Chemometrics Based Extraction of Polyphenolics from Fresh Tea Leaves and Processed Tea Showing In-Silico Docking and Anti-oxidative Theronostic Dietary Adjuvant in Alzheimer

Koushik Bhandari, Rajeev Singla, Baishakhi De, Bijoy Ghosh, Prakash Katakam, Dilip Kumar Khushwaha, Rohit Gundamaraju, Gargi Sen, Gargi Saha, Anirban Mitra, Analava Mitra
2015 Indo Global Journal of Pharmaceutical Sciences   unpublished
Aim of the study is to chemometrically optimize the extraction procedure of tea polyphenolics, evaluate antioxidant potentials of fresh tea leaves and made tea grown in the non-traditional tea zone of IIT Kharagpur by in vitro assays, in silico docking studies and in vitro AChE inhibitory assays. Total tea polyphenolics, flavonoids and volatile contents of aqueous and methanolic extracts of fresh tea leaves and made tea were estimated by UV, HPLC and GC-MS analysis. The extraction process
more » ... ters were optimized by central composite design of chemometrics to maximize polyphenol yield. Antioxidant properties were studied by in vitro DPPH radical scavenging, FRAP, ABTS and Dot Blot Assay. In silico GRIP docking studies were done to evaluate the effectivity of tea catechins as antioxidants against the targeted proteins. In vitro AChE inhibitory assay was done to see its anti-Alzheimer effect. Basing on desirability function, 3.75±0.04 g of sample weight and 207.32±0.01 mL of methanol of TV fresh leaf varieties gave percent yield of poly phenols in range of 31.35 ± 2.78-25.14 ± 1.74 and for aqueous extract the polyphenol yield range was from 21.94 ± 2.06-20.13 ± 2.78. Both fresh leaf and made tea of TV 25 variety gave highest polyphenol yields of 31.35±2.78% (methanol) and 9.84±0.79% (aqueous) respectively. In silico GRIP docking studies showed epi-catechin gallate as the most potent antioxidant. The IC50 values for AChE inhibitory assay of black tea (CTC) was found to be 34.18µg/mL. Amongst three varieties (TV 25, TV 26 and TV 23), both fresh leaf and made tea of TV 25 variety showed maximal poly phenol content with highest antioxidant potential and were found to be comparable to Assam clones in this respect. The same fact is also reflected in the AChE inhibitory assay. Considering the significant polyphenol content and anti-oxidant capacity it can be concluded that these tea polyphenols can serve the purpose of adjuvant therapy in Alzheimer.