Background
Acute inflammation is a short-term process, usually appearing within a few minutes or hours and ceasing upon the removal of the
injurious stimulus. It is characterized by five cardinal signs [Dolor (pain), Calor (heat), Rubor (redness), Tumor (swelling) and
Functio laesa (loss of function].
Green tea (Camellia sinensis) belongs to the family theacaceae is the most widely consumed beverage in the world as dietary
supplement that represents approximately 20% of world tea consumption. Many reports have demonstrated the usefulness of the
extracts of green tea in many diseases and conditions like cancer prevention, hyperlipidemia, diabetes mellitus, obesity and in
microbial diseases; but others were demonstrated a contrary results concerning their usefulness in diseases and conditions.
Objective:
The present study was carried out to assess the possible anti-inflammatory effect of aqueous green tea extract (AGTE)
using egg white-induced edema in rats (acute model of inflammation).
Materials and methods:
The anti-inflammatory effect of AGTE was evaluated in acute inflammation model using 18 Sprague Dawley rats and
divided into three groups including distilled water1 ml/kg orally, diclofenac 30 mg/kg IP and AGTE 1.5 % orally. Thirty minutes post
treatment, inflammation was induced by injecting 0.1 ml of fresh egg albumin into the sub plantar surface of the right hind paw and
mean increase in paw edema was measured 30 min, 60 min and 90 min after induction of inflammation using a digitalized vernier
caliper.
Suppression of paw inflammation by either diclofenac or AGTE and the percentage of inhibition of paw edema were assessed.
Results:
The data obtained from this study reported that significant decrease (P<0.05) in paw edema were seen in rats treated with diclofenac
(30mg/kg) IP prior to egg albumin (group II) after 30 min and 60 min, respectively compared to group I animals . A significant
increase in paw edema (P<0.05) were observed in the group II animals compared to group I after 90 min from induction of acute
inflammation by egg albumin. The percent inhibition of paw edema provoked by IP injection of diclofenac prior to egg albumin
(group II) was 3.9%, 3.6% and after 30 and 60min, respectively; while there was no inhibition of paw thickness observed after 90 min
(20.6%).
Concerning the effect of orally-administered AGTE (1.5g %) to rats prior to egg albumin (group III), the results of this study were
demonstrated that the extract produced significant increase in paw edema after 30 min, 60 min and 90 min compared to either group I
and group II animals
The percent of inhibition of paw edema provoked by AGTE given orally to animals prior to egg albumin were not observed but rather
there were an increase in paw thickness (2.77%, 3.4% and 32.2%), after 30, 60 and 90 min, respectively.
Conclusion:
In conclusion, AGTE orally-administered to rats did not show anti-inflammatory activity at different times selected in this study.