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Volume 0, Issue 0 (3-2024)
Materials and methods: 60 male Wistar rats were randomly divided into 6 groups (n=10). For induction of liver and lung toxicity in groups 3, 4, 5, and 6, doxorubicin was injected intraperitoneally (i.p.) in 6 doses of 2 mg/kg every 48 hours. Apigenin was administered orally with a dose of 50 mg/kg in groups 2, 4, and 6. To prevent the formation of nitric oxide (NO), L-NAME was injected i.p. in groups 5 and 6 at 6 doses of 30 mg/kg every 48 hours.
Findings: Apigenin could prevent tissue changes caused by doxorubicin in lung and liver. It also improved weight loss and reduced fibrosis in the lung (p<0.05). Doxorubicin injection and apigenin treatment did not cause significant changes in liver enzymes and liver fibrosis. Inhibition of NO by L-NAME prevented almost all protective effects of apigenin.
Conclusion: Apigenin reduced the damages induced by doxorubicin. It seems that inhibition of nitric oxide decreases the protective effects of apigenin. Apigenin probably exerts its protective effects in liver and lung toxicity caused by doxorubicin by increasing the expression of NO.
Volume 10, Issue 37 (3-2004)
Nitric oxide (NO) is an unstable small molecule which acts as lipophilic free radicals. It is synthesized in different mammalian cells and thought to be involved in many physiological and pathological conditions. There are many evidences that show NO acts as a neurotransmitter in Non-Adrenergic, Non-Cholinergic (NANC) nerves, innervating smooth muscles of digestive system and also has direct influence on smooth muscle cells. Infantile hypertrophic pyloric stenosis(IHPS) is one of the most common pathological conditions among the neonates. It is thought that any failure in NO synthesis could be one of the reasons of IHPS. Pregnant Sprague-Dawley rats were used in this study. Different doses of the L-NAME (20-80mg/kg) as an NO inhibitor in normal saline was injected intraperitoneal (IP) during the last week of pregnancy period per day. The embryos were removed on the day of expected delivery. The stomach and duodenum were dissected, fixed by Bouin solution and tissue processing was done. By using rotatory microtome, 5μ serial cross sections were obtained and stained with Trichrom-Mason and Pop-Nicola. Statistical analysis of macroscopic and light microscopic findings showed that 80mg/kg of L-NAME causes significant changes in embryos of trial group including: IUGR, hind-limb disruption, embryo absorption, pyloric hypertrophy and hyperplasia. On the basis of these results it is believed that 80mg/kg of L-NAME can be one of the reasons of pyloric stenosis in infants.
Volume 11, Issue 39 (6-2004)
Impaired endothelium-dependent relaxation of blood vessels is a common feature in diabetes but the exact underlying mechanisms have not yet been clarified. In the present study, endothelium-dependent vasorelaxation of aortic rings were evaluated in vitro in streptozocin-induced diabetic and age-matched control rats. Moreover, NO synthase activity of aortic endothelial cells was assessed in both diabetic and healthy rats using histochemical staining for NADPH diaphorase activity. The results showed a significant decrease of endothelium dependent relaxation in response to ACh in diabetic rings compared with control. A remarkable attenuation of eNOS activity was also observed in sections of diabetic rat aorta using NADPH diaphorase staining. Furthermore, many endothelial cell membranes were disrupted in diabetic cessations. It can be concluded that a decrease in NOS activity together with a disruption of endothelial cell membranes play a major role in endothelial dysfunction observed in diabetes.
Volume 11, Issue 43 (12-2004)
Abortion techniques are divided into two groups: surgical and medical. Finding drugs with least side effect and more potency is the aim of many researches in the latter technique. In recent years, prostaglandins have been one of the methods of choice in the induction of abortion. However, with recent studies on the mechanism of uteric contraction and cervical dilatation and by recognizing Nitric Oxide as an important mediator of this process, NO donors are object of many studies. With regard to few studies in this field, this research was conducted to compare the effect of intravaginal isosorbide dinitrate(an NO donor) and vaginal suppository of prostaglandin on cervical dilatation. 148 pregnant women with indication of therapeutic abortion in the first trimester were studied in two groups. The two groups were similar in terms of gestational age, parity and cervical dilatation. Cervical dilatation changes in each group during treatment were statistically significant (from 2.26±0.68cm to 4.57±1.62cm in PG and from 2.18±0.63cm to 3.63±1.11cm in ISD group). Also, the cervical dilatation difference between the two groups after treatment was statistically significant (P<0.05)(3.63±1.11cm vs 4.57±1.6cm in ISD and PG group, respectively) Furthermore, abdominal pain was more common in PG group (P<0.05). In conclusion, these two types of treatment are found to produce cervical dilatation, but the efficacy and also incidence of abdominal pain with PG is more common than ISD.
