Safety assessment of desaminotyrosine: Acute, subchronic oral toxicity, and its effects on intestinal microbiota in rats

In this work, the acute and subchronic toxicities of desaminotyrosine (DAT) by oral administration in SD rats and its effects on the intestinal microflora were investigated. The acute toxicity test showed that DAT is a low-toxic substance with a LD50 of 3129 mg/kg. The subchronic toxicity test showed that DAT has no toxicity at a low dose (125 mg/kg/day). However, DAT exhibited obvious toxicities to food intake, liver, kidney, and lung at higher dose (250 mg/kg/day and 500 mg/kg/day). DAT inhibited the food intake of rats in a dose-dependent manner. Serum biochemical analysis showed that DAT can increase the serum glucose level of rats. Fecal microbiota analysis showed that DAT treatment can significantly change the intestinal microflora of rats, the dose of 125 mg/kg/day has the most significant effect on the diversity of intestinal microbiota. In daily application, the side effects caused by DAT might be gastrointestinal irritation, weight loss, liver or kidney injury, and blood sugar elevation. Based on our study, the no-observed-adverse-effect level (NOAEL) of DAT is 125 mg/kg BW/day for rats.

In silico designing, in vitro and in vivo evaluation of potential PPAR-γ agonists derived from aryl propionic acid scaffold

Attributed to several side effects, especially on hepatic tissues and body weight, there is always an urge of innovation and upgrading in already existing medication being used in maintaining diabetic condition. Therefore, in the present work, forty-eight molecules derived from arylpropionic acid scaffold were synthesized and their evaluation against diabetes was carried out. The synthesis of these molecules attributed to excellent dock score displayed by all the structures performed against PPAR-γ receptor site. Subsequently, all the derivatives were primarily deduced for their antidiabetic potential by OGTT. The compounds that showed significant antidiabetic activity in OGT Test and also exhibited high dock scores were assessed further by in vitro PPAR transactivation assay to assure analogy between in vivo and in vitro studies. The antidiabetic activity of these active compounds was then evaluated on STZ induced diabetic model in vivo. The most active compounds were scrutinized for its effect on PPAR-γ gene expression and hepatotoxic effect. Finally, it was recapitulated that these derivatives can provide a new prospect towards the development of antidiabetic agents with fewer side effects.

Gestational Age Dependency in the Prenatal Toxicity and in the Disposition Kinetics of the Novel Anticonvulsant HEPP (D,L-3-Hydroxy-3-ethyl-3-phenylpropionamide) after Subcutaneous Administration in Pregnant Rats

HEPP (D,L-3-hydroxy-3-ethyl-3-phenylpropionamide) is a novel anticonvulsant with promising anticonvulsant profile, which is being actively researched. The potential maternal and embryo/fetal toxicities of HEPP were evaluated in pregnant rats following subcutaneous (s.c.) administration during organogenesis (gestation days 6 through 14, GDs 6–14) and the fetal period (GDs 14–21). Single- and multiple-dose pharmacokinetics were also evaluated at the same periods in order to establish possible correlations with some maternal or embryo/fetal toxicity end points. Embryotoxicity was mainly indicated by a significant dose-concentration dependency in the increase in resorptions, high percentage of fully resorbed litters, and decrease in embryo body weights during the GD6–14 dosing period. No gross external alterations were observed in live fetuses. There was no indication of maternal toxicity; but a marked increase in maternal body weight was evident following dosing from GD14 to GD21. The maternal plasma profile following single subcutaneous dose of 50 mg/kg on both GD14 and GD21 showed a monoexponential elimination pattern. Statistically significant differences between treatments (GD14 versus GD21) were observed in elimination ( kel = 0.12 versus 0.15 h−1), absorption ( ka = 2.01 versus 3.14 h−1), maximum plasma concentration time points ( Tmax = 1.49 versus 1.01 h); maximum plasma concentration ( Cmax = 40.23 versus 36.31 μg/ml) and areas under the concentration-time curve (AUCs0– ∞ = 421.88 versus 274 μg h/ml. Based on comparisons of Cmax, Tmax, and AUCs0– ∞ between the actual data and single intraperitoneal (i.p.) data previously published, the s.c. administration exhibited slower disposition and higher absorbed amount. After multiple-dose administrations of 50 and 100 mg/kg every 12 h (07:00 and 19:00 h), steady-state plasma levels were lower than the computer prediction, and only slight accumulation was observed. In both dosing periods HEPP levels were similar in mothers and offspring at steady-state conditions. The high incidence of embryo death and reduced embryo weight at GD6–14 dosing compared to GD14–21 dosing suggest that embryos are more sensitive to the deleterious effects of HEPP than fetuses; however, the faster elimination observed at late gestation could also contribute to the lower toxicity observed during the fetal period. Because the maternal HEPP plasma levels and the AUC values were positively correlated with embryo/fetal toxicity end points, both pharmacokinetic parameters could be reliable indicators of offspring exposure and consequently of potential toxicity. These data suggest that the length of time that HEPP is present in the maternal plasma at a sufficiently high concentration could be determinant of adverse effects in the offspring.

