Prostanoids as friends, not foes: Further evidence from the interference by cycloxygenase-inhibitory drugs when inducing tolerance to experimental arthritigens in rats

Nephroprotective effect of Apium graveolens L. against Cisplatin-induced nephrotoxicity

Background

Cisplatin is extensively used in treating cancers, and its primary side-effect is nephrotoxicity. It accumulates in proximal convoluted tubules where it promotes cellular damage by oxidative stress, apoptosis, and inflammation, etc. In Unani medicine, Tukhm-e-Karafs(Apium graveolens L.) (TK) is mentioned in the literature to manage various kidney ailments due to its diuretic and deobstruent activities.

Objective

To investigate the nephroprotective effects of powder of TK in Cisplatin-induced nephrotoxicity in an animal model and to validate the Unani claim of its nephroprotective action.

Material and methods

In curative protocol, cisplatin (5 mg/kg body weight i.p) was administered on day one and powder of TK (500 and 1000 mg/kg p.o.) from the sixth day onwards for ten days. TK (500 and 1000 mg/kg p.o.) was given for ten days and Cisplatin (5 mg/kg body weight i.p) on day 11 in the protective model. At the end of the study, all the animals were sacrificed, and renal biochemical parameters were determined. KIM-1 level was also investigated in the kidney homogenate in conjunction with histopathological inspection of kidney tissues.

Results

Significant increase in serum creatinine and BUN, presence of mononuclear cell infiltration, tubular dilation and vacuolation in renal histopathology, and increased KIM-1 level confirmed the nephrotoxicity due to Cisplatin. TK's administration protects the kidney as suggested by the changes in biochemical renal function, decreased level of KIM-1, and improvement in histopathological changes.

Conclusion

The result advocated that TK prevented renal injury and maintained normal renal function in both models. It may be due to improved clearance of Cisplatin from kidney tubules and reduction in reactive oxygen species (ROS) produced by the inflammatory response.

[Prostaglandins and the immune response at the intestinal submucosal level. A potential site for interference with the repeated use of paracetamol and ibuprofen at a young age?]

Immune deviations have been shown to exponentially increase in young children. As a consequence, research investigating possible environmental reasons for this increase is considered a public health priority. An improved understanding of the immunity of the intestinal submucosal lamina propria has demonstrated the importance of prostaglandins (PGE2s) on its local development with general immune consequences further on. PGE2s appear at this intestinal submucosal level from the metabolism of arachidonic acid mediated by type-2 cyclooxygenases (COX2s) situated in the membranes of many immune cells. The potential risk of repeated inhibition of PGE2 synthesis at a young age has been demonstrated in experiments with animals systemically exposed to a non-steroidal anti-inflammatory drug (NSAID). The repeatedly exposed animal cannot develop tolerance to food antigens and exhibits autoimmune deviations. Acetaminophen (paracetamol) and ibuprofen are analgesic and antipyretic medications given to children either alone or in combination, most often without medical prescription. Recently, it has been demonstrated that paracetamol, like ibuprofen, also carries, besides its central action, a non-selective inhibitory action on peripheral COXs. However, this inhibitory action only relates to physiological concentrations of arachidonic acid and explains the difference in their respective anti-inflammatory effects. Since recently published data have repeatedly reported an increase of immune deviations associated with paracetamol exposure at a young age, it appears important to better understand the possible negative impact of excessive and repetitive inhibitions of the physiological synthesis of prostaglandins by COX2s in childhood during which all immune mechanisms are built up at the intestinal submucosal level. Therefore, a well-designed prospective strategy for pharmacovigilance of these COX inhibitors repeatedly given during childhood is urgently needed.

Hydro-methanolic extract of cornus MAS L. And blood glucose, lipid profile and hematological parameters of male rats

BACKGROUND

Cornus mas L, an olive-shaped red-colored single-seeded fruit, is used in traditional medicine in different parts of Europe and Asia.

