Inhibitory effect of sodium salicylate on nitric oxide production from TM4 sertoli cells

The Beneficial Biological Properties of Salicylic Acid

Salicylic acid is a phytochemical with beneficial effects on human well-being. Salicylic acid is a phenolic compound and is present in various plants where it has a vital role in protection against pathogenic agents. Natural sources include fruits, vegetables and spices. The most famous and defined effect of salicylic acid is prostaglandin synthesis inhibition. Salicylic acid has antiinflammatory effects through suppression of transcription of genes for cyclooxygenase. Most of the pharmacological properties of salicylic acid can be contributed to the inhibition of prostaglandin synthesis. Also, it was discovered that salicylic acid has other in vivo cyclooxygenase-independent pathways. Since salicylic acid does not inhibit cyclooxygenase considerably, the anti-inflammatory effect is not a consequence of direct inhibition of cyclooxygenase activity. Because of its fundamental role, it was suggested that inhibition of nuclear factor kappa B by salicylic acid is one of the key anti-inflammatory mechanisms of action for salicylates. One of the most studied properties of salicylic acid is its antioxidative activity. Salicylic acid is a confirmed inhibitor of oxidative stress. Salicylic acid is capable of binding iron. This fact is significant for antioxidative effect of salicylic acid because iron has an important function in the course of lipid peroxidation.

Effect of diclofenac on germ cell apoptosis following testicular ischemia-reperfusion injury in a rat

Recent evidence suggests that enhanced cell apoptosis is responsible for germ cell loss following testicular ischemia-reperfusion (IR) injury. A nonsteroidal anti-inflammatory drug diclofenac sodium (Voltaren) is a prostaglandin-synthesis inhibitor, which is widely used in many testicular disorders. The purpose of the present study was to examine the effect of diclofenac (DIC) on germ cell apoptosis in the ischemic and contralateral testes following testicular IR in a rat. Forty rats were divided randomly into four experimental groups of ten rats each: group A (Sham)-Sham operated animals; group B (Sham-DIC)-Sham operated rats that were treated with DIC given subcutaneously at a dose of 10 mg/kg, once daily, 24, 48 and 72 h following operation; group C (IR) underwent 90 min of unilateral testicular IR; group D (IR-DIC)-rats underwent 90 min of unilateral testicular IR and were treated with DIC similarly to group B. Ninety-six hours following operation, the rats were sacrificed and testes were harvested. Johnsen's criteria and the number of germinal cell layers were used to categorize the spermatogenesis. TUNEL assay was used to determine germ cell apoptosis in both the ischemic and contralateral testes. Statistical analysis was performed using the non-parametric Kruskal-Wallis ANOVA test, with P less than 0.05 considered statistically significant. Testicular ischemia in rats led to histological damage in the ipsilateral testis. In the contralateral testis, minimal damage was observed. Germ cell apoptosis in both the ischemic and the contralateral testes increased significantly after IR. Treatment with DIC did not change histologic parameters of spermatogenesis in both the ischemic and contralateral testes, but decreased germ cell apoptosis in both testes following testicular IR. We conclude that testicular ischemia causes an increase in germ cell apoptosis in the contralateral testis. Diclofenac may be beneficial for spermatogenesis following testicular IR by decreasing germ cell apoptosis.

Non-steroidal anti-inflammatory drug sodium salicylate, but not diclofenac or celecoxib, protects against 1-methyl-4-phenyl pyridinium-induced dopaminergic neurotoxicity in rats

We evaluated the hydroxyl radical (*OH) scavenging action of nonsteroidal anti-inflammatory drugs (NSAIDs), sodium salicylate (SA), diclofenac and celecoxib in Fenton's reaction and their neuroprotective effects in 1-methyl-4-phenylpyridinium (MPP(+))-induced striatal dopamine (DA) depletion in rats. Salicylate hydroxylation procedure employing HPLC-electrochemistry was used to assay formation of *OH in Fenton's reaction in test tubes. While SA dose- and time-dependently hydroxylated itself and inactivated *OH, celecoxib (up to 10 mM) showed no effect on *OH formation and diclofenac caused a reduction in *OH generation only at high doses (100 microM-10 mM). Administration of the non-selective cyclooxygenase (COX) inhibitor, SA (50, 100 mg/kg, i.p.) significantly attenuated striatal DA depletion caused by intrastriatal infusion of MPP(+) (100 nmol in 4 microl). Treatment with another nonselective, reversible COX inhibitor, diclofenac (5, 10 mg/kg) did not protect against MPP(+)-induced DA depletion. The selective COX-2 inhibitor, celecoxib (2.5-50 mg/kg) treatment exacerbated MPP(+)-induced decrease in DA. Failure of celecoxib or diclofenac to render protection in animals against MPP(+)-induced DA depletion indicates absence of prostaglandin involvement in MPP(+) action. These results also suggest that the neuroprotective ability of SA is independent of prostaglandin mediation. A relationship between inactivation of *OH by SA and its ability to protect DA depletion in the striatum caused by MPP(+) indicates a direct involvement of *OH in the action of this neurotoxin. The present study establishes potent neuroprotective activity of SA and suggests the use of aspirin in adjuvant therapy in Parkinson's disease.