Volume 12, Issue 48 (9-2005)
Background & Aim: Occlusion of organs artery results in ischemia and the opening of occluded artery leads to tissue lesion identified as reperfusion injury(RI). Oxygen-derived free radicals seem to be involved in the reperfusion injury. In this experimental study the effects of 5-aminosalicylic acid(5-ASA), a prescribed drug for ulcerative colitis, was assessed. 5-ASA is a potent scavenger of oxygen-derived free radicals in the RI of the kidney in a uninephrectomized rat model. Materials & Methods: Male Wistar rats of 200-250g were pretreated with 5-ASA(300mg/kg). Ischemia-reperfusion(IR) injury was induced by left renal artery clipping for 45 min plus 24 or 48h reperfusion, while the right kidney was being removed. After 24 or 48h of IR injury, creatinine and nitric oxide(NO) levels in serum and urine, as the main parameters for evaluating of renal function, were determined. Results: After 24h of IR injury, 5-ASA(300mg/kg) not only obviously increased the levels of serum creatinine but also decreased the content of urinary creatinine and serum nitric oxide compard with the control group(P<0.05-0.0001). Whereas after 48h of IR injury, 5-ASA(300mg/kg) had no obvious effects on these parameters. Conclusion: 5-ASA(300mg/kg) used I.P 24h prior to the initiation of RI, in a time-dependent manner, induced nephrotoxicity. Further studies on renal biopsy, laboratory findings and immunofluorescence microscopy for assessment of mechanisms involved in 5-ASA renal toxicity is suggested.
Volume 13, Issue 51 (6-2006)
Background & Aim: Nitric oxide(NO) is a molecule with expanded and numerous roles in biologic system of the body. It shows antitumor and antimicrobial activities. Stimulation of macrophages by different microorganisms leads to the production of a large amount of NO with toxic property that causes the death of microorganisms. Mechanisms related to NO perform an important role in host’s defense against fungal infections. In candidial infections NO is regarded as the most important factor in killing candida albicans by polimorphonuclear cells. Material & Method: This experimental study was designed to investigate antifungal potential of two NO donor complexes namely DPTA/NO(Dipropylenetriamine nitric oxide) and DEA/NO(Diethyleamine nitric oxide) per se and in combination with antifungal drugs such as ketoconazole and amphotricin B against candida albicans, candida parapsilosis, candida tropicalis, candida glabrata, and cryptococcus neoformans. In order to do so, we determined MIC(Minimum Inhibitory Concentration) and MFC(Minimum Fungicidal Concentration) of the above-mentioned complexes as per NCCLS(National Committee of Clinical Laboratory Standards) using microdilution broth method. Results: The obtained findings showed that DPTA/NO complex per se exerted antifungal effects. In addition, this complex revealed synergic effects on C. tropicalis, C. glabrata II, and cryptococcus neoformans(FIX<0.5) and additive effects on C. albicans, C. parapsilosis, and C. glabrata I(0.5
Volume 13, Issue 52 (9-2006)
Background & Aim: Nitric Oxide(NO) is one of the ten smallest lipophilic molecules synthesized from L-Arginine, O2 and NADPH by nitric oxide synthase enzyme(NOS). NO has various biological activities in different systems. For instance, it plays both protective and cytotoxic roles in immune system, while in cardiovascular system it has physiologic role which controls vascular tonicity. One of the NOS isoforms known as iNOS(inducible NOS) can be induced by variety of some gram negative bacteria membrane that leads to NO production for long period of time. Due to important biological roles of glucose and NO, the present study was designed to investigate the effect of LPS on the level of glucose and NO in serum of SD rats. Materials & Methods: In this study 50 SD male rats with the average weight of 250-300 gram were chosen. Rats were divided into five groups(10 rats in each group). First group received 0.2mg/kg, second group 0.4mg/kg, third group 0.8 mg/kg LPS, fourth group 0.8ml/kg salin via IP injection and the fifth group did not receive any compound. After blood collection and separation of serum, NO level was measured by Griess reagents and glucose by colorimetric method. Results: The obtained results showed that with increased LPS injection, the level of NO increased in group 1, 2 and 3 respectively. The latter group had the maximum level of NO as compared to control group(P<0.05). Glucose concentration increased significantly in third group(P<0.05). Conclusion: It is concluded that increased level of NO production was due to induction of iNOS enzyme by LPS and was dose dependent, and increased level of NO led to increased level of glucose concentration.
