EFFECTS OF CELECOXIB AND ROFECOXIB ON NEUTROPHILES AND LYMPHOCYTE COUNTS IN RATS (COMPARATIVE STUDY).

Non steroidal anti-inflammatory drugs NSAIDs one of the most commonly used drugs all over the world specially for treatment of chronic disease their effect on immune system should be considered in selection of member of non steroidal anti inflammatory drug The objective of this study is to determine whether Celecoxib and Rofecoxib are associated with a lower incidence leucopenia Thirty (30) Sprague-Dawely male rats were used during this study . The animals were divided in to three groups : group 1 – Control , group 2 received Celecoxib and group 3 received Rofecoxib for 1 month duration .Samples of blood before and after treatment were taken for determination of total W.B.C , neutrophiles and lymphocyte counts. The results were as fallow: 1-Celecoxib 15 mg/kg/day and Rofecoxib 10 mg/kg/day caused significant reduction in total W.B.C , Neutrophiles and Lymphocyte counts . 2-Rofecoxib 10 mg/kg/day caused the less reduction in total W.B.C. count, neutrophiles and lymphocyte counts as compared with Celecoxib 15 mg.kg.day/ day


EFFECTS OF CELECOXIB AND ROFECOXIB ON NEUTROPHILES AND LYMPHOCYTE COUNTS IN RATS (COMPARATIVE STUDY
after birth , some lymphocyte are formed in the bone marrow , but most are formed in the bone marrow, thymus and spleen from precursor cells that originally came from the bone marrow.lymphocytes enter the blood stream for the most part via the lymphatic .it has been calculated that in human 3.5 x 10x10 lymphocyte per day enter the circulation via the thoracic duct alone, however this count include the cells that enter the lymphatic and thus traverse the thoracic duct more than once .thelymphocyte are the key of the immune system which has the ability to produce antibodies against millions of different foreign agent that may invade the body.

Blood samples
Before drug administration, 1 ml of blood was taken from each rat for measurement total W.B.C., neutrophiles and lymphocyte counts.The blood was withdrawn from the caudal artery at the ventral aspect of the tail at the junction with the body.After one month of drug administration the blood was taken from each rat for measurement of, total W.B.C., neutrophiles and lymphocyte Counts.These blood samples were obtained directly from the heart after labratomy.1).Rofecoxib 10 mg/ kg /day for 1-month treatment caused less reduction in total W.B.C counts as compared with Celecoxib 15 mg /kg/day for the same period of treatment (Table 3).There were significant no differences in the percentage of reduction in total W.B.C counts between Celecoxib and Rofecoxib (Table 2).5).Also it was found that Rofecoxib 10 mg /kg/day for 1 month treatment caused less reduction in lymphocytes counts (P<0.018) as compared with Celecoxib 15 mg /kg /day (P<0.025) for the same period of treatment (Table 5).Also the results showed a significant differences between Celecoxib, and Rofecoxib (Table 6).The selection of rats as animal model in this study is due to the fact that rats are considered as good model for study of gastrointestinal lesions induced by NSAIDs. (4)Due to their gastrointestinal toxicity, NSAIDs have been widely studied for many years, especially since 1993 when 2 isoforms of cyclo-oxygenase was discovered.The discovery of inducible cyclo-oxygenase enzyme (Cox-2) has given a new way in the development of a safer anti-inflammatory drugs.The results of animal experiments and early clinical studies with selective Cox-2 inhibitors are quite impressive.This study support that these selective Cox-2 inhibitors will represent an effective gastrointestinal sparing alternative to classical NSAIDs.They will be beneficial in other clinical situation in which Cox-2 is over expressed, beside their therapeutic indication. (5)

