-Wallis and Friedman test (for histopathology analysis) by using SPSS v.22 software.

RESULTS

Macroscopically evaluations and measurement of wound size showed increased wound healing process in the treated groups. The complete improvement was created on the 14th day. The wound site was not observed on the 22nd day. But the wound site was observed on the 22nd day in the control group. Also, comparison of the percentage of wound healing between the treated and control groups on 3rd, 7th, 14th, and 22nd days showed a significant difference (p < 0.05). Comparison of the H&E stained sections in the studied groups showed that treated groups were effective on wound healing in comparison with the control group.

CONCLUSIONS

Encapsulated extract of Satureja khuzistanica in hydrogel alginate may accelerate wound improvement and increase the rate of wound healing without scar formation.

The Effect of Caffeic Acid on Spermatogonial Stem Cell-type A Cryopreservation

BACKGROUND

Cancer treatment methods can lead to male infertility .in this regard, cryopreservation of spermatogonial stem cells (SSC) and cell-to-person transplantation after the course of treatment to resolve the problem of infertility is a good one. The cryopreservation of SSC is an important process as it can help on the return of spermatogenesis. However, during this process, the stem cells often become damaged which degrades their value for experiments and treatments. Caffeic acid (CA) is an antioxidant that has been shown to increase the viability of cells under stress. The aim of this study was to investigate the effect of CA has on spermatogonial stem cell (SSC) cryopreservation.

METHODS

Spermatogonial stem cells isolated from the testes of Balb/c mice pups were cultured in laminincoated dishes, purified using CD90.1 microbeads, then cryopreserved in vitrification media supplemented with 10 µM CA either through a slow or rapid freezing process. After thawing, cell viability was evaluated. Expression of Bax, Fas, Bcl-2 and P53 genes was determined by real-time PCR. Gel electrophoresis was used to confirm the results of the real-time PCR.

RESULTS

The viability of the SSCs that were rapidly frozen and treated with CA was observed to be significantly reduced compared to the control group (p < 0.003). The viability SSCs that received CA and underwent the slow freezing treatment was significantly reduced compared to controls (p < 0.002). The expression levels of BAX, BCL-2, and Fas in the rapid freeze-thaw group didn't significantly change. However, the levels of P53 expression were shown to increase. In the group of SSCs that underwent the slow freezing process, the BAX gene expression levels increased, while the levels of BCL-2 gene expression decreased. No significant changes in the level of Fas and P53 expression were detected. When comparing the groups that received CA treatment, SSCs that were rapidly frozen showed an up-regulation of Fas and P53 expression and a down-regulation of Bcl-2 and Bax expression.

CONCLUSION

Caffeic acid may protect intact SCCs during the cryopreservation process through stimulating the induction of apoptosis in injured SSCs. Supplementing the vitrification media with CA has a superior effect on the preservation of SSCs.

Protective effects of persian honey, Apis Mellifera Meda Skorikov on side effects of chemotherapy and ischemia/reperfusion induced testicular injury

Introduction The aim of the present study was to survey the protective effect of pretreatment with Persian honey on amelioration of side effects of chemotherapy and ischemia/reperfusion induced testicular injury. Materials and methods Forty adult's male wistar rats were divided into four groups of ischemia-reperfusion (IR), honey + ischemia-reperfusion (HIR), Busulfan (B) and Busulfan intraperitoneally+ honey (BH). The seminiferous tubules were rated for their modified spermatogenesis index (SI) by Johnsons score. Detection of single- and double-stranded DNA breaks at the early stages of apoptosis was performed using the in-situ cell death detection kit. Total serum concentration of Follicle-stimulating hormone (FSH) , Luteinizing hormone (LH) and testosterone was measured using ELISA. All data were expressed as mean ± SD and significance was set at p≤0.05. Results Honey improved SI in the HIR and BH groups and serum levels of FSH and LH in the BH and HIR groups (p<0.001). Also, serum levels of testosterone were significantly higher in BH and HIR groups. But, apoptotic cells in IR and B groups significantly increased (p<0.001), while in HIR and BH groups, the number of apoptotic cells decreased and the positive cells of TUNEL (TdT-mediated dUTP-X nick end labelling) staining were detected in spermatocytes and spermatid. Discussion Pretreatment with honey protect testis against chemotherapy and testicular IR injury, increase FSH and LH and testosterone and decrease the cellular damage and apoptosis. Honey can decrease the side effects of chemotherapy on reproductive system and prevent sterility.

