Obesity remains a global problem. In search of phytochemicals that have antiobesity potential, th... more Obesity remains a global problem. In search of phytochemicals that have antiobesity potential, this study evaluated α,β-amyrin, a triterpenoid mixture from Protium heptaphyllum, on high-fat diet-induced obesity in mice. Groups of mice (n = 8) were fed a normal diet or a high-fat diet, and were orally treated or not treated with either α,β-amyrin (10 or 20 mg/kg) or sibutramine (10 mg/kg) for 15 weeks. Variables measured at termination were body weight, visceral fat accumulation, adipocyte surface area, peroxisome proliferator-activated receptor gamma, and lipoprotein lipase expressions in adipose tissue, the levels of plasma glucose and insulin, the satiety hormones ghrelin and leptin, the digestive enzymes amylase and lipase, and the inflammatory mediators TNF-α, interleukin-6, and MCP-1. Results showed that α,β-amyrin treatment resulted in lower high-fat diet-induced increases in body weight, visceral fat content, adipocyte surface area, peroxisome proliferator-activated receptor ...
ABSTRACT In the search for novel natural compounds effective against visceral nociception, the tr... more ABSTRACT In the search for novel natural compounds effective against visceral nociception, the triterpenoid mixture alpha- and beta-amyrin, isolated from Protium heptaphyllum resin, was assessed in two established mouse models of visceral nociception. Mice were pretreated orally with alpha- and beta-amyrin (3, 10, 30, and 100 mg/kg) or vehicle, and the pain-related behavioral responses to intraperitoneal cyclophosphamide or to intracolonic mustard oil were analyzed. The triterpenoid mixture showed a dose-related significant antinociception against the cyclophosphamide-induced bladder pain, and at 100 mg/kg, the nociceptive behavioral expression was almost completely suppressed. Intracolonic mustard oil-induced nociceptive behaviors were maximally inhibited by 10 mg/kg alpha- and beta-amyrin mixture in a naloxone-reversible manner. While pretreatment with ruthenium red (3 mg/kg, s. c.), a non-specific transient receptor potential cation channel V1 (TRPV1) antagonist, also caused significant inhibition, the alpha (2)-adrenoceptor antagonist, yohimbine (2 mg/kg, s. c.), showed no significant effect. The triterpene mixture (10 mg/kg, p. o.) neither altered significantly the pentobarbital sleeping time, nor impaired the ambulation or motor coordination in open-field and rotarod tests, respectively, indicating the absence of sedative or motor abnormalities that could account for its antinociception. These results indicate that the antinociceptive potential of alpha- and beta-amyrin possibly involves the opioid and vanilloid (TRPV1) receptor mechanisms and further suggests that it could be useful to treat visceral pain of intestinal and pelvic origins.
trans-Dehydrocrotonin (t-DCTN), the diterpenoid from Croton cajucara Bentham, exhibits hypoglycem... more trans-Dehydrocrotonin (t-DCTN), the diterpenoid from Croton cajucara Bentham, exhibits hypoglycemic and hypolipidemic activities, but in high doses is associated with a discrete hepatotoxicity. In the search for measures to mitigate this, pretreatment with the antioxidants N-acetylcysteine and vitamin E has been examined. Mice that received a high dose t-DCTN (100 mg/kg) manifested hepatic damage, as evidenced by significant elevations in serum ALT and AST, and hepatic GSH, and histological alterations, which could be obliterated by pretreatment with vitamin E, but not with N-acetylcysteine, possibly by creating an effective antioxidant balance.