OBJECTIVES

In the present study, 40 male Wistar rats were randomly divided into five groups, and the effects of 21 days of intraperitoneally (IP) administration of 50, 200 and 400 mg/kg body weight of C. mas hydro-methanolic extract on the rats hematological and biochemical parameters were investigated. The experimental study was carried out in Tabriz, Iran.

MATERIALS AND METHODS

The hematology and biochemical tests were performed by the Technicon H1 Hematology Analyzer and enzymatic methods, respectively.

RESULTS

The results indicated that all doses of the extract caused significant (P < 0.05) decreases in the hemoglobin distribution width (HDW) (2.3 ± 0.2 vs. 2.5 ± 0.2, P = 0.049) and platelet distribution width (PDW) (56.5 ± 1.8 vs. 63.9 ± 3.6, P = 0.001) of the treated groups vs. control group, whereas only high doses caused significant elevation in the mean corpuscular hemoglobin concentration (MCHC) (30.3 ± 0.8 vs. 28.6 ± 0.6, P = 0.047), mean platelet volume (MPV) (5.0 ± 0.6 vs. 4.1 ± 0.3, P = 0.002), total platelet mass (PCT) (0.33 ± 0.07 vs. 0.26 ± 0.01, P = 0.050), and significant decrease in the red cell distribution width (RDW) (13.8 ± 0.4 vs. 14.7 ± 1.3, P = 0.048) of the treated groups vs. control group.

CONCLUSIONS

Decreasing effect of the extract on platelet activity might classify it as an alternative for antiplatelet therapy in cardiovascular diseases (CVD). The results of this study suggested that further investigations with higher doses of C. mas fruit extract are necessary to obtain significant protective and nonprotective changes in hematological and biochemical parameters.

Paracetamol (acetaminophen): a blessing or a hidden curse?

This Journal has recently published a splendid review of all you need to know about paracetamol (Graham et al. 2013), an analgesic widely used in the long-term management of arthritis. It clearly presents the science and hard facts. This commentary, by contrast, discusses some aspects of the metapharmacology of paracetamol; particularly by asking questions of how we might extract more benefit and suffer less adverse reactions when using this analgesic in the context of non-transient inflammation. As both a drug and a toxin, paracetamol exemplifies how beneficial and/or deleterious responses may be conditioned by circumstances (disease stress, nutritional status, fasting, etc.).

Marine oil dietary supplementation reduces delayed onset muscle soreness after a 30 km run

Objective

Runners are prone to delayed onset muscle soreness (DOMS) during long distance training. This especially holds for unaccustomed training volumes at moderate to high intensities. We investigated the effects of a marine oil complex, PCSO-524®, derived from the New Zealand green-lipped mussel (formulated as Lyprinol® and Omega XL®) on DOMS after a 30 km training run.

Methods

Initially, peak oxygen uptake of 32 distance runners (4 female, 28 male; median age 45 years, range 28–53) was measured on a treadmill with a 1.5 km hour⁻¹ increase every 4 minutes starting from 8.5 km hour⁻¹. At least 1-week after this initial test, they participated in a 30 km road run at a speed corresponding to about 70% of their individual peak oxygen uptake on a flat terrain. Before and after (0, 24, and 48 hours) the run, blood concentration of creatine kinase (CK) were measured and pain sensation was determined (pain scale from 0 = no pain to 10 = extremely painful). Runners were then matched in pairs based on maximal CK and peak oxygen uptake, and allocated randomly into two different groups. One group was supplemented with 400 mg per day of PCSO-524® for 11 weeks, the other group with an olive oil placebo. After that period, CK and pain sensations were remeasured following a second 30 km run at the same speed and on the same terrain.

Results

The general pattern of soreness in the PCSO-524® supplemented group was reduced by 1.1 units (standard error 0.41) compared to the placebo (P < 0.05), the effects being greater in lesser trained runners (P < 0.05). CK levels were positively associated with pain sensation (P < 0.05), but trends toward lower CK in the PCSO-524® group, which were also more pronounced in the lesser trained runners, were not statistically significant.

Conclusion

Pain sensations experienced by distance runners following a 30 km run were reduced by supplementation with the marine oil complex PCSO-524®, an effect which was greater in lesser trained runners.