Investigation of anti-inflammatory, antinociceptive and antipyretic activities of Stahlianthus involucratus rhizome ethanol extract

ETHNOPHARMACOLOGICAL RELEVANCE

Stahlianthus involucratus (Zingiberaceae) has long been used in traditional medicine to treat inflammation, pain, and fever. However, no pharmacological study of this plant has been reported to confirm these activities. The aim of this study was to investigate the anti-inflammatory, antinociceptive and antipyretic activities of Stahlianthus involucratus rhizome ethanol extract (SiE) in animal models.

MATERIALS AND METHODS

Anti-inflammatory activity of SiE was investigated in rats using ethyl phenylpropiolate (EPP)-induced ear edema, carrageenan- and arachidonic acid (AA)-induced hind paw edema, and cotton pellet-induced granuloma formation models. Acetic acid-induced writhing response in mice and tail-flick test in rats as well as yeast-induced hyperthermia in rats were used to investigate the antinociceptive and antipyretic activities, respectively.

RESULTS

SiE significantly inhibited EPP-induced ear edema, carrageenan- and AA-induced hind paw edema. Its inhibitory effect in carrageenan-induced hind paw edema seemed to be in a dose-dependent manner. In cotton pellet-induced granuloma formation, SiE showed suppressive effects on granuloma formation but not on body weight gain and dry thymus weight. It could normalize serum alkaline phosphatase activity to nearly normal level. SiE also possessed a significant inhibitory effect, which seemed to be dose-dependent, on acetic acid-induced writhing response, whereas only at the highest dose of SiE could significantly increase test reaction time at all time-points in tail-flick test. However, no antipyretic activity was observed.

CONCLUSIONS

These results suggest that SiE possesses anti-inflammatory and antinociceptive, but not antipyretic, activities. This study therefore rationalizes the traditional use of SiE for the treatment of inflammation and pain.

Multiple compound-related adverse properties contribute to liver injury caused by endothelin receptor antagonists

Drug-induced liver injury has been observed in patients treated with the endothelin receptor antagonists sitaxentan and bosentan, but not following treatment with ambrisentan. The aim of our studies was to assess the possible role of multiple contributory mechanisms in this clinically relevant toxicity. Inhibition of the bile salt export pump (BSEP) and multidrug resistance-associated protein 2 was quantified using membrane vesicle assays. Inhibition of mitochondrial respiration in human liver-derived HuH-7 cells was determined using a Seahorse XF(e96) analyzer. Cytochrome P450 (P450)-independent and P450-mediated cell toxicity was assessed using transfected SV40-T-antigen-immortalized human liver epithelial (THLE) cell lines. Exposure-adjusted assay ratios were calculated by dividing the maximum human drug plasma concentrations by the IC50 or EC50 values obtained in vitro. Covalent binding (CVB) of radiolabeled drugs to human hepatocytes was quantified, and CVB body burdens were calculated by adjusting CVB values for fractional drug turnover in vitro and daily therapeutic dose. Sitaxentan exhibited positive exposure-adjusted signals in all five in vitro assays and a high CVB body burden. Bosentan exhibited a positive exposure-adjusted signal in one assay (BSEP inhibition) and a moderate CVB body burden. Ambrisentan exhibited no positive exposure-adjusted assay signals and a low CVB body burden. These data indicate that multiple mechanisms contribute to the rare, but potentially severe liver injury caused by sitaxentan in humans; provide a plausible rationale for the markedly lower propensity of bosentan to cause liver injury; and highlight the relative safety of ambrisentan.

Prophylactic effect of egualen sodium, a stable azulene derivative, on gastrointestinal damage induced by ischemia/reperfusion, double antiplatelet therapy and loxoprofen in rats

