Ninety-day oral toxicological profiling of Kolaviron (an extract of Garcinia kola) in male and female rats

There remains an insufficiency of data on the long-term toxicological profile of Garcinia kola Heckel and its extract, Kolaviron (KV), despite several studies on its pharmacological effects. This research was designed to investigate the long-term histopathological, hematological, biochemical, hormonal, reproductive, and oxidative effects of 90 days administration of KV to male and female rats, as well as additional 30 days reversibility study to assess the potential for reversal of induced effects. Fifty-six male and female Wistar rats divided into four groups were treated orally with distilled water/propylene glycol, 20 mg/kg KV, 100 mg/kg KV, and 500 mg/kg KV for 90 days. At the end of 90 days and 30 additional days of reversibility study, 5 ml blood was collected from animals for relevant analyses. Vital organs were harvested for histopathological assessments. In this study, KV did not elicit any adverse effect on histopathological presentations of vital organs which were generally non-abnormal. There was significant increase (p < 0.05) in LEU, MON, EOS%, BAS%, HCT (male animals) and LYM%, EOS%, BAS%, RBC, hemoglobin and MCH (female animals). There was significant diminution (p < 0.05) in cholesterol, triglycerides, LDL, and VLDL levels, with significant increase (p < 0.05) in HDL level in both male and female animals. KV elicited a non-significant increase in sperm count accompanied by a significant increase (p < 0.05) in levels of Follicle stimulating hormone (FSH) and testosterone in male rats. Furthermore, KV elicited significant (p < 0.001-0.05) elevation in the levels of GSH, SOD and CAT, and diminution in the level of MDA. The findings in this study suggest that long-term administration of KV is considerably safe with some variations in response between male and female animals. The possible sustenance of observed effects after cessation of KV administration, lipid lowering, erythropoiesis inducing, and immune system boosting activities of KV were confirmed in this study.

Bioprospecting for Anti-COVID-19 Interventions From African Medicinal Plants: A Review

The emergence of the novel coronavirus (SARS-CoV-2) that emanated from Wuhan in China in 2019 has become a global concern. The current situation warrants ethnomedicinal drug discovery and development for delivery of phytomedicines with potential for the treatment of COVID-19. The aim of this review is to provide a detailed evaluation of available information on plant species used in African traditional medicines with antiviral, anti-inflammatory, immunomodulatory, and COVID-19 symptoms relieving effects. Literature from scientific databases such as Scopus, PubMed, Google scholar, African Journals OnLine (AJOL), Science Direct, and Web of Science were used for this review. A total of 35 of the 38 reviewed plants demonstrated a wide range of antiviral activities. Bryophyllum pinnatum, Aframomum melegueta, Garcinia kola, Sphenocentrum jollyanum, Adansonia digitata, Sutherlandia frutescens, Hibiscus sabdariffa, Moringa oleifera, and Nigella sativa possess a combination of antiviral, immunomodulatory, anti-inflammatory, and COVID-19 symptoms relieving activities. Nine, 13, and 10 of the plants representing 23.7%, 34.2%, and 26.3% of the plants studied had antiviral activity with 3 other activities, antiviral activity with 2 other activities, and antiviral with one pharmacological activity alone, respectively. The plants studied were reported to be relatively safe at the subchronic toxicity level, except for 2. The study provides baseline information on the pharmacological activities, toxicity, and chemical components of 9 African medicinal plants with antiviral, immunomodulatory, anti-inflammatory, and symptoms relieving activities, thereby making the plants candidates for further investigation for effectiveness against COVID-19.

Ameliorative effect of Kolaviron, an extract of Garcinia kola seeds, on induced hypertension

OBJECTIVES

Early diagnosis and management of known cardiovascular disease risk attributes such as hypertension lessens morbidity and mortality as well as increase quality of life of patients. This present study was modelled to investigate the ameliorative effect of Kolaviron, an extract of Garcinia kola Heckel seeds, in ethanol- and sucrose-induced hypertension.

METHODS

Test animals were divided into six groups of six animals each for each hypertensive model. Animals were treated daily with distilled water (10 ml/kg); 35% ethanol (3 g/kg) or sucrose (5-7%); Kolaviron (50, 100 and 200 mg/kg) separately plus ethanol or sucrose and Amlodipine (0.14 mg/kg) separately plus ethanol or sucrose for 8 weeks. Systolic, diastolic and mean arterial pressures were determined using non-invasive BP system after 8 weeks. Blood was obtained for the assessment of biochemical parameters, lipid profile and antioxidant indices. Vital organs were collected for approximation of tissue antioxidant levels.

RESULTS

Results show that Kolaviron at various doses and Amlodipine significantly reduced (p<0.05-0.001) the elevated systolic, diastolic, and mean arterial pressures produced by ethanol and sucrose administration. Additionally, Kolaviron and Amlodipine significantly overturned (p<0.05-0.001) the reduction in GSH, SOD and CAT, and elevation in MDA levels elicited by ethanol and sucrose. Furthermore, Kolaviron and Amlodipine produced significant reduction (p<0.001) in levels of cholesterol, triglycerides and low-density lipoproteins, as well as significant increase (p<0.01-0.001) in levels of high-density lipoproteins.

CONCLUSIONS

Results from this study demonstrate that Kolaviron possibly possesses significant antihypertensive effect which may possibly be attributed to its antioxidant effects and relative improvement of lipid profile.

COVID-19 Pandemic: A Case for Phytomedicines

Coronavirus disease 2019 (COVID-19) is an infection caused by a newly discovered coronavirus which was identified in Wuhan, China. The race is on globally to repurpose drugs for COVID-19 and develop a safe and effective vaccine against the disease. There is an urgent need to search for effective remedies against COVID-19 from the rich and extensive flora of Africa and the world. A literature search was conducted to obtain information on drugs with the potential for effectiveness in the treatment of COVID-19 based mostly on outcomes of preclinical studies and a few clinical investigations. This was considered important to this perspective as some of the identified mechanisms of action may be related to potential anti-COVID-19 actions of phytomedicines. The findings from the literature search were also used to establish the need for exploration of phytomedicines in the fight against COVID-19. This perspective identifies the need to preserve the rich tradition of herbal medicine in Africa, repositioning it by inculcating all aspects of discovery, development, and chemical evaluation of pharmaceuticals from medicinal plants for effective management of prevalent diseases. The identified mechanisms of action of current drugs under consideration for the treatment of COVID-19 include preventing fusion of SARS-CoV-2 with human cells; decrease acidity in endosomes, cell membrane-derived vesicles for transportation of the virus within the host cell and within which the virus can replicate; and blockade of the production of proinflammatory cytokines. Phytomedicines may possibly elicit either one or a combination of these effects. The case for the exploration of phytomedicines against COVID-19 is strengthened by the emergence of a number of conventional drugs from medicinal plants and the emergence of botanicals with proven efficacy for some medical conditions. Caution against indiscriminate use of medicinal plants in the guise of treating COVID-19 has been highlighted and the need for reliable preclinical and clinical studies.

Anxiolytic- and antidepressant-like activities of hydroethanol leaf extract of Newbouldia laevis (P.Beauv.) Seem. (Bignoniaceae) in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Newbouldia laevis (Bignoniaceae) is a woody tropical plant commonly found in southwest Nigeria. Ethnobotanical survey and literature revealed its application in the management of CNS disorders e.g. psychosis, insomnia, convulsions and associated anxiety and depression. This study evaluated the anxiolytic and antidepressant activities of the hydroethanol leaf extract of N. laevis in mice.

MATERIALS AND METHODS

The hole-board (HBT), elevated plus maze (EPMT), light/dark exploration (LDET), open field (OFT), social interaction (SIT) (anxiolytic activity), forced swim (FST) and tail suspension (TST) (antidepressant property) tests were employed in this investigation. Mice randomly allotted to different groups were treated orally with distilled water (10 ml/kg), diazepam (1 and 3 mg/kg), imipramine (20 mg/kg) and N. laevis (25-200 mg/kg). The mice were subjected to the various tests 60 min post-treatment.

RESULTS

In the HBT, N. laevis (25 and 100 mg/kg) increased the number of sectional crossings significantly (p < 0.05). In the OFT, N. laevis (25-200 mg/kg) increased the number of general square crossings, centre square crossings, rearings and assisted rearings (p < 0.05). In the EPMT, the extract (25 and 50 mg/kg) increased the open arms time spent, number of head dips and entry (p < 0.05). In the LDET, N. laevis increased the number of transitions at 100 and 200 mg/kg (p < 0.05). For the SIT, N. laevis (25 and 200 mg/kg) increased the frequency and duration of interaction respectively (p < 0.05). In the FST and TST, N. laevis (25-200 mg/kg) increased the latency and reduced the total duration of immobility (p < 0.05). The effect of the extract on duration of immobility was significantly reversed by sulpiride (Dopamine D₂ receptor antagonist).

CONCLUSION

The hydroethanol leaf extract of N. laevis possesses anxiolytic- and antidepressant-like activities, the later possibly mediated by dopaminergic enhancement(s).