Volume 14, Issue 56 (11-2007)
Background & Aim: Although studies have shown the central effects of Endocannabinoid on erection, its' peripheral effect is unknown. The purpose of this study was to investigate the effect of the endogenous cannabinoid anandamide on the nonadrenergic noncholinergic(NANC) relaxant responses to electrical field stimulation in isolated rat corpus cavernosum, a crucial tissue in erectile function. Material and Methods: The rat corporeal strips were mounted under tension in a standard oxygenated organ bath with guanethidine sulfate(5 µM) and atropine(1 µM)(to produce adrenergic and cholinergic blockade). The strips were precontracted with phenylephrine hydrochloride(7.5 µM) and electrical field stimulation was applied at different frequencies(2, 5, 10, 15 Hz) to obtain NANC-mediated relaxation. Anandamide(0.3, 1 and 3 µM in separate groups) was added 20-min before electrical stimulation. In another group, the selective cannabinoid CB1 receptor antagonist AM251(1 µM), the selective cannabinoid CB2 receptor antagonist AM630(1 µM) and a vanilloid receptor antagonist capsazepine(3 µM) were separately added to the bathing medium 45-min before anandamide(1 µM) administration. Using western blotting, the existence of cannabinoid and vanilloid receptors were assessed in this tissue. Each group consisted of six rats. This study was an experimental study. Statistical analysis of the data was performed by one-way analysis of variance(ANOVA) followed by Newman-keuls post hoc test. Statistical significance was considered when P<0.05. Results: The results showed that the NANC relaxant responses were significantly enhanced in the presence of anandamide at 1 and 3 µM. The potentiating effect of anandamide(1 µM) on relaxation responses was significantly lessened by either AM251(1 µM) or capsazepine(3 µM), but not by AM630(1 µM)(P<0.01). Neither of these antagonists had influence on relaxation responses. Preincubation with the nitric oxide synthase inhibitor L-NAME(1 µM) significantly inhibited the relaxation responses in the presence or absence of 1 µM anandamide(P<0.001). Although at 30 nM, L-NAME did not influence NANC responses, it significantly reduced(P<0.01) the attentuating effect of anandamide on NANC responses. Anandamide(1 µM)) had no influence on concentration-dependent relaxant responses to sodium nitroprusside(10nM-1mM), an NO donor. Western blotting revealed the existence of cannabinoid CB1(but not CB2) and vanilloid VR1 receptors in rat corpus cavernosum. Conclusion: For the first time, our results indicated the potentiating activity of anandamide on NANC-mediated relaxation of rat corpus cavernosum through both CB1 and vanilloid receptors. The NO-mediated component of the NANC relaxant responses to electrical stimulation is involved in this enhancement. Also it was shown that CB1 and VR1 receptors are present in this tissue.
Volume 15, Issue 0 (9-2008)
Background & Aim:
treatment, as an estrogen antagonist, induces cell death in rat's developing hippocampus. Estrogen has a
variety of physiological effects on the nervous system, including regulation of cognitive functions, learning,
aging, angiogenesis, neurogenesis, and neuroprotective effects. In the present study, we demonstrated the
effects of TAM as an estrogen antagonist on nitric oxide synthase activity in rat's developing hippocampal
pyramidal neurons.
Maternal steroids modulate various functions in the developing brain. Tamoxifen (TAM)Material and Method:
animals were divided randomly into control, experimental and sham groups. Each group contained full term
embryo (E
group received a total of four doses of TAM,i.e. 250 mg/kg TAM in propylene glycole was injected
intraperitoneally twice a day for two days. Their hippocampus was removed 6 hours after the last injection.
