Lotfi Aarab

Modulation of egg white protein allergenicity under physical and chemical treatments

Abstract Hen eggs are one of the most common causes of food allergic reactions. Egg white, which is generally considered more allergenic than egg yolk, has four major allergenic proteins namely, ovomucoid, ovalbumin, ovotransferrin and lysozyme which are defined as immunodominant egg white proteins (EWP). The objectives of the present work were first to evaluate sensitivity to EWP of the population in the region of Fez-Meknes in Morocco, and then to study the effect of acid treatment and heating on the allergenicity of EWP. A cross-sectional study was carried out at the University Hospital in Fez and at analytical laboratories in Meknes in which 446 adults were recruited to establish a serum bank. Sera bank was used to evaluate specific IgE reactivity to EWP and the reactivity of this IgE to native and to heat- and acid-treated EWP. Immunoblots were also carried out to characterise the allergenic components. The results showed that 9.5% of the patients reported allergy to food. Among these patients, 4.2% reported allergy to eggs, 2.5% to peanuts and 0.4% to wheat flour. The study of the effect of temperature and acidity on the allergenicity of EWP showed that more than 50% of sera showed a decrease superior to 30% under heating or acid treatment. With a combination of these treatments, 75% of the sera showed a reduction of more than 30%. By means of immunoblot, we have shown that ovotransferrin and lysozyme are the major allergens for the population studied.

Screening of immunomodulatory activity of total and protein extracts of some Moroccan medicinal plants

Herbal and traditional medicines are being widely used in practice in many countries for their benefits of treating different ailments. A large number of plants in Morocco were used in folk medicine to treat immune-related disorders. The objective of this study is to evaluate the immunomodulatory activity of protein extracts (PEs) of 14 Moroccan medicinal plants. This activity was tested on the proliferation of immune cells. The prepared total and PEs of the plant samples were tested using MTT (3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide) assay on the splenocytes with or without stimulation by concanavalin-A (Con-A), a mitogenic agent used as positive control. The results of this study indicated different activity spectra. Three groups of activities were observed. The first group represented by Citrullus colocynthis, Urtica dioica, Elettaria cardamomum, Capparis spinosa and Piper cubeba showed a significant immunosuppressive activity. The second group that showed a significant immunostimulatory activity was represented by Aristolochia longa, Datura stramonium, Marrubium vulgare, Sinapis nigra, Delphynium staphysagria, Lepidium sativum, Ammi visnaga and Tetraclinis articulata. The rest of the plant extracts did not alter the proliferation induced by Con-A. This result was more important for the PE than for the total extract. In conclusion, this study revealed an interesting immunomodulating action of certain PEs, which could explain their traditional use. The results of this study may also have implications in therapeutic treatment of infections, such as prophylactic and adjuvant with cancer chemotherapy.

Evaluation of the sensitivity of Moroccans to shrimp tropomyosin and effect of heating and enzymatic treatments

ABSTRACT The aim of this work was to evaluate the IgE-sensitivity to shrimp tropomyosin (ST) in a Moroccan population from Fez region, and then to study the effect of temperature and enzymatic digestion on the allergenicity of ST. This work was conducted with a questionnaire completed by a sera-bank, obtained from 500 patients recruited from Fez Hospitals. Their sera were analyzed for specific IgE-sensitivity to ST. From questionnaire, 9.8% reported allergy to fish and shellfish where shrimp was one of the most common species causing allergy in patients. Evaluation of specific IgE showed that 10.2% of patients present higher values. Further indirect ELISA and Dot-blot results indicated that ST showed a decrease in the human IgE binding under heating or pepsin hydrolysis. These results demonstrate that this population was sensitive to ST and the sensitivity could be reduced by heating and more where it was digested by pepsin.

Effets antidépresseurs, antinociceptifs et immunomodulateurs des extraits aqueux et protéique de Berberishispanica Boiss. & Reut. du Maroc