Estradiol-induced antinociceptive responses on formalin-induced nociception are independent of COX and HPA activation

Estrogen modulates pain perception but how it does so is not fully understood. The aim of this study was to determine if estradiol reduces nociceptive responses in part via hypothalamic-pituitary-adrenal (HPA) axis regulation of cyclooxygenase (COX)-1/COX-2 activity. The first study examined the effects of estradiol (20%) or vehicle with concurrent injection nonsteroidal antiinflammatory drugs (NSAIDs) on formalin-induced nociceptive responding (flinching) in ovariectomized (OVX) rats. The drugs were ibuprofen (COX-1 and COX-2 inhibitor), SC560 (COX-1 inhibitor), or NS398 (COX-2 inhibitor). In a second study, estradiol's effects on formalin-induced nociception were tested in adrenalectomized (ADX), OVX, and ADX+OVX rats. Serum levels of prostaglandins (PG) PGE(2) and corticosterone were measured. Estradiol significantly decreased nociceptive responses in OVX rats with effects during both the first and the second phase of the formalin test. The nonsteroidal antiinflammatory drugs (NSAIDs) did not alter nociception at the doses used here. Adrenalectomy neither altered flinching responses in female rats nor reversed estradiol-induced antinociceptive responses. Estradiol alone had no effect on corticosterone (CORT) or prostaglandin levels after the formalin test, dissociating the effects of estradiol on behavior and these serum markers. Ibuprofen and NS398 significantly reduced PGE2 levels. CORT was not decreased by OVX surgery or by estradiol below that of ADX. Only IBU significantly increased corticosterone levels. Taken together, our results suggest that estradiol-induced antinociception in female rats is independent of COX activity and HPA axis activation.

Interactions of estradiol and NSAIDS on carrageenan-induced hyperalgesia

How exogenous estrogen affects inflammatory responses is poorly understood despite the large numbers of women receiving estrogen-alone hormone therapy. The aim of this study was to determine if estradiol alters injury- or inflammation-induced nociceptive responses after carrageenan administration in females and whether its effects are mediated through cyclo-oxygenase (COX) and prostaglandins (PG). To this end, paw withdrawal latencies and serum levels of PGE2 and PGD2 were measured in rats treated with estradiol (0, 10, 20, and 30%) and/or SC560 (COX-1 inhibitor) or NS398 (COX-2 inhibitor) after intraplantar carrageenan administration. Estradiol significantly increased withdrawal latencies before (baseline condition) and after carrageenan administration to one hindpaw. NS398 was anti-nociceptive only in carrageenan treated animals. SC560 increased withdrawal latencies in both paws at 1 and 5hours after carrageenan administration. Co-administration of estradiol and NS398, but not SC560, was additive except for a prolonged anti-nociceptive effects of estradiol combined with NS398. The anti-nociceptive effect extended beyond that observed with either drug or estradiol alone at the 5-hour time point. Estradiol had no significant effect on PGE2 serum levels, but both COX antagonists decreased them. Although neither estradiol nor the COX inhibitors alone had an effect on PGD2 serum levels, co-administration of NS398 and estradiol significantly elevated PGD2 levels. Taken together, our results suggest that estradiol is anti-nociceptive in the thermal test and reduces carrageenan-induced hyperalgesia. These effects are minimally altered through PG-mediated mechanisms.

Secretory phospholipase A₂-mediated progression of hepatotoxicity initiated by acetaminophen is exacerbated in the absence of hepatic COX-2

