Comparative study on the preventive effect of saffron carotenoids, crocin and crocetin, in NMU-induced breast cancer in rats

Objective: Crocin [Cro] and crocetin [Crt] are two widely known saffron carotenoids, which exert anticancer effects by different mechanisms. Here, we investigated and compared the preventive effect of Cro and Crt at the initiation and promotion stages of breast cancer induction in an animal model

Materials and Methods: In this experimental study, female Wistar albino rats were injected with three doses of N-methyl-N-nitrosourea [NMU]. The preventive intervention was done at different times for the initiation and promotion stages. Thus, Cro/Crt was administered by gavage 20 days before, or one week after, the first NMU injection, for the prevention at the initiation or promotion stages respectively. The treatment was repeated every three days, and continued up to the end of experiment. Tumor appearance was checked by palpation and some parameters were determined after sacrifice

Results: Tumor volume, latency period, and tumor number were significantly decreased in the rat groups treated with both saffron carotenoids for prevention at both the initiation and promotion stages. Tumor incidence was 77% due to NMU injection, which was decreased to 45 and 33% [on average] after Cro and Crt administration, respectively. In addition, enkephaline degrading aminopeptidase [EDA] was decreased significantly in the ovaries of the animals, however, changes in the brain were not significant

Conclusion: Crt/Cro showed a significant protective effect against the NMU-induced breast cancer in rats. However, Crt was more effective than Cro and prevention at the initiation stage was more effective than at the promotion stage

[Assessment of oral glycine and lysine therapy on receptor for advanced glycation end products and transforming growth factor beta expression in the kidney of streptozotocin-induced diabetic rats in comparison with normal rats]

Today, diabetic nephropathy is considered to be one of the most common causes of end stage renal disease. Uncontrolled hyperglycemia, and consequently, production of advanced glycation end products activate pathways which play key roles in diabetic nephropathy. Among these pathways, high expression of receptor for advanced glycation end products [RAGE] and transforming growth factor beta [TGFbeta] are notable. In this study, in order to find compounds which can prevent the incidence or progression of diabetic nephropathy, we examined the effects of glycine and lysine amino acids on expression of RAGE and TGFbeta in kidney tissue of diabetic rats. After rendering rats with diabetes with streptozotocin [STZ], they were divided into different groups and were treated with oral 1% glycine and 0.1% lysine in drinking water for 12 weeks. Blood glucose and serum AGEs were measured during this time. Changes in RAGE and TGFbeta expression were assessed by semi quantitative reverse transcription polymerase chain reaction [RT-PCR] method. Results show that both glycine and lysine administration for 12 weeks not only caused a significant reduction in blood glucose and AGEs in diabetic rats, but also led to a significant reduction in RAGE and TGFbeta expression in comparison to non-treated diabetic rats. These results show that oral glycine and lysine, as chemical chaperones, have the ability to prevent diabetic nephropathy by decreasing RAGE and TGFbeta expression. This may be due to the effect of these chemical chaperones in the reduction of hyperglycemia and serum AGEs in diabetic rats. Since the positive effects of these amino acids in diabetic nephropathy have been observed in previous studies, the determination of their dose in future studies seems necessary

[Assessment of crocin toxicity on the rat liver]

Crocin, the carotenoid isolated from saffron, has numerous medicinal properties which include anticancer and antioxidant activities. Some antioxidants, such as carotenoids, can act as pro-oxidants at higher dosages and therefore induce tissue damage. In this situation antioxidant defense systems in the liver activate to prevent tissue damage. This study investigates the possible toxic effects of crocin on the liver of normal rats. Normal rats were randomly divided into four groups. Group 1 was treated with normal saline as the control and groups 2 to 4 were treated different doses of 50, 100 and 200 mg/kg crocin intraperitoneally once a week for four weeks. Animals were killed one week after the last injection. Serum profile of the rats that included ALT, AST, ALP, urea, uric acid and creatinine, as well as the activity of antioxidant enzymes [SOD, CAT and GPx], GSH content, and lipid and protein oxidation by measurement of MDA and protein carbonyl levels were assessed in the liver. In addition, we conducted histopathological examinations of the liver specimens. We studied different crocin concentrations that have been used to treat various diseases. There were no significant changes in serum parameters, GSH, MDA, protein carbonyls and activities of CAT and SOD at the different crocin concentrations. Histopathological examination did not show any changes in the liver. Only the higher dose [200 mg/kg] decreased GPx activity which might be reversible over the long-term. Crocin, at the studied doses showed no toxic effects on the rat liver