Journal of Agricultural and Food Chemistry, Sep 1, 2009
In the search for potential antiobese agents from natural sources, this study investigated the ef... more In the search for potential antiobese agents from natural sources, this study investigated the effects of betulinic acid (BA), a pentacyclic triterpene from Clusia nemorosa L. (Clusiaceae), in mice on a high-fat diet (HFD). Adult male Swiss mice (n = 8) treated or not with BA (50 mg/L, in drinking water) were fed a HFD during 15 weeks. Mice treated with BA and fed a HFD showed significantly (P < 0.05) decreased body weights, abdominal fat accumulation, blood glucose, plasma triglycerides, and total cholesterol relative to their respective controls fed no BA. Additionally, BA treatment, while significantly elevating the plasma hormone levels of insulin and leptin, decreased the level of ghrelin. However, it caused a greater decrease in plasma amylase activity than the lipase. These findings suggest that BA has an antiobese potential through modulation of fat and carbohydrate metabolism, and it may be a suitable lead compound in the treatment of obesity.
Aims of the study: Calophyllum brasiliense (Camb.) is a medicinal tree that grows particularly in... more Aims of the study: Calophyllum brasiliense (Camb.) is a medicinal tree that grows particularly in the hilly and forested regions of Brazil. Preparations from its stem bark are popular remedies for the treatment of chronic ulcers. Since earlier investigations on bark extracts evidenced gastroprotective and gastric acid inhibitory properties, this study evaluated the effects of hydroethanolic extract (HEECb) and the dichloromethanic fraction (DCMF), from Calophyllum brasiliense stem bark, against Helicobacter pylori, in vitro and in vivo. Materials and methods: The in vitro assays were performed using the disk diffusion and broth microdilution methods to determine the minimum inhibitory concentration (MIC) values. The test substances were evaluated in vivo taking into account the delay in the gastric ulcer healing in Wistar rats, infected with Helicobacter pylori. Results: DCMF appeared the most active and potent in vitro against Helicobacter pylori growth with an MIC of 31 g/mL. In the in vivo assays, rats ulcerated by acetic acid, and inoculated with Helicobacter pylori showed a marked delay in ulcer healing. Treatment with HEECb (50, 100 and 200 mg/kg) and DCMF (100 and 200 mg/kg) reduced the ulcerated area in a dose-dependent manner. While DCMF, at 200 mg/kg, increased the prostaglandin E 2 (PGE 2 ) level, both HEECb and DCMF decreased the number of urease-positive animals, as confirmed by the reduction of Helicobacter pylori presence in histopathological analysis.
The purified fraction (PF) of the rhizome of Wilbmndia sp. (Cucurbitaceae) that contained two nor... more The purified fraction (PF) of the rhizome of Wilbmndia sp. (Cucurbitaceae) that contained two nor-cucurbitacin glucosides (WG, and WCJ demonstrated potent antimflammatory, antitumour and antifertility effects in rats and mice at oral doses ranging from 50 to 200 mg/kg. In rat, it significantly inhibited carrageenan-induced hind paw oedema and granulomatous lesion, while in mice the increased vascular permeability induced by acetic acid was markedly reduced. The PF exhibited an antitumour effect in rats bearing Walker 256 carcinosarcoma and also demonstrated cytotoxic action against KB cells in uitro. In regularly cycling mice, PF treatment suppressed the incidence of the oestrus phase of the reproductive cycle suggesting a possible antiovulatory effect. The rats that received PF from days 1 to 7 of pregnancy showed either a total absence or a reduced number of implantations in utero. The PF failed to exhibit abortifacient, oestrogenic or antioestrogenic actions. The results indicate that the nor-cucurbitacin glucosides of W i l b~n d i a sp. possess a novel spectrum of pharmacological activity different from that of cucurbitacins described earlier from other plants of this family.