Troxerutin protect sperm, seminiferous epithelium and pituitary-gonadal axis from torsion-detorsion injury: An experimental study

BACKGROUND

Troxerutin is a flavonoid antioxidant that protect different organ against damage caused by ischemia-reperfusion.

OBJECTIVE

The aim of this study was to evaluate the effect of troxerutin in reducing the damages caused by ischemia-reperfusion in rat's testis.

MATERIALS AND METHODS

40 Male Wistar rats (2 month old) were divide to four groups (n=10). Group1 (sham), Group 2 (control, ischemia-reperfusion (I/R) without treatment), Group 3 (I/R+150 mg/kg of troxerutin), and group 4 (I/R+20 mg/kg of vitamin C). Treatment of group 3 and group 4 during torsion (twists 720 counter clock at 90 min) followed by 50 days detorsion. After 50 days, blood samples were collected and rats in all study groups were killed and their testes were removed, and fixed with Bouin's solution. Testis was stained with hematoxylin and eosin dye and the level of testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured with ELISEA methods. TUNEL was employed to detect apoptosis. Epididymis caudal part was removed and total sperm count was determined. Johnson techniques were used for assessment of seminiferous tubules quality.

RESULTS

Troxerutin treated group has higher Johnson score's (p≤0.001), antiapoptotic properties (p≤0.001), sperm count (p=0.065), and higher LH (p≤0.001), FSH (p≤0.001) and testosterone (p=0.002) levels than control group. Vitamin C treated group showed increase level of testosterone but didn't show significant differences on the number of apoptotic cells, Johnson scores, LH, FSH and sperm count than control group.

CONCLUSION

Troxerutin has protective effects on testicular torsion induced injury and can ameliorate spermatogenesis in the torsion-detorsion models.

Effects of pomegranate peel extract on histopathology, testosterone levels and sperm of testicular torsion–detorsion induced in adult Wistar rats

Background

In the present study, effects of pomegranate peel extract have been evaluated on decreasing the damage induced by testis torsion.

Methods

In this study, 30 adult Wistar rats were randomly divided into three groups of control, experimental (1) and experimental (2). Control: no ischemia, received vehicle alone, exposed to sham operation. Experimental (1): Received the vehicle alone during ischemia followed by 60 days’ reperfusion. Experimental (2): After performing ischemia reperfusion, 500 mg/kg of pomegranate peel extract has been used for 60 days. Blood samples and sperm samples were collected. Testes were harvested and stained with haematoxylin and eosin to study the structure of seminiferous tubules.

Results

The statistical comparison between sperm count and their viability and testosterone hormone amount showed a significant difference between control and experimental (1) groups and control and experimental (2) groups. The results showed an improvement of morphological condition of seminiferous tubules.

Conclusions

Pomegranate peel extract has revealed desirable changes on the effective parameters in infertility.

Immunogenicity of a fusion protein containing PilQ and disulphide turn region of PilA from Pseudomonas aeruginosa in mice

Interference with bacterial adhesion is a new means to prevent or treat bacterial infections. In this experimental study we evaluated the immunogenic properties of a chimeric protein composed of PilQ and disulphide turn region of PilA from Pseudomonas aeruginosa in mice as an anti-adhesion based vaccine. First of all, a chimeric bivalent protein composed of PilQ and PilA was constructed and following subcutaneous immunization with merely the purified protein or in its admixed form with alum, the immunogenicity of the chimeric antigen was assessed in BALB/c mice. Then, the characteristics of the developed antibodies were studied by ELISA. Furthermore, the immunoreactivity of the purified recombinant protein was confirmed by immunoblotting. Alum as a common adjuvant boosted immunogenicity of the construct, resulting significantly greater anti-pili IgG titre. Mice antibody response consisted of IgG1, IgG2a, IgG2b and IgG3 subtypes with predominance of IgG1 subclass. The developed antibodies were capable to inhibit motility of PAO1 strain. In conclusion, our primary results revealed that the designed recombinant protein is a protective construct and may be used as a potential candidate for prophylactic purposes against P. aeruginosa infection.