[ effect of crocin and its mechanism of action on chronic pain induced by spinal cord contusion in a rat model]

Various approaches have been offered for resolution of pain resulting from spinal cord injuries. One approach is the use of herbal and natural products. In the present research, as a preliminary study, we investigate the effect of crocin on chronic pain induced by contusion in the rat spinal cord [SCI]. We randomly divided female Wistar rats into five groups. Groups I and II were contused at the L1 level and immediately treated with crocin [50 mg/kg]. These groups were sacrificed after 2 hours and 1 week, respectively. The remaining three groups consisted of group III [control group], group IV [treated with crocin and no contusion], and group V [the contused group that underwent no treatment]. Groups III-V were sacrificed after one week. The mechanical behavioral test that used Von Frey hairs; the thermal behavioral test that used a hot-plate and the locomotor recovery test with Basso, Beattie and Bresnahn [BBB] scoring were conducted daily to evaluate the extent of injury and recovery of the rats. The calcitonin-gene related peptide [CGRP] was determined in the animals' plasma by the ELISA kit. The results showed a significant increase in plasma CGRP of contused rats that significantly reduced following crocin treatment. The behavioral tests were not changed significantly due to this treatment. The present study shows the beneficial effects of crocin treatment that may occur by decreasing CGRP on chronic pain induced by SCI. This project is continuing using higher dose of crocin for longer time.

High expression of cyclin D1 and p21 in N-nitroso-N-methylurea-induced breast cancer in wistar albino female rats

N-nitroso-N-methylurea [NMU] induces breast cancer in rodents, particularly in rats. This model of breast cancer is very similar to human breast cancer. As a continuation of our recent work, we investigated the expressions of cyclin D1 and p21 in NMU-induced breast cancer of Wistar Albino rats. In this experimental study, mammary carcinoma was induced in female Wistar Albino rats by a new protocol which included the intraperitoneal injection of NMU [50 mg/kg] at 50, 65, and 80 days of the animal's age. The animals were weighed weekly and palpated in order to record the numbers, location, and size of tumors. Subsequently tumor incidence [TI], latency period [LP], and tumor multiplicity [TM] were reported. About four weeks after the tumor size reached 1.5 cm[3], rats were sacrificed. Cyclin D1 and p21 expressions in tumors and normal mammary glands from normal rats were measured by reverse-transcription polymerase chain reaction [RT- PCR] and Western blot analysis. Statistical analysis of the data was performed using SPSS software version 16.0. The efficiency of tumor induction was 65%, LP was 150 days, and a TM of 1.43 +/- 0.53 per rat was noted. RT-PCR and Western blot data indicated significant [p<0.05] induction of both cyclin D1 and p21 expressions in rat mammary tumors compared with normal tissue from the control group. These results indicate an efficient mammary tumor induction protocol for this type of rat, which is accompanied by an increase in cyclin D1 and p21 expressions

Historical uses of saffron: identifying potential new avenues for modern research