We examined the effect of egualen, a stable azulene derivative, against gastric damage induced by ischemia/reperfusion (I/R), gastric bleeding induced by double antiplatelet therapy with aspirin (ASA) plus clopidogrel, and small intestinal damage generated by loxoprofen, and investigated the possible mechanisms involved in its protective action. Male C57BL/6 mice or SD rats were used under urethane anesthesia (gastric lesions) or in a conscious (intestinal lesions) state. I/R-induced gastric injury was produced in mice by clamping the celiac artery for 30 min, followed by reperfusion for 60 min. Gastric bleeding was induced in rats by luminal perfusion with 25 mM ASA+50 mM HCl for 2 hours in the presence of clopidogrel (30 mg/kg). To produce small intestinal lesions the rats were given loxoprofen (60 mg/kg) p.o. and killed 24 hours later. Egualen was given i.d. 60 min before I/R or ASA perfusion, while given p.o. twice 30 min before and 6 hours after loxoprofen. Egualen significantly prevented the I/R-induced gastric damage, and the effect was equivalent to that of seratrodast (TXA2 antagonist). This agent also significantly suppressed gastric bleeding induced by ASA plus clopidogrel, similar to PGE2. Likewise, egualen significantly prevented loxoprofen-induced damage in the small intestine, accompanied by an increase in the secretion of mucus and suppression of bacterial invasion as well as iNOS expression. These results suggest that egualen has a prophylactic effect against various lesions in the gastrointestinal mucosa, probably through its characteristic pharmacological properties, such as TXA2 antagonistic action, local mucosal protection, and stimulation of mucus secretion.

Antitumour and cytogenetic effects of modified steroidal derivatives of propenoic acid: in vivo/in vitro studies

BACKGROUND

Modified steroidal derivatives (PK11-PK14) of p-bis(2-chloroethyl)aminophenyl propenate (PK15) were used to study their antitumour activity on Lewis lung carcinoma (LLC) and their effect on sister chromatid exchanges (SCEs) and human lymphocyte proliferation kinetics.

MATERIALS AND METHODS

LLC was tested in this study. C57BL mice were used for in vivo chemotherapy evaluation and the antitumour activity was assessed. Lymphocyte cultures were used to study the genotoxic effect in vitro.

RESULTS

PK15 and PK11 were the most effective against LLC, causing significant inhibition of tumour growth. PK11 and PK15 induced significant increase in SCE rates. A correlation was observed between the cytogenetic effect and the antitumour effectiveness.

CONCLUSION

The order of the antitumour effectiveness of PK11-PK15 resembled the order of the cytogenetic damage induced by the same compounds in vitro.

Effects of LTB4 receptor antagonism on pulmonary inflammation in rodents and non-human primates

Asthma, chronic obstructive pulmonary disease (COPD) and acute lung injury/acute respiratory distress syndrome (ALI/ARDS) are characterized by neutrophilic inflammation and elevated levels of leukotriene B4 (LTB4). However, the exact role of LTB4 pathways in mediating pulmonary neutrophilia and the potential therapeutic application of LTB4 receptor antagonists in these diseases remains controversial. Here we show that a novel dual BLT1 and BLT2 receptor antagonist, RO5101576, potently inhibited LTB4-evoked calcium mobilization in HL-60 cells and chemotaxis of human neutrophils. RO5101576 significantly attenuated LTB4-evoked pulmonary eosinophilia in guinea pigs. In non-human primates, RO5101576 inhibited allergen and ozone-evoked pulmonary neutrophilia, with comparable efficacy to budesonide (allergic responses). RO5101576 had no effects on LPS-evoked neutrophilia in guinea pigs and cigarette smoke-evoked neutrophilia in mice and rats. In toxicology studies RO5101576 was well-tolerated. Theses studies show differential effects of LTB4 receptor antagonism on neutrophil responses in vivo and suggest RO5101576 may represent a potential new treatment for pulmonary neutrophilia in asthma.

A dynamic target-based pharmacophoric model mapping the CD4 binding site on HIV-1 gp120 to identify new inhibitors of gp120-CD4 protein-protein interactions

A dynamic target-based pharmacophoric model mapping the CD4 binding site on HIV-1 gp120 was built and used to identify new hits able to inhibit gp120-CD4 protein-protein interactions. Two compounds showed micromolar inhibition of HIV-1 replication in cells attributable to an interference with the entry step of infection, by direct interaction with gp120. Inactivity of compounds toward a M475I strain suggested specific contacts with the Phe43 cavity of gp120.

Study on the mechanism of photosensitive dermatitis caused by ketoprofen in the guinea pig

