The PTPN22 C1858T (R620W) functional polymorphism in inflammatory bowel disease.

OBJECTIVE: In view of the discrepant data regarding the association between the protein tyrosine phosphatase non-receptor 22 (PTPN22) rs2476601 (R620W, 1858C→T) polymorphism and susceptibility to autoimmune diseases including inflammatory bowel diseases (IBD), we investigated whether this functional single-nucleotide polymorphism influences IBD risk in a group of Moroccan patients. RESULTS: This is the first report on the prevalence of PTPN22 (R620W) variant in a Moroccan cohort. No evidence of statistically significant differences was observed when the PTPN22 (R620W) allele and genotype distribution among IBD, Crohn's disease (CD), ulcerative colitis (UC) patients and healthy controls were compared. The frequency of the variant allele in healthy subjects was 1.77% compared to 2.56% in the IBD patients and 1.85% in CD patients. Furthermore, the frequency of this allele was increased in UC patients compared to controls (4.17% vs. 1.77%, OR = 2.42, 95% CI 0.82-7.08; P = 0.09), but the difference was not statistically significant. Our data suggest a lack of association between PTPN22 R620W variant and IBD susceptibility in Moroccan patients.

Activation of MITF by Argan Oil Leads to the Inhibition of the Tyrosinase and Dopachrome Tautomerase Expressions in B16 Murine Melanoma Cells.

Argan (Argania spinosa L.) oil has been used for centuries in Morocco as cosmetic oil to maintain a fair complexion and to cure skin pimples and chicken pox pustules scars. Although it is popular, the scientific basis for its effect on the skin has not yet been established. Here, the melanogenesis regulatory effect of argan oil was evaluated using B16 murine melanoma cells. Results of melanin assay using B16 cells treated with different concentrations of argan oil showed a dose-dependent decrease in melanin content. Western blot results showed that the expression levels of tyrosinase (TYR), tyrosinase-related protein 1 (TRP1), and dopachrome tautomerase (DCT) proteins were decreased. In addition, there was an increase in the activation of MITF and ERK1/2. Real-time PCR results revealed a downregulation of Tyr, Trp1, Dct, and Mitf mRNA expressions. Argan oil treatment causes MITF phosphorylation which subsequently inhibited the transcription of melanogenic enzymes, TYR and DCT. The inhibitory effect of argan oil on melanin biosynthesis may be attributed to tocopherols as well as the synergistic effect of its components. The results of this study provide the scientific basis for the traditionally established benefits of argan oil and present its therapeutic potential against hyperpigmentation disorders.

Toxicity Profile of the Aqueous Ethanol Root Extract of Corrigiola telephiifolia Pourr. (Caryophyllaceae) in Rodents.

Corrigiola telephiifolia Pourr. (Caryophyllaceae) is a Moroccan medicinal plant. Despite its popular usage, no study has been published concerning its toxicological profile. The acute toxicity of C. telephiifolia root extract was evaluated by giving it orally to mice at single doses of 5000, 10000, and 14000 mg/kg bodyweight. The extract was also administered at doses of 5, 70, and 2000 mg/kg bodyweight per day to rats for a forty-day toxicity study. No mortality or signs of toxicity were observed in the acute study. In the forty-day study in rats, the extract at 5 mg/kg/day showed no toxicological effects in either sex. At 70 mg/kg/day, the treated group differed from the control only by a significant decrease in serum concentrations of sodium and chloride ions (P < .05). At the dose of 2000 mg/kg/day, the extract significantly increased the serum concentrations of creatinine, alkaline phosphatase, gamma-glutamyltransferase and phosphorus (P < .05) all suggestive of functional nephrotoxicity and hepatotoxicity. The relative bodyweight of both sexes decreased at the dose of 2000 mg/kg/day, with a fast recovery for males. Histological examination did not reveal any treatment-related effects. In conclusion, Corrigiola extract appears safe at the doses used ethno-medicinally. Much higher doses pose toxicological risks.