ABSTRACT
Objective: Crinum jagus is used in traditional African medicine in the treatment of epilepsy, pain and inflammations. Methods: Anticonvulsant activity was investigated using picrotoxin (PCT) and strychnine (STR) tests in experimental paradigm. Results: Crinum jagus leaf methanol extract (200, 400, and 800?mg?kg?1) potentiated hexobarbitone-induced sleeping time and significantly (p<0.05) shortened the duration of convulsions in PCT-induced seizures. Delay in the onset of convulsions in PCT-induced seizure were very significant (p<0.05). Reduction in the frequency of seizures was also significant (p<0.05) in the test. Diazepam (5?mg?kg?1) was used as reference anticonvulsant drugs in the experimental models. While, CJB failed to protect the animals against picrotocin-induced convulsion. Neither the extract of CJL nor CJB confer significant effect on STR-induced convulsion. Flumazenil (GABA receptor antagonist) and cyproheptadine (5-HT2 receptor antagonist) blocked the effect of CJL extract in the PCT tests significantly suggesting that Crinum jagus may be acting by enhancing the effects of the GABAergic and serotonergic systems. Conclusion: The data obtained suggest that methanol leaf extract of C. jagus possessed significant anticonvulsant effect, thereby confirming the traditional uses of C. jagus in the treatment of epilepsies; mechanisms of which may involve interaction with GABAergic and serotonergic pathway.
ABSTRACT
Aim: To investigate anti-inflammatory and antinociceptive potentials of aqueous stem bark extract of Khaya senegalensis A. Juss (Meliaceae) in rodents. Methodology: Anti-inflammatory activity of aqueous stem bark extract of K. senegalensis (AKS) was studied in different models. Effect of the extract in acute inflammation was tested in carrageenan-induced rat paw edema and its effect in chronic inflammation was evaluated using cotton pellet-induced granuloma test. Croton oilinduced ear edema in mice was used to investigate the effect of the extract on topical inflammation. Antinociceptive property of AKS was evaluated using three models of nociception: hot-plate test, acetic acid-induced writhing in mice and formalin-induced paw licking in rats. Membrane stabilizing effect of AKS was tested in heat and hypotonicity-induced hemolysis. The mechanism of antinociceptive effect of the extract was evaluated by pre-treating rats with metoclopramide, a dopamine (D2) antagonist (1.5 mg/kg body wt.) and naloxone, an opioid receptor antagonist (5 mg/kg body wt.). One hour after these treatments, the rats were given AKS (150 mg/kg p.o) and their reaction time in hot-plate was assessed. Free-radical scavenging activity of the extract was measured by decrease in the absorbance of 1, 1-Diphenyl-2-picrylhydrazyl (DPPH) methanol solution. Results: The extract produced significant (P<0.05) and dose-dependent inhibition of ear edema in mice. It also caused a significant (P<0.05) reduction in granuloma formation and paw edema in rats. At concentration range of 125 - 500 μg/ml, AKS significantly (P<0.05) protects the erythrocyte membrane against lysis induced by heat and hypotonic medium. It also significantly (P<0.05) reduced the licking/biting time of the formalininjected rat paw in the early (19 - 51 % reduction) and late (13 - 57 % reduction) phases. The extract demonstrated significant (P<0.05) antinociceptive activity in the hot-plate and writhing tests and exhibited good scavenging effect on DPPH free radical. Conclusion: The study demonstrated that Khaya senegalensis stem bark aqueous extract possesses anti-inflammatory activity and antinociceptive effect mediated via central and peripheral mechanisms. Further studies on the plant may produce lead molecules for the development of new anti-inflammatory drugs.
ABSTRACT
Aims: To investigate seasonal variation in anti-diabetic and hypolipidemic activities of Momordica charantia fruits harvested at different seasons of the year, namely spring, summer, autumn and winter. Methodology: Air-dried and pulverized fruit samples were extracted by soaking in 70% methanol for 72h. The filtrate was concentrated using rotary evaporator. The yields of spring (MME), summer (JME), autumn (SME) and winter (DME) samples were 8.4, 7.1, 4.8 and 5.1% respectively. For each of the four fruit samples, rats were divided into six groups of six rats each. First group served as normal control (non-diabetic). The remaining five groups were made diabetic by administering alloxan (120mg/kg body weight) intraperitoneally. Second group served as diabetic control. Third, fourth and fifth groups were treated with oral doses of 200, 400 and 600mg/kg body weight of Momordica charantia fruit extracts respectively. The sixth group received oral dose of glibenclamide (5mg/kg body weight) which served as the standard drug. These treatments were repeated daily for 28 days. Results: Treatment with methanol extracts of Momordica charantia caused a significant (p<0.01) and dose-dependent changes with respect to blood glucose level and lipid profile in all the four samples, when compared with the untreated animals. The highest activity was observed with spring sample, followed by the summer sample. Autumn and winter samples have more or less similar but lesser effects than summer sample. Conclusion: The results of this study showed that anti-diabetic and hypolipidemic effects of Momordica charantia fruit extract vary during different seasons of the year. The spring sample produced the highest activity. This suggests that the active principles in Momordica charantia fruit that are responsible for its antidiabetic and hypolipidemic activity vary in quantity and/or quality during different seasons of the year and reach the peak during spring.