SIGNIFICANCE AND IMPACT OF THE STUDY

In this study we examined the potential of integrated PilQ/PilA (QA) antigen as a vaccine candidate against Pseudomonas aeruginosa. Nowadays, anti-adhesion based vaccines are considered as new means to prevent or treat bacterial infections. Our study revealed that chimeric protein PilQ and disulphide turn region of PilA triggers production of specific antibodies. This humoral immune responses augmented when QA was administered in combination with an adjuvant. The results demonstrated efficacy of the designed recombinant chimeric antigen as an effective candidate in prevention of P. aeruginosa infection.

Selenium Ameliorate Peripheral Nerve Ischemic-Reperfusion Injury via Decreased TNF-α

Selenium is considered as a trace element that plays antioxidant role in the body. So, the aim of this study was to evaluate the effect of selenium on ameliorating of sciatic nerve ischemia-reperfusion injury. Eighty (80) adult male Wistar rats weighing 250-300 g were used. They were divided into 10 groups (n = 8). Then, femoral vessels were obstructed by using 4/0 silk and splitknot techniques. After 3-h ischemia for all the groups, reperfusion was applied for different periods: 3, 7, 14, and 28 days. In half of each experimental group, 0.2 mg/kg selenium was injected intraperitoneally, coinciding with ischemia. After reperfusion, according to the grouping, rats were killed by using high dose of anesthetic drug and then sciatic nerve was removed and fixed. Then, tissue samples were processed and subsequently stained with hematoxylin-eosin, apoptosis, and immunohistochemistry stains. On the third day of reperfusion, the amount of TNF-α as an inflammatory marker of ischemia-reperfusion acute phase increased. On the seventh day of reperfusion, the amount of NF-кB as an apoptotic index and infiltration of mast cells increased in the tissue as a result of development of inflammation. But, on the 14th day of reperfusion, the amount of NF-кB as an apoptotic index decreased to the lowest amount. On the 28th day of reperfusion, the amount of TNF-α as an inflammatory marker decreased to its lowest level. Prescription of selenium concurrent with development of ischemia can reduce the damage caused by sciatic nerve ischemia-reperfusion.

Honey improves spermatogenesis and hormone secretion in testicular ischaemia-reperfusion-induced injury in rats

This study was conducted to survey the protective effect of pre-treatment with Persian honey during post-ischaemia reperfusion on ischaemia-reperfusion (IR)-induced testis injury. Animals were divided into four groups of IR, honey + ischaemia- reperfusion (HIR), vitamin C + ischaemia- reperfusion (VIR) and carbohydrates + ischaemia- reperfusion (CIR). The testes were examined for spermatogenesis index. Detection of single- and double-stranded DNA breaks at the early stages of apoptosis was performed. Total serum concentration of FSH, LH and testosterone was measured using ELISA. All data were expressed as mean ± SD in each group, and significance was set at p ≤ .05. Spermatogenesis index was significant in the HIR group (p < .001). Serum levels of FSH and LH were significantly higher in the CIR and HIR groups. Serum levels of testosterone were significantly higher in VIR and HIR groups. Apoptotic cells in IR and CIR groups increased significantly statistically (p < .001), while in HIR and VIR groups, the number of apoptotic cells decreased and the positive cells of TUNEL staining were detected in spermatocytes and spermatid. The present study indicates that honey decreases the cellular damage and apoptosis during testicular I/R injury, with significant protective effects on reproductive hormone production.

