Abstract:
Present research project was an attempt to explore the functional/nutraceutical worth of
locally grown green tea variety (Qi-Men) against lifestyle-related disorders. For the purpose,
green tea catechins and epigallocatechin gallate (EGCG) were characterized and
subsequently utilized for the preparation of functional drink and then tested in experimental
rats modeling. Regarding chemical composition, green tea is rich in polyphenols with special
reference to flavonoids including catechins. Among minerals, potassium and calcium were
present in substantial amount whilst sodium, manganese, iron and zinc in relatively less
quantity. Optimization of extraction conditions was carried out using various solvents
(aqueous ethanol, aqueous methanol, water) and time intervals (20, 40, 60 min) to improve
extraction efficiency of catechins. EGCG, a major fraction of green tea catechins was also
separated through solvent partition method. HPLC quantification of catechin fractions
revealed that maximum amount of epigallocatechin (EGC), epigallocatechin gallate (EGCG),
epicatechin gallate (ECG) and epicatechin (EC) was extracted with aqueous ethanol at 40
min. In vitro analysis for antioxidant activity and DPPH radical scavenging ability of
catechins and EGCG proved their excellent antioxidant potential. Based on the results of
extraction efficiency, HPLC analysis and in vitro tests, one best treatment from extracted
catechins was selected for the preparation of functional drink (Green Cool). In product
development phase, three functional drinks were prepared i.e catechins containing drink,
EGCG enriched drink and a control for comparison purpose. Drinks were subjected to
physico-chemical analysis during two months storage that showed non-substantial effect on
total soluble solids (TSS) whilst pH and acidity were affected significantly. Color of the
drinks measured through CIELAB system, affected non-momentously. Hedonic response of
the functional drinks remained acceptable during storage. Efficacy trials were carried out in
male Sprague Dawley rats to explore the nutraceutical worth of drinks against ailments
arising due to unhealthy lifestyle. For the purpose, four studies were performed on the basis
of various diets given to rats i.e. study I (normal diet), study II (high cholesterol diet), study
III (high sucrose diet), study IV (high cholesterol + high sucrose diet). Functional drinks
containing catechins and EGCG resulted in significant reduction in body weight of rats
indicating their effectiveness against obesity and allied discrepancies. Maximum reduction in
body weight gain was in study II and III i.e. 10.73 to 8.49 % and 10.12 to 10.49% in groups
consumed catechins and EGCG, respectively. Likewise, cholesterol and LDL were
substantially reduced by functional drinks however, effect was more pronounced in catechins
group in which 14.42% decrease was observed in study IV and 30.43% in study II,
respectively. HDL was non-significantly affected by the treatments. Triglycerides were also
reduced by drinks carrying bioactive molecules in rats provided diets rich in cholesterol and
sucrose. Serum glucose and insulin levels were also mitigated by functional drinks
containing catechins and EGCG. Similarly, antioxidant potential was improved as indicated
by elevated serum glutathione level and decreased thiobarbituric acid reactive substances
(TBARS) via both drinks containing catechins and EGCG but latter was more effectual for
the purpose. Organs to body weight ratio remained unaffected by functional drinks.
Furthermore, serum biochemistry values were within normal range revealing safety of use.
From the present investigation, it is deduced that drinks supplemented with catechins and
EGCG are effective against obesity, hypercholesterolemia, hyperglycemia and oxidative
stress therefore, can be a part of diet based therapy for attenuation of lifestyle-related
disorders.