Acridocarpus Smeathmannii (DC.) Guill. & Perr. Root enhanced reproductive behavior and sexual function in male wistar rats: Biochemical and pharmacological mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Novel therapeutic opportunities from medicinal agents continue to arouse scientific interest in recent times. Still, there is a dearth of information as regards experimental evidence generated from medicinal plants that would yield pharmacological agents for the treatment of erectile dysfunction. Acridocarpus Smeathmannii (DC.) Guill. & Perr. Root (ASR) has a long history as an aphrodisiac in African traditional medicine. Thus, this study investigated the reproductive potentials and associated biochemical mechanisms of its hydroethanolic extract (HEASR) in male Wistar rats. Also, the bioactive compounds were identified.

MATERIALS AND METHODS

Fifty-four male albino rats (180 ± 20 g) were divided into nine groups of six rats/group. Control, group 1 received normal saline (10 mL/kg). Groups 2-6 rats were administered sildenafil (1.43 mg/kg/day), mesterolone (0.36 mg/kg/day), doxazocin (0.03 mg/kg/day), HEASR1 (50 mg/kg/day) and HEASR2 (200 mg/kg/day) respectively. Others received co-administration of HEASR2 with standard drugs. Treatment lasted for 28 days via oral gavage.

RESULTS

An acute oral toxicity of HEASR up to 2 g/kg produced no mortality in mice p.o. while the median lethal dose was estimated to be 810 mg/kg i.p. HEASR2 administration or in combination with sildenafil, mesterolone and doxazocin increased mounting frequencies on day 28 by 77.44%, 122.65%, 148.5% and 93.88% and sperm counts by 38.29%, 55.21%, 42.48%, and 48.98% respectively in treated rats. HEASR2 + sildenafil elevated testosterone and follicle stimulating hormone levels by 36.33% and 24.55% while HEASR2 + doxazocin elevated luteinizing hormone levels by 97.44% in rats. HEASR modulated prostate-specific antigen and malondialdehyde levels respectively. Reduced glutathione, superoxide dismutase, and catalase activities were raised in five selected organs. Serum nitric oxide but not cyclooxygenase-2 or tumor necrosis factor-α levels was moderately improved in rats.

CONCLUSION

Overall, the results obtained demonstrated the potential of HEASR as a male reproductive enhancer, thus justify its folklore applications. Further, octadecanoic acid ethyl ester was the most abundant bioactive component present.

Protective effect of carvedilol alone and coadministered with diltiazem and prednisolone on doxorubicin and 5-fluorouracil-induced hepatotoxicity and nephrotoxicity in rats

This study investigated the protective effects of carvedilol alone and coadministered with prednisolone and diltiazem on doxorubicin (DOX) and 5‐fluorouracil (5‐FU)‐induced toxicity. Each of 2 pools of 70 female rats were randomly allotted into 10 groups of 7 animals each and treated as follows: Group 1: normal saline (10 mL/kg); Group 2: normal saline and DOX (40 mg/kg)/5‐FU (20 mg/kg) alone; Group 3: gallic acid (200 mg/kg) and DOX/5‐FU; Group 4: carvedilol (0.075 mg/kg) and DOX/5‐FU; Group 5: carvedilol (0.15 mg/kg) and DOX/5‐FU; Group 6: carvedilol (0.30 mg/kg) and DOX/5‐FU; Group 7: diltiazem (3.43 mg/kg) and DOX/5‐FU; Group 8: diltiazem (3.43 mg/kg), carvedilol (0.15 mg/kg), and DOX/5‐FU; Group 9: prednisolone (0.57 mg/kg) and DOX/5‐FU; and Group 10: prednisolone (0.57 mg/kg), carvedilol (0.15 mg/kg), and DOX/5‐FU. Treatments were done p.o. for 16/14 days for the DOX/5‐FU models. DOX/5‐FU was administered i.p. to the rats in Groups 2‐10 on day 14/10‐14. On day 17/15 (DOX/5‐FU), blood samples were collected, and liver and kidneys of rats were harvested for antioxidant and histopathological assessments. Carvedilol alone and coadministered with prednisolone significantly (P < .05) decreased alanine aminotransferase level compared with administration of DOX alone. Carvedilol alone and coadministered with diltiazem significantly (P < .05) decreased creatinine level compared with administration of DOX/5‐FU alone. Carvedilol alone and coadministered with diltiazem and prednisolone significantly (P < .05) increased the level of hepatic superoxide dismutase and catalase, and decreased malondialdehyde compared with DOX administration alone. Histopathological observations correlated with results of biochemical and antioxidant analyses. Carvedilol administered alone and coadministered with diltiazem and prednisolone reduced the effect of DOX/5‐FU‐induced hepatic and renal toxicities due to enhanced in vivo antioxidant activity. The protective effect was more prominent in the doxorubicin model compared with the 5‐fluorouracil test. Coadministration of carvedilol with either diltiazem or prednisolone did not show better protection relative to carvedilol alone.

Investigation of Antidepressant, Anxiolytic and Sedative Activities of the Aqueous Leaf Extract of Musa sapientum Linn. (Banana; Musaceae)

BACKGROUND

Musa sapientum Linn. (Musaceae) is used in traditional African medicine in the management of mental disorders. This study was conducted to evaluate the central nervous system activities of the aqueous leaf extract of M. sapientum (MS). MATERIALS AND METHODS: MS (50, 100 and 200 mg/kg, p.o.) was administered to separate groups of mice 1 h before behavioural studies. The antidepressant effect was studied using the forced swimming test (FST) and tail suspension test (TST) while the elevated plus maze (EPM) and the hole-board tests were used to evaluate the anxiolytic effect. The probable mechanism of antidepressant-like effect was also investigated.

RESULTS

MS (50, 100 and 200 mg/kg) produced significant (P<0.0001) reduction in the duration of immobility with peak effect at 200 mg/kg (79.6%) in FST and 66.9 % in TST respectively when compared with control. The pre-treatment of mice with prazosin (α₁-adrenoceptor antagonist, 62.5 µg/kg, i.p.) and sulpiride (dopamine D₂ receptor antagonist, 50 mg/kg, i.p.) significantly prevented the antidepressant effect produced by MS in FST. However, pre-treatment of mice with metergoline (5-HT₂ receptor antagonist, 4 mg/kg, i.p.) and yohimbine (α₂-adrenoceptor antagonist, 1 mg/kg, i.p.) did not prevent the antidepressant effect of MS. In the EPM test, MS did not significantly increase open arm exploration. It also did not significantly increase the number of head dips in the hole-board test.

CONCLUSIONS

Results showed that MS had antidepressant activity possibly mediated through α₁-adrenergic and D₂ dopaminergic receptors, without significant anxiolytic effect.

Methionine and vitamin B-complex ameliorate antitubercular drugs-induced toxicity in exposed patients

Tuberculosis therapy utilizes drugs that while effective cause treatment‐related toxicity. Modulation of antitubercular drugs‐induced toxicity by methionine and vitamin B‐complex in patients was evaluated. 285 treatment‐naïve tuberculosis patients at the Chest Clinics of Infectious Diseases Hospital, Yaba and General Hospital, Lagos in Lagos, Nigeria was prospectively recruited and allotted into test (antitubercular medicines, methionine and vitamin B‐complex) and control groups (antitubercular medicines). Data on adverse drug reactions and blood samples were collected at initiation, 2 months and 6 months, and then analyzed. Red blood cells and packed cell volume were significantly higher (P < 0.05) in the test group compared to control at 6 months of therapy. At the end of 2 months, results showed a significant decrease (P < 0.001) in aspartate aminotransferase, alkaline phosphatase, alanine aminotransferase, urea, creatinine and total bilirubin in the test group compared to control. Reduced glutathione and superoxide dismutase were significantly increased (P < 0.001) and malondialdehyde significantly decreased (P < 0.001) in the test versus control groups at the end of 2 and 6 months. Adverse drug reactions were significantly lower (P < 0.001) in the test group (32.4%) compared to control group (56.2%), with 1 death. Hepatotoxicity was significantly higher (P = 0.026) in control (6.9%), compared to test group (0%). Alcohol and cigarette smoking were significantly (P = 0.019 and P = 0.027) associated with the occurrence of adverse drug reactions. Methionine and vitamin B‐complex modulated hepatic, renal, hematological, antioxidant indices and adverse effects in patients administered antitubercular medicines. Such interventions can enhance compliance and better treatment outcomes in tuberculosis patients.