To investigate the mechanism on photosensitive dermatitis caused by ketoprofen (KP) in humans, the following experiments were performed by topical application on guinea pigs. The phototoxicity study involving treatment with 10% solution of KP, its enantiomers (R-KP and S-KP), loxoprofen, and flurbiprofen revealed no phototoxic reactions. In the photoallergenicity study, KP and its enantiomers (0.5-2% solution) induced skin reaction at all dosages; however, loxoprofen and flurbiprofen (1-5% solution) did not induce such a photoallergenic reaction. These results suggest that the chemical structure of the benzophenone chromophore in KP would be one of the important factors for induction of the photoallergy since both loxoprofen and flurbiprofen do not possess this structure and hence lack photoallergenic potential. Furthermore, to assess time profiles of KP concentration in the skin and plasma, guinea pigs received a repeated topical application of R-KP and S-KP at a dosage of 40 mg/kg over a period of 3 days. Plasma KP concentrations were extremely low as compared to skin KP concentrations and were not detected at 72 h after the final dosing. At 24 h after the final dosing, KP concentrations in the skin with R-KP and S-KP treatment were 187.4 and 254.7 microg/g, respectively, and their half-lives were 80.5 and 84.4 h, respectively. KP concentrations at 336 h after final dosing were 11.3 microg/g for R-KP and 15.7 microg/g for S-KP treatment. The acylglycerol-combined KP concentrations at 336 h were 2% or less as compared to KP concentrations with R-KP and S-KP treatment. There were no differences in KP concentrations in the skin between R-KP and S-KP and in combined KP concentrations between the enantiomers. The present study indicates that photosensitive dermatitis after topical application of KP in humans, caused by photoallergenicity and not phototoxicity, can be reproduced in the animal testing, and suggests that the skin reaction may be caused by the long period of retention of KP in the skin.

Anti-inflammatory Activity of 4,4'-Dihydroxy-.ALPHA.-truxillic Acid

The oral anti-inflammatory activity of 4,4'-dihydroxy-alpha-truxillic acid (1) was compared with that of two other nonsteroidal anti-inflammatory drugs, loxoprofen sodium (LOX) and diclofenac sodium (DIC). The activity of 1 against the inflammatory pain response induced by formalin was comparable to that of LOX, but weaker than that of DIC. In the monosodium urate (MSU)-induced acute inflammatory model, 1 showed stronger anti-inflammatory activity than both LOX and DIC. The ED50 value for 1 was 4.5 micromol/kg, while the values for LOX and DIC were 65 and 25 micromol/kg, respectively. Otherwise, the oral single-dose toxicity of 1 was investigated in both sexes of Sprague-Dawley rats administered once at a dose of 2000 mg/kg. 1 showed no death, clinical signs, changes in body weight or pathological findings related to the treatment. In addition, no mutagenicity was observed in the reverse mutation assay. Furthermore, 1 did not show any ulcerogenic activity at doses ranging from 30 to 300 mg/kg in rat. Thus, 1 might be considered to be an effective anti-inflammatory agent with no deleterious adverse effect.

Ultrasound-Assisted Conversion of Toxic β-Asarone into Nontoxic Bioactive Phenylpropanoid: Isoacoramone, A Metabolite ofPiper MarginatumandAcorus Tararinowii

Ultrasound-assisted synthesis of bioactive isoacoramone (1), a metabolite of Piper marginatum and Acorus tararinowii, has been achieved by oxidation of toxic beta-asarone (2) with potassium permanganate/copper sulphate/alumina into asaronaldehyde (3) followed by treatment with ethylmagnesium iodide to provide 1-(2,4,5-trimethoxy)phenyl-1-propanol (4) which upon further oxidation with potassium permanganate/copper sulphate afforded 1 in 64% yield (overall 32%). Toxicological evaluation of 1 reveals it to be nontoxic up to 60 mg/kg b.w.

The combination therapy of Ephedra herb and Loxoprofen caused gastric lesions in mice

The combination therapy of a Kampo formula and an analgesic-antipyretic agent is often used for the common cold in Japan. We investigated the effect of such a combination therapy, using the Ephedra herb, which is a common ingredient of Kakkon-to and Mao-to, and Loxoprofen, a nonsteroidal anti-inflammatory drug (NSAID), on fever induced in an experimental model of mice under strong stress. The combination therapy of Ephedra herb and Loxoprofen caused gastric mucosal lesions and loss of body weight. It is considered that this combination therapy should be avoided because of its adverse effects.

Alkylating reactivity and herbicidal activity of chloroacetamides

The relationship between S- and N-alkylating reactivity and herbicidal activity within a series of chloroacetamides, including several commercial herbicides and newly synthesised analogues was studied. The S-alkylating reactivity of selected chloroacetamides, as well as those of atrazine and chlorfenprop-methyl, was determined by in vitro GSH conjugation at a ratio of GSH to alkylating agent of 25:1. A spectrophotometric reaction using 4-(4-nitrobenzyl)pyridine was used to characterise the N-alkylating reactivity of the chemicals. Our results indicate that a reduced level of N-alkylating reactivity correlates with an improved herbicidal efficacy at a practical rate. However, the phytoxicity of the molecules is not simply dependent on chemical reactivities, but strictly related to the molecular structure, indicating that lipophilicity, uptake, mobility and induction of detoxifying enzymes may also be decisive factors in the mode of action.

