Underlying mechanisms behind the neuroprotective effect of vanillic acid against diabetes-associated cognitive decline: An in vivo study in a rat model

Hippocampal synaptic dysfunction, oxidative stress, neuroinflammation, and neuronal loss play critical roles in the pathophysiology of diabetes-associated cognitive decline (DACD). The study aimed to investigate the effects of vanillic acid (VA), a phenolic compound, against DACD and explore the potential underlying mechanisms. Following confirmation of diabetes, rats were treated with VA (50 mg/kg/day; P.O.) or insulin (6 IU/rat/day; S.C.) for 8 consecutive weeks. The cognitive performance of the rats was evaluated using passive-avoidance and water-maze tasks. Long-term potentiation (LTP) was induced at hippocampal dentate gyrus (DG) synapses in response to high-frequency stimulation (HFS) applied to the perforant pathway (PP) to evaluate synaptic plasticity. Oxidative stress factors, inflammatory markers, and histological changes were evaluated in the rat hippocampus. This study showed that streptozotocin (STZ)-induced diabetes caused cognitive decline that was associated with inhibition of LTP induction, suppression of enzymatic antioxidant activities, enhanced lipid peroxidation, elevated levels of inflammatory proteins, and neuronal loss. Interestingly, chronic treatment with VA alleviated blood glucose levels, improved cognitive decline, ameliorated LTP impairment, modulated oxidative-antioxidative status, inhibited inflammatory response, and prevented neuronal loss in diabetic rats at a level comparable to insulin therapy. The results suggest that the antihyperglycemic, antioxidative, anti-inflammatory, and neuroplastic properties of VA may be the mechanisms behind its neuroprotective effect against DACD.

Sesamin mitigates lead-induced behavioral deficits in male rats: The role of oxidative stress

Lead (Pb) is a well-known toxic pollutant that has negative effects on behavioral functions. Sesamin, a phytonutrient of the lignan class, has shown neuroprotective effects in various neurological disorder models. The present study was undertaken to evaluate the putative protective effects of sesamin against Pb-induced behavioral deficits and to identify the role of oxidative stress in male rats. The rats were exposed to 500 ppm of Pb acetate in their drinking water and simultaneously treated orally with sesamin at a dose of 30 mg/kg/day for eight consecutive weeks. Standard behavioral paradigms were used to assess the behavioral functions of the animals during the eighth week of the study. Subsequently, oxidative stress factors were evaluated in both the cerebral cortex and hippocampal regions of the rats. The results of this study showed that Pb exposure triggered anxiety-/depression-like behaviors and impaired object recognition memory, but locomotor activity was indistinguishable from the normal control rats. These behavioral deficiencies were associated with suppressed enzymatic and non-enzymatic antioxidant levels, and enhanced lipid peroxidation in the investigated brain regions. Notably, correlations were detected between behavioral deficits and oxidative stress generation in the Pb-exposed rats. Interestingly, sesamin treatment mitigated anxio-depressive-like behaviors, ameliorated object recognition memory impairment, and modulated oxidative-antioxidative status in the rats exposed to Pb. The results suggest that the anti-oxidative properties of sesamin may be one of the underlying mechanisms behind its beneficial effect in ameliorating behavioral deficits associated with Pb exposure.

The Protective Effects of Policosanol on Learning and Memory Impairments in a Male Rat Model of Alzheimer's Disease

Alzheimer's disease (AD), the most common form of dementia, is characterized by a progressive decline in cognitive performance and memory formation. The present study was designed to investigate the effect of policosanol (PCO) on cognitive function, oxidative-antioxidative status, and amyloid-beta (Aβ) plaque formation in an AD rat model induced by intracerebroventricular (ICV) injection of Aβ_1-40. Healthy adult male Wistar rats were randomly divided into seven groups: control, sham (5 μL, ICV injection of phosphate-buffered saline), AD model (5 μL, ICV injection of Aβ), acacia gum (50 mg/kg, 8 weeks, gavage), PCO (50 mg/kg, 8 weeks, gavage), AD + acacia gum (50 mg/kg, 8 weeks, gavage), and AD + PCO (50 mg/kg, 8 weeks, gavage). During the ninth and tenth weeks of the study, the cognitive function of the rats was assessed by commonly used behavioral paradigms. Subsequently, oxidative-antioxidative status was examined in the serum. Moreover, compact Aβ plaques were detected by Congo red staining. The results showed that injection of Aβ impaired recognition memory in the novel object recognition test, reduced the spatial cognitive ability in the Morris water maze, and alleviated retention and recall capability in the passive avoidance task. Additionally, injection of Aβ resulted in increased total oxidant status, decreased total antioxidant capacity, and enhanced Aβ plaque formation in the rats. Intriguingly, PCO treatment improved all the above-mentioned neuropathological changes in the Aβ-induced AD rats. The results suggest that PCO improves Aβ-induced cognitive decline, possibly through modulation of oxidative-antioxidative status and inhibition of Aβ plaque formation.

