Glucose utilization and anti-oxidative mechanisms of the aqueous hunteria umbellata seed extract in alloxan-induced diabetic rats.

In South-west Nigeria, water decoctions of Hunteria umbellata seeds are highly valued by traditional healers in the local management of diabetes mellitus, obesity and hyperlipidemia. Previous studies hypothesized one of the antihyperglycemic mechanisms of the aqueous seed extract of Hunteria umbellata (HU) to be mediated probably via increased peripheral glucose utilization. The present study, therefore, was designed at evaluating the peripheral glucose utilization and anti-oxidative mechanisms of 50 mg/kg, 100 mg/kg and 200 mg/kg of HU in alloxan-induced diabetic rats in Groups IV-VI rats as well as in the control groups (Groups I-III). Experimental type 1 DM was induced in male Wistar rats through intraperitoneal injection of 150 mg/kg of alloxan monohydrate in cold 0.9% normal saline after which the diabetic rats were orally treated with 50-200 mg/kg of HU for 14 days. Effects of HU on the rat body weight, percentage body weight changes and fasting blood glucose (FBG) were determined on days 1 and 15 of the experiment. Also, on day 15 of the experiment, HU effect on serum insulin, liver enzyme markers, proteins, albumin, triglyceride, total cholesterol and lactate dehydrogenase as well as on hepatic tissue oxidative stress markers, liver glycogen and glucose-6-phosphatase were determined after sacrificing the rats under diethyl ether anesthesia. Results showed that oral treatments with 50-200 mg/kg of HU caused significant (p<0.0001) improvements in the weight loss caused by alloxan-induced diabetes, while causing significant (p<0.05, p<0.001 and p<0.0001) dose-related reductions in the FBG levels despite causing non-significant (p>0.05) alterations in the serum INS levels in the treated rats. Also, repeated oral treatment with HU caused significant (p<0.0001) reversal in the decrease and increase in the hepatic glycogen levels and glucose-6-phosphatase activity, respectively, caused by alloxan-induced diabetes. Similar significant (p<0.0001) and complete reversal effects were recorded in the serum hepatic enzyme markers, total protein, albumin, triglyceride, total cholesterol and lactate dehydrogenase as well as on hepatic tissue oxidative stress markers such as superoxidase dismutase (SOD), catalase (CAT), malonialdehyde (MDA) and reduced glutathione (GSH) of HU-treated rats when compared to that of untreated alloxan-induced diabetic rats. In conclusion, results of this study showed HU treatment to significantly ameliorate the hyperglycemia and oxidative stress in alloxan-induced diabetic rats which was mediated via increased hepatic glycogen deposit, decreased hepatic glucose-6-phosphatase activity and improvement in antioxidant/free radicals scavenging activities.

Oxidative stress and micronutrient therapy in malaria: an in vivo study in Plasmodium berghei infected mice.

Free radical production from oxidative stress induced by malaria infection plays a major role in the pathogenesis of malaria. However, the use of agents with antioxidant activity may interfere with malaria progression. The study involves an in vivo evaluation of the role of some antioxidant micronutrients in the modulation of malaria infection. Rodent malaria model using Plasmodium berghei NK-65 strain (chloroquine sensitive) was used for the study. Forty five mice of either sex weighing 20.05 +/- 0.02 g were procured for the study. Forty mice were inoculated intraperitoneally with 1 x 10(7) million Plasmodium berghei infected erythrocyte and were administered with 0.2 mL of distilled water, 0.2 mL of vehicle; Tween 80 (control and vehicle group), chloroquine 25 mg kg(-1) and artesunate 4 mg kg(-1) (standard drug group), vitamin A 60 mg kg(-1), vitamin E 100 mg kg(-1), selenium 1 mg kg(-1), zinc 100 mg kg(-1) (test group F, G, H and I, respectively) 72 hours post inoculation. Antioxidant micronutrients demonstrated significant (p < 0.05) schizonticidal activity when compared with negative control during the 4 day curative test. Erythrocyte membrane disability was most markedly elevated in the tween 80 group (426.15%), followed closely by the chloroquine (373.85%) treated group and artesunate group (329.23%) and least in the zinc treated group (32.31%). There was no significant (p > 0.05) difference in MCFI values (0.115 +/- 0.002; 0.114 +/- 0.002 g dL(-1)) between vitamin A treated group and selenium treated group respectively. However, this was significant (p < 0.05) between the micronutrient treated groups and the control (negative, positive and vehicle). Conclusively, antioxidant micronutrients have antimalarial activity which may be due potentiation of erythrocyte membrane stabilization.

The novel antihyperglycaemic action of Hunteria umbellata seed fractions mediated via intestinal glucose uptake inhibition.