Apoptosis and suppression of tumor growth by artepillin C extracted from Brazilian propolis

Artepillin C was extracted from Brazilian propolis. Artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) has a molecular weight of 300.40 and possesses antibacterial activity. When artepillin C was applied to human and murine malignant tumor cells in vitro and in vivo, artepillin C exhibited a cytotoxic effect and the growth of tumor cells was clearly inhibited. The artepillin C was found to cause significant damage to solid tumor and leukemic cells by the MTT assay, DNA synthesis assay, and morphological observation in vitro. When xenografts of human tumor cells were transplanted into nude mice, the cytotoxic effects of artepillin C were most noticeable in carcinoma and malignant melanoma. Apoptosis, abortive mitosis, and massive necrosis combined were identified by histological observation after intratumor injection of 500 microg of artepillin C three times a week. In addition to suppression of tumor growth, there was an increase in the ratio of CD4/CD8 T cells, and in the total number of helper T cells. These findings indicate that artepillin C activates the immune system, and possesses direct antitumor activity.

Anti-inflammatory, analgesic and anti-pyretic effects of d-2-[4-(3-methyl-2-thienyl)phenyl]propionic acid (M-5011), a new non-steroidal anti-inflammatory drug, in rats and guinea pigs

Anti-inflammatory, analgesic and anti-pyretic effects of d-2-[4-(3-methyl-2-thienyl)phenyl]propionic acid (M-5011), a new non-steroidal anti-inflammatory drug (NSAID), were compared with those of indomethacin, diclofenac sodium and ketoprofen in rats and guinea pigs. Anti-inflammatory effect of M-5011 on ultraviolet-induced erythema in guinea pigs was 11.7 and 1.8 times more potent than that of indomethacin and ketoprofen, respectively. Inhibitory effect of M-5011 on carrageenin-induced paw edema was 2 and 1.5 times more potent than that of indomethacin and diclofenac sodium, respectively. Analgesic effect of M-5011 on dry yeast-induced hyperalgesia or adjuvant-induced arthritic pain was equipotent to that of indomethacin, diclofenac sodium or ketoprofen. Anti-pyretic effect of M-5011 on yeast-induced pyrexia in rats was 4.2 and 4.6 times more potent than that of indomethacin and ketoprofen, respectively. Inhibitory effect of M-5011 on prostaglandin E2 production in the exudate of air-pouch inflammation induced by carrageenin was 1.75 times more potent than that in the non-inflamed site (stomach). As a result, gastric ulcerogenic activity of M-5011 was half that of indomethacin in rat. These results suggest that M-5011 shows more potent anti-inflammatory and anti-pyretic effects and equipotent analgesic effect with low gastro-ulcerogenic activity compared with classical NSAIDs.

Preferential cytotoxicity to tumor cells of 3,5-diprenyl-4-hydroxycinnamic acid (artepillin C) isolated from propolis

A tumoricidal substance was isolated from Brazilian propolis as guided by cytotoxicity assay on HuH 13 (human hepatocellular carcinoma) cell and was characterized to be 3-[4-hydroxy-3,5-bis (3-methyl-2-butenyl) phenyl]-2-propenoic acid (3,5-diprenyl-4-hydroxycinnamic acid (artepillin C)). It exhibited preferential cytotoxicity to tumor cells cultured in vitro. The cytotoxicity observed seemed to be partly attributable to apoptosis-like DNA fragmentation. The compound showed anti-tumor activity more effective than that of 5-fluorouracil to transplantable human tumor cell lines when tested on histoculture drug response assay system.

NS-398, a novel non-steroidal anti-inflammatory drug with potent analgesic and antipyretic effects, which causes minimal stomach lesions

1. NS-398 (N-[2-cyclohexyloxy-4-nitrophenyl] methanesulfonamide) is a new non-steroidal anti-inflammatory drug (NSAID) with analgesic and antipyretic effects. 2. The anti-inflammatory potency of NS-398 in rat carrageenin-induced edema was as potent as that of indomethacin and 8 times more potent than diclofenac. In rat adjuvant arthritis, NS-398 showed a therapeutic effect comparable to that seen with loxoprofen but less than that seen with indomethacin and diclofenac. 3. The analgesic potency of NS-398 in rat adjuvant arthritic pain was much the same as that of indomethacin, and was about 3-5 times higher than that of diclofenac and loxoprofen. In the Randall-Selitto method in rats, NS-398 was 2-7 times as potent as loxoprofen, diclofenac and indomethacin. In acetic acid-induced writhing in mice, NS-398 was equipotent to indomethacin and diclofenac. 4. In LPS-induced fever in rats, NS-398 was 1.5-4.5 times as potent as loxoprofen and indomethacin, but less potent than diclofenac. 5. NS-398 produced little gastric ulceration in doses of up to 1000 mg/kg, while reference drugs produced distinct stomach lesions in doses of 10-30 mg/kg. 6. NS-398 inhibited prostaglandin (PG) endoperoxide synthase from sheep seminal vesicle microsomes less potent than that of ibuprofen.