Sub-Chronic Toxicity of the Hydroethanolic Leaf Extract of Telfairia occidentalis Hook. f. (Cucurbitaceae) in Male Rats

Background: Due to its nutritional and medicinal values, the leaf of Telfairia occidentalis Hook f. (Cucurbitaceae) is consumed in different parts of Nigeria. Acute and sub-chronic toxicity of the hydroethanolic leaf extract of Telfairiaoccidentalis were investigated in this study. Methods: Sixty-four male rats were randomized into four different groups of 16 animals each and were separately administered 80, 400 and 2000 mg/kg T. occidentalis orally (p.o.) for 60 days. Animals were sacrificed and blood samples were collected for hematological and biochemical analyses. Vital organs were harvested and evaluated for in vivo antioxidants and histopathological changes. Results: A significant (p < 0.05) reduction in weight of the testes, compared to the control group, was observed in the group treated with 2000 mg/kg extract. No significant change was observed in the weight of other vital organs relative to the control group. There were significant (p < 0.01) increases in sperm motility and count in the group administered 80 mg/kg extract and significant (p < 0.001) reductions in both parameters at 2000 mg/kg. There were significant increases in the levels of hemoglobin and packed cell volume at 80 and 2000 mg/kg of the extract. In respect of liver function parameters, significant reductions in aspartate aminotransferase and alanine aminotransferase levels at doses of 400 and 2000 mg/kg relative to control were observed. Compared to control, the extract significantly reduced (p < 0.05) the level of total cholesterol (400 mg/kg) and caused a significant increase in the level of high-density lipoprotein (80, 400 and 2000 mg/kg). Significant (p < 0.05) increase in the level of malondialdehyde, decrease in superoxide dismutase level and histopathological abnormalities were observed in the testes at 2000 mg/kg. Upon cessation of treatment with T. occidentalis for 30 days, the observed effects were reversed. Conclusions: The findings showed that the hydroethanolic leaf extract of Telfairia occidentalis is relatively non-toxic on acute and sub-chronic exposures at low to moderate doses, with the potential to elicit anti-anemic effects, reduce the risk of atherosclerosis and cardiovascular disease, and enhance antioxidant status in the brain and liver. Although possibly beneficial at low to moderate doses, the extract could be harmful to the testes with prolonged oral exposure at high dose.

Polycyclic Aromatic Hydrocarbon, Haematological and Oxidative Stress Levels in Commercial Photocopier Operators In Lagos, Nigeria

BACKGROUND

Human exposure to hazardous substances in the environment has been known to play an important role in the pathogenesis of some diseases. Photocopying machines have become a cheap source of self-employment in Nigeria. For obvious reasons the highest level of patronage is encountered in the campuses of educational institutions. However, the persons who operate the machines are always exposed to possible hazards associated with the job without protective devices.

OBJECTIVE

This study investigated the levels of oxidative stress, polycyclic aromatic hydrocarbon (PAH) and haematological parameters in blood samples of photocopier operators.

METHODS

The experimental procedure involved 50 consented subjects selected based on some criteria. The haematological parameters, oxidative stress and PAH levels were determined using standard methods.

RESULTS

The results showed no significant difference (p ≥ 0.05) in the haematological parameters between the test subjects and the controls. However, there were duration on the job (yrs) dependent significant decrease in the level of superoxide dismutase (SOD) of the photocopier operators compared with the controls (> 5 years p≤ 0.0001; 4-5 years p≤0.001). The level of reduced glutathione (GSH) was significantly decreased across all lengths of duration on the job compared with the controls.

CONCLUSION

The findings in this study revealed increased level of oxidative stress in photocopier operators with no significant change in haematological parameters. The health implication of operating photocopiers call for quick health education and intervention tailored to monitoring and guiding the photocopier operators. This will help to prevent or manage continuous exposure to the hazards of photocopying machines.

Antidiarrhoeal activity of aqueous leaf extract of Caladium bicolor (Araceae) and its possible mechanisms of action

ETHNOPHARMACOLOGICAL RELEVANCE

Caladium bicolor (Araceae) is a horticulture plant also used by some traditional medicine practitioners in the treatment of diarrhoea and other gastrointestinal disorders. This study was conducted to evaluate the antidiarrhoeal activity of the aqueous leaf extract of C. bicolor and its possible mechanisms of action in rodents.

MATERIALS AND METHODS

Normal and castor oil-induced intestinal transit and castor oil-induced diarrhoea tests were carried out in mice while gastric emptying and enteropooling tests were conducted in rats following the administration of distilled water (10 ml/kg, p.o.), C. bicolor extract (1-50mg/kg, p.o.) and loperamide (5mg/kg, p.o.). The probable mechanisms of action of C. bicolor was investigated following pre-treatment with yohimbine (10mg/kg, s.c.; α2-adrenoceptor antagonist), pilocarpine (1mg/kg, s.c.; non-selective muscarinic receptor agonist), prazosin (1mg/kg, s.c.; α1-adrenoceptor antagonist) and propranolol (1mg/kg, i.p.; non-selective β-adrenoceptor antagonist) 15 min prior to administration of C. bicolor extract (50mg/kg, p.o.). After 30 min of pre-treatment with these drugs, the mice were subjected to the castor oil-induced intestinal transit test.

RESULTS

C. bicolor extract did not produce significant (p>0.05) effect on normal intestinal transit unlike loperamide which caused significant (p<0.001) inhibition (61.57%). The extract caused significant (p<0.001) dose-dependent inhibition of castor oil-induced intestinal transit with peak effect, 100% inhibition, elicited at the dose of 50mg/kg compared to 86.97% inhibition for loperamide. Yohimbine and pilocarpine most significantly (p<0.001) reversed this effect of the extract. In the castor oil-induced diarrhoea test, the extract (1mg/kg) and loperamide significantly (p<0.05, 0.01) delayed the onset of diarrhoea. For diarrhoea score, the extract (1 and 50mg/kg) inhibited diarrhoea development (47.53% and 43.83% inhibition, respectively) like loperamide (5mg/kg; 54.94%). The in vivo antidiarrhoeal index of the extract at 1 and 50mg/kg was 50.07% and 42.81% respectively compared to 58.15% for loperamide.

CONCLUSIONS

The results obtained in this study suggest that the aqueous leaf extract of C. bicolor possess antidiarrhoeal activity due to its anti-motility effect possibly via antagonist action on intestinal muscarinic receptors and agonist action on intestinal α2-adrenoceptors. This justifies the use of the extract in traditional medicine for the treatment of diarrhoea.

90 Days toxicological assessment of hydroethanolic leaf extract of Ipomoea asarifolia (Desr.) Roem. and Schult. (Convolvulaceae) in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ipomoea asarifolia (Convolvulacae), commonly known as "morning glory" is found across West Africa. Preparations of the plant are used traditionally for the treatment of diverse ailments including diabetes, neuralgia, arthritic pain and stomach ache. This study was designed to assess the safety profile of the hydroethanolic leaf extract of I. asarifolia through a 90-day subchronic toxicity study in rats.

MATERIALS AND METHODS

I. asarifolia was administered p.o. at doses of 40, 200 and 1000mg/kg to separate groups of rats for 90 days. Distilled water was given p.o. to rats in the control group. Some set of rats in each group were left for additional 30 days without administration of the extract for reversibility study. Animals were weighed weekly and relevant parameters were assayed at the end of the main and reversibility study periods.

RESULTS

There was no significant change (p>0.05) in the body weight of rats, and food and water intake in I. asarifolia treated groups compared with control. I. asarifolia (40-1000 mg/kg) significantly but reversibly reduced (p<0.05, 0.001) sperm motility and count. The extract did not generally cause significant change (p>0.05) in the weight of vital organs and haematological parameters except in the case of reversible reduction in the level of haemoglobin and red blood cell count (p<0.01; 40 mg/kg). The level of biochemical parameters and electrolytes were not significantly changed (p>0.05) except for the reversible reduction in the level of aspartate aminotransferase (AST; p<0.0001; 200 and 1000 mg/kg) and increase in the level of Na(+) (p<0.01; 200 mg/kg). The level of kidney reduced glutathione (GSH) was reversibly increased (p<0.01; 1000 mg/kg) while the level of enzymatic and non-enzymatic in vivo antioxidants was generally comparable and not significantly different (p>0.05) from control in respect of all other vital organs. Histological presentations were generally normal in respect of the liver, kidneys, brain, heart, lungs, pancreas, spleen and testes.

CONCLUSIONS

The findings in this study suggest that the hydroethanolic leaf extract of I. asarifolia is relatively safe administered orally for an extended period with potential renal in vivo antioxidant activities. However, the extract may cause reversible male sterility, anaemia and hypernatraemia.

Evaluation of neuropharmacological effects of aqueous leaf extract of Albizia glaberrima (Leguminosae) in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Albizia glaberrima is a shrub found in the deciduous forest and jungle of the coastal plain of West Africa. Preparations of the plant are used traditionally in the treatment of fever, pain and central nervous system disorders, including epilepsy. This study was conducted to investigate the neuropharmacological effects of the aqueous leaf extract of Albizia glaberrima in mice.

MATERIALS AND METHODS

The hole-board, elevated plus-maze, thiopentone-induced sleep (anxiolytic/sedative-hypnotic), traction, climbing, inclined screen (muscle relaxant), strychnine-, picrotoxin- and pentylenetetrazole (PTZ)-induced convulsion (anticonvulsant) tests were employed in this study.