RésuméL’épine-vinette d’Espagne, Berberis hispanica Boiss. & Reut., est indiquée dans la pratique traditionnelle marocaine contre les inflammations, les affections hépatiques, les métrorragies et les désordres digestifs. Dans cette étude, nous avons démontré de très intéressants effets anti-dépresseurs, antinociceptifs et immunomodulateurs, suite à l’administration intrapéritonéale (IP) de l’extrait aqueux à 120mg/kg et protéique à 20 mg/kg de Berberis hispanica chez la souris. Ces effets pharmacologiques ont été étudiés en utilisant le modèle de la nage forcée « dépression », le test de la plaque chaude « nociception », et la technique de la cytométrie en flux « immunomodulation ». Ce travail rapporte d’éventuelles applications thérapeutiques de Berberis hispanica originaire du Maroc, en fonction de la procédure d’extraction entreprise, dans les traitements de certaines pathologies, à savoir la dépression, la douleur et les dysfonctionnements du système immunitaire.AbstractThe Spain Barberry, Berberis hispanica Boiss. & Reut., is indicated in the traditional Moroccan medicine against inflammation, liver disease, bleeding and digestive disorders. In this study, we have shown an interesting antidepressive, antinociceptive and immunomodulatory effects after intraperitoneal (IP) administration of aqueous extract at 120mg/kg and proteic extract at 20mg/kg of Berberis hispanica. We have evaluated these pharmacological effects through the forced swimming model “depression”, the hot plate test “nociception” and flow cytometry technique “immunomodulation” in mouse. Depending on the extraction procedure, this work shows some possible therapeutic applications of Berberis hispanica from Morocco in the treatment of some diseases like depression, pain and immune system disturbances.

Effect of heating and enzymatic hydrolysis on casein cow milk sensitivity in Moroccan population

ABSTRACT The objectives of the present work were first to evaluate the sensitivity to cow raw milk of the population of Fez, and then to study the effect of heating and pepsin hydrolysis on the allergenicity of casein. A cross-sectional study was carried out in Fez Hospitals, in which 1000 patients were recruited to establish a sera bank used to evaluate specific IgE to cow milk and to casein. Then, we evaluated the reaction of human IgE to heated and pepsin-hydrolysed casein. The results showed that 11.5% of the population studied self-reported reactions to foods. From them, 3.6% reported allergy to milk. Evaluation of specific IgE to cow raw milk showed that 11.9% of patients presented higher specific IgE levels. The treatments of casein indicated that both heating and pepsin hydrolysis totally decreased its binding on the human IgE.

Acute and sub-chronic toxicity studies of the aqueous extract from leaves of Cistus ladaniferus L. in mice and rats

ETHNOPHARMACOLOGICAL RELEVANCE Cistus ladaniferus L. (C.ladaniferus) (Cistaceae) is an aromatic shrub native to the Mediterranean region. The leaves are widely used in traditional medicine throughout Morocco for the treatment of various diseases including, diabetes, diarrhea, inflammation, and skin ailments. However, to the best of our knowledge, no systematic study concerning its toxicity profile has been reported. AIM OF THE STUDY The study carried out evaluates the potential toxicity of the aqueous extract from leaves of the C.ladaniferus (CL extract) shrub, through the method of acute and sub-chronic oral administration in mice and rats. MATERIALS AND METHODS During the acute toxicity study, male and female mice were orally administrated with CL aqueous extract at single doses of 500, 1000, 2000, 3000 and 5000mg/kg (n = 5/group/sex). Abnormal behavior, toxic symptoms, weight, and death were observed for 14 consecutive days to assess the acute toxicity. During the sub-chronic toxicity study, the aqueous extract was administered orally at doses of 500, 700 and 1000mg/kg (n = 6/group) daily to Wistar rats of both sexes for 90 days. The general behavior of the rats was observed daily, and their body weight was recorded weekly. A urinalysis, biochemical analysis, hematological analysis, macroscopic examination and histopathological examination of several organs were conducted at the end of the treatment period. RESULTS During the acute toxicity test, when mice were administered doses of 3000 and 5000mg/kg, the CL extract produced a 10-30% mortality rate, respectively, and induced signs of toxicity. However, no mortality or adverse effect was noted at the doses of 1000 and 2000mg/kg. The median lethal dose (LD50) of the extract was estimated to be more than 5000mg/kg. In the subchronic study, the CL extract induced no mortality or treatment-related adverse effects with regard to body weight, general behavior, relative organ weights, urine, hematological, and biochemical parameters. Histopathological examination of vital organs showed normal architecture suggesting no morphological alterations. Moreover, the CL extracts improved lipid profile and exhibited a significant hypoglycemic effect in all doses tested in rats. CONCLUSION The results of the present study suggest that treatment with the CL extract for 13 weeks does not appear to produce significant toxicity, except at high dose. Therefore, the use of appropriate levels of the CL extract as a traditional medicine remedies should have a wide margin of safety for its therapeutic use.

Sensitivity of Moroccans to sardine parvalbumin and effect of heating and enzymatic treatments

ABSTRACT The aim of this study was to evaluate the IgE sensitivity to sardine parvalbumin (SP) in a Moroccan population from Fez region, and then to study the effect of temperature and enzymatic digestion on the allergenicity of SP. This work was conducted with a questionnaire completed by a sera-bank, obtained from 1008 patients recruited from Fez Hospitals. Their sera were analyzed for specific IgE against SP. From the questionnaire, 8.1% reported adverse reactions to fish and shellfish, where sardine was the most common species causing adverse reactions in patients. Evaluation of specific IgE showed that 7.8% of patients present higher values. Further indirect ELISA and dot-blot results indicated that SP, a major fish allergen, showed a reduction in the human IgE binding under heating and pepsin hydrolysis. These results demonstrate that this population was sensitive to SP and the sensitivity could be reduced by heating and more where it was digested by pepsin.