The Journal of pharmacy and pharmacology, Jan 12, 2016
(-)-Myrtenol is a natural fragrance monoterpenoid structurally related to α-pinene found in diver... more (-)-Myrtenol is a natural fragrance monoterpenoid structurally related to α-pinene found in diverse plant essential oils. This study was aimed to assess the anti-ulcerogenic potential of (-)-myrtenol against ethanol-induced gastric lesions and to elucidate the underlying mechanism(s). Gastroprotective activity of (-)-myrtenol was evaluated using the mouse model of ethanol-induced gastric damage. To elucidate the gastroprotective mechanism(s), the roles of GABA, prostaglandins, nitric oxide and KATP channels were assessed. Besides, the oxidative stress-related parameters and the mucus content in gastric tissues were analysed. (-)-Myrtenol at oral doses of 25, 50 and 100 mg/kg significantly decreased the severity of ethanol-induced gastric lesions affording gastroprotection that was accompanied by a decrease in the activity of myeloperoxidase and malondialdehyde, an increase in GPx, SOD, and catalase activity in gastric tissues, and with well-maintained normal levels of nitrite/nitrate, gastric mucus and NP-SHs. Pretreatment with GABA-A receptor antagonist flumazenil, the COX inhibitor indomethacin, and NO synthesis inhibitor L-NAME but not with KATP channel blocker glibenclamide significantly blocked the (-)-myrtenol gastroprotection. These results provide first-time evidence for the gastroprotective effect of (-)-myrtenol that could be related to GABAA -receptor activation and antioxidant activity.
RefDoc, THE reference in scientific document supply / Refdoc, la référence en fourniture de docum... more RefDoc, THE reference in scientific document supply / Refdoc, la référence en fourniture de documents scientifiques ...
The effect of quinine, a cinchona alkaloid, was studied on gastrointestinal transit in mice. Intr... more The effect of quinine, a cinchona alkaloid, was studied on gastrointestinal transit in mice. Intraperitoneal (i.p.) administration of quinine inhibited the intestinal propulsion of a charcoal suspension at a dose of 100 mg/kg, comparing favorably with 5 mg/kg morphine. In an attempt to probe into the mechanism underlying this inhibition, a possible modulation by minoxidil (1 mg/kg, p.o.) and glibenclamide (1 mg/kg, p.o.), the drugs that, respectively, open and close ATP-sensitive K+ channels was tested on gastrointestinal transit in animals treated or not with quinine or morphine. While minoxidil produced no significant change of normal transit, glibenclamide significantly increased it. However, both drugs blocked the quinine-induced reduction in gastrointestinal transit. In contrast, the inhibitory effect of morphine on gastrointestinal transit was not modified by either drug. The effects of quinine as well as of morphine on gastrointestinal transit were significantly antagonized by naloxone (2 mg/kg, s.c.), a mu-opioid receptor antagonist but not by yohimbine (1 mg/kg, i.p.), an alpha2-adrenoceptor antagonist. Furthermore, quinine at a lower dose (25 mg/kg) that showed no per se effect on gastrointestinal transit, significantly potentiated the response to 2.5 mg/kg morphine. Although the role of ATP-sensitive K+ channels in the action of quinine and morphine was not clarified by the present results, a possible involvement of endogenous opioid(s) in the quinine-induced inhibition of gastrointestinal transit can be suggested.
