[Changes in ulcerogenic response to non-steroidal anti-inflammatory drugs (NSAIDs) in adjuvant arthritic rats]

Morus mesozygia leaf extract ameliorates behavioral deficits, oxidative stress and inflammation in Complete Freund's adjuvant-induced arthritis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Morus mesozygia Stapf (Moraceae), otherwise referred to as African mulberry, is utilized domestically as a remedy for a variety of inflammatory disorders including rheumatism.

AIM

The anti-arthritic effect of the ethylacetate fraction of M. mesozygia leaf extract (EAFMm) was assessed on complete Freund's adjuvant (CFA)-induced arthritis in male Wistar rats.

METHOD

Groups of male Wistar rats were injected with CFA (0.2 mL; 10 mg/mL) in the plantar surface of their right hind paws and treated orally with EAFMm (50 and 100 mg/kg) or its vehicle daily for 28 days. The effect on joint inflammation and mechanical nociception threshold, behavioral deficits (spontaneous motor activity in the open field test and depressive-like symptoms in the forced swim test) was evaluated. The levels and activities of the biomarkers of oxidative-nitrosative stress (reduced glutathione, superoxide dismutase, nitrite, and malondialdehyde) and inflammatory markers [TNF-α, IL-6, COX-2, NFκB and myeloperoxidase] were also analysed.

RESULTS

The EAFMm at the doses of 50 and 100 mg/kg produced a dose dependent reduction in joint inflammation and mechanical hyperalgesia, and as well improved behavioral deficits like spontaneous motor activity and depressive-like behavior. The EAFMm also significantly reduced oxido-nitrosative stress response in the joint and brain tissues. It also decreased TNF-α, interleukin-6 levels and myeloperoxidase enzyme activities in joints and brain tissues of rats. Furthermore, EAFMm attenuated the activity of NFκB and reduced the cyclooxygenase -2 protein expression level in joint tissues.

CONCLUSION

The ethylacetate fraction of Morus mesozygia leaf extract demonstrated anti-arthritic activity and ameliorated co-morbid depressive-like behavior via inhibition of oxidative stress and inflammation in a rat model of arthritis.

The role of magnesium in different inflammatory diseases

Magnesium deficiency (MgD) can cause inflammation in human body. The known mechanisms of inflammation caused by MgD include activation of phagocytic cells, opening of calcium channels, activation of the N-methyl-D-aspartate (NMDA) receptor, and activation of nuclear factor (NF)-κB. In addition, MgD causes systemic stress response through neuroendocrinological pathways. The inflammation caused by MgD can result in pro-atherogenic changes in the metabolism of lipoproteins, endothelial dysfunction, and high blood pressure. Studies suggest that magnesium may play an important role in the pathophysiology of some inflammatory diseases. Several clinical trials and laboratory studies have been done on the functional role of magnesium. In this study, we review some inflammatory diseases, in which the magnesium has a role in their pathophysiology. Among these diseases, diabetes, asthma, preeclampsia, atherosclerosis, heart damage, and rheumatoid arthritis have been highlighted.

Therapeutic effects of gel ointments containing tranilast nanoparticles on paw edema in adjuvant-induced arthritis rats

Tranilast (TL), an antiallergic agent, has been clinically used in the treatment of bronchial asthma, although its clinical use has been limited by its poor solubility in water, photodegradation and systemic side effects. In this study, we prepared a gel ointment containing TL nanoparticles (TLnano gel ointment), and investigated its usefulness. In addition, we demonstrated the preventive effects of the TLnano gel ointment on inflammation in adjuvant-induced arthritis (AA) rats. The TLnano gel ointment was prepared using Bead Smash 12 (a bead mill) and additives including sodium docusate, 2-hydroxypropyl-β-cyclodextrin, methylcellulose and Carbopol 934; the mean particle diameter of the TL nanoparticles was 71.0±25.4 nm. In in vitro skin penetration experiments, the amount of penetrated TL, the penetration rate (Jc) and the penetration coefficient through the skin (Kp) of the TLnano gel ointment were significantly higher than those of a gel ointment containing TL microparticles (TLmicro gel ointment; particle diameter 50.5±26.3 µm). The TL concentrations in the skin tissue and plasma of rats receiving the TLnano gel ointment were also higher than in rats receiving the TLmicro gel ointment. In addition, the application of the TLnano gel ointment attenuated the increase in paw edema of the hind feet of AA rats in comparison with AA rats treated with the TLmicro gel ointment. These results suggest that TL nanoparticles can be applied to the formulation of a transdermal system, and that a transdermal formulation using TL nanoparticles might be a delivery option for the clinical treatment of RA.