Animals at the same gestational age were used as shams and controls. The latter received only propylene
glycole. The hippocampus was dissected out and stored in fixative and sucrose. Cryostat sections were thawmounted
on gelatin slides. The sections were incubated for NADPH-diaphorase histochemistry by light
microscope. Independent sample t-test and SPSS version 11.0 were used to analyze the data.
The present experimental study was conducted on twelve groups of adult rats. The22), one-day neonate (P1), one-week neonate (P7), and three -week neonate (P21). The experimentalResults:
thickness increases so that the most thickness is seen in the third week after birth. Considering the short halftime
of TAM, it was observed that tamoxifen had its greatest effects on E
estrogen receptors. In the group that didn't receive tamoxifen, due to the presence of estrogen NADPHdiaphorase
activity, which indicates NOS activity level, strengthened. On the other hand, the animals which
received tamoxifen in the early stage showed a decrease in NADPH-diaphorase activity owing to estrogen
receptor blockade. Furthermore, the number of neural cells in CA1 hippocampal region showed a decrease in
proportion to the reduction in NOS activity level in this region. The decreased number of neural cells and NOS
activity, which was seen in E
We found that in the early stage of development cellular density decreases and gradually cellular22, P1 and P7 groups and blockaded22, P1 , P7 groups, seems to be due to the short half-time of tamoxifen.Conclusion:
oxide-mediated growth and development of hippocampal pyramidal cells.
These findings indicate that estrogen and selective estrogen modulators can influence nitricVolume 16, Issue 0 (9-2009)
Backhground & Aim: Several lines of evidence have indicated that NO might be important in the pathogenesis of RA. NO could be synthesized by an enzyme called inducible nitric oxide synthase (iNOS). iNOS is expressed in the synovium, cartilage and lymphomononuclear cells of synovial fluid and lymphocytes and monocytes of peripheral blood of RA patients. Several studies have shown that iNOS gene (NOS2A) polymorphisms have been associated with a number of inflammatory and autoimmune diseases. In the present study the frequency of NOS2A gene polymorphism at positions -1659 C/T and +150 C/T was investigated in patients with RA and control subjects.
Material and Method: In the present case- control study the frequency of NOS2A gene polymorphisms at positions -1659 C/T and +150 C/T was investigated in 176 patients with RA and 232 control subjects using PCR-Allele specific and PCR-RFLP methods, respectively. SPSS version 10,
Chi-square and Fisher's exact tests were used to study the differences in genotype and allele frequencies between patients and controls.
Results: The results of the present study showed a significant difference in NOS2A -1659 C/T polymorphism between the patients and controls (P=0.03). Wild type homozygote (CC) was significantly higher in normal subjects (75%) than patients (64.2%). No significant difference was observed between RA patients and controls in NOS2A +150 C/T polymorphism (P=0.33). Furthermore, there was no significant association between different clinical and paraclinical findings including erosion, deformity of joints, rheumatoid nodules, extra articular manifestations, CRP, RF and age of onset and -1659 C/T and +150 C/T NOS2A gene polymorphisms.
Conclusion: To the best of our knowledge this study was the first research on the NOS2A gene polymorphisms in RA patients. Our results revealing the significant correlation between -1659 C/T genotypes and RA, indicates the importance of iNOS polymorphism in the patients and suggest further studies in other ethnic groups.
Volume 20, Issue 108 (6-2013)
Background: In recent years, increasing evidence suggest that free radicals plays an important role in the pathogenesis of multiple sclerosis and Experimental Autoimmune Encephalomyelitis (EAE), an animal model of multiple sclerosis. Therefore, All-Trans Retinoic Acid (ATRA) as an antioxidant may be effective in ameliorating disease severity.
Methods : The present research is an experimental-interventional study . EAE was induced by immunization of female C57BL/6 mice with MOG35-55 peptide and complete Freund's adjuvant. EAE mice were placed in two therapeutic groups (n=7 per group).Also, 7 mice served as normal (non-EAE) controls. Treatment with ATRA (25mg/Kg-every other day) was initiated in treatment group at day 12 when the treatment group developed a disability score. EAE control received vehicle alone with same schedule. Signs of disease were recorded daily until the day 33 when mice were sacrificed. Then, the levels of nitric oxide in spleen cell culture supernatant and total antioxidant capacity of plasma in mice were evaluated.