The hepatoprotective effect of ternatin, a tetramethoxyflavone from Egletes viscosa L. was invest... more The hepatoprotective effect of ternatin, a tetramethoxyflavone from Egletes viscosa L. was investigated in mice against acetaminophen-induced hepatic damage and lethality. Hepatotoxicity was assessed by quantifying serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactic dehydrogenase (LD) and malondialdehyde (MDA) concentration in liver homogenates as well as by histopathological examination of liver tissue. Acetaminophen (300 mg/kg) produced liver damage in mice as manifested by a 29-, 23-and 7-fold rise in serum levels of ALT, AST and LD, respectively, compared with controls. Ternatin (25 and 50 mg/kg) was able to prevent significantly (p`0.05) acetaminophen-induced acute increase in serum enzymes. In addition, the severity of histological alterations induced by acetaminophen as evidenced by centrilobular necrosis and cellular infiltration were greatly diminished in animals that received ternatin. The data suggest a hepatoprotective activity of ternatin in mice against toxicity induced by acetaminophen. #
The antinociceptive effect of leaf essential oil from Psidium guajava and its major constituents,... more The antinociceptive effect of leaf essential oil from Psidium guajava and its major constituents, -caryophyllene and ␣-pinene was assessed using chemical (formalin and acetic acid) and thermal (hot-plate) nociceptive tests in adult male albino mice. Oral administration of 100, 200 and 400 mg/kg of essential oil produced a significant antinociceptive effect in the formalin test and at 200 and 400 mg/kg in the acetic acid-induced writhing test. Of the major components only ␣-pinene, but not the -caryophyllene, demonstrated significant antinociception in the formalin test. Neither the essential oil nor the major components could exert any significant effect in the hotplate test. Pretreatment of mice with caffeine (20 mg/kg, i.p.), significantly inhibited the antinociceptive effect of essential oil in the formalin test. Naloxone (1 mg/kg, s.c.), the opioid antagonist, however, failed to antagonize it. These results suggest that the antinociceptive effect of P. guajava essential oil is probably mediated by endogenously released adenosine.
1,8-Cineole (cineole), a terpenoid oxide present in many plant essential oils displays an inhibit... more 1,8-Cineole (cineole), a terpenoid oxide present in many plant essential oils displays an inhibitory effect on some types of experimental inflammation in rats, i.e. paw oedema induced by carrageenan and cotton pellet-induced granuloma. Cineole also inhibits in mice, the acetic acid-induced increase in peritoneal capillary permeability and the chemical nociception induced by intraplantar formalin and intraperitoneal acetic acid. Activity was present in these tests, at an oral dose range of 100-400 mg/kg. In the formalin test, the antinociceptive effect of cineole was not reversed by pretreatment of mice with naloxone (1 mg/kg, s.c.), a m-opioid receptor antagonist, suggesting the involvement of a non-opioid mechanism. Cineole demonstrated a significant inhibitory effect on locomotion and also potentiated the pentobarbital sleeping time in mice, indicating a plausible depressant effect on the central nervous system. The present results, when taken together with the recent reports that describe the inhibitory effects of cineole on the formation of prostaglandins and cytokines by stimulated monocytes in vitro, may provide additional evidence for its potential beneficial use in therapy as an antiinflammatory and analgesic agent.
Polarographic methods have been developed for the determination of two cephalosporins namely cefo... more Polarographic methods have been developed for the determination of two cephalosporins namely cefotaxime (CTX) and ceftriaxone (CTR) in pharmaceutical formulations. Well defined peaks at potentials -1.432 V vs. SCE for CTX and -1.627 V vs. SCE for CTR were obtained in the presence of tungsten (VI). The method has been successfully applied for the determination of above mentioned cephalosporins in commercial dosage forms. The salient features of this investigation are presented in this communication.
... Essential Oil Preparation Plants were cultivated at the Medicinal Plants Garden and their exc... more ... Essential Oil Preparation Plants were cultivated at the Medicinal Plants Garden and their excicatae deposited at the Prisco Bezerra Herbarium of the Federal University of Ceará, Brazil, under the numbers 24,150 ... Glauce SBViana, Tiago G. do Vale, VSN Rao and FJA Matos ...
trans-Dehydrocrotonin (t-DCTN), a 19-nor-clerodane diterpene isolated from the bark of Croton caj... more trans-Dehydrocrotonin (t-DCTN), a 19-nor-clerodane diterpene isolated from the bark of Croton cajucara Benth. (Euphorbiaceae) demonstrated a significant hypoglycemic activity in alloxan-induced diabetic rats but not in normal rats, at oral doses of 25 and 50 mg/kg body weight. The drug also effectively lowered the blood sugar levels in glucose fed normal rats. The hypoglycemic effect of t-DCTN was almost comparable to that produced by glibenclamide (2 mg/kg), a clinically useful drug. The results indicate the antihyperglycemic potential of t-DCTN.
