The present study aimed at evaluating the protective role of daily (chronic) oral treatment of adult male rats with either alprazolam, ALZ, drug (0.3 mg/kg b.wt) or the herb valerian ,VAL, extract (300 mg/kg b.wt) against immune modulatory effect of daily (chronic) exposure of animals to restraint (RST) stress (2.5 h /day) for 4 weeks. Rats were divided into 6 groups (10 rats each); group 1: Unstressed control animals; group 2: RST rats; group 3: non-RST + ALZ treated rats; group 4: non- RST + VAL extract treated rats; group 5: RST + ALZ treated rats; group 6: RST + VAL extract treated rats. Blood samples were withdrawn from the retro- orbital venous plexus of each rat under slight ether anesthesia into EDTA and plain glass tubes for measuring total count and proportions of WBCs and separating sera samples, respectively. RST exposed rats showed significant decreases in WBCs count, lymphocyte, monocyte, granulocyte proportions and serum TNF-α, and a significant increase in serum cortisol level as compared to control group. While exposure of rats to VAL extract only did not cause any significant change in all measured parameters, ALZ exposed rats showed significant decreases in WBCs count, granulocyte proportion, serum cortisol and TNF-α levels, but had no significant change in lymphocyte and monocyte proportions. Oral administration of the herb extract to stressed rats revealed its ability to markedly and significantly reverse the immunosuppressive actions of RST stress on all immune parameters measured except serum cortisol level which was not affected. On the contrary, oral administration of ALZ to stressed rats was not able to alleviate the actions of RST stress on all immune parameters measured except monocyte proportion which was reversed by the drug. It could be concluded that VAL extract was found to be more safe and effective than ALZ drug in alleviating the immunosuppression induced in restraint stress exposed rats.
Key words: Alprazolam; Valerian; Restraint stress; Cortisol; TNF-α; WBCs.
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