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Sa.71. Antidiabetic and In Vitro Free Radical Scavenging Activity of Helicteres Isora Roots
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Sa.71. Antidiabetic and In Vitro Free Radical Scavenging Activity of Helicteres Isora Roots Venkatesh Sama, Nazia Zareen, Prthibha Rajkumari, Madhava Reddy. G. Pulla Reddy College of Pharmacy, Hyderabad, India Helicteres isora(Sterculiaceae)roots in traditional medicine is claimed to be useful in diabetes. The antihyperglycemic and hypolipidemic activities of butanolic extract of H. isora root were investigated in strepozotocin-induced diabetic rats and its in vitro free radical scavenging activity was also investigated. Treatment with butanolic extract of H. isora at dose levels of 250 mg/kg and 125 mg/kg caused reduction of blood glucose by 33.23 and 27.49% respectively, within one-hour time after oral treatment. Maximum reduction in blood glucose level was observed at 3rd hour. This effect of the butanol extract at both the dose levels is quantitatively more than the effect caused by the standard drug glibenclamide (5 mg/kg). It was found that, with a daily administration of butanolic extract (125 and 250 mg/kg), there was dose dependent fall in blood glucose by 41.38 and 54.18% respectively on day 10, where as glibenclamide caused a significant reduction of 26.94% in plasma glucose levels. The butanolic extract at 250 mg/kg and glibenclamide had significantly lowered (16%) the triglyceride levels, which may be attributed to the increase in insulin production in STZ induced hyperglycemic animals by activation of the enzyme lipoprotein lipase. The treatment of diabetic animals with butanolic extract of H. isora has shown a significant reduction (21%) in total cholesterol. The decrease in triglyceride and total cholesterol levels could be through its control of hyperglycemia. The radical scavenging effect of the butanolic extract of H. isora on DPPH radical was examined and results were promising. IC50 was found to 26 µg/mg. The total phenol content of butanolic extract was found to be 480 mg GAE/gm of the extract. The observed antihyperglycemic activity may be attributed to the total phenols. doi:10.1016/j.clim.2008.03.292
Sa.72. Defective Dendritic Cell Function in Children with Type 1 Diabetes Heterozygous for the PTPN22 C1858T Polymorphism Novella Rapini, 1 Elisabetta Del Duca, 1 Nunzio Bottini, 3 Patrizia Saccucci, 2 Simona Piccinini, 1 Marta Porcari, 1 Susanna Arcano, 1 Federica Angelini, 1 Maria Luisa Manca Bitti.1 1Tor Vergata University, Rome, Italy; 2Tor Vergata University, Rome, Italy; 3University of Southern California, Los Angeles, CA The missense PTPN22 C1858T polymorphism recently emerged as an important risk factor for Type 1 Diabetes (T1D). The PTPN22 gene encodes the lymphoid tyrosine phosphatase Lyp, a negative regulator of T cell receptor signalling. The 1858T allele leads to a gain-of-function phenotype of Lyp, which in turns determines a defect of T and B cell activation. We investigated whether alterations of dendritic cells (DCs) are present in T1D patients carrying the C1858T(C/T) polymorphism. DCs from 11 T1D children
Abstracts homozygous for 1858C allele (C/C) and 3 T1D children heterozygous for 1858T allele (C/T) were derived from peripheral blood monocytes and stimulated with either LPS or CD40L to induce maturation (mDC). The expression of CD80, CD86 and HLA-DR and the production of IL-10, IL-12 and IFN-γ were tested. mDC from patients of C/T genotype showed an impaired up-regulation of HLA-DR (MFI C/T:23,4 ± 7,8 vs. C/ C:52,8 ± 31,1) upon CD40L stimulation when compared with ones from patients of C/C genotype. The co-stimulatory molecules CD80 and CD86 were reduced in mDC from C/T patients upon both LPS (MFI CD80 C/T: 34,8 ± 1,4 vs. C/C: 41,9 ± 11,4; CD86 C/T 110,5 ± 68,2 vs. C/C: 149,3 ± 69,8) and CD40L (MFI CD80 C/T:14,7 ± 1,6 vs. C/C:24,2 ± 8,4; CD86 C/T 29,3 ± 29,1 vs. C/C: 95,8 ± 63,7) stimulation. Upon LPS stimulation we observed a reduction of IL-10 (C/T: 80,8 ± 75,5 pg/ml vs. C/ C:219,8 ± 252,9 pg/ml), IL-12 (C/T: 147,5 ± 255,4 pg/ml vs. C/ C: 672,7 ± 698,9 pg/ml) and IFN-γ (C/T: 36,7 ± 25,8 pg/ml vs. C/C: 349,6± 574,3 pg/ml) production by mDC generated from C/T patients. Our preliminary data suggest that an altered phenotype and function of DC are present in T1D patients carrying the 1858T allele. doi:10.1016/j.clim.2008.03.293