Obesity remains a global problem. In search of phytochemicals that have antiobesity potential, th... more Obesity remains a global problem. In search of phytochemicals that have antiobesity potential, this study evaluated α,β-amyrin, a triterpenoid mixture from Protium heptaphyllum, on high-fat diet-induced obesity in mice. Groups of mice (n = 8) were fed a normal diet or a high-fat diet, and were orally treated or not treated with either α,β-amyrin (10 or 20 mg/kg) or sibutramine (10 mg/kg) for 15 weeks. Variables measured at termination were body weight, visceral fat accumulation, adipocyte surface area, peroxisome proliferator-activated receptor gamma, and lipoprotein lipase expressions in adipose tissue, the levels of plasma glucose and insulin, the satiety hormones ghrelin and leptin, the digestive enzymes amylase and lipase, and the inflammatory mediators TNF-α, interleukin-6, and MCP-1. Results showed that α,β-amyrin treatment resulted in lower high-fat diet-induced increases in body weight, visceral fat content, adipocyte surface area, peroxisome proliferator-activated receptor ...
ABSTRACT In the search for novel natural compounds effective against visceral nociception, the tr... more ABSTRACT In the search for novel natural compounds effective against visceral nociception, the triterpenoid mixture alpha- and beta-amyrin, isolated from Protium heptaphyllum resin, was assessed in two established mouse models of visceral nociception. Mice were pretreated orally with alpha- and beta-amyrin (3, 10, 30, and 100 mg/kg) or vehicle, and the pain-related behavioral responses to intraperitoneal cyclophosphamide or to intracolonic mustard oil were analyzed. The triterpenoid mixture showed a dose-related significant antinociception against the cyclophosphamide-induced bladder pain, and at 100 mg/kg, the nociceptive behavioral expression was almost completely suppressed. Intracolonic mustard oil-induced nociceptive behaviors were maximally inhibited by 10 mg/kg alpha- and beta-amyrin mixture in a naloxone-reversible manner. While pretreatment with ruthenium red (3 mg/kg, s. c.), a non-specific transient receptor potential cation channel V1 (TRPV1) antagonist, also caused significant inhibition, the alpha (2)-adrenoceptor antagonist, yohimbine (2 mg/kg, s. c.), showed no significant effect. The triterpene mixture (10 mg/kg, p. o.) neither altered significantly the pentobarbital sleeping time, nor impaired the ambulation or motor coordination in open-field and rotarod tests, respectively, indicating the absence of sedative or motor abnormalities that could account for its antinociception. These results indicate that the antinociceptive potential of alpha- and beta-amyrin possibly involves the opioid and vanilloid (TRPV1) receptor mechanisms and further suggests that it could be useful to treat visceral pain of intestinal and pelvic origins.
trans-Dehydrocrotonin (t-DCTN), the diterpenoid from Croton cajucara Bentham, exhibits hypoglycem... more trans-Dehydrocrotonin (t-DCTN), the diterpenoid from Croton cajucara Bentham, exhibits hypoglycemic and hypolipidemic activities, but in high doses is associated with a discrete hepatotoxicity. In the search for measures to mitigate this, pretreatment with the antioxidants N-acetylcysteine and vitamin E has been examined. Mice that received a high dose t-DCTN (100 mg/kg) manifested hepatic damage, as evidenced by significant elevations in serum ALT and AST, and hepatic GSH, and histological alterations, which could be obliterated by pretreatment with vitamin E, but not with N-acetylcysteine, possibly by creating an effective antioxidant balance.