Mitochondrial Dysfunction and Parkinson's Disease: Pathogenesis and Therapeutic Strategies

Parkinson's disease (PD) is a common age-related neurodegenerative disorder whose pathogenesis is not completely understood. Mitochondrial dysfunction and increased oxidative stress have been considered as major causes and central events responsible for the progressive degeneration of dopaminergic (DA) neurons in PD. Therefore, investigating mitochondrial disorders plays a role in understanding the pathogenesis of PD and can be an important therapeutic target for this disease. This study discusses the effect of environmental, genetic and biological factors on mitochondrial dysfunction and also focuses on the mitochondrial molecular mechanisms underlying neurodegeneration, and its possible therapeutic targets in PD, including reactive oxygen species generation, calcium overload, inflammasome activation, apoptosis, mitophagy, mitochondrial biogenesis, and mitochondrial dynamics. Other potential therapeutic strategies such as mitochondrial transfer/transplantation, targeting microRNAs, using stem cells, photobiomodulation, diet, and exercise were also discussed in this review, which may provide valuable insights into clinical aspects. A better understanding of the roles of mitochondria in the pathophysiology of PD may provide a rationale for designing novel therapeutic interventions in our fight against PD.

Possible mechanisms involved in the protective effects of chrysin against lead-induced cognitive decline: An in vivo study in a rat model

Lead (Pb) is a highly poisonous environmental pollutant that can induce cognitive decline. Chrysin, a natural flavonoid compound, has anti-oxidative, anti-inflammatory, and neuroprotective properties in different neurodegenerative disorders. The present study was designed to examine the putative effects of chrysin against Pb-induced cognitive impairment and the possible involved mechanisms. Adult male Wistar rats were exposed to Pb acetate (500 ppm in standard drinking water) either alone or in combination with daily oral administration of chrysin (30 mg/kg) for eight consecutive weeks. During the eight-week period of the study, the cognitive capacity of the rats was evaluated by employing both novel object recognition and passive avoidance tests. On day 56, hippocampal synaptic plasticity (long-term potentiation; LTP) was recorded in perforant path-dentate gyrus (PP-DG) synapses to assess field excitatory postsynaptic potentials (fEPSPs) slope and population spike (PS) amplitude. Subsequently, pro- and anti-inflammatory cytokines and histological changes were evaluated in the cerebral cortex and hippocampus of the rats. Moreover, Pb levels in blood and brain tissues were assessed. The results showed that Pb exposure causes cognitive decline, inhibition of hippocampal LTP induction, imbalance of pro- and anti-inflammatory cytokines, enhancement of Pb levels in blood and brain tissues, and neuronal loss. However, chrysin treatment improved cognitive dysfunction, ameliorated hippocampal LTP impairment, modulated inflammatory status, reduced Pb concentration, and prevented neuronal loss in the Pb-exposed rats. The results suggest that chrysin alleviates Pb-induced cognitive deficit, possibly through mitigation of hippocampal synaptic dysfunction, modulation of inflammatory status, reduction of Pb concentration, and prevention of neuronal loss.

Sesamin: Insights into its protective effects against lead-induced learning and memory deficits in rats

BACKGROUND

Lead (Pb) is one of the most hazardous pollutants that induce a wide spectrum of neurological changes such as learning and memory deficits. Sesamin, a phytonutrient of the lignan class, exhibits anti-inflammatory, anti-apoptotic, and neuroprotective properties. The present study was designed to investigate the effects of sesamin against Pb-induced learning and memory deficits, disruption of hippocampal theta and gamma rhythms, inflammatory response, inhibition of blood δ-aminolevulinic acid dehydratase (δ-ALA-D) activity, Pb accumulation, and neuronal loss in rats.