Co-administration of water containing magnesium ion prevents loxoprofen-induced lesions in gastric mucosa of adjuvant-induced arthritis rat

Non-steroidal anti-inflammatory drugs (NSAIDs) comprise one of the most frequently used classes of medicines in the world; however, NSAIDs have significant side effects, such as gastroenteropathy, and rheumatoid arthritis patients taking NSAIDs are more susceptible to NSAID-induced gastric lesions as compared to patients with other diseases. In Asian countries, loxoprofen has been used clinically for many years as a standard NSAID. We demonstrate the preventive effect of the co-administration of water containing magnesium ion (magnesium water, 1-200 µg/kg) on the ulcerogenic response to loxoprofen in adjuvant-induced arthritis (AA) rats. Oral administration of loxoprofen (100 mg/kg) caused hemorrhagic lesions in the gastric mucosa of AA rats 14 d after adjuvant injection, and, following loxoprofen administration, the lesion score of AA rats was significantly higher than that of normal rats. The expression of inducible nitric oxide synthase (iNOS) mRNA and nitric oxide (NO) production in the gastric mucosa of AA rats were also increased by the administration of loxoprofen, and the increase in lesions and NO were prevented by the administration of aminoguanidine, an iNOS inhibitor. The co-administration of magnesium water decreased the ulcerogenic response to loxoprofen in AA rats. In addition, the co-administration of magnesium water attenuated the increase in iNOS mRNA expression and NO production in AA rats receiving loxoprofen. These results suggest that the oral co-administration of magnesium water to AA rats has a potent preventive effect on the ulcerogenic response to loxoprofen, probably by inhibiting the rise in iNOS and NO levels in the gastric mucosa.

Involvement of interleukin 18 in indomethacin-induced lesions of the gastric mucosa in adjuvant-induced arthritis rat

It is well known that nonsteroidal anti-inflammatory drugs (NSAIDs) have significant side effects, such as gastroenteropathy, and rheumatoid arthritis patients taking NSAIDs are more susceptible to NSAIDs-induced gastric lesions in comparison with other patients. The pathogenic mechanism of these lesions is not fully understood. We demonstrate whether interleukin 18 (IL-18) expression relate the aggravation of gastric lesion in adjuvant-induced arthritis (AA) rats following the oral administration of indomethacin. Arthritis was induced by injecting 50 microl of a suspension of 10mg/ml heat-killed butyricum (Mycobacterium butyricum) in Bayol F oil into the plantar region of the right hind foot and tail of Dark Agouti rats resulting in an arthritis incidence of 100%. Two weeks after injection, the rats were administered indomethacin (40mg/kg) orally, and were killed under deep ether anesthesia 6h later. The gastric mucosa was then examined. Oral administration of indomethacin caused hemorrhagic lesions in the gastric mucosa of AA rats, and the lesion score for AA rats following indomethacin treatment was significantly higher than for normal rats administered indomethacin. The expression of the IL-18 mRNA and mature IL-18 protein in the gastric mucosa of AA rats administered indomethacin were also higher in comparison with normal rats receiving indomethacin. In addition, interferon-gamma and nitric oxide levels in the gastric mucosa of AA rats were increased by the oral administration of indomethacin. It is possible that IL-18 expression in AA rats is more sensitive to indomethacin, and the IL-18 may play a role in the aggravation of gastric lesions in AA rats treated with indomethacin.

Analgesic, antipyretic and Ulcerogenic properties of an indigenous formulation--Kalpaamruthaa

A modified indigenous Siddha formulation Kalpaamruthaa (KA), containing Semecarpus anacardium nut milk extract (SA), dried powder of Emblica officinalis (EO) fruit and honey was evaluated for its analgesic, antipyretic and Ulcerogenic properties. Both SA and KA, at a dose of 150 mg/kg b. wt were compared with the standard drug diclofenac sodium. KA exhibited an enhanced effect on all properties compared with that found with sole SA treatment, and is likely to be due to synergistic and additive interactions within the complex mixture of phytochemicals present in KA.

Role of L-arginine in ibuprofen-induced oxidative stress and neutrophil infiltration in gastric mucosa

It has been proposed that neutrophil and oxygen dependent microvascular injuries may be important prime events in gastrointestinal (GI) toxicity of non-steroidal antiinflammatory drugs (NSAIDs). L-arginine (L-ARG) is an essential amino acid which participates in many important biochemical reactions associated to the normal physiology of the organism. In these experimentations, we studied the role of L-ARG, aminoacid precursor of NO synthesis, on ibuprofen (IB) induced gastric lesions, and also on the inflammatory and oxidative mechanisms related to mucosal damage. Oral administration of IB (100 mg kg(-1)), produced severe damage on gastric mucosa, which was more important after 6 h test-period, and was accompanied by a significant increment in myeloperoxidase (MPO) activity, as index of neutrophil activation, as well as lipid peroxidation (LP) levels and xanthine oxidase (XO) activity. However, no changes were observed in total mucosal glutathione (tGSH), nor glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activity. Simultaneous treatment with equimolar doses of L-ARG (oral and i.p.), considerably reduced the number and intensity of lesions, and at the same time (6 h) the maximum protection was also observed. In addition, L-ARG inhibited the IB-induced LP and XO enhancement, but did not produce changes in leukocyte infiltration, tGSH, GSH-Px and SOD activity. These findings suggest that (1) L-ARG protective effect on gastric mucosa against IB-induced mucosal lesions could be explained by a local effect and also might be due to the systemic action of the aminoacid; (2) the active oxygen species, derived both from XO and activated neutrophils, could play a role in the pathogenesis of gastric injury induced by IB, (3) L-ARG exhibit a protective effect against IB-induced mucosal damage, probably through the inhibition of oxidative stress derived via xanthine-XO, but it does not block the oxygen free radical production through polymorphe nuclear leukocytes.