Carcinogenicity study of gamma-oryzanol in F344 rats

The carcinogenic potential of gamma-oryzanol, a drug mainly used for the treatment of hyperlipidaemia, was studied in F344 rats. Groups of 50 males and 50 females were fed a diet containing 0 (control), 200, 600 or 2000 mg gamma-oryzanol/kg body weight/day for 2 yr. Although females in the highest dose group (2000 mg/kg body weight) showed a slight decrease in body weight at 104 wk, there were no treatment-related changes in general condition, food consumption, mortality, organ weight or haematology. Histopathological examination showed various tumours in all groups, including the control group. In the control and 2000-mg/kg groups, high tumour incidences were observed in the testes, pituitary and thyroid of males, and in the pituitary, uterus and mammary gland of females; however, there was no significant increase in the incidence of any tumours between the control and the 2000-mg/kg groups. The findings indicate that under the experimental conditions described gamma-oryzanol was not carcinogenic in F344 rats.

Carcinogenicity study of gamma-oryzanol in B6C3F1 mice

The carcinogenic potential of gamma-oryzanol, a drug mainly used for the treatment of hyperlipidaemia, was studied in B6C3F1 mice. Groups of 50 males and 50 females were fed a diet containing 0 (control), 200, 600 or 2000 mg gamma-oryzanol/kg body weight/day for 78 wk. No treatment-related changes were observed in general condition, body weight, food consumption, mortality, organ weight or haematology. Histopathological examinations showed various tumours in all groups, including the control group. In the control and 2000-mg/kg groups, relatively high tumour incidences were observed in the liver of males and in the haematopoietic organs of females. However, there was no statistically significant difference in the incidence of any tumours between the control and the 2000-mg/kg groups. The findings indicate that under the experimental conditions described gamma-oryzanol was not carcinogenic in B6C3F1 mice.

DNA-damaging, mutagenic, clastogenic and cell-cell communication inhibitory properties of gamma-oryzanol

As a part of short-term safety assessment of gamma-Oryzanol, the genotoxic or the carcinogenic initiation activity was studied in three genetic toxicity tests and the promotion activity was studied in a cell-cell communication inhibitory test. gamma-Oryzanol showed the negative response in the bacterial DNA repair test (Rec-assay), the bacterial reverse mutation tests (Ames test) and the rat bone marrow chromosome aberration test. Also, gamma-Oryzanol showed the negative response in the metabolic cooperation inhibition test using Chinese hamster V79 cells.

[Complex experimental evaluation of the meat of broilers after the use of the antioxidant fenozan 1K in their feed]

The results of biochemical tests on fenozan general toxicity and its aftereffects and the experimental data on chemical content and ++amino+acid range of chicken meat and and fenozan residue in it demonstrated harmlessness of the meat of chicken fed up by a new antioxidant, fenozan 1K. Thus, the problem of using the analyzed chicken meat in population's dietary practice has been solved.

Suprofen-induced uricosuria. A potential mechanism for acute nephropathy and flank pain

Suprofen, a nonsteroidal anti-inflammatory drug, has been associated with the onset of acute flank pain, hematuria, and transient renal dysfunction after the ingestion of one or two doses, particularly in young males. Potential mechanisms of this nephropathy were evaluated in normal males following ingestion of suprofen (200 mg) on two occasions: the first with ad libitum fluid intake and the second during forced water diuresis. On the first study occasion, creatinine clearance, the fractional excretions of uric acid (FEUA) and sodium (FENa), the urinary concentration of undissociated uric acid, and the urinary excretions of prostaglandins and glomerular and tubular proteins were assessed. On the second occasion, inulin and PAH clearances and FEUA and FENa were determined. Within 90 min after suprofen administration, the FEUA increased from 8.8 +/- 2.6 to 35.5 +/- 9.6% (p less than 0.05). Urine became supersaturated for uric acid during ad libitum fluid intake. Glomerular filtration rate, renal plasma flow, and FENa decreased significantly, while prostaglandin and protein excretions did not change. The findings are consistent with acute uric acid nephropathy as a mechanism of suprofen-induced renal dysfunction.

