acetyl-11-ketoboswellic-acid and nimesulide

Cyclooxygenase (COX) and lipoxygenase (LOX) are responsible for the metabolism of arachidonic acid into inflammatory metabolites, prostaglandins and leukotrienes, respectively. The upregulation of these enzymes in the central nervous system has been demonstrated to be responsible for the increased neuronal vulnerability to degeneration. Kainic acid, a glutamate receptor agonist and responsible for neuronal excitotoxicity and oxidative damage via different mechanisms, is capable of stimulating mRNA of both COX-2 and 5-LOX in the brain. The present study was designed to study the effects of COX inhibitors (indomethacin, nimesulide, rofecoxib) and a 5-LOX inhibitor (acetyl-11-keto-beta-boswellic acid; AKBA) and the combination of these inhibitors (dual inhibition) on kainic acid induced excitotoxicity and oxidative and nitrosative damage in mice. The results from the present study indicated that AKBA, indomethacin, and nimesulide per se did not produce any change in the behavioural parameters after kainic acid administration; however, rofecoxib per seproduced a significant increase in the latency of clonic (seizure-like) movement and a decrease in mortality rate as compared with kainic acid treated animals. In combination studies AKBA, rofecoxib, and nimesulide produced a more pronounced effect than either of these drugs alone. Further, the effect of AKBA combined with rofecoxib was significantly more marked when compared with AKBA combined with nimesulide. Besides this, identical results were found for the effect of these agents and their combination against oxidative damage induced by kainic acid. These findings indicate the potential role of COX-2 inhibitors and also their combination with the 5-LOX inhibitor in kainic acid induced excitotoxicity and oxidative damage by virtue of their antioxidant effect and suggest the need for the development of dual inhibitors for the treatment of neuronal excitotoxicity.

Topics: Administration, Oral; Animals; Antinematodal Agents; Brain; Catalase; Cyclooxygenase 2 Inhibitors; Drug Synergism; Drug Therapy, Combination; Epilepsy, Tonic-Clonic; Glutathione; Indomethacin; Injections, Intraperitoneal; Kainic Acid; Lactones; Lipid Peroxidation; Lipoxygenase Inhibitors; Male; Mice; Mice, Inbred Strains; Nitric Oxide; Peroxidase; Sulfonamides; Sulfones; Triterpenes

The present study was aimed to assess the combined effects of cyclooxygenase and 5-lipoxygenase (COX/5-LOX) inhibitors in different animal models of nociception. Naproxen, nimesulide and rofecoxib are well-established antinociceptive agents acting via COX inhibition. AKBA (acetyl-keto-beta-boswellic acid) is a 5-LOX inhibitor. AKBA (50-200 mg/kg) produced a dose dependent and significant antinociceptive effect in different animal models of nociception. Based on the earlier reports from our laboratory, sub effective doses of all the three COX Inhibitors were selected and they were administered (naproxen, 5 mg/kg; nimesulide, 1 mg/kg; and rofecoxib, 1 mg/kg) with AKBA (100 mg/kg). This produced a more significant antinociceptive effect as compared to per se effect observed in all the three models of nociception. However, the effect of combination of nimesulide with AKBA was more pronounced as compared to naproxen and rofecoxib and their combination with AKBA. The present finding provided an evidence for the potentiation of antinociceptive effect of NSAIDs with AKBA. Such a combination may help to reduce the therapeutic doses of conventional NSAIDs and also reduce side effects (gastric, cardiac and renal) that are popularly associated with the NSAIDs.

Topics: Analgesics; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cyclooxygenase Inhibitors; Dose-Response Relationship, Drug; Lactones; Lipoxygenase Inhibitors; Mice; Naproxen; Pain Measurement; Prostaglandin-Endoperoxide Synthases; Sulfonamides; Sulfones; Triterpenes

Several inflammatory processes play a critical role in brain aging and are associated with increased vulnerability to neurodegeneration. Cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX), two enzymes involved in the oxygenation of the arachidonic acid, are upregulated in the central nervous system during aging and are associated with different aging-related brain pathologies. The present experiment was performed to study the effects of 5-LOX inhibitor, acetyl-11-keto-beta-boswellic acid (AKBA), nimesulide (preferential COX-2 inhibitor), and their combination on cognitive performance of young and aged mice, using elevated plus maze test. Chronic administration of AKBA (100 mg/kg, p.o.) and nimesulide (2.42 mg/kg, p.o.) for 15 days significantly reversed the aging-induced retention deficit in mice. Coadministration of AKBA and nimesulide enhanced the cognitive performance in aged mice when compared with that in per se treatment. The aging-related increase in oxidative damage (increased LPO and decreased GSH) was reversed by AKBA, nimesulide, and their combination. Further, per se COX and LOX inhibitors and their combination did not produce any alteration in gastrointestinal parameters; they also reversed the aging-induced motor dysfunction in the aged animals. On the basis of these observations, present findings indicated that the combination of COX and LOX inhibitors (dual inhibitors) may provide a new therapeutic innovation for the treatment of aging-related brain disorders such as Alzheimer's disease and different motor dysfunctions with adequate gastrointestinal tolerability.

Topics: Aging; Animals; Brain; Cyclooxygenase Inhibitors; Drug Synergism; Epithelium; Female; Glutathione; Lipid Peroxidation; Lipoxygenase Inhibitors; Male; Malondialdehyde; Memory; Mice; Motor Activity; Psychomotor Performance; Stomach; Sulfonamides; Triterpenes