Giuseppina Benoni

Oxygen free radicals interact with indomethacin to cause gastrointestinal injury

In the present study it was shown that, unlikely MK447, a known oxygen free radical compound, PGE2 is much less effective against indomethacin-induced G.I. ulcers than against ethanol damage. It seems likely that factors other than PG deficiency (such as oxygen free radicals), could be involved in the pathogenesis of NSAID-induced G.I. damage. Some compounds that can capture free radicals (aminopyrine, thiourea and its derivative, MK 447) or that inhibit the lipoxygenase pathway (MK 447, salicylazosulfapyridine, BW 755, benoxaprofen) are able to abolish indomethacin-induced G.I. damage. After irradiation with hydroxyl free radicals, indomethacin reacts with them to cause marked G.I. injury, even at a submaximal dose, one poorly ulcerogenic by itself. The above findings suggest that oxygen free radicals are one of the causal factors in the formation of NSAID-induced G.I. side effects.Some of the data in this paper were presented at Fermo, August 31, 1984 (Advanced course on ‘oxygen and sulfur radicals in chemistry and medicine’) and at the 9th Iuphar International Congress of Pharmacology in London, July 30, 1984.

Safety implications regarding use of phytomedicines

ObjectiveSince the approach of the general population to phytomedicine is that the therapy therapy is natural and therefore safe, the aim of this study was to investigate the relationship between the use of herbal compounds, alone or in combination with traditional drugs, and the appearance of side-effects among a sample of Italian women.MethodsOur research was conducted over a 5–month period in the outpatient ambulatories of an urban university general hospital. The sample population consisted of women who were interviewed about phytotherapy use on the basis of a pre-structured questionnaire.ResultsAmong 1,063 women contacted, 1,044 completed the interview and 491 (47%) reported taking at least one herbal compound in the last year; 272 women (55.4%) consumed only phytomedicines, while 219 (44.6%) also took traditional drugs. Seventy-three different herbal products were used, 32 were consumed in association with traditional drugs. Forty-seven of 491 (9.6%) women reported side-effects, 22 after taking only phytomedicines (8.1%), 25 in combination with traditional drugs (11.4%). The observed adverse manifestations included the following: gastrointestinal after dandelion, propolis or fennel; cardiovascular after liquorice, ginseng, and green tea; dermatological after propolis, thyme, arnica, and passionflower; and neurological after guarana and liquorice. Drugs taken in association and potentially involved in adverse reactions were NSAIDs, antibiotics, benzodiazepines, antihypertensives and oral contraceptives. In some cases (n=5), side-effects were so serious to justify an admission to the hospital. In 29/47 of cases (61.7%), the adverse reaction was not communicated to the doctor.ConclusionsOur data confirm that herbal products are largely taken on a self-treatment basis, and users have the convinction that these therapies are natural and therefore safe.

Anti-inflammatory potency and gastrointestinal toxicity of a new compound, nitronaproxen

Naproxen and its derivative nitronaproxen at the doses of 5 and 10 mg kg-1 were compared for their acute anti-inflammatory efficacy in a carrageenan oedema model and gastrointestinal toxicity in rats. Moreover, the effects of the two drugs were evaluated in the adjuvant arthritis, after chronic doses of 4 and 8 mg kg-1 administered orally for 18 days. The oedema reduction was maintained much longer (until 5 h) with nitronaproxen; the inhibition of arthritis was 50% or more with both doses of the examined drugs. From the histological examination of the stomachs, an extensive mucosal vasocongestion and haemorrhagic lesions have been observed in some rats treated with naproxen. The percentages of animals with ulcers were 50, 100 and 10 with naproxen 6 and 18 mg kg-1 and nitronaproxen 54 mg kg-1 respectively. A better gastrointestinal tolerability has been observed in arthritic and oedemic rats treated with nitronaproxen compared to naproxen: this could be due to the presence of nitric oxide that acts in maintaining the tissue perfusion and integrity.

Use of herbal products among 392 Italian pregnant women: focus on pregnancy outcome.

The present study aimed to explore the use of herbal products among a sample of Italian pregnant women and the possible influence of herbal consumption on pregnancy outcome.