Inhibition of mitochondrial beta-oxidation of fatty acids by pirprofen. Role in microvesicular steatosis due to this nonsteroidal anti-inflammatory drug

Administration of pirprofen may produce microvesicular steatosis of the liver in humans. The effects of pirprofen on the mitochondrial beta-oxidation of fatty acids have been investigated in mice. In vitro, addition of 2 mM pirprofen decreased by 50% the formation of [14C]acid-soluble beta-oxidation products, and decreased by 70% the formation of [14C]CO2 upon incubation of hepatic mitochondria with [14C]palmitic acid, ATP, carnitine and coenzyme A. In vivo, administration of pirprofen (2 mmol . kg-1 i.p.), 1 hr before that of [U-14C]palmitic acid, decreased by 70% the exhalation of [14C]CO2 during the next 6 hr. Administration of pirprofen (2 mmol . kg-1 i.p.), 1 hr before the measurement, decreased plasma beta-hydroxybutyrate by 60%, plasma acetoacetate by 30% and blood glucose by 40%. Administration of pirprofen (2 mmol . kg-1 i.p.) 6 hr before sacrifice, doubled hepatic triglycerides content and produced microvesicular steatosis of the liver. We conclude that pirprofen inhibits the mitochondrial beta-oxidation of fatty acids in mice, thus explaining the microvesicular steatosis observed in mice and in some human subjects.

Comparative studies on the gastrointestinal lesions caused by several nonsteroidal anti-inflammatory agents in rats

The gastrointestinal toxicity of a single oral administration of five nonsteroidal anti-inflammatory agents (NSAIDs) to rats was compared, by a method using 51Cr-labeled red blood cells (RBC), and by macroscopic and microscopic examination. From the profile of gastrointestinal bleeding, the NSAIDs could be divided into a group consisting of aspirin (ASA), oxaprozin (OXP) and 2-[4-(3-methyl-2-butenyl)phenyl]propionic acid (TA), which caused only a transient increase in fecal blood loss based on a gastric lesion, and another group including indomethacin (IM) and ibuprofen (IP), which produced a biphasic increase in the blood loss. The initial phase was caused not only by a gastric lesion but also an intestinal lesion, and the secondary phase originated only in the intestinal lesion. The order of potency causing blood loss was IM much greater than IP greater than ASA much greater than TA greater than OXP. The safety ratio of OXP and TA was shown to be more favorable than that of the other three drugs.

Synthesis of 3-phenyl-3-phenylthiopropionic acids, amides, amines and studies on their pharmacological properties

The addition of mercaptobenzene to cinnamic acids yielded 3-phenyl-3-phenylthiopropionic acids which were then converted to the amides. The latter compounds were reduced to the amines with lithium aluminum hydride. Some of the obtained amides displayed significant biological activity.

Subchronic feeding study in beagle dogs of 2,2'-oxamidobis[ethyl 3(3,5-di-tert-butyl-4-hydroxyphenyl) propionate]

The effect of subchronic feeding of 2,2'-oxamidobis[ethyl 3(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], Naugard XL-1 (CAS number 70331-94-1), was studied in beagle dogs. The dose levels of Naugard XL-1 used were 2000, 6300, and 20,000 ppm in the diet. Body weight gain and food consumption, organ weight, hematological, clinical chemical, and urine analysis data, and ophthalmic, gross, and histopathological examinations were used to study possible toxic or pathologic effects. No treatment-related effects were seen in any variable of either male or female animals exposed to Naugard XL-1 at any dose level.

[Acute toxicity of intrarectally administered (ketoprofen (T10) in rat weanlings]

Acute toxicity of Ketoprofen, a nonsteroidal antiinflammatory analgestic, was studied using rat weanlings. Ketoprofen was intrarectally administered in the form of a mixture with T10, a basic materials for suppositaries. The results obtained were as follows: LD50 of KP was estimated to be 434 mg/kg in male weanlings and 496 mg/kg in female weanlings. These values were about four times higher than those obtained from our previous study (Shimpo et al., 1981) using six-weeks old adult rats of both sexes. The fact indicated that rat weanlings were far tolerant to KP intrarectally administered than young adult rats. Intrarectal administration of KP at high doses, caused death between the second and the seventh day after administration. Gross and histopathological examinations revealed that dead weanlings carried perforative peritonitis with ulcers mainly in jejunum and ileum not in rectum. It was therefore suggested that the ulcer was produced in small intestine by entero-hepatic circulation of KP and finally mortal peritonitis occurred.

[Pharmacological study of pirprofen]

Pirprofen is a new non-steroidal anti-inflammatory drug. Its formula is 2 - (3 - chloro - 4 (3 - pyrrolin - 1 - yl)-phenyl) propionic acid. As demonstrated by the nitrogen nucleus and the the 2 pKA values, the molecule is similar to that of an amino acid. The classical pharmacological studies have proven its powerful anti-inflammatory action. Certain new techniques have enabled the identification of the mechanism of action of pirprofen in the inflammatory process. In addition, pirprofen seems able to slow down the evolution of certain experimental models of osteoarthritis. The mechanism of this effect is unknown.