During the ancient times, saffron [Crocus sativus L.] had many uses around the world; however, some of these uses were forgotten throughout the history. But a newly formed interest in natural active compounds brought back the attention toward historical uses of saffron. Understanding different uses of saffron in the past can help us finding the best uses at present. In this study, we reviewed different uses of saffron throughout the history among different nations. ISI web of Science and Medline, along with references of traditional Iranian medicine were searched for historical uses of saffron. Saffron has been known since more than 3000 years ago by many nations. It was valued not only as a culinary condiment, but also as a dye, perfume and as a medicinal herb. Its medicinal uses ranged from treating eye problems to genitourinary and many other diseases in various cultures. It was also used as a tonic agent and antidepressant drug among many nations. Saffron has had many different uses such as a food additive and a palliative agent for many human diseases. Thus, as an important medicinal herb, it is a good candidate with many promising potentials to be considered for new drug design

Crocin Bleaching Assay Using Purified Di-gentiobiosyl Crocin [alpha-crocin] from Iranian Saffron

Crocin bleaching assay [CBA] is a new method for determination of antioxidant capacity. In CBA, addition of hydrogen to the conjugated double bonds of crocin results in reduction of crocin and increase in the absorbance at 440 nm, which is considered as a measure of antioxidant potential. Here CBA method was set up using di-gentiobiosyl crocin or a-crocin from Iranian saffron. Then, the antioxidant activity of some known antioxidants i.e. L-ascorbie acid, bilirubin, Trolox, uric acid, and some plasma samples of infants, were tested. The results were compared to that obtained by ferric reducing antioxidant power [FRAP] as a standard method. Di-gentiobiosyl crocin was extracted and purified from Iranian saffron as previously described by us. Then, the CBA procedure using alpha-crocin was done in 2 different aquatic conditions, >50% or >90% of water. Results were analyzed by both the Bors method [calculating the relative rate constants

[rel] and the Tsimidou method [calculating the percent of alpha-crocin bleaching inhibition=% Inh]. Our results indicated the following order of antioxidant potential for the above mentioned agents: ascorbic acid > uric acid > Trolox. However, these results are very similar to the data reported by others, but they are strongly related to the aqueous condition. In addition, uric acid showed different properties at different concentrations; so that it showed the antioxidant activity at low concentrations but it acted as a prooxidant at higher concentrations. Bilirubin interfered with this test, possibly because its maximum absorbance is close to the crocin. The obtained data for the antioxidant capacity of the serums was comparable with FRAP assay, except for the sample that contains high bilirubin concentration. In conclusion, it seems that CBA using the main fraction of crocin [alpha-crocin] is a simple and useful method for determination of antioxidant potential of aqueous samples. In addition, the CBA ability to distinguish the samples that contain bilirubin or high uric acid content is helpful in clinical laboratories

[Quantitative and comparative analysis of major metabolites [crocin, picrocrocin and safranal] in different packages of Iranian saffron by HPLC]

Saffron is the dried stigmas of Crocus sativus L. which has various therapeutic properties in addition to its use as a spice. More than 80% of the world present production of saffron which is about 190 tons is produced in Iran. To compare the quality of saffron' from different parts of the world, researcher used one sample from each country. Since cultivation of saffron is done in different geographical areas of Iran, it seems that the results of these studies, using only one sample of Iranian saffron, are not consistent with the scientific and statistical rules. More over the results of therapeutical studies using saffron extracts from different sources with different concentrations of effective elements would not give reproducible results. As an affirmative reason, here we compared the saffron's important components, crocin, picrocrocin and safranal, from different packages produced by some companies. Five certified saffron packages, prepared by different companies named: Ehteshamiyeh, Tarvand, Abbaszadeh, Sabagh and Novin-Saffron were analyzed using HPLC with an UV/Vis detector. To avoid the conflict of inerest, these samples were randomly labeled as 1 to 5. Results indicated that all of the samples contained these ingredients at the standard levels, but the highest level of crocin as a carotenoid was seen in the sample 3, and sample 1 and 2 contained the highest concentrations of monoterpene aldehydes, picrocrocin and safranal, respectively. According to the obtained results and the vast area under the saffron cultivation with various climates, it is confirmed that one sample of saffron is not a measure of all of the Iranian saffron. Our research is continuing