Evaluation of selenium on kidney function following ischemic injury in rats; protective effects and antioxidant activity

Introduction: Renal dysfunction is caused by ischemia-reperfusion (I/R) injury, which is a common problem in kidney surgery or kidney transplantation. The human body consists of enormous complex antioxidant systems, which inquires adequate selenium (Se) absorption for normal physiologic function. It is known that Se has some antioxidant effects. Objectives: In the present research, effects of the Se on damages caused by I/R injury investigated. Materials and Methods: In this experimental research, four groups of rats (weighing 220±10 g) used, include control group, I/R group, healthy group treated with Se for two weeks, and I/R group with two-week Se treatment. On the test day, I/R was treated in both right and left renal arteries for 45 minutes and the reperfusion was done for 24 hours. Results: In I/R group, the amount of urea and serum creatinine (Cr) was an injury indicator of the kidney cells which showed a significant increase compared with the control group. When the treatment with Se significantly reduced these indicators, glutathione (GSH) enzyme levels reduced significantly in the second group and the enzyme levels increased due to Se treatment in the fourth group. Furthermore, malondialdehyde (MDA) enzyme levels increased in I/R group due to the Se treatment in the fourth group which was significantly reduced. In addition, the tissue damage was reduced in the fourth group compared with I/R group. Conclusion: Se has a protective effect against the I/R injury. This effect might be due to the antioxidant properties of Se.

Allele specific-PCR and melting curve analysis showed relatively high frequency of β-casein gene A1 allele in Iranian Holstein, Simmental and native cows

There are two allelic forms of A1 and A2 of β-casein gene in dairy cattle. Proteolytic digestion of bovine β-casein A1 type produces bioactive peptide of β-casomorphin-7 known as milk devil. β-casomorphin-7 causes many diseases, including type 1 diabetes, cardiovascular disease syndrome, sudden death and madness. The aim of the present study was to determine the different allelic forms of β-casein gene in Iranian Holstein, Simmental and native cattle in order to identify A1 and A2 variants. The blood samples were collected randomly and DNA was extracted using modified salting out method. An 854 bp fragment including part of exon 7 and part of intron 6 of β-casein gene was amplified by allele specific polymerase chain reaction (AS-PCR). Also, the accuracy of AS-PCR genotyping has been confirmed by melting temperature curve analysis using Real-time PCR machinery. The comparison of observed allele and genotype frequency among the studied breeds was performed using the Fisher exact and Chi-squared test, respectively by SAS program. Obtained results showed the A1 allele frequencies of 50, 51.57, 54.5, 49.4 and 46.6% in Holstein, Simmental, Sistani, Taleshi and Mazandarani cattle populations, respectively. The chi-square test was shown that no any populations were in Hardy-Weinberg equilibrium for studied marker locus. Comparison and analysis of the test results for allelic frequency showed no any significant differences between breeds (P&gt;0.05). The frequency of observed genotypes only differs significantly between Holstein and Taleshi breeds but no any statistically significant differences were found for other breeds (P&gt;0.05). A relatively high frequency of β-casein A1 allele was observed in Iranian native cattle. Therefore, determine the genotypes and preference alleles A2 in these native and commercial cattle is recommended.

Evaluation of alginate hydrogel cytotoxicity on three-dimensional culture of type A spermatogonial stem cells

The culture of spermatogonial cells for future transplantation, based on the specific biology of these cells is important and necessary. Recently, the use of scaffolds especially alginate for culturing stem cells has been the focus of many researchers. The aim of this study was to evaluate the cytotoxicity of alginate hydrogels to cultures of type A spermatogonial stem cells. Spermatogonial stem cells of 6day-old immature mice were isolated by surgery; thereafter, the cells were purified by MACS using antibodies against thy-1 and C-kit and cultured on a layer of laminin. After purification, spermatogonial stem cells were encapsulated in alginate hydrogels. After one month of encapsulation and culture in DMEM culture medium containing 10ng/ml GDNF, cells were removed from hydrogel and were examined for viability, cell morphology and structure, cytotoxicity and expression of apoptosis genes Fas, P53, Bax, Bcl2, Caspase3 by staining with trypan blue, scanning electron microscopy, LDH test, and Real time PCR, respectively. The encapsulation did not change the morphology and viability of spermatogonial stem cells. Investigations showed that spermatogonial stem cells preserve by the high viability (74.08%) and cytotoxicity of alginate hydrogel was estimated to be 5%. Expression of Fas gene increased in main group compared with the control group, and expression of Bax and P53 was reduced in main group compared with the control group. Expression of Bcl2 and Caspase3 genes did not show any significant difference between the main group and the control group. Considering the lack of cytotoxicity and antioxidant properties of alginate hydrogel scaffold and high viability of cells, this three-dimensional scaffold is applicable for culturing and encapsulation of spermatogonial stem cells.