Activité antioxydante et composition chimique des huiles essentielles de quatre espèces de thym du Maroc

Abstract The chemical composition of four Thymus species essential oils (T. capitatus, T. ciliatus, T. bleicherianus and T. algeriensis) was determined by GC and GC/SM. The essential oil of T. capitatus is dominated by carvacrol (70.92%), that of T. ciliatus by thymol (44.2%), that of T. bleicherianus contains α-terpinene (42.23%) and thymol (23.95%) as major chemical constituents, while that of T. algeriensis is formed mainly by camphor (27.7%) and α-pinene (20.5%). The antioxidant activity was determined by the DPPH test. The essential oil of T. capitatus, T. ciliatus and T. bleicherianus show strong antioxidant activity with (IC50 = 69,04 μg/ml, 74,025 μg/ml and 77,8 μg/ml) respectively, compared to the essence of T. algeriensis and other species of thyme in the literature.

Evaluation of the IgE reactivity of common pandora parvalbumin in a Moroccan population and action of heating and enzymatic treatments

ABSTRACT The aim of this study was to evaluate the immunoglobulin E (IgE) sensitivity to common pandora (Pagellus erythrinus) parvalbumin (CPP) in a Moroccan population from the Fez region, and then to study the effect of temperature and enzymatic digestion on the allergenicity of CPP. This work was conducted with a questionnaire completed by a sera-bank, obtained from 500 patients recruited from Fez hospitals. Their sera were analyzed for specific IgE against CPP. Evaluation of specific IgE showed that 11.8% of patients present higher values (>150 IU/ml). Further indirect ELISA and dot-blot results indicated that CPP showed a decrease in the binding of anti-IgE under heating with an average diminution of 41.9%, while pepsin hydrolysis reduced IgE recognition by 22.9%. These results demonstrate that this population was sensitive to CPP and the sensitivity could be reduced by heating and pepsin hydrolysis with an action higher with temperature than enzymatic digestion processing.

Évaluation des propriétés antioxydantes, anti-inflammatoires et photoprotectrices des lipides de Lawsonia inermis

RésuméDans cette étude, nous nous sommes intéressés à évaluer les propriétés cosmétiques des lipides des feuilles de Lawsonia inermis. L’étude de l’activité photoprotectrice des lipides a été évaluée par le test d’absorbance en UV en utilisant le spectrophotomètre UV-visible. Nous avons montré que l’extrait lipidique et l’extrait d’acétate d’éthyle de Lawsonia inermis présentent une absorbance en UV qui est plus forte en UVB. L’effet antioxydant de l’extrait lipidique a été réalisé par le test utilisant le radical libre DPPH (2,2’-diphényl-1-picrylhydrazyle). Les résultats obtenus ont montré que l’extrait lipidique est doué d’activité antioxydante importante avec un IC50 de 0,019 mg/ml, comparé à 0,07 mg/ml pour le butylhydroxytoluène. L’activité anti-inflammatoire d’extrait lipidique de Lawsonia inermis a été évaluée chez les lapins par le test d’inflammation provoquée par injection de la carragénine. Les résultats ont révélé que l’extrait lipidique réduit l’inflammation de façon très significative, l’inhibition maximale de l’inflammation a atteint 90,30 % pour les lipides de Lawsonia inermis. Cette valeur a été supérieure à celle obtenue pour le diclofénac qui est de 78,5 %.AbstractIn this study we were interested in assessing the cosmetic properties of Lawsonia inermis. The evaluation of photoprotective activity of Lawsonia inermis was done by determining ultraviolet (UV) absorbances using the UVvisible spectrophotometer. We showed that the lipids and ethyl acetate extract of Lawsonia inermis exhibit important UV absorbance, which is higher in UVB. The antioxidant effect of lipid extract is tested in vitro by the free radical 2,2’-diphenyl-1-picrylhydrazyl (DPPH) test. The results obtained showed that the lipid extract possessed high antioxidant activity with an IC50 of 0.019 mg/ml compared to 0.07 mg/ml for butylhydroxytoluene (BHT). The antiinflammatory activity of lipid extract of Lawsonia inermis was evaluated in rabbits by carrageenan inducing inflammation test. The results obtained showed that the lipid extract reduces inflammation very significantly. Maximal inhibition of inflammation reached 90.30% for Lawsonia inermis lipids. This value was higher than that obtained for diclofenac, which is 78.5%.