Effects of NSAIDs on total W.B. C counts of rats
In the present study it was found that Celecoxib 15 mg/kg/day and Rofecoxib 10 mg /kg/day caused significant reduction in total W.B.C counts (P< 0.05).These finding are similar to the findings of Maria Victoria et al 2000. (6)who had found a significant decrease in total W.B.C counts after treatment with Celecoxib and Rofecoxib in human being.The proposed explanation for this leucopenia are through immunologically mediated mechanism, either through immune suppression of bone marrow white blood cell precursors or peripheral destruction. (7)ffects of NSAIDs on neutrophiles and lymphocyte counts In this study it was found that Celecoxib 15 mg/kg/day and Rofecoxib 10 mg /kg/day produce a significant reduction of both, neutrophiles and lymphocyte counts ( P < 0.05 ) .It was observed that Rofecoxib caused less reduction in total W.B.C, neutrophiles and lymphocyte counts and this can be explained by that the mechanism of reduction of neutrophiles counts by NSAIDs act through a direct toxic effect on the bone marrow , or may be combined by immunological mechanism , (8) our results are in agreement with that obtained by cryer etal (1998) who found that celecoxib15 mg/kg/day and rofecoxib 10 mg /kg/day produce a significant reduction of both, neutrophiles and lymphocyte counts.

Conclusion and Recommendation
Our work has shown that: 1-Celecoxib and Rofecoxib in a dose of (15mg/kg/day, 10 mg/kg /day) cause significant reduction in total W.B.C., neutrophiles and lymphocyte counts.2-Rofecoxib in a dose of 10mgl kg for one month show less reduction in a total W.B.C. count ( -6.25%) as compared by Celecoxib in a dose 15 mg.kg day for one month (-8.45%) .3-Rofecoxib in a dose of 10mgl kg for one month show less reduction in a neutrophiles count(-12.76%)as compared with Celecoxib 15 mg.kg.day for one month (-16.48).4-Rofecoxib in a dose of 10 mg.kg.day for one month show less reduction in lymphocyte count (-1.56%) as compared with Celecoxib in a dose of 15 mg.kg.day ( -12.45) for one month .theseresult deserve clinical evaluation in those with long use of NSAIDs specially those patients with Immune-compromised state like AIDES (HIV virus), Diabetes Mellitus and others .

2 - 2 )
study is an attempt to re-evaluate two new members of NSAIDs Rofecoxib and Celecoxib ,which are selective Cox-2 inhibitors ,in regard to their effects on neutrophiles and lymphocyte count to select the most appropriate on for immune-compromised patient .Materials and Methods: materials Animals thirty healthy adult males Sprague-Dawley rats with weight ranging between 200-230 gm, and aged between 18-20 weeks were obtained from the National Center for Drug Control and Research/ Baghdad.The rats were kept in cages, each cage contained five animals.The animals were left to acclimatize to the animal house condition for one week and were fed with standard rodent chew diet and tap water.Drugs used in experiment: 1-Rofecoxib tablets: selective Cox-2 inhibitors NSAIDs obtained as Dioxx ®, each tablet contains Rofecoxib 25 mg, Batch No. 2-03 manufactured by Dafar drugs Company.Celecoxib capsules : selective Cox-2 inhibitor NSAIDs obtained as Celebrex, 200 mg /cap.Batch No. Oll-534620 manufactured by G .D. Searle and CO.USA.Experimental animals Animals were randomly divided in to following groups 1-Group 1: Control group contained 10 animals , all the animals of this group were kept on standard rodent chew diet and tap water through out the duration of experiment .2-Group 2: Celecoxib group, contained 10 animals ,all the animals of this group were given Celecoxib 15 mg/kg once daily for one month.. 3-Group 3 : Rofecoxib group, contained 10 animals ,all the animals of this group were given Rofecoxib 10 mg/kg once daily for one month.The doses of the drugs used above are the typical doses in rats for assessment of gastric damage induced by NSAIDs ‫ز‬ All the drugs were diluted in normal saline and were administrated as liquid solutions through stomach tube according to .animalsbody weight .
of total W.B.C., neutrophiles and lymphocyte counts.Make a 1 in 20 dilution of blood by adding0.1 ml of blood to 0.38 ml of diluting fluid in a 75 X 10-mm glass or plastic tube.The method of counting is according to Daci and Lewis,2001.totalW.B.C counts revealed that Celecoxib 15 mg/ kg /day and Rofecoxib 10 mg/kg/day for 1-month treatment caused significant reduction in total W.B.C count (p < 0.05) as compared with control group (control-1) (Table

Table ( 2
):Comparison of mean differences from baseline in total WBC counts in animals treated with Celecoxib 15 mg/kg/day and Rofecoxib 10 mg/kg/day for 1-month.

Table ( 5
): Effects of different types of Cox-2 inhibitors on lymphocytes counts.