In vitro study of the PLA2 inhibition and antioxidant activities of Aloe vera leaf skin extracts

<p>Abstract</p> <p>Background</p> <p>In the present work we determined the total phenolic content of <it>Aloe vera </it>leaf skin (AVLS) extracts by using various solvents (hexane, chloroform-ethanol (1/1), ethyl acetate, butanol and water). We have also evaluated the antioxidant and the anti-PLA2 properties of these extracts by measuring their inhibition potency on the human pro-inflammatory phospholipase A2 (group IIA).</p> <p>Results</p> <p>The water extract exhibits the highest inhibitory effect with an IC₅₀= 0.22 mg/ml and interestingly no effect was observed on the digestive phospholipase A2 (group IB) even at a concentration of 5 mg/ml. Antioxidant activities were also analyzed and the most active extracts were observed when using chloroform ethanol (1/1) and ethyl acetate (IC₅₀= 0.274 and 0.326 mg/ml, respectively). Analysis of the total phenolic content reveals that the water extract, with the best anti-PLA2 effect, was poor in phenolic molecules (2 mg GAE/g). This latter value has to be compared with the chloroform-ethanol and the ethyl acetate extracts (40 and 23.8 mg GAE/g, respectively), mostly responsible for the antioxidant activity.</p> <p>Conclusion</p> <p>A significant correlation was established between the total phenolic content and the antioxidant capacity but not with the anti PLA2 activity. Results from phytochemical screening suggest that the anti PLA2 molecules were probably catechin tannins compounds.</p

Identification of a new Arylsulfatase A (ARSA) gene mutation in Tunisian patients with metachromatic leukodystrophy (MLD)

International audienceMetachromatic leukodystrophy (WILD) is an autosomal recessive, lysosomal storage disease caused by a deficiency of the enzyme arylsulfatase A (ARSA). The aim of the present study was to identify the molecular basis of MILD in Tunisian population. Two Tunisian patients with late infantile MILD were studied. Both patients were homozygous for a new missense mutation that causes a substitution of Trp in Gly p.W124G. This is the first mutation of ARSA gene described in Tunisian population. (C) 2009 Elsevier B.V. All rights reserved

Determination of arylsulfatase A pseudodeficiency allele and haplotype frequency in the Tunisian population

International audienceArylsulfatase A (ASA) is a lysosomal enzyme involved in the catabolism of cerebroside sulfate. ASA deficiency is associated with metachromatic leukodystrophy (MLD). Low ASA activities have also been reported in a more common condition with no apparent clinical consequences termed ASA pseudo-deficiency (ASA-PD) which is associated with two linked mutations in the ASA gene (c.1049A > G and c.*96A > G). This study aimed to investigate the frequency of the two ASA-PD variants and their linkage disequilibrium (LD) among Tunisians. ASA-PD variants were detected in 129 healthy Tunisians and their frequencies were compared to those described worldwide. The frequency of the PD allele was estimated at 17.4 % for the overall sample, with c.1049A > G and c.*96A > G frequencies of 25.6 and 17.4 %, respectively. This study also revealed a high LD between the two ASA-PD variants (r (2) = 0.61). Inter-population analysis revealed similarities in the ASA-PD genetic structure between Tunisians and populations from Middle East with c.*96A > G frequencies being the highest in the world. A significant North vs. South genetic differentiation in the ASA-PD frequency was also observed in Tunisian population who seems genetically intermediate between Africans, Middle-Easterners and Europeans. This is the first report on the allele frequency of the ASA-PD in North Africa, revealing a relatively high frequency of the PD allele among Tunisians. This study gives also evidence on the importance of discriminating ASA-PD allele from pathological mutations causing MLD and supporting enzymatic activity testing with both sulfatiduria determination and genetic testing in the differential diagnosis of MLD in the Tunisian population