RESULTS

Albizia glaberrima extract at 200mg/kg significantly increased the duration of head dips (p<0.05) and number of open arms entry (p<0.01) compared with control in the hole-board and elevated plus-maze tests, respectively. At 400mg/kg, Albizia glaberrima extract significantly reduced the number of sectional crossings relative to control. The extract at 400mg/kg significantly (p<0.05) increased the duration of sleep compared with control in the thiopentone-induced hypnosis test. Albizia glaberrima extract at 200mg/kg and diazepam (5mg/kg) significantly (p<0.05, 0.01) increased the post-treatment climbing time and reduced the latency to slide down in the climbing and inclined screen tests, respectively. The extract was not effective in the strychnine-induced seizure model, while in the picrotoxin test Albizia glaberrima extract at 100mg/kg significantly (p<0.05) reduced the duration of convulsion while reducing mortality at 400mg/kg, as was the case with diazepam (2mg/kg). The extract and diazepam significantly (p<0.01, 0.001) increased onset and reduced duration of convulsion, with significant level of protection against convulsion and reduction in mortality in the PTZ-induced seizure model. Preliminary phytochemical screening of the extract revealed the presence of phenols>tannins>saponins>flavonoids. The extract was found to be relatively non-toxic when administered p.o. up to 5000mg/kg and the LD50 was 398.11mg/kg when administered i.p.

CONCLUSIONS

The aqueous leaf extract of Albizia glaberrima possesses dose-dependent anxiolytic/muscle relaxant (low dose) and sedative-hypnotic/anticonvulsant (high dose) activities possibly mediated via enhancement of GABAergic inhibitory actions.

Hepatoprotective and in vivo antioxidant activities of the hydroethanolic leaf extract of Mucuna pruriens (Fabaceae) in antitubercular drugs and alcohol models

AIM

Hepatotoxicity is a significantly increasing health problem worldwide, and the extent of the problem has stimulated interest in the search for hepatotherapeutic agents from plants. This study investigated the hepatoprotective and in vivo antioxidant activities of the hydroethanolic extract of Mucuna pruriens leaves in antitubercular and alcohol-induced hepatotoxicity assays in rats.

METHOD

In each of the models used, seven groups were allotted. The different groups received normal saline (10 mL·kg(-1), p.o.); hepatotoxicant (isoniazid-rifampicin, INH-RIF, 100 mg·kg(-1), i.p. or 20% ethanol 5 g·kg(-1), p.o.) and normal saline (10 mL·kg(-1), p.o.); hepatotoxicant and extract at doses of 100, 200, and 400 mg·kg(-1) p.o.; hepatotoxicant and silymarin 50 mg·kg(-1) p.o.; and extract at 400 mg·kg(-1) p.o. On the 21(st) day of treatment, blood was collected for assessment of serum biochemical parameters and harvested liver samples were assessed for antioxidants.

RESULTS

The hepatotoxicants significantly (P < 0.05-0.001) increased the levels of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), bilirubin, and malondialdehyde (MDA); and reduced the levels of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and reduced glutathione GSH compared to control. M. pruriens significantly reversed (P < 0.05-0.001) the elevation in the level of ALT, AST, ALP, and bilirubin caused by the hepatotoxicants. The extract (200 and 400 mg·kg(-1)) significantly reversed (P < 0.05) the diminution in the level of in vivo antioxidants and increased the level of MDA produced by INH-RIF. M. pruriens (100-400 mg·kg(-1)) elicited significant reduction (P < 0.001) in the level of MDA compared to the alcohol group. Silymarin also reversed the deleterious effects of the hepatotoxicants.

CONCLUSION

The hydroethanolic extract of Mucuna pruriens leaves possesses hepatoprotective activity with enhancement of in vivo antioxidants as a possible mechanism of action.

Anticancer activity of the phytomedicine DAS-77

This study was designed to investigate the anticancer activity of extracts of the phytomedicine DAS-77. The sulforhodamine B (SRB) in vitro cytotoxicity assay, Sarcoma-180 (S-180) ascites and solid tumor, and L1210 lymphoid leukemia in vivo models were employed. DAS-A001 (ethanol extract, IC50 12 and 13 µg/mL with HCT-116 and PC3, respectively); DAS-A002 (hydroethanol extract, IC50 <5 and 13 µg/mL with HCT-116 and PC3, respectively); DAS-A003 (aqueous extract, IC50 <5 µg/mL with THP-1); and DAS-A004 (dichloromethane:methanol extract; IC50 <5 and 17 µg/mL with HCT-116 and PC3, respectively) demonstrated significant activity in vitro. DAS-A002 and DAS-A003 (80-120 mg/kg) elicited significant (P < .05-.001) dose-dependent inhibition of tumor growth in the S-180 ascites model. Peak effects were produced at the highest dose of 120 mg/kg with inhibition values of 87.50% and 89.23% for DAS-A002 and DAS-A003, respectively, compared with a value of 97.27% for 5-FU (20 mg/kg). As regards the S-180 solid tumor model, inhibition of tumor growth was found to be 52.56% and 37.95%, respectively, for DAS-A002 and DAS-A003. The effect of DAS-A002 was comparable and not significantly different (P > .05) from that of 5-FU (20 mg/kg; 50.18% inhibition). DAS-A003 but not DAS-A002 showed significant activity in the leukemia model with 177.78% increase in mean survival time relative to 211.11% for 5-FU. Findings in this study suggest that the hydroethanol and aqueous extracts of DAS-77 possess significant anticancer activity.

Effects of ethanolic dried leaf extract of Lecaniodiscus cupanioides on antioxidant enzymes and biochemical parameters in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Lecaniodiscus cupanioides is widely used in West African folk medicine for the treatment of inflammatory conditions, fevers and bacterial infections.

AIM OF THE STUDY

To evaluate the potential toxic effects of the ethanolic dried leaf extract of Lecaniodiscus cupanioides (LC) on antioxidant enzymes in selected organs and biochemical parameters.

MATERIALS AND METHODS

Crude ethanolic extract of Lecaniodiscus cupanioides dried leaves was prepared. A 90-day sub-chronic toxicity study was conducted using albino rats. Reconstituted Lecaniodiscus cupanioides was administered at a dosage of 400, 800 and 1600 mg/kg (high dose) with a control group receiving 10 ml/kg orally. Histopathological studies of major organs and blood chemistry analysis were performed on blood obtained via cardiac puncture after euthanization. Selected organs (liver, kidney and brain) were harvested for antioxidant and histopathological assessments.

RESULTS

The extract produced significant (p<0.05) increases in the weights of liver, kidney and brain at 800 mg/kg and 1600 mg/kg compared to the control. Biochemical analysis showed significant increase in Alanine transferase (ALT) at 800 mg/kg and 1600 mg/kg. Assay for antioxidant enzymes showed a reversible decrease in the activity of Catalase (CAT), Superoxide dismutase (SOD) and Glutathione (GSH) with an increase in Malondialdehyde (MDA) at 800 mg/kg and 1600 mg/kg Lecaniodiscus cupanioides. Histopathological study showed reversible congestion in the brain, liver, and kidney at 800 mg/kg and 1600 mg/kg.

CONCLUSION

Findings in this study reveal that the ethanolic dried leaf extract of Lecaniodiscus cupanioides has the potential for inhibiting in vivo antioxidant enzymes activity and causing hepatotoxicity after prolonged exposure.

Ameliorative Effect of Hydroethanolic Leaf Extract of Byrsocarpus coccineus in Alcohol- and Sucrose-Induced Hypertension in Rats

Hypertension remains a major health problem worldwide considering the prevalence of morbidity and mortality. Plants remain a reliable source of efficacious and better tolerated drugs and botanicals. This study was designed to investigate the effect of the chemo-profiled hydroethanolic leaf extract of Byrsocarpus coccineus in ethanol- and sucrose-induced hypertension. Groups of rats were treated orally (p.o.) with distilled water (10 ml/kg), ethanol (35%; 3 g/kg), sucrose (5-7%), and B. coccineus (100, 200, and 400 mg/kg), and nifedipine together with ethanol and sucrose separately for 8 weeks. At the end of the treatment period, blood pressure and heart rate of rats were determined. Blood was collected for serum biochemical parameters and lipid profile assessment, and the liver, aorta, kidney, and heart were harvested for estimation of in vivo antioxidants and malondialdehyde (MDA). Results obtained in this study showed that B. coccineus at the various doses administered reduced the systolic, diastolic, and arterial blood pressure elevated by ethanol and sucrose. Also, the extract reversed the reduction in catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GPx), and superoxide dismutase (SOD) induced by ethanol and sucrose. The level of MDA was reduced compared to the ethanol- and sucrose-induced hypertensive group. With respect to lipid profile, administration of B. coccineus at the various doses reduced the levels of triglycerides, low-density lipoprotein (LDL), cholesterol, and atherogenic indices, compared to the ethanol and sucrose groups. In conclusion the hydroethanolic leaf extract of B. coccineus exerted significant antihypertensive effect and this is probably related to the antioxidant property and improvement of lipid profile observed in this study.