Journal of Agricultural and Food Chemistry, Sep 1, 2009
In the search for potential antiobese agents from natural sources, this study investigated the ef... more In the search for potential antiobese agents from natural sources, this study investigated the effects of betulinic acid (BA), a pentacyclic triterpene from Clusia nemorosa L. (Clusiaceae), in mice on a high-fat diet (HFD). Adult male Swiss mice (n = 8) treated or not with BA (50 mg/L, in drinking water) were fed a HFD during 15 weeks. Mice treated with BA and fed a HFD showed significantly (P < 0.05) decreased body weights, abdominal fat accumulation, blood glucose, plasma triglycerides, and total cholesterol relative to their respective controls fed no BA. Additionally, BA treatment, while significantly elevating the plasma hormone levels of insulin and leptin, decreased the level of ghrelin. However, it caused a greater decrease in plasma amylase activity than the lipase. These findings suggest that BA has an antiobese potential through modulation of fat and carbohydrate metabolism, and it may be a suitable lead compound in the treatment of obesity.
Aims of the study: Calophyllum brasiliense (Camb.) is a medicinal tree that grows particularly in... more Aims of the study: Calophyllum brasiliense (Camb.) is a medicinal tree that grows particularly in the hilly and forested regions of Brazil. Preparations from its stem bark are popular remedies for the treatment of chronic ulcers. Since earlier investigations on bark extracts evidenced gastroprotective and gastric acid inhibitory properties, this study evaluated the effects of hydroethanolic extract (HEECb) and the dichloromethanic fraction (DCMF), from Calophyllum brasiliense stem bark, against Helicobacter pylori, in vitro and in vivo. Materials and methods: The in vitro assays were performed using the disk diffusion and broth microdilution methods to determine the minimum inhibitory concentration (MIC) values. The test substances were evaluated in vivo taking into account the delay in the gastric ulcer healing in Wistar rats, infected with Helicobacter pylori. Results: DCMF appeared the most active and potent in vitro against Helicobacter pylori growth with an MIC of 31 g/mL. In the in vivo assays, rats ulcerated by acetic acid, and inoculated with Helicobacter pylori showed a marked delay in ulcer healing. Treatment with HEECb (50, 100 and 200 mg/kg) and DCMF (100 and 200 mg/kg) reduced the ulcerated area in a dose-dependent manner. While DCMF, at 200 mg/kg, increased the prostaglandin E 2 (PGE 2 ) level, both HEECb and DCMF decreased the number of urease-positive animals, as confirmed by the reduction of Helicobacter pylori presence in histopathological analysis.
The purified fraction (PF) of the rhizome of Wilbmndia sp. (Cucurbitaceae) that contained two nor... more The purified fraction (PF) of the rhizome of Wilbmndia sp. (Cucurbitaceae) that contained two nor-cucurbitacin glucosides (WG, and WCJ demonstrated potent antimflammatory, antitumour and antifertility effects in rats and mice at oral doses ranging from 50 to 200 mg/kg. In rat, it significantly inhibited carrageenan-induced hind paw oedema and granulomatous lesion, while in mice the increased vascular permeability induced by acetic acid was markedly reduced. The PF exhibited an antitumour effect in rats bearing Walker 256 carcinosarcoma and also demonstrated cytotoxic action against KB cells in uitro. In regularly cycling mice, PF treatment suppressed the incidence of the oestrus phase of the reproductive cycle suggesting a possible antiovulatory effect. The rats that received PF from days 1 to 7 of pregnancy showed either a total absence or a reduced number of implantations in utero. The PF failed to exhibit abortifacient, oestrogenic or antioestrogenic actions. The results indicate that the nor-cucurbitacin glucosides of W i l b~n d i a sp. possess a novel spectrum of pharmacological activity different from that of cucurbitacins described earlier from other plants of this family.