We have previously reported that among the other death proteins, hepatic secretory phospholipase A₂ (sPLA₂) is a leading mediator of progression of liver injury initiated by CCl₄ in rats. The aim of our present study was to test the hypothesis that increased hepatic sPLA₂ released after acetaminophen (APAP) challenge mediates progression of liver injury in wild type (WT) and COX-2 knockout (KO) mice. COX-2 WT and KO mice were administered a normally non lethal dose (400 mg/kg) of acetaminophen. The COX-2 KO mice suffered 60% mortality compared to 100% survival of the WT mice, suggesting higher susceptibility of COX-2 KO mice to sPLA₂-mediated progression of acetaminophen hepatotoxicity. Liver injury was significantly higher at later time points in the KO mice compared to the WT mice indicating that the abatement of progression of injury requires the presence of COX-2. This difference in hepatotoxicity was not due to increased bioactivation of acetaminophen as indicated by unchanged cyp2E1 protein and covalently bound ¹⁴C-APAP in the livers of KO mice. Hepatic sPLA₂ activity and plasma TNF-α were significantly higher after APAP administration in the KO mice. This was accompanied by a corresponding fall in hepatic PGE₂ and lower compensatory liver regeneration and repair (³H-thymidine incorporation) in the KO mice. These results suggest that hindered compensatory tissue repair and poor resolution of inflammation for want of beneficial prostaglandins render the liver very vulnerable to sPLA₂-mediated progression of liver injury. These findings are consistent with the destructive role of sPLA₂ in the progression and expansion of tissue injury as a result of continued hydrolytic breakdown of plasma membrane phospholipids of perinecrotic hepatocytes unless mitigated by sufficient co-induction of COX-2.

Anti-inflammatory glucocorticoid drugs: reflections after 60 years

This review considers the problem of the serious concomitant side effects of powerful anti-inflammatory drugs modelled upon the principal human glucocorticoid hormone, cortisol. The very nature of the original bio-assays to validate their cortisol-like hormonal and anti-inflammatory activities ensured that pleiotropic toxins were selected for clinical studies. Other complicating factors have been (1) considerable reliance on bio-assays conducted in laboratory animals that primarily secrete corticosterone, not cortisol, as their principal anti-inflammatory adrenal hormone; (2) some differences in the binding of xenobiotic cortisol analogues (vis á vis cortisol) to transport proteins, detoxifying enzymes and even some intra-cellular receptors; (3) the "rogue" properties of these hormonal xenobiotics, acting independently of--but still able to suppress--hormonal mechanisms regulating endogenous cortisol; and (4) problems of intrinsic/acquired "steroid resistance", diminishing their clinical efficacy, but not necessarily all their toxicities. The rather gloomy conclusion is that devising new drugs to reproduce the effect of multi-potent hormones may be a recipe for disaster, in contexts other than simply remedying an endocrine deficiency. Promising new developments include "designed" combination therapies that allow some reduction in total steroid doses (and hopefully their side effects); sharpening strategies to limit the actual duration of steroid administration; and resurgent interest in searching for more selective analogues (both steroidal and non-steroid) with less harmful side effects. Some oversights and neglected areas of research are also considered. Overall, it now seems timely to engage in some drastic rethinking about (retaining?) these "licensed toxins" as fundamental therapies for chronic inflammation.

Beyond conventional DMARDs: extending TNF-regulant therapies to the vast majority/less privileged who do need them

This article is a plea to find (better) ways to extend the benefits of anti-cytokine therapies to ensure they will become available as widely as possible. Pessimistically, this will probably involve substituting more affordable, although somewhat less specific, non-biological agents for present target-specific bio-DMARDs (disease-modifying antirheumatic drugs) to ensure far wider distribution of benefits. Optimistically, new developments in technology and bio-engineering might dramatically reduce costs of present 'biological' therapies. (The antibiotics we now take for granted were once also horrendously expensive.). Pragmatically, one goal for this mission should include seriously pursuing more research and pilot clinical trials of non-protein combination therapies able to control: (i) TNF or other pro-inflammatory cytokines; and also (ii) other mediators sustaining chronic inflammation (-->pain, effusion, fibrosis, porosis, etc.). This can be immediately facilitated by drawing upon the immense resources of non-prescription Asia-Pacific traditional therapies--particularly when these have already been shown to either reduce TNF synthesis or control TNF-induced responses in preclinical studies. Could this be a major goal for the next decade, helping rectify some of the omissions of the current Bone & Joint Decade 2000-2010?