@article {492, title = {Antidiabetic Activity Studies of White Tea (Camellia sinensis (L.) O. Kuntze) Ethanolic Extracts in Streptozotocin-nicotinamide Induced Diabetic Rats}, journal = {Pharmacognosy Journal}, volume = {10}, year = {2018}, month = {December 2017}, pages = {186-189}, type = {Original Article}, chapter = {186}, abstract = {

Background: The high polyphenol content of white tea exhibits antiseptic and antioxidant properties that can prevent free radicals, inhibit oxidative stress and inflammation associated with various diseases such as obesity, diabetes and other degenerative diseases. Oral administration of white tea ethanolic extract (WTE) is expected to use as an alternative in the treatment of diabetes mellitus. Objective: This study aims to evaluate the effect of WTE on reducing fasting blood glucose levels in diabetic rats. Methods: Antidiabetic activity study of white tea extract performed on diabetic Sprague-Dawley male rats induced streptozotocin-nicotinamide for 14 days of oral administration. The antidiabetic effect compared to normal control, diabetic control, and standard control groups. Results: The administration of WTE for 14 days showed decreased fasting blood glucose level in diabetic rats. The dose of 100 mg/kg BW of WTE has the highest effect on reducing fasting glucose level significantly compared to negative control group (p\<0.05). The content of flavonoids, especially catechin compounds are suspected to play a role in lowering fasting blood glucose levels. Conclusion: The administration of WTE for 14 days has potentially antidiabetic activity in diabetic rats induced streptozotocin-nicotinamide.

}, keywords = {Antidiabetic, Camellia sinensis, Catechin, Hypoglycemic, Streptozotocin, White tea}, doi = {10.5530/pj.2018.1.31}, url = {http://fulltxt.org/article/417}, author = {Lia Ardiana and Rani Sauriasari and Berna Elya} } @article {493, title = {Dipeptidyl peptidase IV Inhibitory Activity of Fraction from White Tea Ethanolic Extract (Camellia sinensis (L.) Kuntze) ex vivo}, journal = {Pharmacognosy Journal}, volume = {10}, year = {2018}, month = {December 2017}, pages = {190-193}, type = {Original Article}, chapter = {190}, abstract = {

Background: Treatment for type-2 diabetes mellitus focuses on the incretin hormone, Glucagon-Like Peptide-1 (GLP-1). However, it has a short half-life. Inhibition of the enzyme Dipeptidyl peptidase IV (DPP IV) required maintaining the active form of GLP-1. Based on the previous studies on the highest activity of DPP IV enzyme inhibition of white tea extract, this study conducted on the fraction of white tea extract using rat blood serum (ex vivo). Objectives: This study aims to evaluate the inhibitory activity of fraction from white tea extract. Methods: White tea leaves extracted with ethanol. The inhibitory activity determined by using rat blood serum as DPP IV enzyme source (ex vivo), AMC (7-amino 4-methyl coumarin) as fluorescence substrate of DPP IV and sitagliptin as the standard reference. The the cleavage of fluorescence reaction product observed by a microplate reader with \λex = 360 nm and \λem = 460 nm at 37oC. Data expressed as mean \± SD and the IC50 value determined by nonlinear regression curve and fit using Prism Graph 7. Result: Methanol fraction (250 \μg/mL) has the greater inhibition percentage (50.487\%), and the fraction of n-hexane and ethyl acetate are 32.417\% and 36.541\%. The methanol fraction IC50 value is 227 \μg /mL. Conclusion: The methanol fraction is the most active to inhibit DPP IV enzyme.

}, keywords = {Antidiabetic, Camellia sinensis, Dipeptidyl peptidase IV, DPP IV, Fraction, White tea.}, doi = {10.5530/pj.2018.1.32}, url = {http://fulltxt.org/article/418}, author = {Meiliza Ekayanti and Rani Sauriasari and Berna Elya} }