The Journal of pharmacy and pharmacology, Jan 12, 2016
(-)-Myrtenol is a natural fragrance monoterpenoid structurally related to α-pinene found in diver... more (-)-Myrtenol is a natural fragrance monoterpenoid structurally related to α-pinene found in diverse plant essential oils. This study was aimed to assess the anti-ulcerogenic potential of (-)-myrtenol against ethanol-induced gastric lesions and to elucidate the underlying mechanism(s). Gastroprotective activity of (-)-myrtenol was evaluated using the mouse model of ethanol-induced gastric damage. To elucidate the gastroprotective mechanism(s), the roles of GABA, prostaglandins, nitric oxide and KATP channels were assessed. Besides, the oxidative stress-related parameters and the mucus content in gastric tissues were analysed. (-)-Myrtenol at oral doses of 25, 50 and 100 mg/kg significantly decreased the severity of ethanol-induced gastric lesions affording gastroprotection that was accompanied by a decrease in the activity of myeloperoxidase and malondialdehyde, an increase in GPx, SOD, and catalase activity in gastric tissues, and with well-maintained normal levels of nitrite/nitrate, gastric mucus and NP-SHs. Pretreatment with GABA-A receptor antagonist flumazenil, the COX inhibitor indomethacin, and NO synthesis inhibitor L-NAME but not with KATP channel blocker glibenclamide significantly blocked the (-)-myrtenol gastroprotection. These results provide first-time evidence for the gastroprotective effect of (-)-myrtenol that could be related to GABAA -receptor activation and antioxidant activity.
RefDoc, THE reference in scientific document supply / Refdoc, la référence en fourniture de docum... more RefDoc, THE reference in scientific document supply / Refdoc, la référence en fourniture de documents scientifiques ...
The effect of quinine, a cinchona alkaloid, was studied on gastrointestinal transit in mice. Intr... more The effect of quinine, a cinchona alkaloid, was studied on gastrointestinal transit in mice. Intraperitoneal (i.p.) administration of quinine inhibited the intestinal propulsion of a charcoal suspension at a dose of 100 mg/kg, comparing favorably with 5 mg/kg morphine. In an attempt to probe into the mechanism underlying this inhibition, a possible modulation by minoxidil (1 mg/kg, p.o.) and glibenclamide (1 mg/kg, p.o.), the drugs that, respectively, open and close ATP-sensitive K+ channels was tested on gastrointestinal transit in animals treated or not with quinine or morphine. While minoxidil produced no significant change of normal transit, glibenclamide significantly increased it. However, both drugs blocked the quinine-induced reduction in gastrointestinal transit. In contrast, the inhibitory effect of morphine on gastrointestinal transit was not modified by either drug. The effects of quinine as well as of morphine on gastrointestinal transit were significantly antagonized by naloxone (2 mg/kg, s.c.), a mu-opioid receptor antagonist but not by yohimbine (1 mg/kg, i.p.), an alpha2-adrenoceptor antagonist. Furthermore, quinine at a lower dose (25 mg/kg) that showed no per se effect on gastrointestinal transit, significantly potentiated the response to 2.5 mg/kg morphine. Although the role of ATP-sensitive K+ channels in the action of quinine and morphine was not clarified by the present results, a possible involvement of endogenous opioid(s) in the quinine-induced inhibition of gastrointestinal transit can be suggested.