Dose and time-dependent sub-chronic toxicity study of hydroethanolic leaf extract of Flabellaria paniculata Cav. (Malpighiaceae) in rodents

Flabellaria paniculata Cav. (Malpighiaceae) is a climbing shrub, the preparations of which are used in the treatment of wounds and ulcers in Nigeria and Ghana. This study investigated the sub-chronic toxicity profile of the hydroethanolic leaf extract of F. paniculata (HLE-FP). HLE-FP was administered p.o. (20, 100, and 500 mg/kg) for 30 and 60 days to different groups of rats. Control animals received 10 ml/kg distilled water. In the group of animals for reversibility study, HLE-FP administration ceased on the 60th day and animals were monitored for a further 15 days. Results showed that oral treatment with HLE-FP for 30 days caused significant (p < 0.05) reductions in weight gain pattern compared to control. These changes were sustained with 60 days treatment. However, no significant (p > 0.05) differences in relative organ weights between control and treatment groups were observed. HLE-FP-treated rats showed significant (p < 0.05) increases in Hb, PCV and RBC on day 30 and significant (p < 0.05) increases in MCV and MCH indices on day 60 compared to control. There were significant (p < 0.05) elevations in serum K⁺, urea and creatinine compared to control. The liver function tests showed slight but non-significant alterations in relevant parameters when compared to control. Biochemical findings were supported by histopathological observations of vital organs including the kidney and liver. Toxicities observed in respect of kidney function were irreversible at 15 days of stoppage of treatment. In the acute toxicity study, HLE-FP given p.o. caused no lethality at 5000 mg/kg but behavioral manifestations like restlessness, generalized body tremor, feed, and water refusal were observed. The i.p. LD₅₀ was estimated to be 2951.2 mg/kg. Findings in this study showed that HLE-FP is relatively non-toxic on acute exposure and generally safe on sub-chronic administration, but could be deleterious on the kidneys on prolonged oral exposure at a high dose. Thus, caution should be exercised with its long-term usage.

Evaluation of the antidiarrhoeal activity of the hydroethanolic leaf extract of Pupalia lappacea Linn. Juss. (Amaranthaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Pupalia lappacea is a medicinal plant found in savannah and woodland localities and forest path sides from Senegal to Southern Nigeria. It has been used in the management of diarrhoea in Nigerian traditional medicine. This study was designed to evaluate the antidiarrhoeal activity of the hydroethanolic leaf extract of Pupalia lappacea (PL).

MATERIALS AND METHODS

The antidiarrhoeal activity of PL was evaluated using the normal and castor oil-induced intestinal transit, castor oil-induced diarrhoea, gastric emptying and intestinal fluid accumulation tests in rodents.

RESULTS

PL (100-400mg/kg, p.o.) produced a significant dose-dependent decrease in normal and castor oil-induced intestinal transit compared with the control group (distilled water 10ml/kg, p.o.). This effect was significantly (P<0.05) inhibited by pilocarpine (1mg/kg, s.c.) but not by yohimbine (10mg/kg, s.c.), prazosin (1mg/kg, s.c.), or propranolol (1mg/kg, i.p.). The extract produced a dose-dependent and significant increase in the onset of diarrhoea. PL (100-400mg/kg) also reduced the diarrhoea score, number and weight of wet stools. The in-vivo antidiarrhoeal index (ADIin vivo) of 56.95% produced by the extract at the dose of 400mg/kg was lower compared to that produced by loperamide 5mg/kg (77.75%). However, PL (400mg/kg) significantly increased gastric emptying in rats but significantly reduced the volume of intestinal content in the intestinal fluid accumulation test. Phytochemical analysis of the extract revealed the presence of alkaloids, saponins, and fixed oils and fats. The acute toxicity studies revealed that the extract is relatively safe when given orally; no death was recorded at a dose of 10g/kg.

CONCLUSION

Results showed that the hydroethanolic leaf extract of Pupalia lappacea possesses antidiarrhoeal activity possibly mediated by antimuscarinic receptor activity.

Toxicological evaluation of the lyophilized fruit juice extract of Annona muricata Linn. (Annonaceae) in rodents

Abstract Background: Annona muricata Linn. (Annonaceae) (AM) fruit juice is widely consumed either raw or after processing in tropical countries because of its very juicy, creamy and sweet character including its medicinal importance. The safety of AM fruit was investigated in Sprague-Dawley rats for acute and 60-day subchronic toxicity effects. Methods: Rats were administered distilled water (DW) and AM daily at doses of 80, 400 and 2000 mg/kg orally for 60 days. At the end of the study, blood samples were assayed for biochemical and hematological parameters. Vital organs were harvested and assessed for antioxidants and histopathology. Results: There was no mortality recorded up to 2000 mg/kg following acute administration. There were no significant changes in vital organ weights and hematological and biochemical parameters. However, significant (p<0.05) reduction in platelet count and packed cell volume was observed at 2000 and 400 mg/kg, respectively, which was reversed after cessation of treatment. Interestingly, subchronic oral administration of AM (80, 400 or 2000 mg/kg) significantly (p<0.001) increased sperm count and motility in comparison to vehicle-treated control. AM long-term treatment induced significant (p<0.05, <0.01 and <0.001) increases in the levels of glutathione, superoxide dismutase (SOD) and catalase, respectively, in the liver and kidney. Conversely, AM (2000 mg/kg) produced significant (p<0.001) increase in malondialdehyde level with decreased (p<0.05) SOD activity in the brain. Conclusions: The study established that AM did not induce any significant toxic effect, indicating that it is safe in rats following oral administration for 60 consecutive days.

Protective effect of selected calcium channel blockers and prednisolone, a phospholipase-A2 inhibitor, against gentamicin and carbon tetrachloride-induced nephrotoxicity

The ameliorative effect of calcium channel blockers (CCBs) and a phospholipase-A2 inhibitor in drug-/chemical-induced nephrotoxicity was investigated. Rats were divided into 7 groups of 5 rats in each group. In the gentamicin model, group I rats were pretreated with normal saline (10 ml kg−1), while groups II–VII rats were pretreated with normal saline (10 ml kg−1), ascorbic acid (10 mg kg−1), nifedipine (0.86 mg kg−1), verapamil (4.3 mg kg−1), diltiazem (3.43 mg kg−1), and prednisolone (0.57 mg kg−1), respectively, perorally 1 h before intraperitoneal (i.p.) injection of gentamicin (40 mg kg−1) for 14 days. In the carbon tetrachloride (CCl4) model, rats were pretreated with CCBs and prednisolone for 7 days before inducing nephrotoxicity with 20% CCl4 (1.5 ml kg−1). Rats were thereafter killed and blood and tissue samples were collected for assessments. I.p. injections of gentamicin and CCl4 caused significant hypernatremia, hypokalemia, hypocalcemia, hypophosphatemia, and hyperchloremic alkalosis and reduced renal tissue levels of antioxidants. Also, significant reductions in the hemoglobin, packed cell volume, red blood cells, and platelet indices were observed. Pretreatments with nifedipine (0.86 mg kg−1), verapamil (4.3 mg kg−1), diltiazem (3.43 mg kg−1), and prednisolone (0.57 mg kg−1) significantly ameliorated the deleterious effects of gentamicin and CCl4 possibly via antioxidant and anti-lipoperoxidation mechanisms. The results obtained in this study suggest potential clinical usefulness of tested CCBs and prednisolone in drug-/chemical-induced nephrotoxicity.

Effect of subclinical, clinical and supraclinical doses of calcium channel blockers on models of drug-induced hepatotoxicity in rats

Drug-related hepatotoxicity is the leading cause of acute liver failure, and hepatic problems are responsible for a significant number of liver transplantations and deaths worldwide. Calcium has been associated with various metabolic processes that lead to cell death and apoptosis, and increased cytosolic Ca(2+) has been implicated in hepatotoxicity. This study was designed to investigate the effects of calcium channel blockers (CCBs) on isoniazid-rifampicin, zidovudine and erythromycin-induced hepatotoxicity in rats. Treatment groups comprised control, hepatotoxicant, hepatotoxicant along with each of silymarin, nifedipine, verapamil and diltiazem at subclinical, clinical and supraclinical doses. A day to the end of treatment for each model, rats were subjected to the hexobarbitone-induced hypnosis test. On the last days of treatment, blood samples were collected and serum was analyzed for relevant biochemical parameters. Animals were sacrificed after blood collection and livers were harvested, and samples obtained for in vivo antioxidant indices assay and histopathology. The hepatotoxicants significantly increased serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP), as well as duration of sleep in the hypnosis test. These drugs significantly reduced the hepatic levels of reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and increased the level of malondialdehyde (MDA). The CCBs at the various doses significantly reversed the effects of isoniazid-rifampicin, zidovudine and erythromycin. The results obtained in this study suggest that the CCBs possess hepatoprotective activity in drug-induced hepatotoxicity and may be beneficial at the subclinical and clinical doses.

