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Abstract The hydroalcoholic extract (HAE) of Ageratum conyzoides leaves was studied for its antiinflammatory effect on subacute (cotton pellet-induced granuloma) and chronic (formaldehyde-induced arthritis) models of inflammation in rats. The [...]

The hydroalcoholic extract (HAE) of Ageratum conyzoides leaves was studied for its antiinflammatory effect on subacute (cotton pellet-induced granuloma) and chronic (formaldehyde-induced arthritis) models of inflammation in rats. The absence or presence of toxicity by prolonged use of HAE was also evaluated through biochemical and hematological analysis of rats blood samples using daily oral doses of 250 or 500 mg/kg body wt., during 90 days. The results showed that the group of rats treated with HAE (250 mg/kg body wt.; p.o.) had a 38.7% (p < 0.05) reduction in cotton-pellet granuloma. The development of chronically induced paw edema was also reduced significantly (p < 0.05) by the plant extract. The toxicity study did not show any treatment-related abnormalities in biochemical and hematological parameters. The biochemical analysis from blood samples drawn from group of rats treated orally with 500 mg/kg body wt. did, however, present 30.2% (p < 0.05) reduction of SGPT activity as compared to the corresponding control group. These results confirm the antiinflammatory properties of A. conyzoides, with no apparent hepatotoxicity.

Purpose: Although the clinical efficacy of alpha1-adrenoceptor (alpha1-AR) antagonists for the treatment of benign prostatic hyperplasia is not disputed, their mechanism of action and ability to maintain long-term effectiveness have only recently been investigated. Since it is known that chronic administration of receptor antagonists causes up-regulation in the targeted receptor, we examined the effects of chronic administration of doxazosin, a nonspecific long acting alpha1-AR antagonist, on the properties of alpha1-AR subtypes in the rat prostate., Materials and Methods: Rats were treated with doxazosin (2 or 4 mg/kg daily subcutaneously, supplemented with 4 mg/kg daily orally) for 8 or 12 weeks. Prostatic alpha1-AR properties at the protein and gene transcript levels were quantified by radioligand receptor binding and real-time reverse transcriptase-polymerase chain reaction, respectively., Results: Treated rats that received the highest levels of doxazosin had significantly heavier prostates compared with age matched controls. After 12 weeks of treatment radioligand binding studies with radiolabeled alpha1-AR antagonist demonstrated no significant differences in the density of total alpha1-ARs in the prostate, whereas the results of real-time reverse transcriptase-polymerase chain reaction showed up-regulation in the mRNA expression levels of all 3 alpha1-AR subtypes (alpha1A, alpha1B and alpha1D) in the ventral and dorsolateral regions of the rat prostate., Conclusions: These data demonstrate that chronic treatment with doxazosin causes an alteration in the properties of the alpha1-AR system in the rat prostate. These findings may provide insight into the long-term effectiveness of alpha1-AR antagonists in the treatment of benign prostatic hyperplasia.

As age-related changes occur in the properties of the endothelin (ET) receptor system in several mammalian tissues, and as there are significant amounts of functional ET receptors in the vas deferens, we investigated the age-related changes in the ET receptor system at the protein and mRNA levels in the rat vas deferens. The ET system was investigated in the vasa deferentia of 3 weeks, 3 months and 22 months old rats. ET receptors were characterized and quantified at the protein level by radioligand receptor binding, and gene transcript levels of ET-1, ET-3, ET converting enzyme-1 (ECE-1), and ET(A) and ET(B) receptor subtypes were quantified by real-time reverse transcription polymerase chain reaction (RT-PCR). The results of radioligand receptor binding assays demonstrate that there is a higher density of total ET receptors in the vas deferens of 3 weeks old rats than in 3 months and 22 months old rats, and that the predominant ET receptor is of the ET(A) subtype in all three ages. Real-time RT-PCR data show that the predominant mRNA expression of ETs and their receptors in all age groups studied are ET-1 and the ET(A) receptor subtype, respectively. Furthermore, ET-1, ET-3, ECE-1, and ET(A) and ET(B) receptor subtype mRNAs are expressed at higher levels in the 3 weeks old rats as compared with the other two age groups. These results demonstrate the presence of age-related changes in the properties of the ET receptor system at both protein and mRNA levels in the rat vas deferens.