Supplementation freeze-thawed media with selenium protect adipose-derived mesenchymal stem cells from freeze-thawed induced injury

Successful freezed-thaw of adipose-derived mesenchymal stem cells (ADMSCs) could be a major step in regenerative medicine as well as in the cloning of animal breeds. The aim of this study was to evaluate the efficacy of selenium on the optimizing of freezed-thaw media in the ADMSCs. ADMSCs were extracted from NMRI mice and purified with positive selection Monoclonal CD105 Antibody (PE) and negative selection Monoclonal CD31 and CD45 Antibody using MACS method as well as differentiation to adipose and bone tissue. ADMSCs were divided into four groups. ADMSCs were freezed-thaw under standard condition with or without the addition of 5 ng/ml selenium to both the cryopreservation and thawing solutions. Frozen cells were thawed after four months and viability and cytotoxicity of the cells were analyzed by the Trypan blue test and MTT assay respectively. RNA was extracted and cDNA was synthesized and the expression of apoptotic genes (P53, Fas, Bax, Caspase3, and Bcl2) was examined using Real time-PCR Rotor gene 2009. This study compares slow and rapid methods of cryopreservation. After thawing, viability of the cells treated with selenium was higher than the control group in rapid and slow cryopreserved ADMSCs. Also, the percentage of living cells in the slow cooling method was considerably more than with the rapid cooling method. After analysis of the results using Real time-PCR, the Bcl2 gene was shown to be expressed in both the rapid and slow cooling methods. In the rapid cooling group in addition to the BCL-2 gene, p53 was also expressed. It appears that selenium prevented the apoptotic genes from expression due to its anti-apoptotic effects. The slow cooling method is better and more optimized for ADMSCs protecting them from oxidative damage to a greater extent compared to the rapid cooling method.

[Evaluation of miR-122 level in the plasma of chronically HCV infected patients]

MicroRNAs (miRNAs) are small non-coding RNA molecules, which have an important function in regulating RNA stability and gene expression. They also can circulate in a cell-free form in the blood thatmakes them potential disease markers. The liver contains various classes of miRNAs in which miR-122 accounts for about 70% of all miRNAs and it has been proved that its level increases in case of liver damage. Here, we investigated plasma levels of miR-122 as a useful disease parameter in patients with chronic hepatitis C (CHC) infection. Thirty five hemophilia and thalassemia patients with CHC were studied. The total RNA was extracted from plasma samples, and miR-122 levels were measured by qPCR and then compared with the specific liver markers. The plasma levels of alanine transaminase (ALT) and aspartate transaminase(AST) were correlated with plasma miR-122 level in CHC patients, and the level of circulating miR-122 in healthy individual groups were rarely lower than those of patients with CHC. In our study, miR-122 levels correlated well with markers of liver inflammatory activity. Plasma miR-122 can be assumed to be another marker in liver similar to the currently used specific markers such as ALT and AST for evaluation of liver damage in hepatitis C virus (HCV) infected patients. Moreover, the correlation between miR-122 and ALT was shown to be higher than between miR-122 and AST.

The effect of progesterone treatment after ovarian induction on endometrial VEGF gene expression and its receptors in mice at pre-implantation time

OBJECTIVES

Progestrone is a prequisite for pre-implantation angiogenesis and induce decidual angiogenesis. It is unknown the effect of progestrone administration on the endometrium of hyperstimulated mice at pre-implantation time.

MATERIAL AND METHODS

Adult female NMRI mice were divided in three groups [control group, ovarian stimulated group and progestrone treated mice after ovarian stimulation]. Uterine horn samples removed at pre-implantation time in each group. Motic image Plus 2 software was used to assess the quantitative vascular parameters of endometrium. Gene expression was determined for vascular endothelial growth factor (VEGF), FMS-like tyrosine kinase (FLT) and Kinase insert domain protein receptor (FLK) genes using the real time PCR method. Data analysis was done with LinReg PCR and Rest-RG software.