Anxiolytic activity of aerial part hydroethanolic extract of Allium ascalonicum Linn. (Liliaceae) in mice

Background: Allium ascalonicum Linn. (Liliaceae) is a mildly aromatic annual herb used to flavor food. Ethnobotanical survey revealed application of A. ascalonicumin the treatment of central nervous system (CNS) disorders.  Objective: To investigate the anxiolytic activity of aerial part hydroethanolic extract of A. ascalonicum. Methods: The hole-board, elevated plus maze, light/dark exploration, open field and social interaction tests were used in this study. Groups of mice were treated orally with distilled water (10 ml/kg), diazepam (1 mg/kg), and A. ascalonicum (50-400 mg/kg). Evaluations were done 1 h post-treatment and the duration of observation was mostly 5 min. In the hole-board test, mice were observed for number/duration of head dips and number of sectional crossings. In the elevated plus maze test, the time spent in the open/closed arms and the number of entries by mice were observed. In the light/dark exploration test, the latency of entry into the dark box, time spent in the light and dark compartments, number of rearing and assisted rearing were determined. In respect of the open field test, observations were made for the number of rearing, assisted rearing, and sectional crossings. In the social interaction test, pairs of mice were observed for number of interactions including sniffing, following, and partner grooming. Results: In the hole-board test, A. ascalonicum significantly (p<0.05, 0.01) increased the number/duration of head dips and number of sectional crossings. In the elevated plus maze test, A. ascalonicum significantly (p<0.05) increased the number of entries into the open arm with corresponding reduction in number of entries into the closed arm. In the light/dark exploration test, A. ascalonicum significantly (p<0.05, 0.01) increased the latency of entry into the dark box, time spent in the light box, and number of rearing and assisted rearing. In respect of the open field test, A. ascalonicum significantly (p<0.05, 0.01) increased the number of sectional crossings and rearing. Considering the social interaction test, A. ascalonicum significantly (p<0.05) increased the number of interactions. Peak anti-anxiety effects were mostly observed at the dose of 100 mg/kg. Conclusion: The aerial part hydroethanolic extract of Allium ascalonicum possesses anxiolytic properties. Keywords: Allium ascalonicum, Liliaceae, anxiolytic activity, medicinal plants, traditional medicine.

Effect of Flabellaria paniculata Cav. extracts on gastric ulcer in rats

Background

The leaves and root of Flabellaria paniculata (Malpighiaceae) are frequently used in the treatment of wounds and ulcers in Nigerian folk medicine. The purpose of this study was to compare the effect of ethanolic extracts from the leaves (FPL) and root (FPR) of F. paniculata on gastric ulcers in rats.

Methods

The effect of FPL and FPR (100, 200 and 400 mg/kg) was evaluated in ethanol and indomethacin gastric ulcer models. Control groups for FPL and FPR were orally treated with 3% Tween 20 and distilled water respectively. FPL was further investigated in pylorus ligation model. Misoprostol and cimetidine were used as reference.

Results

FPL significantly (P < 0.05) reduced gastric lesions by 82.22% and 67.32% in ethanol and indomethacin induced ulcer models at 100 mg/kg respectively while FPR (100, 200 and 400 mg/kg) did not exert significant effect in the two models. In pylorus ligation model, FPL exerted a significant preventive antiulcer effect as indicated by reduction in gastric volume at 200 and 400 mg/kg doses. Only 400 mg/kg of the extract exerted a significant reduction in ulcer index when compared with the control group. The oral route LD₅₀ of FPL was estimated to be 4570 mg/kg while that of FPR was 2754 mg/kg. The LD₅₀ in intraperitoneal injection was estimated to be 1202.26 and 1380.38 mg/kg for FPL and FPR respectively. The phytochemical investigation showed that both extracts possess triterpenoids and saponin, while the presence of flavonoid was detected only in FPL.

Conclusions

The results of this study indicated that FPL and not FPR is effective against experimentally induced gastric ulcers. The presence of varied phytochemical constituents probably influenced the pharmacological differences between the two extracts.

Sub-chronic toxicity study of the methanol root extract of Cnestis ferruginea

CONTEXT

Cnestis ferruginea (CF) Vahl ex DC (Connaraceae) is a shrub abundant in West Africa. Root preparations are used in traditional medicine to treat diverse conditions.

OBJECTIVE

To evaluate the sub-chronic toxicological effects of the methanol root extract of CF.

MATERIALS AND METHODS

Groups of adult rats of both sexes were treated daily with distilled water (DW) and CF at doses of 80 (sub-therapeutic dose), 400 (therapeutic dose), and 1000 (supra-therapeutic dose) mg/kg orally for 90 days. Animals were weighed weekly and observed for behavioral and morphological changes. At the end, rats were sacrificed and blood samples collected for hematological and biochemical analysis. Vital organs were harvested, weighed, and assessed for in vivo antioxidants and histopathological changes. Sperm analysis and reversibility study were done, and mortality was recorded.

RESULTS

CF at the therapeutic dose did not produce any significant irreversible deleterious effects on the weight of animals and vital organs, in vivo antioxidants, histopathological presentation, hematological, biochemical, and sperm parameters. Platelet anomaly was elicited as a delayed effect. Effects at the sub- and supra-therapeutic doses were similar but with delayed anemia in females and weight reduction and sterility in males as possible side effects. CF generally showed a potential to induce in vivo antioxidants.

DISCUSSION AND CONCLUSION

Findings suggest that CF given over an extended period possess the potential to cause induction of in vivo antioxidants especially in the ovary. Possible side effects identified with CF, which necessitate caution, include delayed platelet anomaly and anemia in females, weight reduction, and sterility in males.

A 90 day chronic toxicity study of Nigerian herbal preparation DAS-77 in rats

Background

The herbal preparation DAS-77, used for the treatment of various ailments in Nigeria, contains the milled bark of Mangifera indica L. and root of Carica papaya L. Toxicological assessment of the preparation was carried out in this study.

Methods

In the acute toxicity study, DAS-77 was administered to mice p.o. up to 20 g/kg in divided doses and i.p. at 250–3000 mg/kg. Mortality within 24 h was recorded. In the chronic toxicity study, rats were treated p.o. for 90 days at doses of 80, 400 (therapeutic dose, TD) and 2000 mg/kg. By 90 days, animals were sacrificed and blood samples collected for hematological and biochemical analysis. Organs were harvested for weight determination, antioxidants and histopathological assessments.

Results

DAS-77 did not produce any lethality administered p.o. up to 20 g/kg in divided doses but the i.p. LD₅₀ was 1122.0 mg/kg. At TD, DAS-77 produced significant (p < 0.05) reductions in body weight, food intake and K⁺, and increases in ovary weight, neutrophils and HDL, which were reversible. Histopathological presentations were generally normal. Effects at the other doses were comparable to those at TD except for reversible increases in antioxidants in the liver, kidney and testes, and sperm abnormality, and reductions in liver enzymes, sperm motility and count.

Conclusions

Findings in this study revealed that DAS-77 is relatively safe with the potential for enhancing in vivo antioxidant activity. However, possibly reversible side-effects include electrolyte imbalance and sterility in males.

Analgesic and antipyretic activities of Drymaria cordata (Linn.) Willd (Caryophyllaceae) extract

Drymaria cordata (Linn.) Willd (Caryophyllaceae) is an herbaceous plant widely used in traditional African medicine (TAM) for the treatment of diverse ailments including painful and febrile conditions. This study was conducted to investigate the analgesic and antipyretic properties of the whole plant extract of D. cordata. The acetic acid-induced writhing, formalin, and tail clip tests were used to evaluate analgesic activity while the 2,4-dinitrophenol (DNP)-, d-amphetamine-, and yeast-induced hyperthermia tests were used to investigate antipyretic activity in rodents. D. cordata (100, 200, and 400 mg kg(-1), p.o) produced significant (p<0.05) analgesic activity in the mouse writhing, formalin (second phase), and tail clip tests. The effects of D. cordata were generally comparable to those of acetylsalicylic acid (ASA, 100 mg kg(-1), p.o) and morphine (2 mg kg(-1), s.c). Also, D. cordata produced significant (p<0.05) dose-dependent inhibition of temperature elevation in the 2,4-DNP and yeast-induced hyperthermia models with peak effects produced at the dose of 400 mg kg(-1). The effect at this dose was comparable to that of ASA in the two models. In the d-amphetamine method, D. cordata produced significant (p<0.05) dose- and time-dependent reduction of temperature elevation with peak effect produced at the dose of 200 mg kg(-1). The effect of the extract at this dose was greater than that of ASA. The results obtained in this study demonstrate that the aqueous whole plant extract of Drymaria cordata possesses analgesic and antipyretic properties mediated through peripheral and central mechanisms.

Antidiarrhoeal activity of DAS-77 (a herbal preparation)

BACKGROUND

DAS-77 is a traditional herbal preparation composed of the young callous bark of mango (Mangifera indica Linn., Anacardiaceae) and the dried root of pawpaw (Carica papaya Linn., Caricaceae). This phytomedicine is claimed to have beneficial effects in the treatment of gastrointestinal disorders, including diarrhoea.

OBJECTIVE

To investigate the antidiarrhoeal effect of DAS-77 using standard pharmacological models.

