Evaluation of the antidiarrhoeal and antidiabetic activities of the leaf aqueous extract of Syzygium cordatum hoscht. ex C.Krauss (Mytraceae) in rodents

Syzygium cordatum Hoscht. ex C.Krauss is widely used by traditional medicine practitioners to treat many ailments including diarrhoea and diabetes. Despite the folklore use, little evidence can be found in literature to corroborate the claims of therapeutic success of the plant species. The objective of the study was to investigate the antidiarrhoeal and antidiabetic activities of the leaf aqueous extract of the plant species in mice and rats, respectively. The antidiarrhoeal activity of the leaf aqueous extract of S. cordatum was investigated using castor oil-induced diarrhoeal test. The antidiabetic activity of the plant extract was studied using streptozotoxin-induced diabetes in rats. Acute toxicity study of plant extract was also carried out using a standard method. Leaf aqueous extract of S. cordatum significantly reduced the number of diarrhoeal episodes, decreased the stool mass and delayed the onset of castor oil-induced diarrhoea in mice. Loperamide was shown to protect the animals against castor oil-induced diarrhoea. Both the leaf aqueous extract of S. cordatum and chlorpropamide significantly lowered the blood glucose levels in both normal and streptozotoxin-induced diabetic rats. The LD50 value obtained for the plant extract was over 4000 mg kg-1 orally. The results obtained suggest that the leaf aqueous extract of S. cordatum has both antidiarrhoeal and antidiabetic activities. This justifies the folklore use of the plant species by traditional medicine practitioners to treat diarrhoea and diabetes. The relatively high LD50 value obtained for the leaf aqueous extract shows that the plant species is non toxic to mice.Web of Scienc

Antinociceptive and Anti-Inflammatory Activities of Leaf Methanol Extract of Cotyledon orbiculata L. (Crassulaceae)

Leaf methanol extract of C. orbiculata L. was investigated for antinociceptive and anti-inflammatory activities using acetic acid writhing and hot-plate tests and carrageenan-induced oedema test in mice and rats, respectively. C. orbiculata (100–400 mg/kg, i.p.) significantly inhibited acetic acid-induced writhing and significantly delayed the reaction time of mice to the hot-plate-induced thermal stimulation. Paracetamol (300 mg/kg, i.p.) significantly inhibited the acetic acid-induced writhing in mice. Morphine (10 mg/kg, i.p.) significantly delayed the reaction time of mice to the thermal stimulation produced with hot plate. Leaf methanol extract of C. orbiculata (50–400 mg/kg, i.p.) significantly attenuated the carrageenan-induced rat paw oedema. Indomethacin (10 mg/kg, p.o.) also significantly attenuated the carrageenan-induced rat paw oedema. The LD50 value obtained for the plant species was greater than 4000 mg/kg (p.o.). The data obtained indicate that C. orbiculata has antinociceptive and anti-inflammatory activities, justifying the folklore use of the plant species by traditional medicine practitioners in the treatment of painful and inflammatory conditions. The relatively high LD50 obtained shows that C. orbiculata may be safe in or nontoxic to mice

Involvement of gamma aminobutyric acid in the anticonvulsant effect of the leaf methanol extract of Ruta graveolens L. (Rutaceae) in mice

The possible involvement of gamma aminobutyric acid (GABA), in the anticonvulsant effect of Ruta graveolens L. was investigated by studying the effect of the leaf methanol extract against seizures elicited by either pentylenetetrazole (PTZ), bicuculline, picrotoxin or N-Methyl-DL-Aspartic acid (NlvIDLA) in mice. Leaf methanol extract of Ruta graveolens, phenobarbitone, diazepam and muscimol significantly antagonized seizures induced by PTZ, bicuculline or picrotoxin. Combined treatment of subeffective doses of R. graveolens and muscimol significantly antagonized seizures induced by PTZ, bicuculline or picrotoxin. Dimethylsulfoxide (DMSO) or phenytoin did not significantly affect the seizures produced by PTZ, bicuculline or picrotoxin. Ruta graveolens, phenobarbitone, diazepam, phenytoin or DMSO did not significantly affect seizures produced by NlvIDLA. LY233053 significantly antagonized seizures produced by NlvIDLA. Combined treatment of sub-effective doses of LY233053 and Ruta graveolens did not significantly alter NlvIDLA-induced seizures. The phytochemical qualitative analysis of the plant species showed the presence of tannins, cardiac glycosides, saponins, flavonoids, triterpene steroids and alkaloids. The LD50 value obtained following oral administration of the leaf methanol extract of R. graveolens was above 4000 mg kg-1 .The HPLC fingerprint of the plant species revealed certain characteristic peaks at 350 run. The data obtained in this study, indicate that the leaf methanol extract of R. graveolens has anticonvulsant activity. The data obtained also indicate that GABA mechanism may probably be involved in the anticonvulsant effect of the plant extract. The relatively high LD50 obtained for the plant species, given orally, indicates that it is safe in mice.Web of Scienc