[Acute toxicity of ketoprofen intrarectally administered in rats, with special reference to histopathological changes (author's transl)]

Acute toxicity was studied on Ketoprofen, one of the non-steroidal antiinflammatory analgesics, using SPF rats. Ketoprofen was intrarectally administered in three forms such as pure powder (KP), KP suspension in CMC solution (KP-CMC) and a mixture of KP with powdered basic materials of capsule (KP-T10). The results obtained were as follows:1. LD50 values of terms of KP were 84 mg/kg in male rats and 122 mg/kg in female rats when KP-CMC was administered intrarectally, and 117 mg/kg in male and 92 mg/kg in female when KP-T10 was administered intrarectally., while peroral administration of KP-CMC showed LD50 values of 68 mg/kg in males and 78 mg/kg in females in terms of KP. 2. Major toxic signs of KP were ulceration on small intestines and peritonitis. Degeneration of hepathocytes and decrease in thymus lymphocytes were also observed. 3. Minimum lethal dose of KP-T10 was slightly higher than that of KP-CMC.

[Toxicological study on the anorectal irritation and systemic organ toxicity evoked by long-term intrarectal administration of ketoprofen in rabbits (author's transl)]

Ketoprofen (KP) was administered intrarectally and perorally to rabbits weighing approximately 3 kg of both sexes for a period of 13 weeks, in order to study the anorectal irritation and chronic systemic organ toxicity of KP which was capsulated with the soft T10 capsule for rectal administration and with a hard capsule for peroral administration. Doses of capsulated drugs for one animal were 9.0 mg and 4.5 mg in terms of KP. All animals treated by these dose levels survived without showing any abnormal symptoms. Intrarectal administration of KP-T10 did not produce any mucosal lesions in digestive tracts, while peroral administration of KP with hard capsule induced ulcers in cecum or anus, and congestion in small intestines in a small number of cases. No pathological change was recognized in organs except for digestive tracts in all cases by autopsy. From the above results, it can be seen that the suppository of KP capsulated by the soft T10 does not show any irritating effect on anorectal mucosa and has no toxic effect on all organs systemically. Then, a suppository of KP-T10 can be used more harmlessly than the peroral capsulated KP.

Anti-inflammatory activity of an imidazopyridine derivative (miroprofen)

Anti-inflammatory activity of 2-[p-(2-imidazo[1,2-a]pyridyl) phenyl]propionic acid (Y-9213, miroprofen) was studied on various experimental models. Miroprofen was found to be as active as indomethacin against the exudative inflammation such as pleuritis in rats induced by Evans blue-carrageenin and the peritonitis in mice induced by acetic acid, and against the local Shwartzman reaction in rabbits. Miroprofen also inhibited the formation of edema induced by carrageenin or kaolin in rats' paws at lower doses. Against the proliferation of connective tissues, miroprofen showed the inhibitory action at higher doses. The ulcerogenic activity of miroprofen in rats was less potent than that of indomethacin, and as active as that of phenylbutazone. These findings indicate that miroprofen may be more effective in suppressing pain responses and acute inflammation accompanied with increased vascular permeability.

Comparison of gastrointestinal effects of aspirin and fenoprofen. A double blind crossover study

Sixteen men received 3904 mg of aspirin, 2400 mg of fenoprofen, or placebo daily for 1 week in a double blind and crossover trial. Fecal blood loss was measured by 51Cr labeled red cells; gastric and duodenal pathology were observed endoscopically. There was more (P less than 0.05) blood loss (4.96 ml) after aspirin than after fenoprofen (2.46 ml) or placebo (0.79 ml). By endoscopic examination, aspirin induced more (P less than 0.05) gastrointestinal pathology than fenoprofen or placebo, and there was a correlation of 0.70 between the two methods used in this study.

Pharmacological studies on 2- and 4-pyridylethylamides of acetyltropic acid (PAT-2 and PAT-4)

Two new compounds: 2- and 4-pyridylmethylamides of acetyltropic acid (PAT 2 and PAT-4) show spasmolytic effects on isolated guinea pig ileum, have mydriatic actevity in rabbits and block restraint produced ulceration in rats. PAT-4 causes a strong inhibition of the salivary secretion in mice. Both of the test compounds inhibit also the effects of ACh and vagus stimulation on the blood pressure and have local anaesthetic activity. PAT-4 inhibits the aggressive behaviour in mice and rats, prolongs the hexobarbital sleeping time, increases the pain treshold and inhibits the oxotremorine induced tremor in mice. Both PAT-2 and PAT-4 had no effect on the convulsant action of pentetrazole. EEG findings show that central cholinolytic activity is present in both compound tested.