Results: ATRA significantly alleviated the clinical signs of established EAE. Upon antigen-specific re-stimulation of splenocytes, nitric oxide production was significantly reduced in TRA-treated group and reached in the range of normal mice. In addition, reduction in antioxidant capacity of serum in ATRA-treated EAE mice was prevented.
Conclusions: At least part of the beneficial effects of ATRA in the treatment of EAE may be done by suppressing nitric oxide levels and improving antioxidant defense potential.
Volume 20, Issue 115 (1-2014)
Background: Cardiovascular
disease is one of the main causes of morbidity and mortality in postmenopausal
women. Physiological decrease in estrogen levels and accumulation of
visceral fat and being overweight, increase the risk of cardiovascular
disorders in the menopausal years. The aim of this study was to
determine the effects of aerobic exercising on plasma nitric oxide level and
vessel endothelium function in postmenopausal women.
Methods: In
this semi-experimental study, twenty-three healthy postmenopausal women with
the average of age: 54.4±5.56 years were randomly divided into two exercise
group (n= 13) and control (n=10) group. The exercise group performed aerobic
exercise for eight weeks, three sessions per week with 50-70% of maximum heart
rate reserve. The duration of each training session was increased from 30 to 45
minutes gradually. During this period, the control group did not participate in
any regular exercise program. Before and after aerobic
training program, anthropometric measurements, VO2 max, nitric oxide
concentrations and Flow Mediated Dilation (FMD) of all subjects were measured.
Data were analyzed with paired t-student test at a significance level of
p<0.05.
Results: Eight weeks of
aerobic exercise, led to a significant reduction in weight and body fat VO2max
(p=0.001), FMD index (p=0.026) and nitric oxide concentration (p=0.003) were
significantly increased after aerobic exercise program.
Conclusions: Eight
weeks of aerobic exercise induced increasing in nitric oxide and improving the
vessel endothelium function in postmenopausal women and it can be said that
regular exercise may probably have a preventive effect for the development of
cardiovascular disease in postmenopausal women.
Volume 20, Issue 117 (3-2014)
Background: Multiple sclerosis (MS ( is one of the chronic autoimmune diseases of the central nervous system with unknown etiology. Nitric oxide (NO) as a free radical has contradictory effect on the central nervous system and on MS disease. Nitric oxide is one of the distractive factors of the immune system and is a factor in the destruction of myelin. On the other hand, there is an interaction between NO and memory. In this study, the effects of stimulation and suppression of the NO system have been investigated on the memory of MS .
Methods : In this experimental 35 male rats were anesthetized and a cannula was placed in the hippocampus CA1 region, later were divided into five groups, including: control, sham, Ethidium Bromide (EB) (3 μL / rat), L-Arginine (15/1 μg / rat and), EB (3 μL / rat) + L-Arginine (15/1 μg / rat and). The Morris water maze was used for studying the spatial memory. Data analysis was performed by using one way ANOVA.
Results: Administration of EB as the inducer of MS disease caused the impairment of spatial memory, L-Arginine improved spatial learning and memory in healthy rats, L-Arginine improves spatial memory in rats with MS.
Conclusions: In MS rats , L-Arginine improved the spatial memory. It seems that NO by activating intracellular secondary messenger pathways improves the declined spatial memory during MS disease.
Volume 21, Issue 120 (6-2014)
Background : Hypertension is one of the major cardiovascular risk factors after the fifth decades of life in women but mechanisms responsible for the increase in blood pressure are complex. The present study was performed to assess the effect of aerobic exercise in endothelin-1, C-reactive protein and nitric oxide in hypertensive postmenopausal women (HPW).
Methods: In a randomized controlled trial, 20 hypertensive postmenopausal, sedentary women, aged 50–55 years were randomized to an rhythmic aerobic exercise intervention of moderate-intensity (50%–65% maximal heart rate), for 45-60 min/day, and 3 days/week for 6 weeks(n=10 per each groups). Systolic and diastolic blood pressure values and alsoplasma levels of endothelin-1, C-reactive protein and nitric oxide were measured before and after the intervention. Data were analyzed by paired and independent t tests (p<0.05).
Results : A significant reduction in both systolic and diastolic blood pressure values (p=0.001, p=0.008, respectively) was seen after aerobic exercise which was accompanied by markedly increase of nitric oxide (p=0.002) and significantly decrease in plasma ET-1(p=0.001) and C-reactive protein (p=0.001) concentrations in the HPW.