RESULTS

Comparison between progestrone treated mice after ovarian stimulation with control group showed that increase in rate of VEGF gene expression [0.775] and decrease in rate of FLK [6.072] and FLT [1.711] gene expression. Analysis of the data on quantitative vascular parameters were indicated remarkable increase in quantitative vascular parameters of progestrone treated mice compare to control group.

CONCLUSION

Biological effect of progestrone on the vascular changes after ovarian stimulation resulted in an increase in VEGF receptors experession, it seems that induced angiogenesis by progesterone could result in better condition for implantation.

Reduction of autophagy markers mediated protective effects of JNK inhibitor and bucladesine on memory deficit induced by Aβ in rats

Autophagy, the process of self-degradation of cellular components, has an important role in neurodegenerative diseases, such as Alzheimer's disease. In this study, we investigated the effects of SP600125 as c-Jun N-terminal kinase (JNK) inhibitor and bucladesine as a cyclic adenosine 3',5'-monophosphate (cAMP) analog on spatial memory and expression of autophagic factors in Aβ-injected rats. Male Wistar rats were used. Rats were randomly allocated into five groups as following: amyloid beta (Aβ)-only group, Aβ + SP600125 (30 μg/1 μ/side, n = 7) and/or bucladesine (100 μM/1 μl/side, n = 7), and the normal control (vehicle only) group. The treatments were administered bilaterally to the CA1 sub-region of the hippocampus stereotaxically. Spatial reference memory was performed using Morris Water Maze 21 days later. The expression of authophagy markers (beclin1, Atg7, Atg12, and LC3 II/LC3 I) in the hippocampus was evaluated using western blotting. Compared to the vehicle group, Aβ administration reduced spatial reference learning (P < 0.001) and memory (P < 0.01) and upregulated the expression of beclin1, Atg7, Atg12, and LC3 II/I (P < 0.0001). Compare to Aβ-only group, the administration of SP600125 and/or bucladesine improved spatial reference learning (P < 0.001) and memory (P < 0.01). Compared to the Aβ-only group, the treatment with SP600125 and/or bucladesine also reduced beclin1, Atg7, Atg12, and LC3 II/I (P < 0.0001) which was similar to amount of normal rats. In summary, it seems that the improvement of spatial memory by SP600125 and/or bucladesine in Aβ-injected rats is in relation with normalizing of autophagy to the physiologic level, possibly through neuroprotection and/or neuroplasticity.

Synergistic effects of nitric oxide and exercise on revascularisation in the infarcted ventricle in a murine model of myocardial infarction

It has been shown that density of microvessels decreases in the left ventricular after myocardial infarction (MI). The change of angiogenic and angiostatic factors as the main factors in revascularisation after exercise training in area at risk is not determined yet in MI. Therefore, the aim of the present study was the effect of exercise training and L-arginine supplementation on area at risk angiogenesis in myocardial infarction rat. Four weeks after surgery (Left Anterior Descending Coronary artery Ligation), myocardial infarction rats were divided into 4 groups: Sedentary rats (Sed-MI); L-arginine supplementation (La-MI); Exercise training (Ex-MI) and Exercise + L-arginine (Ex+La). Exercise training (ET) lasted for 10 weeks at 17 m/min for 10-50 min day(-1). Rats in the L-arginine-treated groups drank water containing 4 % L-arginine. After ET and L-arginine supplementation, ventricular function was evaluated and angiogenic and angiostatic indices were measured at ~1 mm from the edge of scar tissue (area at risk). Statistical analysis revealed that gene expression of VEGF as an angiogenic factor, angiostatin as an angiostatic factor and caspase-3 at area at risk decrease significantly in response to exercise training compared to the sedentary group. The capillary and arteriolar density in the Ex groups were significantly higher than those of the Sed groups. Compared to the Ex-MI group, the Ex+La group showed a markedly increase in capillary to fiber ratio. No significant differences were found in infarct size among the four groups, but cardiac function increased in response to exercise. Exercise training increases revascularization at area at risk by reduction of angiostatin. L-arginine supplementation causes additional effects on exercise-induced angiogenesis by preventing more reduction of VEGF gene expression in response to exercise. These improvements, in turn, increase left ventricular systolic function and decrease mortality in myocardial infarction rats.