METHODS

Sesamin treatment (30 mg/kg/day; P.O.) was started simultaneously with Pb acetate exposure (500 ppm in standard drinking water) in rats, and they continued for eight consecutive weeks.

RESULTS

The results showed that chronic exposure to Pb disrupted the learning and memory functions in both passive-avoidance and water-maze tests, which was accompanied by increase in spectral theta power and theta/gamma ratio, and a decrease in spectral gamma power in the hippocampus. Additionally, Pb exposure resulted in an enhanced tumor necrosis factor-alpha (TNF-α) content, decreased interleukin-10 (IL-10) production, inhibited blood δ-ALA-D activity, increased Pb accumulation, and neuronal loss of rats. In contrast, sesamin treatment improved all the above-mentioned Pb-induced pathological changes.

CONCLUSION

This data suggests that sesamin could improve Pb-induced learning and memory deficits, possibly through amelioration of hippocampal theta and gamma rhythms, modulation of inflammatory status, restoration of the blood δ-ALA-D activity, reduction of Pb accumulation in the blood and the brain tissues, and prevention of neuronal loss.

Identification of Conformational B-cell Epitopes in Diphtheria Toxin at Varying Temperatures Using Molecular Dynamics Simulations

The changes in temperature levels can potentially affect the toxins in terms of stability and immunological properties via alteration of their structures. Diphtheria Toxin (DT) is highly considered by scientists since its mechanism of action is similar to those of most bacterial toxins, such as botulinum, tetanus, and anthrax. The protection of conformational B-cell epitopes is critically important in the process of diphtheria vaccine production. This study aimed to evaluate the conformational changes of the DT structure at three different temperature levels (27˚C, 37˚C, and 47˚C) using molecular dynamic simulations. Secondary structures were analyzed in YASARA software. According to the results, significant decreases were observed in percentages of the β-sheets, turns, and the helices of the DT structure at 47˚C in comparison with those at 27˚C and 37˚C. Furthermore, the tertiary structure of the DT was compared at different temperatures using the contact map. Accordingly, the results showed that the root-mean-square deviation of the DT structure increased upon temperature rising. In addition, amino acids D68, G128, G171, C186, and K534-S535 at 27˚C and 37˚C, as well as amino acids G26, P38, S291, T267, H384, A356, and V518 at 47˚C showed higher root mean square fluctuation values. The finding demonstrated that the stability of the DT structure decreased at high temperature (47˚C). The solvent-accessible surface area diagram showed that the hydrophobicity of the DT structure increased via temperature rising, and the amino acid residues belonging to B-cell epitopes extended through increasing temperature. However, B-cell epitopes belonging to the junction region of chains A and B were only present at 37˚C. The results of this study are expected to be applicable for determining a suitable temperature level for the production process of the diphtheria vaccine.

Racial differences in mammographic density in Brazil: implications for mammographic screening

Background

Mammographic density (MD)-the amount of radio-dense fibroglandular tissue seen on a mammogram - is a stronger biomarker of susceptibility to breast cancer and a major determinant of the sensitivity of mammographic screening. This study examined for the first time racial differences in MD in Brazil.

Methods

555 women (215 from the Longitudinal Study of Adult Health - ELSA-Brasil and 340 users of the Unified Health System - SUS) in Bahia were enrolled into the study. Participants completed an interview, had their heights and weights measured, and underwent a 2-view (cranio-caudal (CC) and medio-lateral-oblique (MLO)) digital mammography of each breast. MD was measured on the left MLO image using the semi-automated Cumulus software, and expressed as the percentage (PMD) of the breast area occupied by fibroglandular tissue. Linear regression models were fitted to assess ethnicity-PMD associations adjusting for age at mammography, body mass index (BMI) and reading batch (minimally-adjusted) and further for socio-economic and reproductive variables.

Results

The study population comprised 95 White (W), 270 Brown-mixed (Bm) and 169 Black (B) women, with a mean age at mammography of 58 (SD = 5.4) years. 63% W, 69% Bm and 49% B women had low educational level; 24% W, 47% Bm and 31% B women had ≥4 children. Minimally-adjusted analysis showed that relative to W women, PMD was 23% (1.23; 95% CI 1.04-1.45) higher in Bm and 4% (1.04; 0.89-1.21) higher in B; however, further adjustment for socio-economic and reproductive variables attenuated the racial differences (fully-adjusted model: 16% (1.16; 0.96-1.40) and 9% (1.09; 0.92-1.29) for Bm and B, respectively.