Conclusions: A program of supervised aerobic exercise improves hypertension and may attenuate the increased inflammatory and vasoconstrictor mediators by increasing the bioavailability of nitric oxide.
Volume 26, Issue 3 (5-2019)
Background: High blood pressure is a threat to the health of individuals, especially women. In order to overcome this threat, the purpose of this study was to investigate the effect of eight weeks of resistance training on blood pressure and Nitric oxide and Apelin levels in women with pre-hypertension.
Methods: For this purpose, 24 women with pre-hypertension aged from 30 to 45 years old were randomly divided into two groups of exercise and control. The training group performed three resistance training sessions per week for eight weeks. One day before and 48 hours after the last session of the training, blood sampling was taken from the subjects. The changes of Apelin and Nitric oxide levels were measured by Elisa method. Paired t-test and independent t-test were used for within and between groups comparisons, respectively (p<0.05).
Results: The results showed that Apelin and Nitric oxide levels increased significantly (p <0.001) and systolic and diastolic blood pressure decreased significantly (p <0.001) in the training group. However, no significant changes were observed in the control group.
Conclusion: Performing an eight-week moderate-intensity resistance training program can reduce the levels of blood pressure, apelin, and Nitric oxide in women with pre-hypertension.
Volume 28, Issue 2 (4-2021)
Background and Aims: Beetroot juice has been shown to increase endurance and high-intensity training performance. In addition, after consuming beetroot juice supplementation, the performance of periodic exercise in recreational (non-professional) athletes also improves. Therefore, we assessed the impact of a period of BR consumption on the performance of amateur trained soccer players following high-intensity intermittent exercise. The popularity of exercise nutrition is growing exponentially among athletes to boost their athletic performance. As a result, upon the improvement of contraction / relaxation, the generation of power and strength enhances the short-term intermittent running. Nitric oxide (NO) is a signaling molecule that is capable of improving vascular function, mitochondrial respiration, glucose homeostasis, and skeletal muscle contractions. However, the consumption of nitrate-rich vegetables (NO3-), such as lettuce, spinach, and beetroot (BR) have been identified as an alternative source and precursor of NO. The consumption of NO3- and increase of NO production decrease oxidative stress in skeletal muscle, handle calcium, and increase contractile force and production capacity in type II muscle fibers, increase time to fatigue, and improve the exercise performance. BR is rich in foods such as sugar, phenolic compounds, and ascorbic acid. BR is a rich source of NO3- commonly consumed because it possesses high contents of betacyanin and polyphenol and it produces more NO molecules than NO salts. The ergogenic effects of NO3-rich sources were first reported in metabolic adaptations following endurance training. Athletes in team or individual sports aim to increase performance in high-intensity interval training. High-intensity exercise results in a transition from low- to high-intensity and changes in metabolic conditions. In recent years, nitrate supplementation has been shown to have a significant effect on anaerobic exercise and high-intensity interval exercise. The effect of nitrate-rich BR juice support the improvement of the performance of high-intensity intermittent exercise in team sports; however, the length of the intake period and the time interval of nitrate-rich supplementation prior to the performance of the experiment are not completely clear. Based on these findings, we hypothesized that supplementation of BR in amateur trained soccer players could improve physiological and functional parameters. Therefore, we assessed the impact of a period of BR consumption on the performance of amateur trained soccer players following high-intensity intermittent exercise.