Sa.73. Modulation of Dendritic Cells as Intervention Strategy in Type 1 Diabetes Wendy Unger, Sandra Laban, Arno van der Slik, Bart Roep. LUMC, Leiden, Netherlands Type 1 diabetes is characterized by T cell mediated autoimmune destruction of the pancreatic β cells. Monocyte-derived DC modulated either with dexamethasone (dex) or 1α,25-dihydroxyvitamin D3 (VD3) are T cell suppressive. We are therefore addressing whether vaccination with modulated DC can be exploited to regain tolerance in T1D patients. In this study we compared modulated DC with standard DC with regard to phenotype and influence on naïve T cell priming. Treatment of DC with either DEX or VD3 renders these cells in a semi-mature state even upon activation induced by LPS or CD40-triggering. Both treatments abrogated the ability to secrete IL-12p70, but not IL10, and affected the T-cell stimulatory function. Moreover, priming of naïve T-cells with both VD3- and DEX-DC led to the induction of robust regulatory T-cells, which are able to suppress the activation and proliferation of responder Tcells. VD3-DC, but not DEX-DC, have a higher expression of molecules related to the induction of apoptosis than nontreated DC, which corroborates with our previous finding that VD3-DC selectively induce apoptosis in committed Tcells. Importantly, modulation with either DEX or VD3 arrests DC in a stable, tolerogenic mode, as their phenotype remains unaltered when encountering a pro-inflammatory signal even 5 days after maturation. Together, these findings suggest that both DEX- and VD3-DC possess durable tolerogenic features and are potentially useful to specifically down-regulate unwanted immune responses and induce immune tolerance in T1D patients. doi:10.1016/j.clim.2008.03.294
Sa.71. Antidiabetic and In Vitro Free Radical Scavenging Activity of Helicteres Isora Roots Venkatesh Sama, Nazia Zareen, Prthibha Rajkumari, Madhava Reddy. G. Pulla Reddy College of Pharmacy, Hyderabad, India Helicteres isora(Sterculiaceae)roots in traditional medicine is claimed to be useful in diabetes. The antihyperglycemic and hypolipidemic activities of butanolic extract of H. isora root were investigated in strepozotocin-induced diabetic rats and its in vitro free radical scavenging activity was also investigated. Treatment with butanolic extract of H. isora at dose levels of 250 mg/kg and 125 mg/kg caused reduction of blood glucose by 33.23 and 27.49% respectively, within one-hour time after oral treatment. Maximum reduction in blood glucose level was observed at 3rd hour. This effect of the butanol extract at both the dose levels is quantitatively more than the effect caused by the standard drug glibenclamide (5 mg/kg). It was found that, with a daily administration of butanolic extract (125 and 250 mg/kg), there was dose dependent fall in blood glucose by 41.38 and 54.18% respectively on day 10, where as glibenclamide caused a significant reduction of 26.94% in plasma glucose levels. The butanolic extract at 250 mg/kg and glibenclamide had significantly lowered (16%) the triglyceride levels, which may be attributed to the increase in insulin production in STZ induced hyperglycemic animals by activation of the enzyme lipoprotein lipase. The treatment of diabetic animals with butanolic extract of H. isora has shown a significant reduction (21%) in total cholesterol. The decrease in triglyceride and total cholesterol levels could be through its control of hyperglycemia. The radical scavenging effect of the butanolic extract of H. isora on DPPH radical was examined and results were promising. IC50 was found to 26 µg/mg. The total phenol content of butanolic extract was found to be 480 mg GAE/gm of the extract. The observed antihyperglycemic activity may be attributed to the total phenols. doi:10.1016/j.clim.2008.03.292