Conclusions

The racial differences in PMD were mainly accounted by ethnic differences in socio-economic and reproductive-related factors.

Implications Further studies should examine whether racial differences in PMD in Brazil lead to racial differences in false negative and interval cancer rates of mammographic screening.

Key messages

In Brazil, ethnic differences in socio-economic and reproductive-related factors are responsible for racial differences in mammographic density. More research is needed to address racial differences in breast cancer risk in Brazil.

Predictors of multimorbidity among the Kurdish population living in the Northwest of Iran

BACKGROUND

There is limited information about the predictors of multimorbidity (MM) among ethnic minority older adults in Iran. This study aimed to examine the impact of sociodemographic and lifestyle factors on the prevalence of MM, among older Kurdish people living in the Northwest of Iran.

METHODS

The current study was conducted in Bukan city located in West Azarbaijan province in the Northwest of Iran. The data for this study was based on the enrolment phase of a longitudinal study on ageing among the Kurdish population aged 50-94 yearswhich was designed according to the elderly component of the PERSIAN Cohort in Iran. Stratified random sampling was used to select people aged 50 + from eight health centres in Bukan from Oct 2017 to Dec 2018. Those who accepted the invitation and completed the baseline questionnaire were included in this study (N = 1493; Response rate 75%). A range of different factors,including sociodemographic and lifestyle factors as well as self-reported chronic conditions, was obtained by trained interviewers. MM was defined as "coexistence of two or more chronic conditions in the same person". We included a list of 36 diseases/conditions in this analysis. Descriptive analysis and logistic regression were performed to compare the prevalence of MM according to different factors.

RESULTS

Over a third of the participants (36.6%) had ≥2chronic conditionsand 15.7% had≥3 chronic conditions. Hypertension, diabetes, musculoskeletal conditions, fatty liver, and heart diseases were common chronic conditions. In a fully adjusted logistic regression model, older age (OR_adj = 1.92, 95% CI: 1.48-2.48), being female (OR_adj = 1.49, 95%CI: 1.14-1.94), living without aspouse (OR_adj = 1.81, 95%CI: 1.34-2.44), and inadequate consumption of fruit and vegetables (OR_adj = 1.33, 95%CI: 1.06-1.67) were associated with the higher prevalence of MM.

CONCLUSION

This study found that the prevalence of MM is relatively high among older Kurdishadults. Sociodemographic differences in the prevalence of MM might be of interest tothe health care system,and the prevalence of common chronic conditions in this study may highlight the need forlifestyle modifications in this community.

Chrysin attenuates traumatic brain injury-induced recognition memory decline, and anxiety/depression-like behaviors in rats: Insights into underlying mechanisms

RATIONALE

Cortical and hippocampal neuronal apoptosis and neuroinflammation are associated with behavioral deficits following traumatic brain injury (TBI).

OBJECTIVES

The present study was designed to investigate the potential protective effects of flavonoid chrysin against TBI-induced vestibulomotor impairment, exploratory/locomotor dysfunctions, recognition memory decline, and anxiety/depression-like behaviors, as well as the verified possible involved mechanisms.

METHODS

Chrysin (25, 50, or 100 mg/kg/day; P.O.) was administered to rats immediately after diffuse TBI induction, and it was continued for 3 or 14 days. Behavioral functions were assessed by employing standard behavioral paradigms at scheduled points in time. Three days post-TBI, inflammation status was assayed in both cerebral cortex and hippocampus using ELISA kits. Moreover, apoptosis and expression of Bcl-2 family proteins were examined by TUNEL staining and immunohistochemistry, respectively.

RESULTS

The results indicated that treatment with chrysin improved vestibulomotor dysfunction, ameliorated recognition memory deficit, and attenuated anxiety/depression-like behaviors in the rats with TBI. Chrysin treatment also modulated inflammation status, reduced apoptotic index, and regulated Bcl-2 family proteins expression in the brains of rats with TBI.

CONCLUSIONS

In conclusion, the results suggest that chrysin could be beneficial for protection against TBI-associated behavioral deficits, owing to its anti-apoptotic and anti-inflammatory properties.