The hepatoprotective effect of ternatin, a tetramethoxyflavone from Egletes viscosa L. was invest... more The hepatoprotective effect of ternatin, a tetramethoxyflavone from Egletes viscosa L. was investigated in mice against acetaminophen-induced hepatic damage and lethality. Hepatotoxicity was assessed by quantifying serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactic dehydrogenase (LD) and malondialdehyde (MDA) concentration in liver homogenates as well as by histopathological examination of liver tissue. Acetaminophen (300 mg/kg) produced liver damage in mice as manifested by a 29-, 23-and 7-fold rise in serum levels of ALT, AST and LD, respectively, compared with controls. Ternatin (25 and 50 mg/kg) was able to prevent significantly (p`0.05) acetaminophen-induced acute increase in serum enzymes. In addition, the severity of histological alterations induced by acetaminophen as evidenced by centrilobular necrosis and cellular infiltration were greatly diminished in animals that received ternatin. The data suggest a hepatoprotective activity of ternatin in mice against toxicity induced by acetaminophen. #
The antinociceptive effect of leaf essential oil from Psidium guajava and its major constituents,... more The antinociceptive effect of leaf essential oil from Psidium guajava and its major constituents, -caryophyllene and ␣-pinene was assessed using chemical (formalin and acetic acid) and thermal (hot-plate) nociceptive tests in adult male albino mice. Oral administration of 100, 200 and 400 mg/kg of essential oil produced a significant antinociceptive effect in the formalin test and at 200 and 400 mg/kg in the acetic acid-induced writhing test. Of the major components only ␣-pinene, but not the -caryophyllene, demonstrated significant antinociception in the formalin test. Neither the essential oil nor the major components could exert any significant effect in the hotplate test. Pretreatment of mice with caffeine (20 mg/kg, i.p.), significantly inhibited the antinociceptive effect of essential oil in the formalin test. Naloxone (1 mg/kg, s.c.), the opioid antagonist, however, failed to antagonize it. These results suggest that the antinociceptive effect of P. guajava essential oil is probably mediated by endogenously released adenosine.
1,8-Cineole (cineole), a terpenoid oxide present in many plant essential oils displays an inhibit... more 1,8-Cineole (cineole), a terpenoid oxide present in many plant essential oils displays an inhibitory effect on some types of experimental inflammation in rats, i.e. paw oedema induced by carrageenan and cotton pellet-induced granuloma. Cineole also inhibits in mice, the acetic acid-induced increase in peritoneal capillary permeability and the chemical nociception induced by intraplantar formalin and intraperitoneal acetic acid. Activity was present in these tests, at an oral dose range of 100-400 mg/kg. In the formalin test, the antinociceptive effect of cineole was not reversed by pretreatment of mice with naloxone (1 mg/kg, s.c.), a m-opioid receptor antagonist, suggesting the involvement of a non-opioid mechanism. Cineole demonstrated a significant inhibitory effect on locomotion and also potentiated the pentobarbital sleeping time in mice, indicating a plausible depressant effect on the central nervous system. The present results, when taken together with the recent reports that describe the inhibitory effects of cineole on the formation of prostaglandins and cytokines by stimulated monocytes in vitro, may provide additional evidence for its potential beneficial use in therapy as an antiinflammatory and analgesic agent.
Polarographic methods have been developed for the determination of two cephalosporins namely cefo... more Polarographic methods have been developed for the determination of two cephalosporins namely cefotaxime (CTX) and ceftriaxone (CTR) in pharmaceutical formulations. Well defined peaks at potentials -1.432 V vs. SCE for CTX and -1.627 V vs. SCE for CTR were obtained in the presence of tungsten (VI). The method has been successfully applied for the determination of above mentioned cephalosporins in commercial dosage forms. The salient features of this investigation are presented in this communication.
... Essential Oil Preparation Plants were cultivated at the Medicinal Plants Garden and their exc... more ... Essential Oil Preparation Plants were cultivated at the Medicinal Plants Garden and their excicatae deposited at the Prisco Bezerra Herbarium of the Federal University of Ceará, Brazil, under the numbers 24,150 ... Glauce SBViana, Tiago G. do Vale, VSN Rao and FJA Matos ...
trans-Dehydrocrotonin (t-DCTN), a 19-nor-clerodane diterpene isolated from the bark of Croton caj... more trans-Dehydrocrotonin (t-DCTN), a 19-nor-clerodane diterpene isolated from the bark of Croton cajucara Benth. (Euphorbiaceae) demonstrated a significant hypoglycemic activity in alloxan-induced diabetic rats but not in normal rats, at oral doses of 25 and 50 mg/kg body weight. The drug also effectively lowered the blood sugar levels in glucose fed normal rats. The hypoglycemic effect of t-DCTN was almost comparable to that produced by glibenclamide (2 mg/kg), a clinically useful drug. The results indicate the antihyperglycemic potential of t-DCTN.
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