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Aim: To investigate anti-hyperlipidemic activity of methanol leaf extract of Persea americana (MEPA) in cholesterol-induced hyperlipidemic rats. Methodology: The animals were randomly divided into five groups of 5 rats each. Group1 served as the normal control (NC) and received distilled water. Group 2, the cholesterol-induced hyperlipidemic control (CHOL) was given cholesterol diet (20% groundnut oil, 1% cholesterol and 0.5% cholic acid mixed with rat pellet) orally. Groups 3 and 4 received oral administration of cholesterol diet and MEPA at a dose of 20 and 40 mg/kg body weight respectively, while group 5 was treated orally with cholesterol diet and cholestyramine (0.26g/kg body weight). Cholesterol diet, MEPA and cholestyramine were administered daily for a period of eight weeks. Results: The changes observed in the plasma levels of total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL) and high density lipoprotein (HDL) of hyperlipidemic control rats were reversed by MEPA in a dose-dependent manner. At 20 mg/kg body weight, MEPA significantly (p<0.05) reduced TC, TG and LDL plasma levels by 54.2%, 46.2% and 65.6% respectively, and increased HDL plasma level by 60.0%. At a higher dose of 40 mg/kg, MEPA reduced TC, TG and LDL levels by 60.4%, 69.2% and 87.5% respectively while HDL was increased by 80.0%. There was a significant increase of change in body weight of hyperlipidemic rats compared to the change in normal control. MEPA caused a reduction of change in body weight to nearly that of the normal control. MEPA also dose-dependently caused significant reduction (p<0.05) of plasma lipid peroxidation in the rats. The anti-hyperlipidemic effect of MEPA was comparable to that of the standard drug, cholestyramine. Conclusion: The results of this study showed that Persea americana could be a source of good alternative remedy for hyperlipidemia. Further studies are needed to fully understand the mechanism of action of the plant.
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Aim: To investigate anti-hyperglycemic effect of aqueous extract of Khaya senegalensis stem bark (KSE) in alloxan-diabetic Wistar rats. Methodology: Thirty rats were randomly divided into six groups of 5 animals each. Group I (non-diabetic control) was given distilled water orally. Animals in the remaining five groups were treated with a single dose of alloxan (120mg/kg body weight, i.p) to induce diabetes mellitus. This resulted in significant increase in the fasting blood glucose level of the rats. Group I (non-diabetic control) and group II (hyperglycemic control) then received distilled water orally for 14 days. Group III, IV and V were treated orally with daily doses of 50, 100 and 150 mg/kg body weight of KSE respectively for 14 days. Group VI was given glibenclamide (5mg/kg, p.o) for the same period. Fasting blood glucose was determined by oxidative method in all the groups on day 0 (before treatment), day 7 and day 14. Oral glucose tolerance test and erythrocyte malondialdehyde (MDA) concentration were estimated after the two week treatment. Body weights of the animals were also measured on day 0, day 7 and day 14. Results: Treatment with KSE and glibenclamide caused significant (p<0.05) and dosedependent changes compared to the untreated animals with respect to body weight, blood glucose level and erythrocyte malondialdehyde (MDA) concentration. The antihyperglycemic effect of KSE was comparable to that of the standard drug, glibenclamide. Conclusion: The study showed that aqueous extract of Khaya senegalensis stem bark possesses anti-hyperglycemic activity.
ABSTRACT
Aims: To study anticonvulsant and central nervous system depressant activity of methanol leaf extract of Croton zambesicus (MECZ) in Swiss albino mice and investigate the role of serotonin in these activities. Methodology: Anticonvulsant activity of graded doses (200, 300 and 400 mg/kg p.o) of MECZ was assessed through seizures induced by picrotoxin and pentylenetetrazole (PTZ). Effects of the extract on pentobarbitone-induced sleep and amphetamine-induced stereotype behavior were also evaluated. Possible involvement of serotonergic pathways was studied using cyproheptadine (4mg/kg i.p), a non-selective serotonin antagonist (5-HT1/5HT2). Results: In both picrotoxin and PTZ-induced seizures, the extract significantly delayed onset of seizure (p<0.05) in a dose-dependent manner and provided significant protection against death. There was a dose-dependent increase of pentobarbitone sleeping time and a significant reduction (p<0.05) in the sleep latency. The extract also produced a significant reduction in amphetamine-induced stereotype behavior. Pretreatment with cyproheptadine abolished the anticonvulsant effect of the extract. The inhibitory effect of the extract on amphetamine-induced hyperactivity and its potentiation of pentobarbitone-induced sleep were also reversed by cyproheptadine. Conclusion: The results of this study showed that methanol extract of Croton zambesicus leaf possesses anticonvulsant activity and other CNS depressant activities and these activities are possibly mediated through interaction between serotonergic and GABAergic transmissions.