Ellagic acid protects against diabetes-associated behavioral deficits in rats: Possible involved mechanisms

AIMS

Diabetes mellitus (DM), a chronic metabolic disease, is associated with behavioral deficits. It has been suggested that ellagic acid (EA), a natural polyphenol compound, has potent anti-diabetic, anti-inflammatory, and neuroprotective properties. The present study was aimed to explore the potential protective effects of EA against diabetes-associated behavioral deficits and verified possible involved mechanisms.

MAIN METHODS

Fifty adult male Wistar rats were randomly divided into five groups: i.e., CON: normal rats treated with vehicle (5 ml/kg/day; P.O.), EA: normal rats treated with EA (50 mg/kg/day; P.O.), STZ: diabetic rats treated with vehicle (5 ml/kg/day; P.O.), STZ + INS: diabetic rats treated with insulin (6 IU/rat/day; S.C.), STZ + EA: diabetic rats treated with EA (50 mg/kg/day; P.O.). All the groups were under treatment for eight consecutive weeks. During the seventh and eighth weeks, behavioral functions of the rats were assessed by commonly used behavioral tests. Subsequently, pro- and anti-inflammatory cytokines, neurotrophic factors, and also histological changes were evaluated in both cerebral cortex and hippocampus of the rats.

KEY FINDINGS

Chronic EA treatment attenuated anxiety/depression-like behaviors, improved exploratory/locomotor activities, and ameliorated cognitive deficits in diabetic rats. These results were accompanied by decreased blood glucose levels, modulation of inflammation status, improved neurotrophic support, and amelioration of neuronal loss in diabetic rats. In some aspects, treatment with EA was even more effective than insulin therapy.

SIGNIFICANCE

The current work's data confirms that EA could potentially serve as a novel, promising, and accessible protective agent against diabetes-associated behavioral deficits, owing to its anti-hyperglycemic, anti-inflammatory, and neurotrophic properties.

Reproduction and marriage among male survivors of cancer in childhood, adolescence and young adulthood: a national cohort study

BACKGROUND

Increased survival after cancer in young age has made long-term follow-up studies of high external validity important. In this national cohort study, we explored the impact of cancer in young age on reproduction and marital status in male survivors.

METHODS

Hazard ratios (HRs) and relative risks (RRs) of reproductive and marital outcomes were studied for male survivors of cancer in young age (<25 years) and cancer-free male comparisons, born during 1965-1985, by linking compulsory national registries in Norway.

RESULTS

Male cancer survivors (n=2687) had reduced paternity (HR: 0.72, 95% confidence interval (CI): 0.68-0.76). This was most apparent in survivors of testicular cancer, brain tumours, lymphoma, leukemia and bone tumours, and when diagnosed with cancer before 15 years of age. Male cancer survivors were more likely to avail of assisted reproduction (RR: 3.32, 95% CI: 2.68-4.11). There was no increased risk of perinatal death, congenital malformations, being small for gestational age, of low birth weight or preterm birth in their first offspring. Male cancer survivors were less likely to marry (HR: 0.93, 95% CI: 0.86-1.00), in particular brain tumour survivors.

CONCLUSIONS

In this national cohort study, we demonstrated reduced paternity and increased use of assisted reproduction among male cancer survivors, but no adverse outcome for their first offspring at birth.

The Aqueous Extract of Portulaca Oleracea Ameliorates Neurobehavioral Dysfunction and Hyperglycemia Related to Streptozotocin-Diabetes Induced in Ovariectomized Rats

Diabetes mellitus is one of the most common causes of neuropathy. Although antioxidant and antidiabetic effects of the aqueous extract of purslane (Portulaca oleracea) (AEOP) have been demonstrated before by other researchers, we did not find any study that assessed the psychobiological effects of AEOP in diabetes induced animals. Thirty ovariectomized (OVX) female Wistar rats were randomly divided into 3 groups of control, Dia and Dia+AEOP. The latter group was orally treated by 300 mg/kg of AEOP for 35 days. Dia and Dia+AEOP groups were made diabetic by IP injection of 60 mg/kg of streptozotocin (STZ). The psychobiological effects of AEOP were assessed by Morris water maze (MWM), elevated plus maze (EPM), forced swimming test (FST) and tail pinch stressor (TPS). AEOP significantly decreased hyperglycemia (p<0.001). Diabetes significantly decreased their spatial cognitive performance at the training trial as well as the total distance traveled at the probe trial in MWM (p<0.05). All the diabetes related deficits at training trials were improved by AEOP treatment (p<0.05). AEOP treatment not only improved the motor deficit of Dia group in EPM, but also showed anxiolytic effects compared to both control and Dia groups (p<0.05). In the FST, no differences were observed between any groups (p>0.05). Diabetes significantly increased their non-functional masticatory activity in TPS (p≤0.001) while it was improved in Dia+AEOP group. We showed that AEOP has significant anxiolytic effects and it can improve spatial cognitive performance, locomotor deficit and stress in diabetic OVX rats.