Sa.72. Defective Dendritic Cell Function in Children with Type 1 Diabetes Heterozygous for the PTPN22 C1858T Polymorphism Novella Rapini, 1 Elisabetta Del Duca, 1 Nunzio Bottini, 3 Patrizia Saccucci, 2 Simona Piccinini, 1 Marta Porcari, 1 Susanna Arcano, 1 Federica Angelini, 1 Maria Luisa Manca Bitti.1 1Tor Vergata University, Rome, Italy; 2Tor Vergata University, Rome, Italy; 3University of Southern California, Los Angeles, CA The missense PTPN22 C1858T polymorphism recently emerged as an important risk factor for Type 1 Diabetes (T1D). The PTPN22 gene encodes the lymphoid tyrosine phosphatase Lyp, a negative regulator of T cell receptor signalling. The 1858T allele leads to a gain-of-function phenotype of Lyp, which in turns determines a defect of T and B cell activation. We investigated whether alterations of dendritic cells (DCs) are present in T1D patients carrying the C1858T(C/T) polymorphism. DCs from 11 T1D children
Abstracts homozygous for 1858C allele (C/C) and 3 T1D children heterozygous for 1858T allele (C/T) were derived from peripheral blood monocytes and stimulated with either LPS or CD40L to induce maturation (mDC). The expression of CD80, CD86 and HLA-DR and the production of IL-10, IL-12 and IFN-γ were tested. mDC from patients of C/T genotype showed an impaired up-regulation of HLA-DR (MFI C/T:23,4 ± 7,8 vs. C/ C:52,8 ± 31,1) upon CD40L stimulation when compared with ones from patients of C/C genotype. The co-stimulatory molecules CD80 and CD86 were reduced in mDC from C/T patients upon both LPS (MFI CD80 C/T: 34,8 ± 1,4 vs. C/C: 41,9 ± 11,4; CD86 C/T 110,5 ± 68,2 vs. C/C: 149,3 ± 69,8) and CD40L (MFI CD80 C/T:14,7 ± 1,6 vs. C/C:24,2 ± 8,4; CD86 C/T 29,3 ± 29,1 vs. C/C: 95,8 ± 63,7) stimulation. Upon LPS stimulation we observed a reduction of IL-10 (C/T: 80,8 ± 75,5 pg/ml vs. C/ C:219,8 ± 252,9 pg/ml), IL-12 (C/T: 147,5 ± 255,4 pg/ml vs. C/ C: 672,7 ± 698,9 pg/ml) and IFN-γ (C/T: 36,7 ± 25,8 pg/ml vs. C/C: 349,6± 574,3 pg/ml) production by mDC generated from C/T patients. Our preliminary data suggest that an altered phenotype and function of DC are present in T1D patients carrying the 1858T allele. doi:10.1016/j.clim.2008.03.293
Sa.73. Modulation of Dendritic Cells as Intervention Strategy in Type 1 Diabetes Wendy Unger, Sandra Laban, Arno van der Slik, Bart Roep. LUMC, Leiden, Netherlands Type 1 diabetes is characterized by T cell mediated autoimmune destruction of the pancreatic β cells. Monocyte-derived DC modulated either with dexamethasone (dex) or 1α,25-dihydroxyvitamin D3 (VD3) are T cell suppressive. We are therefore addressing whether vaccination with modulated DC can be exploited to regain tolerance in T1D patients. In this study we compared modulated DC with standard DC with regard to phenotype and influence on naïve T cell priming. Treatment of DC with either DEX or VD3 renders these cells in a semi-mature state even upon activation induced by LPS or CD40-triggering. Both treatments abrogated the ability to secrete IL-12p70, but not IL10, and affected the T-cell stimulatory function. Moreover, priming of naïve T-cells with both VD3- and DEX-DC led to the induction of robust regulatory T-cells, which are able to suppress the activation and proliferation of responder Tcells. VD3-DC, but not DEX-DC, have a higher expression of molecules related to the induction of apoptosis than nontreated DC, which corroborates with our previous finding that VD3-DC selectively induce apoptosis in committed Tcells. Importantly, modulation with either DEX or VD3 arrests DC in a stable, tolerogenic mode, as their phenotype remains unaltered when encountering a pro-inflammatory signal even 5 days after maturation. Together, these findings suggest that both DEX- and VD3-DC possess durable tolerogenic features and are potentially useful to specifically down-regulate unwanted immune responses and induce immune tolerance in T1D patients. doi:10.1016/j.clim.2008.03.294