Investigations of Antioxidant and Hepatomodulatory Potentials of Tea (Camellia sinensis) in Black, Green and Purple Tea Fortified Alcoholic Beverages (6% V/V) Using a Mouse Model

Research Article

Austin J Gastroenterol. 2017; 4(4): 1092.

Investigations of Antioxidant and Hepatomodulatory Potentials of Tea (Camellia sinensis) in Black, Green and Purple Tea Fortified Alcoholic Beverages (6% V/V) Using a Mouse Model

Ochanda SO1,4*, Rashid K2, Ngotho M3, Faraj AK4, Wanyoko JK1, Onyango CA5, Maranga DN6 and Wachira FN7

1Department of Tea and Health, Kenya Agricultural and Livestock Research Organization-Tea Research Institute of Kenya, Kenya

2University of Cologne, Albertus-Magnus-Platz, Germany

3Mount Kenya University, Kenya

4Department of Dairy and Food Science and Technology, Kenya

5Taita Taveta University, Kenya

6Department of Animal Sciences, Institute of Primate Research, Kenya

7South Eastern Kenya University, Kenya

*Corresponding author: Ochanda SO, Kenya Agricultural and Livestock Research Organization -Tea Research Institute of Kenya, Kenya

Received: July 28, 2017; Accepted: November 07, 2017; Published: December 22, 2017


This study was carried out to evaluate the effects of tea (Camellia sinensis) fortified alcoholic beverages on antioxidant status and liver dysfunction biomarkers in mice. Plain and tea fortified alcoholic beverages at 6% (v/v) alcohol content were administered at a dosage of 1mL per mouse every second day for 4 weeks using a gavage needle after which the animals were euthanized. Albumin, total protein, alkaline phosphatase (ALP) and Glutathione (GSH) levels in serum and liver homogenates were assayed. Consumption of plain alcohols without fortification resulted in a significant decrease (P<0.05) in serum GSH and liver albumin as well as a significant (P<0.05) increase in liver marker enzyme alkaline phosphatase when compared to animals supplemented with tea fortified alcohols or water only. Fortification of alcoholic beverages with tea showed significant protection with lowered liver ALP levels and replenishment of antioxidant status. Moreover, tea fortified alcohols induced a significant (P<0.05) increase in liver albumin when compared to animals fed on plain alcohols, implying a general improvement in the nutritional status of the experimental mice. The findings prove that tea has potent hepatoprotective effects against alcohol induced toxicity. The mechanism of the protective effects may involve augmentation of endogenous antioxidants. Beneficial effects of tea in this study could probably be important for the development of new alcohol products with less deleterious effects.

Keywords: Camellia sinensi; Antioxidants; Alcoholic beverages


Alcoholism is posing as a major health problem around the world. This problem is especially prevalent in the African continent and contributes a significant percentage of hospital admission [1]. Metabolism of alcohol is associated with over production of reactive oxygen species (ROS) and subsequent depletion of endogenous antioxidants resulting in oxidative stress [2]. Indeed, a previous study was able to establish that alcohol causes a significant decrease in the levels of key antioxidant enzymes catalase, glutathione peroxidase, and glutathione reductase and superoxide dismutase in rats [3]. Chaturvedi and others corroborated these findings and reported decreased Vitamin C and glutathione levels and a significant increase in the levels of plasma thiobarbituric acid reactive substances in rats fed on alcohol [1]. Consequently as a result of alcohol induced oxidative stress, biological systems are adversely altered with concomitant malfunction of a host of cells and tissues [4]. In this view, therapies aimed against oxidants could be useful in the management of alcohol toxicity.