METHODS

Normal and castor oil-induced intestinal transit, and castor oil-induced diarrhoea tests wore carried out in mice while intestinal fluid accumulation and gastric emptying tests were carried out in rats. Acute toxicity test and preliminary phytochemical analysis were also conducted.

RESULTS

The results obtained in this study revealed that DAS-77 had no significant inhibitory effect on normal intestinal transit, castor oil-induced diarrhoea, intestinal fluid accumulation and gastric emptying. However, the inhibitory effect of DAS-77 was significant (p<0.001) relative to control in the castor oil-induced intestinal transit test. Peak effect was produced at the dose of 100 mg/kg (p.o.). The effect of DAS-77 in this respect was reversed by pilocarpine and propranolol, but not by phenoxybenzamine. DAS-77 did not produce any mortality given p.o. up to 10 g/kg, indicating the relative safety of the preparation. The i.p. LD50 was estimated to be 1122 mg/kg. The remedy was found to contain saponins, tannins, phenols and alkaloids.

CONCLUSION

Findings in this study suggest that DAS-77 possesses antidiarrhoeal activity due to the inhibition of intestinal motility possibly mediated by muscarinic and alpha adrenergic receptors.

Analgesic and anti-inflammatory activities of Cnestis ferruginea Vahl ex DC (Connaraceae) methanolic root extract

ETHNOPHARMACOLOGICAL RELEVANCE

Cnestis ferruginea Vahl ex DC (Connaraceae) is a shrub widely used in traditional African Medicine (TAM) for the treatment of various painful and inflammatory conditions.

AIM OF THE STUDY

The objective of this study was to investigate the analgesic and anti-inflammatory properties of the methanolic root extract of Cnestis ferruginea.

MATERIALS AND METHODS

Analgesic activity was evaluated using the acetic acid-induced writhing, formalin, tail clip, and hot plate tests in mice. The carrageenan- and egg albumin-induced rat paw oedema, formaldehyde-induced arthritis inflammation, and xylene-induced ear oedema tests were used to investigate the anti-inflammatory actions of Cnestis ferruginea.

RESULTS

The methanolic root extract of Cnestis ferruginea (100, 200, and 400mg/kg; p.o.) produced significant (P<0.05) dose-dependent inhibition of pain response elicited by acetic acid and formalin while also increasing the nociceptive reaction latency in the tail clip and hot plate tests. In respect of anti-inflammatory activity, Cnestis ferruginea caused significant (P<0.05) dose-dependent inhibition of oedema development in the carrageenan, egg albumin, formaldehyde, and xylene-induced inflammation tests. The effects of the extract in the various models were generally comparable to those of the standard drugs used.

CONCLUSION

The findings in this study suggest that the methanolic root extract of Cnestis ferruginea possesses analgesic and anti-inflammatory activities possibly mediated through peripheral and central mechanisms involving inhibition of release and/or actions of vasoactive substances (histamine, serotonin and kinins) and prostaglandins. The results justify the use of the extract in TAM for the treatment of painful and inflammatory conditions.

Effects of the hydroethanolic extract of Mucuna pruriens (L.) DC (Fabaceae) on haematological profile in normal and haloperidol treated rats

BACKGROUND

Mucuna pruriens (L.) DC (Fabaceae) is a climbing plant claimed in traditional medicine to possess anti-anaemic effect.

OBJECTIVE

The study is to investigate the effects of the hydroethanolic extract of M. pruriens (MP) on haematological profile in normal and haloperidol treated rats.

METHODS

MP was administered p.o. at doses of 50, 100, 200, and 400 mg/kg to groups of rats daily for 28 days. Control animals received distilled water. Rats were sacrificed on the 28th day and blood samples collected for evaluation of haematological parameters and serum iron. Another set of animals received MP p.o. at same doses but along with haloperidol (0.2 mg/kg, i.p.) daily for 4 days. Three other groups of rats received distilled water, haloperidol, and MP at 400 mg/kg alone. Haematological parameters and serum iron were determined. Extract iron content, phytochemical analysis and acute toxicity studies were also carried out.

RESULTS

MP administered to normal rats for 28 days significantly (p < 0.05) reduced the number of platelets and proportion of neutrophils. In haloperidol treated rats, MP significantly reversed the reduction in mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) values and increased the red blood cell (RBC) count and packed cell volume (PCV). MP also caused significant reduction in the number of platelets and proportion of neutrophils. Administered alone, MP caused a significant increase in the concentration of haemoglobin. The iron content of MP was found to be 61.20 mg/100 g and it was found to contain alkaloids, cardiac glycosides, saponins and tannins. Given up to 10 g/kg p.o., no deaths and visible signs of toxicity were observed while the LD50 for the i.p. route was estimated to be 1509.46 mg/kg.

CONCLUSION

The findings in the study suggest that the hydroethanolic extract of Mucuna pruriens possibly possess beneficial effects in anaemic conditions especially associated with iron deficiency.

Biological effects of Byrsocarpus coccineus in vitro

CONTEXT

Byrsocarpus coccineus Schum. and Thonn. (Connaraceae) is a scandent shrub widely employed as a medicinal remedy for various disease conditions in West Africa.

OBJECTIVE

This study evaluated fractions of B. coccineus for modulation of cytochrome P450 (CYP) enzyme activity, cytokine production, and proliferation.

MATERIALS AND METHODS

The BROD (benzyloxyresorufin O-debenzylase) and BFCOD (benzyloxy-4-[trifluoromethyl]-coumarin O-debenzyloxylase) assays were used to evaluate effect on CYP2B1/2 and CYP3A4 enzyme activity. Effects on cytokine production and proliferation of HT29 cells were investigated using interferon expression assay and MTT (3-3[4,5-dimethyl-2-thiazolyl]-2-5-diphenyl-2H-tetrazolium bromide) assay, respectively.

RESULTS

Fractions derived from the organic solvent extraction of B. coccineus produced significant (p<0.05) stimulation of human hepatic CYP2B1/2 activity in the BROD assay. The greatest effects were elicited at 1 ng/mL corresponding to ∼ 3-fold stimulation of enzyme activity. Enhancement of CYP3A4 enzyme activity was also observed in the BFCOD assay. Other fractions from the organic extract showed significant antiproliferative effects on HT29 cells at 100 μg/mL. Fractions obtained from the aqueous extract of B. coccineus (1 µg/µL) significantly stimulated the expression of IFNα2a and IFNβ in peripheral blood mononuclear cells (PBMC), causing a maximum 26-fold increase of IFNα2a-transcript.

DISCUSSION AND CONCLUSION

The effect on CYP suggests that B. coccineus may reduce the therapeutic efficacy of co-administered drugs. This justifies the need for proper education of patients by healthcare practitioners on the outcomes of drug-herb interactions. This study identifies several in vitro activities that could underlie the attributed uses of this plant in traditional African medicine (TAM).

Anticonvulsant, anxiolytic and sedative activities of the aqueous root extract of Securidaca longepedunculata Fresen

AIM OF THE STUDY

The objective of this study is to investigate the anticonvulsant, anxiolytic and sedative activities of the aqueous root extract of Securidaca longepedunculata.

MATERIALS AND METHODS

The anticonvulsant effect of the aqueous root extract (100, 200 and 400 mg/kg) was evaluated in mice using the strychnine- and picrotoxin-induced seizure models. Its anxiolytic activity was evaluated using the elevated plus maze (EPM) and the Y maze (YM) methods (Hogg, 1996; Yemitan and Adeyemi, 2003) while the hexobarbitone induced sleep and the hole board models were used to evaluate the sedative and exploratory activities in mice respectively. The acute toxicity studies and phytochemical analysis of the extract were also carried out.

RESULTS

The extract (100-400 mg/kg) produced a significant (P<0.01) dose dependent increase in onset of convulsion compared to the control for strychnine- and picrotoxin-induced seizures. It also produced a significant (P<0.01) dose dependent prolongation of the cumulative time spent in the open arms of the elevated plus maze and Y maze compared with the control. The extract (100-400 mg/kg) produced significant (P<0.01) reduction in the time of onset of sleep induced by hexobarbitone. The prolongation of hexobarbitone sleeping time by the extract (200 mg/kg) was comparable to that produced by diazepam (3 mg/kg). At doses of 100-400 mg/kg, the extract produced a dose dependent decrease in exploratory activity of the mice. The reduction in exploratory activity produced by the extract (400 mg/kg) was greater than that of chlorpromazine (1 mg/kg). The results obtained from the experiments indicate that the extract has central nervous system depressant and anxiolytic activities. The LD(50) obtained for the acute toxicity studies using both oral and intraperitoneal routes of administration were 1.74 g/kg and 19.95 mg/kg respectively.

CONCLUSION

These findings justify the use of Securidaca longepedunculata in traditional medicine for the management of convulsion and psychosis.

Hepatoprotective and in vivo antioxidant effects of Byrsocarpus coccineus Schum. and Thonn. (Connaraceae)

ETHNOPHARMACOLOGICAL RELEVANCE

The leaf decoction of Byrsocarpus coccineus (Connaraceae) is drunk for the treatment of jaundice in West African traditional medicine.