Antinociceptive and Anti-Inflammatory Activities of Leaf Methanol Extract of Cotyledon orbiculata L. (Crassulaceae)

Leaf methanol extract of C. orbiculata L. was investigated for antinociceptive and anti-inflammatory activities using acetic acid writhing and hot-plate tests and carrageenan-induced oedema test in mice and rats, respectively. C. orbiculata (100-400 mg/kg, i.p.) significantly inhibited acetic acid-induced writhing and significantly delayed the reaction time of mice to the hot-plate-induced thermal stimulation. Paracetamol (300 mg/kg, i.p.) significantly inhibited the acetic acid-induced writhing in mice. Morphine (10 mg/kg, i.p.) significantly delayed the reaction time of mice to the thermal stimulation produced with hot plate. Leaf methanol extract of C. orbiculata (50-400 mg/kg, i.p.) significantly attenuated the carrageenan-induced rat paw oedema. Indomethacin (10 mg/kg, p.o.) also significantly attenuated the carrageenan-induced rat paw oedema. The LD 50 value obtained for the plant species was greater than 4000 mg/kg (p.o.). The data obtained indicate that C. orbiculata has antinociceptive and anti-inflammatory activities, justifying the folklore use of the plant species by traditional medicine practitioners in the treatment of painful and inflammatory conditions. The relatively high LD 50 obtained shows that C. orbiculata may be safe in or nontoxic to mice

Evaluation of the effects of Olea europaea L. subsp. africana (Mill.) P.S. Green (Oleaceae) leaf methanol extract against castor oil-induced diarrhoea in mice

Olea europaea L. subsp. africana (Mill.) P.S. Green is widely used in South Africa by traditional medicine practitioners to treat diarrhoea. However, little is known scientifically about this South African species in the treatment of diarrhoea. The main aim of the study therefore was to investigate the antidiarrhoeal effect of the leaf methanol extract of the plant species in mice. The antidiarrhoeal activity of the leaf methanol extract of O. europaea subsp. africana was studied using a castor oil-induced diarrhoeal test. The antipropulsive activity of the plant extract was also investigated using the charcoal meal transit test. Standard methods were used to investigate the acute toxicity and effect of O. europaea subsp. africana on castor oil-induced intraluminal fluid accumulation

ANTINOCICEPTIVE, ANTI-INFLAMMATORY AND ANTIPYRETIC ACTIVITIES OF THE LEAF METHANOL EXTRACT OF RUTA GRAVEOLENS L. (RUTACEAE) IN MICE AND RATS