Methods: Forty-two male soccer players competing in the 2nd Iranian amateur league with the mean age of 20.50±0.58, weight of 67.14±2.35, body fat percent of 11.63±1.44, and body mass index of 21.34±0.48 voluntarily participated in the study. First off, all participants were informed about the nature of experimental procedures, including potential risks and benefits and then, received written informed consent. The experimental protocols were approved by the Ethical Committee of Shiraz University, Iran, according to Helsinki DeclarationGuidelines. Participants were asked not to take any sport or medical supplements, or any ergogenic aids during the 4-week experiment period. The current study was randomized, placebo-controlled, cross-over, and double-blind that investigated the effect of BR supplementation on high-intensity intermittent exercise performance in soccer players. High- intensity intermittent running performance was assessed by the Yo-Yo IR1 test and Wingate test in two days. All subjects ingested beetroot juice nitrate- rich (2×70 ml/day; BR) or placebo (PLA) for six-days with seven-days of wash-out between trialsParticipants arrived at the facility 2.5 h after ingesting the last bolus of the supplement (8:30 A.M.). The heart rate was continuously monitored throughout the experiment (Polar Beat, Polar Electro, Kempele, Finland). The experimental protocols were carried out at the same time in every day. Subjects were asked to arrive to the laboratory 90 min before the experiment. They were also requested to be fully hydrated, and consume their least meal at least 3 h before the initiation of the exercise test. Besides, they had to avoid strenuous exercise 36 h before the experimental trials. Before the Yo-Yo test, warm-up was performed for each participant. The Yo-Yo test was carried out on running lanes with a width of 2 m and length of 20 m. The examination consisted of repeated 2 × 20 m runs that progressively increased the speed which was controlled by the audio bleeps from an audio system. Each 20 m running was interspersed by 5 m behind the finishing line marked the running distance that is 10-s active recovery period. Immediately after the termination of the Yo-Yo test, Subjective rating of perceived exertion was carried out in accordance with the Borg's scale ranging from 6–20. Wingate test used for determine of power output and fatigue index. The heart rate and VO2max were measured continuously throughout the Yo-Yo test, and nitrate/nitrite plasma levels were collected prior and post of the six- days nitrate supplementation. Data are expressed as the means and standard deviation (mean ± SD). All statistical analyses were carried out by the SPSS software (version 19.0; IBM Corp, Armonk, NY, USA). The Shapiro-Wilk test , Independent t-test and Pearson correlation coefficients were used. The level of statistical significance was set at p< 0.05.
Results: Compared to PLA, six- days BR supplementation increased mean power (483.91±23.60 vs. 468.77±23.39, p<0.05) and low power (373.31±22.03 vs. 340.41±22.40, p<0.05) and also reduced fatigue index (37.66±5.66 vs. 45.27±7.94; p<0.05). High-intensity intermittent running performance (p= 0.034), VO2max (p= 0.043), nitrate and nitrite plasma levels (P<0.001) were significantly improved in subjects in the BR compared with the PLA.
Conclusion: According to the results of the present study, it seems that 6 days of beet juice supplementation can improve the aerobic and anaerobic performance of trained football players.The main finding of this study is that a 6-day period of BR supplementation led to a marked improvement in the performance of high-intensity intermittent exercise in soccer players. Such an improvement includes a decrease in the heart rate during high-intensity intermittent running tests, as well as an increase in VO2max. We investigated the impact of a 6-day period of BR supplementation on nitrate/nitrite concentrations and performance during the speed and Yo-Yo tests in soccer players. After 6 days BR supplementation, the plasma levels of nitrate/ nitrite, peak power, mean power, low power, and performance in the Yo-Yo test were significantly increased. Also, the heart rate and fatigue index were significantly decreased in the BR compared with the PLA.
Volume 29, Issue 11 (1-2023)
Background & Aims: Osteosarcoma (also called osteogenic sarcoma) is the most common type of cancer that starts in the bones. It is a malignant mesenchymal cell tumour, characterized by pleomorphic spindle-shaped cells, capable of producing an osteoid matrix. Tumour cells metastasize primarily via the haematogenous route. This disease is very aggressive and the tumor formed is fixed, hard and irregular. The cancer cells in these tumors look like early forms of bone cells that normally help make new bone tissue, but the bone tissue in an osteosarcoma is not as strong as that in normal bones. Overall, osteosarcoma is a rare disease, however, children and teens are the most commonly affected age group, but osteosarcoma can develop at any age. Although this disease occurs sporadically, approximately 70% of tumor specimens show an abnormality in the chromosome. Moreover, regulation of cell cycle has been reported to demonstrate inherited defects in some cases. The incidence of osteosarcoma is bimodal. The first peak occurs at the ages of puberty, implying the ages of 15 to 19 in boys and the ages of 10 