AIM OF THE STUDY

To investigate the hepatoprotective and in vivo antioxidant effects of Byrsocarpus coccineus in carbon tetrachloride (CCl(4))-induced hepatotoxicity in rats.

MATERIALS AND METHODS

Group allotment in this study included vehicle, CCl(4), Byrsocarpus coccineus 1000 mg/kg alone, Byrsocarpus coccineus 200, 400, and 1000 mg/kg+CCl(4) and Livolin((R)) 20mg/kg+CCl(4), and treatment was carried out accordingly. On the 7th day, rats were sacrificed and blood was withdrawn by cardiac puncture. The levels and activities of serum biochemical parameters and antioxidant enzymes were then assayed using standard procedures.

RESULTS

CCl(4) significantly (P<0.05) increased the levels of ALT and AST and reduced total protein. In CCl(4) treated animals, Byrsocarpus coccineus (200, 400, and 1000 mg/kg) dose-dependently and significantly decreased ALT, AST and ALP levels with peak effect produced at the highest dose. Conversely, Byrsocarpus coccineus produced significant increases in albumin and total protein levels. The standard drug produced significant effects in respect of ALT (downward arrow), albumin (upward arrow), and total protein (upward arrow). CCl(4) also produced significant (P<0.05) reductions in the activity of catalase, SOD, peroxidase and GSH, and conversely increased MDA level. Byrsocarpus coccineus produced significant and dose-dependent reversal of CCl(4)-diminished activity of the antioxidant enzymes and reduced CCl(4)-elevated level of MDA. The standard drug also significantly increased CCl(4)-diminished antioxidant enzymes activity and reduced CCl(4)-elevated MDA level. In general, the effects of the standard drug were comparable and not significantly different from those of Byrsocarpus coccineus.

CONCLUSION

The results obtained in this study suggest that the aqueous leaf extract of Byrsocarpus coccineus possesses hepatoprotective and in vivo antioxidant effects. This finding justifies the use of this preparation in West African traditional medicine for the treatment of liver disease.

Evaluation of the antidiarrhoeal effect of Sanseviera liberica Gerome & Labroy (Agavaceae) root extract

ETHNOPHARMACOLOGICAL RELEVANCE

The aqueous root extract of Sansevieraliberica (Agavaceae), SL, is used in Traditional African Medicine (TAM) for the treatment of diarrhoea. However, the scientific basis for this usage has not been established.

AIM OF THE STUDY

To evaluate the antidiarrhoeal activity of SL using various pharmacological models.

MATERIALS AND METHODS

The intestinal transit, castor oil induced diarrhoea, enteropooling, and gastric emptying methods were used in this study.

RESULTS

SL (25-400 mg/kg, p.o.) produced significant (P < 0.05) dose dependent reduction in propulsive movement in both the normal and castor oil induced intestinal transit tests in mice. Peak effect was elicited at 200 mg/kg but this effect was lower than that produced by morphine (10 mg/kg, s.c.). The effect of SL on castor oil induced intestinal transit was antagonized by isosorbide dinitrate, IDN (150 mg/kg, p.o.) but not by yohimbine (1 mg/kg, s.c.). In the castor oil induced diarrhoea test, SL significantly delayed the onset and decreased the frequency and severity of diarrhoea. The effect at 200 mg/kg was comparable to that of morphine and was reversed by IDN. SL at the dose of 200 mg/kg significantly reduced the volume of intestinal secretion induced by castor oil but produced no effect on gastric emptying. The extract was practically nontoxic administered p.o. The LD(50) was 631 mg/kg given i.p. Phytochemical analysis revealed the presence of oils, reducing sugars, alkaloids, saponins, anthraquinones, and tannins in the extract.

CONCLUSION

The results obtained in this study suggest that the aqueous root extract of Sanseviera liberica possesses antidiarrhoeal property due to inhibition of gastrointestinal propulsion and fluid secretion, possibly mediated through inhibition of the nitric oxide pathway. This justifies the use of the plant extract in TAM for the treatment of diarrhoea.

Antidiarrhoeal activity of the ethyl acetate extract of Baphia nitida (Papilionaceae)

In our search for plants useful in the treatment of diarrhoea, we investigated the ethyl acetate extract of Baphia nitida (BN) using intestinal transit, enteropooling and gastric emptying tests in mice and rats. In the castor oil intestinal transit test, BN produced a significant (P<0.05) dose dependent decrease in propulsion with peristaltic index (PI) values of 56.85+/-6.76, 36.84+/-3.04 and 31.98+/-2.60%, respectively at doses of 100, 200 and 400mg/kg vs. 89.33+/-6.28% for control. The effect at 400mg/kg was significantly lower than that of morphine, 10mg/kg, s.c. (20.29+/-3.78%), and was antagonized by isosorbide dinitrate, IDN (150mg/kg, p.o.) but not by yohimbine (1mg/kg, s.c.). This effect was not potentiated by atropine (1mg/kg, s.c.). In the castor oil-induced diarrhoea test, BN produced a significant increase in onset of diarrhoea (103.40+/-8.74, 138.80+/-17.04 and 174.8+/-29.04min, 100 to 400mg/kg, vs. 47.60+/-8.76min for control and 226.10+/-12.57min for morphine). The severity of diarrhoea (diarrhoea score) was dose dependently reduced (19.00+/-2.26, 17.04+/-1.89, 15.00+/-2.05, 100 to 400mg/kg, vs. 31.40+/-2.11 for control and 7.7+/-2.2 for morphine). This effect was not antagonized by IDN or yohimbine. The effect on severity was, however, potentiated by atropine. BN also reduced the number and weight of wet stools but did not have any significant effect on intestinal fluid accumulation and gastric emptying. Results obtained suggest that the ethyl acetate extract of Baphia nitida is endowed with antidiarrhoeal activity possibly mediated by interference with the l-arginine nitric oxide pathway and synergistic with antagonistic action on muscarinic receptors.

Antiinflammatory activity of the aqueous leaf extract of Byrsocarpus coccineus

The antiinflammatory effect of the aqueous leaf extract of Byrsocarpus coccineus was evaluated using the carrageenan and egg albumin induced rat paw edema, xylene induced mouse ear edema and formaldehyde induced arthritis inflammation tests. The extract administered orally at doses of 50, 100, 200 and 400 mg/kg b.w produced a significant (P<0.05) dose dependent inhibition of edema formation in all four methods used. The results obtained suggest that the aqueous leaf extract of B. coccineus is endowed with effective antiinflammatory activity mediated via either inhibition of phospholipase A(2) (PLA(2)) activity or cyclooxygenase cascade and by blocking the release of vasoactive substances (histamine, serotonin and kinins). These findings seem to justify the use of the plant in traditional African medicine in the treatment of inflammation, including arthritic conditions.

Evaluation of the antidiarrhoeal activity of Byrsocarpus coccineus

Based on its use in traditional African medicine, the antidiarrhoeal activity of the aqueous leaf extract of Byrsocarpus coccineus, Connaraceae, was evaluated on normal and castor oil-induced intestinal transit, castor oil-induced diarrhoea, enteropooling and gastric emptying. The extract (50, 100, 200 and 400 mg/kg, p.o.) produced a significant (P<0.05) dose dependent decrease in propulsion in the castor oil-induced intestinal transit in mice. The mean peristaltic index (%) for these doses of extract, control (distilled water; 10 ml/kg, p.o.) and morphine (10 mg/kg, s.c.) were 55.27+/-1.86, 53.12+/-3.73, 38.60+/-3.79, 30.25+/-1.27, 89.33+/-5.62 and 20.29+/-3.38, respectively. The effect of the extract at the highest dose was significantly (P<0.05) lower than that of the standard drug. This effect was antagonised by yohimbine (1 mg/kg, s.c.) but not by isosorbide dinitrate (IDN, 150 mg/kg, p.o.). At 200 mg/kg, the extract produced a significant decrease in propulsion in normal intestinal transit. In a dose dependent manner, it delayed the onset of diarrhoea, produced a significant decrease in the frequency of defaecation, severity of diarrhoea and protected the mice treated with castor oil. Mean diarrhoea scores were 30.83+/-1.72, 22.40+/-1.71, 21.43+/-1.32, 13.80+/-0.33, 18.00+/-3.94 and 7.67+/-2.41 for control, extract (50, 100, 200 and 400 mg/kg) and morphine, respectively. This effect was not antagonized by IDN. The extract (400 mg/kg) significantly decreased the volume (ml) of intestinal fluid secretion induced by castor oil (0.60+/-0.23) compared with 1.27+/-0.12 for control. However, there was no significant effect on gastric emptying. The results obtained suggest that Byrsocarpus coccineus possesses antidiarrhoeal activity due to its inhibitory effect on gastrointestinal propulsion, mediated through alpha(2) adrenoceptors, and also inhibition of fluid secretion. Preliminary phytochemical analysis revealed the presence of alkaloids, tannins, saponins, reducing sugars, glycosides and anthraquinones.