We previously have shown that experimental diabetes in rats causes prostatic involution, reduces serum testosterone levels, and causes an upregulation in prostatic endothelin (ET) receptors. Furthermore, insulin treatment normalizes these changes (Saito et al., Mol Cell Biochem 210:1-12, 2000). Since experimental diabetes-induced reduction in serum testosterone may be a factor in the alteration of the ET receptors and of prostatic growth, we investigated the effect of castration, another means of involuting the prostate and decreasing serum testosterone levels, on the expression of ET receptors in ventral and dorsolateral regions of the rat prostate.Three-month-old Sprague-Dawley rats were surgically castrated or sham operated, and then killed on the 7th post-operative day. Biochemical and pharmacological properties, and localization of ET receptors in the rat prostate, were determined by performing a series of binding experiments with [(125)I]ET-1 and by light microscopy autoradiography, respectively. The expression levels of ET-1, ET-3, ET receptor subtypes and endothelin converting enzyme-1 (ECE-1) mRNAs were assessed by relative multiplex reverse transcription polymerase chain reaction (RT-PCR). The total density of ET receptors increases 3.7-fold in the ventral and 2.1-fold in the dorsolateral regions of the castrated rat prostate compared to sham operated animals. Castration causes a 2.4-fold increase in the density of alpha(1)-adrenoceptors (alpha(1)-ARs) in the ventral region of the prostate, but no change in the density of alpha(1)-ARs in the dorsolateral region of the rat prostate. The predominant ET receptor subtype in the rat prostate is the ETA subtype, which is mainly located in the prostatic stroma. In addition, RT-PCR data show an upregulation in the expression of ETB receptor subtype, ET-1 and ECE-1 mRNA in both regions, and a downregulation in the expression of ETA receptor subtype mRNA in the dorsolateral region of the castrated rat prostate. There is no change in the expression of ET-3 mRNA in either region. Castration does not cause significant changes in the pharmacological properties of prostatic ET receptors, i.e., the predominance of ETA receptors in either region of the prostate, or the expression of ETA receptor subtype mRNA in the ventral region of the castrated rat prostate. These results suggest the existence of a region/lobe-specific regulatory role for testosterone in the expression of the ET receptor system in the rat prostate.

A new series of 1,2,4-oxadizoles 6a-g have been synthesised in good yields using the peptide synthesis strategy. The prepared compounds were tested for anti-inflammatory and antimicrobial activities. The anti-inflammatory activities were determined in the rat paw oedema induced by carrageenin. Compounds 6a, c, f and g (i.v.) significantly inhibited the rat paw oedema induced by carrageenin depending upon the dose employed. The compounds were also evaluated for their in vitro antimicrobial activity. Some compounds were found to have significant activity against Gram positive and Gram negative microorganisms.

Significant local analgesic and anti-inflammatory activity has been observed after oral administration of 3-[3-(phenyl)-1,2,4-oxadiazol-5-yl] propionic acid (POPA). Doses of 150 and 300 mg/kg body weight administered orally by gavage to adult (25-35 g) albino mice of both sexes can inhibit acetic acid-induced writhing by 31.0% and 49.5%, respectively (mean +/- SEM writhing numbers during 20 min were 52.0 +/- 6.0 and 38.3 +/- 7.2 vs 75.8 +/- 6.6 for control group which received saline; N = 6). Carrageenin-induced inflammation in the female Wistar rat (200-250 g) can be reduced by 43.3% and 42.2% 3 h after oral administration (gavage) of 75 and 150 mg/kg of POPA (mean +/- SEM, 30.0 +/- 1.3% and 30.6 +/- 2.4% vs 52.9 +/- 3.7% for control group which received saline; N = 5). In the hot plate test on adult albino mice (25-35 g) of both sexes, POPA (150 and 300 mg/kg, po) was totally ineffective (N = 10). Our results indicate that POPA appears to offer potential safety and efficacy as a local analgesic and anti-inflammatory agent with no central nervous system involvement