Nowadays, many therapeutic studies are devoted to phytochemicals due to increased incidences of adverse drug reactions and economic burden on modern systems of medicine [5]. Moreover, a host of plants are rich sources of natural antioxidants with potent radical quenching abilities both in-vivo and in-vitro [6]. Tea (Camellia sinensis) is a perennial tree native to south China and exceptionally rich in antioxidants [7]. Its antioxidant activity is mainly contributed by the high quantities of polyphenols such as flavonol, flavandiols, flavonoids and phenolic acids which constitute more than 30% of the dry weight of the leaves [8]. Tea has for a long time been preferred as a beverage because of its unique flavor and colour. However, the recent research on tea has provided experimental and epidemiological evidence to demonstrate that Camellia sinensis has the ability to boost the body’s antioxidant capacity, making tea a popular health drink [9-12]. Moreover, several studies have appraised the hepatoprotective activity of tea against a number of hepatotoxic chemical agents such as Sodium oxalate [13], Tamoxifen citrate (TAM) [14], Carbon tetrachloride [7], anti-tuberculosis drug Isoniazid-Rifampicin [15], Leflunomide and a combination of Cyromazine and Chlorpyrifos [16]. On the other hand tea which is a natural product has been associated with health benefits because of its high content of phenolic compounds. The health benefits can be transferred to products in which tea has been incorporated. Based on this knowledge, an investigation was made on the hepatoprotective properties of tea against alcohol induced toxicity. Alcoholic beverages fortified with tea were developed and effects of their ingestion tested using mice.

Materials and Methods

Tea samples used in the fortification of the alcoholic beverages

Three different tea types namely aerated black, non-aerated green and non-aerated purple teas were processed and used in the production of the alcoholic beverages used in the research. Raw materials used in the manufacture of the various teas were obtained from the Tea Research Institute (TRI), Timbilil Estate in Kericho (latitude 0°22S, longitude 35°21 E, altitude 2180 m a.m.s.l.). Nonaerated green and aerated black tea was processed from the tea variety TRFK 6/8, while the purple leaf colored variety TRFK 306 was used to process non-aerated purple tea. Freshly harvested young tender shoots comprising of two leaves and a bud were used to process the teas through aeration [17] and non-aeration [18] methods.

Materials for alcoholic beverage production

The ingredients included aerated black and un-aerated green (Clone TRFK 6/8) and non-aerated purple (Clone TRFK 306) Kenyan tea cultivars, milled white sugar, citric acid, raisins, yeast and portable water.

Development and storage of alcoholic beverages

Development of alcoholic beverages was carried out aseptically at the food processing and value addition laboratory of TRI in Kericho, Kenya. Milled white sugar (340 g), raisins (56 g), citric acid (0.5 g), water (1000 mL), yeast (0.8 g) and tea (4 g, 8 g, and 16 g of black, green and purple teas) were mixed together and left to ferment for 14 days. The end products were aseptically filtered, cooled and stored at 20°C. Each set of tea fortified alcoholic beverage had a control without tea.

Experimental animals

All experimental procedures and protocols involving mice strictly adhered to protocols approved by Institutional Animal Care and Use Committee (IACUC) of the National Museums of Kenya-Institute of Primate Research (NMK-IPR), Karen, Kenya. A permit (number IRC/13/12) was obtained for the animal research, prior to the start of the study. A total of 55, eight weeks old female and male adult Swiss white mice weighing between 26-32 g were obtained from IPR rodent breeding colony and used in all experiments. The animals were housed in groups of 5 (different sexes grouped and housed separately), under conventional animal housing conditions within standard mice cages at a temperature of 21-28°C. They were provided ad libitum access to water and standard mice cubes obtained from Unger Feeds Ltd Kenya. Sterile wood-chippings were provided as bedding material. All mice were treated for internal parasites as a precautionary measure using Ivermectin (Ivermectin®, Anupco, Suffolk and England) injected subcutaneously. Carbon dioxide (CO2) was used to euthanize the animals at the end of the experiment as described by Close, et al. [19].

Experimental design

Prior to the start of the research, the study was blinded by random selection of mice and allocation into 11 groups (Table 1) where each animal served as a replicate in a completely randomized design (CRD). The test products, plain and tea fortified alcoholic (6% v/v) beverages were administered orally at a dosage of 1mL per mouse after every second day using a gavage needle. Administration of the test products was continued for 28 days during which time mice were monitored for changes in body weight (bwt) and packed cell volume (PCV). The experiment was terminated through euthanasia 24 h post the last dosage. Liver samples were obtained and whole blood drawn via cardiac puncture, serum separated and stored at -80°C until required for analysis.