Background: Ruta graveolens has been used to treat toothache, earache, rheumatism and fever with little scientific evidence corroborating these uses. Materials and Methods: The leaf methanol extract of Ruta graveolens was evaluated for antinociceptive activity using the acetic acid writhing and hot-plate tests in mice, also anti-inflammatory and antipyretic activities using the carrageenan-induced oedema and E. coli-induced pyrexia tests in rats, respectively. Results: R. graveolens (100 mg/kg, i.p.), significantly reduced the number of acetic acid-induced writhes by 54 %. R. graveolens (400 mg/kg, i.p.), significantly delayed the reaction time in mice to thermal stimulation 15, 30, 45, and 60 min after treatment. Combined treatment of the lowest and sub-effective doses of the leaf methanol extract (25 mg/kg, i.p.), and indomethacin (10 mg/kg, i.p.) significantly reduced the number of acetic acid-induced writhes in mice. The leaf methanol extract of R. graveolens (50 - 400 mg/kg, i.p.), significantly reduced carrageenan- induced oedema over the 4 h period of testing. Combined treatment of the lowest doses of R. graveolens (25 mg/kg, i.p.) and indomethacin (2 mg/kg, i.p.) produced a significant reduction in carrageenan-induced oedema over the 4 h period of testing. R. graveolens (100 - 400 mg/kg, i.p.) significantly reduced E. coli-induced pyrexia over the 5 h period of testing. Given together, the lowest dose of R. graveolens (25 mg/kg, i.p.) and pentoxifylline (10 mg/kg, i.p.) produced a significant reduction in pyrexia induced by E. coli (50 μg/kg, i.m.) over the 5 h period of measurement. The LD50 value obtained for R. graveolens was greater than 4000mg/kg (p.o), suggesting that the plant species may be safe in or nontoxic to mice. Conclusion: The data obtained indicate that R. graveolens has antinociceptive, anti-inflammatory and antipyretic activities, justifying the use of the plant species by traditional medicine practitioners in the management and treatment of pain, inflammation and fever

Epileptogenic potential of mefloquine chemoprophylaxis: a pathogenic hypothesis

<p>Abstract</p> <p>Background</p> <p>Mefloquine has historically been considered safe and well-tolerated for long-term malaria chemoprophylaxis, but prescribing it requires careful attention in order to rule out contraindications to its use. Contraindications include a history of certain neurological conditions that might increase the risk of seizure and other adverse events. The precise pathophysiological mechanism by which mefloquine might predispose those with such a history to seizure remains unclear.</p> <p>Presentation of the hypothesis</p> <p>Studies have demonstrated that mefloquine at doses consistent with chemoprophylaxis accumulates at high levels in brain tissue, which results in altered neuronal calcium homeostasis, altered gap-junction functioning, and contributes to neuronal cell death. This paper reviews the scientific evidence associating mefloquine with alterations in neuronal function, and it suggests the novel hypothesis that among those with the prevalent EPM1 mutation, inherited and mefloquine-induced impairments in neuronal physiologic safeguards might increase risk of GABAergic seizure during mefloquine chemoprophylaxis.</p> <p>Testing and implications of the hypothesis</p> <p>Consistent with case reports of tonic-clonic seizures occurring during mefloquine chemoprophylaxis among those with family histories of epilepsy, it is proposed here that a new contraindication to mefloquine use be recognized for people with EPM1 mutation and for those with a personal history of myoclonus or ataxia, or a family history of degenerative neurologic disorder consistent with EPM1. Recommendations and directions for future research are presented.</p

EFFECT OF OLEA EUROPAEA AFRICANA L. (OLEACEAE) LEAF AQUEOUS EXTRACT ON CASTOR OIL-INDUCED DIARRHOEA IN MICE

The leaf aqueous extract of O. europaea ssp. africana L. was tested for antidiarrhoeal activity against castor oil–induced diarrhoea in mice. Acute toxicity studies and phytochemical analysis of O. europaea africana were also carried out. O. europaea ssp. africana significantly reduced the number of diarrhoeal episodes induced by castor oil. O. europaea ssp. africana also significantly decreased the stool mass produced as a result of castor oil-induced diarrhoea and significantly prolonged the onset of the diarrhoea. The number of animals exhibiting diarrhoea over a five hour period was significantly decreased by O. europaea ssp. africana. Similarly, loperamide completely abolished the diarrhoeal episodes and stool mass, and protected the animals against castor oil-induced diarrhoea. The results obtained suggest that the aqueous extract of O. europaea ssp. africana has antidiarrhoeal properties. The relatively high LD50 of 3475 mg/kg (p.o.) obtained with the aqueous extract indicates that the plant species may be safe and/or nontoxic in mice. The phytochemical analysis done on the plant species showed the presence of saponins, tannins, flavonoids, triterpene steroids and reducing sugars