Inhibition by sodium nitroprusside of the expression of inducible nitric oxide synthase in rat neutrophils

A well‐known nitric oxide (NO)‐releasing compound, sodium nitroprusside (SNP), decreases in a dose‐dependent manner NO synthase (NOS) activity induced in rat neutrophils by treatment with lipopolysaccharide (LPS). This inhibitory action of SNP seems not to be due to its direct effect on the enzyme activity. The strong nitrosonium ion (NO+) character of SNP could be responsible for its inhibition of NOS induction in neutrophils.

Effect of a new non‐steroidal anti‐inflammatory drug, nitroflurbiprofen, on the expression of inducible nitric oxide synthase in rat neutrophils

The effects of a non‐steroidal anti‐inflammatory drug, flurbiprofen, and its nitro‐derivative, nitroflurbiprofen, on inducible nitric oxide synthase in rat neutrophils were examined. Nitroflurbiprofen was shown to inhibit nitric oxide synthase induction caused by lipopolysaccharide administration, while flurbiprofen had no effect on nitric oxide synthase induction. This inhibitory action may be ascribed to nitric oxide released from nitroflurbiprofen.

SPECIAL REPORT: Protective effect of NO on gastric lesions and inhibition of expression of gastric inducible NOS by flurbiprofen and its nitro‐derivative, nitroflurbiprofen

Nitroflurbiprofen (NFP) causes significantly less gastric lesions than flurbiprofen (FP), probably because of its capacity to release nitric oxide (NO) in the stomach. Lipopolysaccharide (LPS), which induces the expression of an inducible type of NO synthase (iNOS) in rat stomach, also reduces gastric mucosal damage elicited by FP. Furthermore, both FP and NFP decrease significantly the amount of mRNA encoding iNOS induced by LPS in the stomach. The inhibitory effect of NFP seems to be due at least in part to its ability to release NO.

Effect of single and repeated doses of a new nitroderivative of acetylsalicylic acid on platelet TXA2 production in rats

The effects of a new ASA-nitroderivative compound, NCX 4016 (ASA-NO2), on platelet TXA2 synthesis after single and repeated doses in the rat were investigated. Compared to ASA, cumulative doses of ASA-NO2 showed similar inhibitory effects on platelet TXA2 synthesis and significant increases in nitrite/nitrate plasma concentrations 1 h after the last drug administration: 24 h later nitrite/nitrate plasma levels returned to the control values, while serum TXA2 concentrations did not change. A time-course study after a single dose of ASA-NO2 showed a significant inhibition of platelet TXA2 production also 24 h after drug administration and a significant increase in nitrite/nitrate plasma levels until 10 h.

Effect of acute exercise on some haematological parameters and neutrophil functions in active and inactive subjects

In this work we studied the possible effects of acute exercise on some haematological parameters and on some functions of neutrophils in seven active and six inactive subjects. Physical exercise (10 min on a cycle ergometer at a heart rate of 150 beats · min−1) induced a significant increase in total leucocyte, lymphocyte and neutrophil concentrations in active subjects; serum iron and ferritin concentrations were lower in active compared to inactive subjects. Cellular adhesion, bactericidal activity and superoxide anion production did not change after exercise, while we also observed some differences between active and inactive subjects before exercise. In particular, the neutrophils from active subjects showed a significantly higher percentage of adhesion, higher bactericidal activity and lower superoxide anion production. In conclusion, the training induced changes in some neutrophil functions, while acute exercise influenced, overall, leucocyte concentrations.

Acute anti-inflammatory activity and gastrointestinal tolerability of diclofenac and nitrofenac

Diclofenac and its derivative nitrofenac were compared to test their anti-inflammatory efficacy and gastrointestinal toxicity in rats.A similar good anti-inflammatory activity of the two drugs was observed in carrageenan oedema and a marked gastrointestinal toxicity was induced by diclofenac, while nitrofenac failed to produce gastric damage even with very high doses (50 and 100 mg/kg).The lack of the gastric ulcers in rats treated with nitrofenac could be due to the absorption of the drug as an inactive inhibitor of PG synthesis and/or to the fact that probably nitric oxide is release in the intestine and plays an important protective role in maintaining the tissue integrity.