Induced adverse effects of prenatal exposure to silver nanoparticles on neurobehavioral development of offspring of mice

Steadily increased use of silver nanoparticles (Ag-NPs), has increased the amount of its exposure to humans and animals. Current scarce knowledge about the influences of prenatal exposure to Ag-NPs on postnatal outcomes, motivated us to investigate whether being exposed to it during pregnancy has any effects on neurobehavioral development of the adult offspring. Thirty virgin female NMRI mice were mated and treated subcutaneously once every three days from gestation day 3 until delivery, by 0, 0.2 and 2 mg/kg of bodyweight (BW) of Ag-NPs. Behavioral functions of adult offspring including spatial memory, passive avoidance learning, stress, anxiety-like behaviors and locomotor activities were assessed by commonly used neurobehavioral paradigms and the results were compared according to treatment and sex. Prenatal exposure to Ag-NPs significantly impaired their cognitive behavior in the Morris water maze. Although no evidence was observed indicating more anxiety-like behaviors in the treated offspring in the elevated plus maze, the number of defecations and leanings in the open field assay and number of passages in the light-dark box were greater in groups prenatally treated by Ag-NPs. Most of the impairments were more apparent in the offspring which had been prenatally exposed to high doses of Ag-NPs, particularly female ones. The present study indicated that the exposure of pregnant animals to Ag-NPs may lead to various neurobehavioral disorders in their offspring. Thus, more attention should be paid to avoid exposure to Ag-NPs, especially from pregnant females.

Carotenoderma in a young woman of normal body mass index with hypothalamic amenorrhoea: a 2-year follow-up case report

Hypothalamic amenorrhoea has been shown to be associated with hypercarotenaemia, but no causal link has been established. Many people are unaware of the health implications of carotenoderma. We report on a 36-year-old woman with normal body mass index and with a history of secondary amenorrhoea for 2 years and carotenoderma for 5 years. She had a history of practising a fixed-menu diet of predominantly leafy greens, exercised intensively and had a stressful job. Blood tests confirmed the presence of hypercarotenaemia and hypogonadotrophic hypogonadism. Carotenoderma subsided after 6 months of lifestyle modification, but she remained amenorrhoeic up to 12 months later. Since then, her condition had relapsed up to the time of 2 years of follow-up. We conclude that hypercarotenaemia/carotenoderma and hypothalamic amenorrhoea are manifestations of a constrained lifestyle rather than causally linked. The presence of carotenoderma should alert public individuals and clinicians, especially in primary care, alike for signs of potential health complications including reproductive dysfunction even without weight problems.

Incidence trends of colorectal cancer in the West of Iran during 2000-2005

BACKGROUND

Colorectal cancer is a main leading cause of cancer death in western countries. Although many studies have been conducted on incidence trends all over the world in recent years, information regarding changes in incidence of colorectal cancer in Iran is insufficient. The present study of colorectal cancer in the west of Iran during recent years was therefore performed.

MATERIALS AND METHODS

The registered data for colorectal cancer cases in National Cancer Registry System were extracted from the Ministry of Health and Medical Education, Center for Disease Control and Management. The codes from 18-21 among cancers were selected for colon and rectum cancers. Incidence rates were standardized directly using WHO population. The significance of incidence rate trends during 2000-2005 was tested through Poisson regression.

RESULTS

762 cases of colorectal cancer were observed during 6 years in this region, with a gender ratio of men to women of 1.2. It increased from 65 cases in 2000 to 213 cases in 2005 or from 1.5 per100,000 per persons per year to 4.8. Significant increasing trends were evident in Kermanshah and Hamadan provinces; however, change did not reach significance in Ilam and Kurdistan provinces.

CONCLUSIONS

Colorectal cancer has an increasing trend in the west of Iran. Although it seems that the increasing rate of colorectal cancer is due to increasing of cancer risk factors, some proportion may be related to the improvement of surveillance systems in Iran.