to 14 in girls. The second peak occurs in the elderly with the age of 75 years. Noteworthy, osteosarcoma is rare before the age of 5. With the application of multimodal chemotherapy, disease-free survival of patients with high-grade osteosarcoma has been improved to more than 60% compared to 10–20% which was reachable with the surgery as the only therapeutic approach. At present, treatment of osteosarcoma is a combination of surgery and chemotherapy both before and after the surgery. Additionally, the use of common chemotherapeutic agents such as high-dose methotrexate, cisplatin, doxorubicin and/or etoposide and ifosfamide frequently causes both acute and long-term toxicity. Although several chemotherapy regimens have been applied in the past 20 years, survival rates of patients are still not satisfying and no practical targeted therapy is discovered. Therefore, it is important to investigate different therapeutic methods and anti-tumor agents in order to find an approach that provides a higher survival rate. Flavonoids possess several biological and pharmacological activities. In addition, flavonoids have the advantage of being less toxic and can be prescribed for an extended duration. Therefore, various plant-derived flavonoids use as drugs have been reported as a modulator for chronic inflammation caused by virus infection and other diseases, such as human papillomavirus, hepatitis virus, SARS-CoV-2, autoimmune disease, type 2 diabetes, cardiovascular diseases, Alzheimer’s disease, Parkinson’s disease, and cancer. Quercetin is a naturally occurring polyphenolic flavonoid, whose chemical name is 3,3′,4′,5,7-Pentahydroxyflavone (C15H10O7), can be found in a wide range of daily foods, such as grains, fruits, and vegetables and in higher levels in capers, buckwheat seeds, radish, onions, apples, red leaf lettuce, asparagus, nuts, and teas. It is reported that oral administration of 1 g quercetin per day is safe and is absorbed up to 60%. Quercetin has a high ability to scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) molecules; therefore, exhibiting beneficial effects in preventing obesity, diabetes, cardiovascular diseases, and inflammation. Furthermore, quercetin is indicated to exert various anti-tumor effects both in vitro and in vivo against several cancers, such as ovarian cancer, colorectal cancer, lymphoma, gastric cancer, and breast cancer. On the other hand, the high toxic effect of quercetin against cancer cells is accompanied with little or no side effects or harm to normal cells. Its wide accessibility, efficacy, and a broad range of activity, and low toxicity as compared with other examined compounds, make it an attractive chemical in the fight against diseases including cancer. It has been recognized and employed as an alternative drug in treating different cancers alone or in combination with other chemotherapeutic drugs. NO is a free radical that regulates several physiological functions and is formed by the conversion of L-arginine to L-citrulline by nitric oxide synthases (NOS). NO is a dual molecule that can have a tumor-protecting or stimulating effect, depending on its local concentration. Certain reports demonstrated a cytotoxic role of NO; others presented a protective role. Many investigations have shown that quercetin has anti-inflammatory activity that pulls out the nitric oxide, catalase, and cytokines, specifically TNF-α, IL-β, and IL-6, which are inflammatory mediators. Therefore, we tried to elucidate the influence of quercetin in order to suggest a new candidate for the treatment of this cancer, on in vitro NO production from Saos2 osteosarcoma cell line
Methods: After 24 hours of culture of Saos2 cells in 96-well plates, different concentrations of quercetin were added to the wells for 72 hours. Cell viability was measured using the colorimetric MTT assay. Briefly, cells were incubated with 0.5mg/mL MTT in DMEM at 37 ºC under 5 % CO2 for 3 h. The blue formazan reduction product, which is generated by the action of the succinate dehydrogenase on the dye only in living cells, was dissolved in 100µL DMSO, and its absorbance was read at 570nm using a Dynex MMX microplate reader. The level of nitrite as an indicator of NO production in the culture medium was measured using modified Griess reagent. In brief, after the experiment, the medium in each well was removed and centrifuged at 10,000 g for 10 min at 20 ºC. Then, 100 µL of the supernatant was mixed with an equal volume of Griess reagent at room temperature for 10 min, and the absorbance was measured at 540 nm using a microplate reader. The nitrite concentration was determined from a sodium nitrite standard curve.
The data were analyzed by one-way ANOVA and P < 0.05 was considered statistically significant.
Results: The results of this study showed that quercetin can decrease the percentage of cell viability of Saos2 cells compared to the control group. The best effective dose is 120 μM. Also, the data showed that quercetin in all concentrations was able to reduce the production of NO levels in Saos2 cells and the best effective concentration is 120 μM.
Conclusion: In this study, it was found that quercetin was able to reduce the viability of Saos2 cells, and part of its effects could be mediated partially by a decrease in NO production. However, further studies are needed on this natural compound.
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