The present study evaluated the antihyperglycaemic effect and mechanism of action of fractions of the aqueous seed extract of Hunteria umbellata (K. Schum.) Hallier f. (HU) in normal and alloxan-induced hyperglycaemic rats. HU was partitioned in chloroform, acetyl acetate and butan-1-ol to give chloroform fraction (HU c), ethyl acetate fraction (HU e), butanol fraction (HU b) and the "residue" (HU m), respectively. 200 mg/kg of each of these fraction dissolved in 5% Tween 20 in distilled water was investigated for its acute oral hypoglycaemic effects in normal rats over 6 hours while its repeated dose antihyperglycaemic effect was evaluated in alloxan-induced hyperglycaemic rats over 5 days. In addition, 50 mg/kg of the crude alkaloid fraction (HU Af) extracted from HU was evaluated for its possible antihyperglycaemic activity in alloxaninduced hyperglycaemic rats using oral glucose tolerance test (OGTT) over 6 hours. Using the solvent system, distilled water-butanol-ammonium hydroxide (2:15:1, v/v/v), HU b was chromatographed and stained with Dragendorff's reagent for confirmatory qualitative analysis for alkaloids. Results showed that oral pre-treatment with 200 mg/kg of HU e, HU b and HU m resulted in a significant (p<0.05, p<0.001) time dependent hypoglycaemic effect, with the butan-1-ol fraction HU causing the most significant (p<0.001) hypoglycaemic effect. In the alloxan-induced hyperglycaemic rats, repeated oral treatment with 200 mg/kg of same HU fractions for 5 days resulted in significant (p<0.05) decreases in the fasting blood glucose concentrations with the most significant (p<0.01) antihyperglycaemic effect also recorded for HU b. Similarly, oral pretreatment with 50 mg/kg of HU Af significantly (p<0.05, p<0.01 and p<0.001) attenuated an increase in the post-absorptive glucose concentration at 1(st) - 6(th) h in the alloxan-induced hyperglycaemic OGTT model. In addition, alkaloid was present in most of the separated spots on the TLC plate. In conclusion, results of this study showed that HU contains a relative high amount of alkaloids which could have accounted for the antihyperglycaemic action of HU that was mediated via intestinal glucose uptake inhibition.

Evaluation of the toxicity and reversibility profile of the aqueous seed extract of Hunteria umbellata (K. Schum.) Hallier f. in rodents.

Hunteria umbellata (K. Schum.) Hallier f. (family: Apocynaceae) is reputed for the folkloric management of labour, pain and swellings, stomach ulcers, diabetes, obesity, and anaemia, with no scientific report of its toxicity and reversibility profile. The present study was, therefore, aimed at investigating the in vivo toxicity and reversibility profile of the aqueous seed extract of Hunteria umbellata (HU). The acute oral and intraperitoneal toxicity studies of HU were determined in Swiss albino mice while its 90-day oral toxicity and toxicity reversibility profile on anthropometric, biochemical, haematological and histopathological parameters were also assessed using standard procedures. Results showed that the LD50 values for the acute oral and intraperitoneal toxicity studies for HU were estimated to be 1000 mg/kg and 459.3 mg/kg, respectively. Visible signs of immediate and delayed toxicities including starry hair coat, respiratory distress, and dyskinesia were observed. For the chronic oral toxicity study, HU administered for 90 days produced significant (p < 0.001) reductions in the weight gain pattern and significant (p < 0.001) and dose related increases in the relative weights of liver, stomach, spleen, testis, lungs and heart, at the 100 and 500 mg/kg of HU. Chronic HU treatment also produced significant (p < 0.05, p < 0.001) dose related reductions in the serum levels of fasting blood glucose, bicarbonate, urea and creatinine while causing non-significant (p > 0.05) alterations in the serum levels of sodium, potassium, alaninine transaminase, aspartate transaminase, alkaline phosphatase, total and conjugated bilirubin, total protein and albumin. Also, chronic oral treatment with HU produced significant (p < 0.05, p < 0.01, p < 0.001) and dose-related increases in the red cell count, packed cell volume, haemoglobin concentration, platelet count, total leucocyte count and lymphocyte differential while producing significant (p < 0.05) reductions in neutrophil and granulocyte differentials. HU also produced histological features of proliferations of the stomach epithelia, lung tissues, splenic white and red pulps, and testicular spermatogenic series. Following 14 days of oral toxicity reversibility test, there was no significant (p>0.05) reversal in the serum levels of the biochemical and haematological parameters investigated, including the HU-induced histological lesions. Overall, results of this study showed that HU has a relatively low oral toxicity profile but its prolonged use, particularly, at high doses should be with great caution.

Biochemical and toxicological studies of aqueous extract of Syzigium aromaticum (L.) Merr. & Perry (Myrtaceae) in rodents.

The effects of long-term administration of boiled aqueous extract of Syzigium aromaticum (SYZ), commonly known as clove (which has been locally employed for treating gastrointestinal tract diseases and also used as food spices), on some biochemical indices, such as body weight, liver functions and blood parameters were studied in adult albino rats of both sexes. Selected doses of 300 and 700 mg kg(-1) were given orally through cannular to groups of animals for a period of 90 days, while the control group received distilled water throughout the duration of study via the same route. Blood samples collected after therapy and assayed for activities of some liver enzymes recorded a significant (p<0.05) and prominent effect on ALP and AST. Measurement of haematological parameters also revealed significant effects (p<0.05; p<0.001) on Hb, RBC (p<0.05), PCV (p<0.001), platelets (p<0.001) and granulocytes (p<0.001). An insignificant reduction was recorded for total WBC. The histopathological study conducted was in consonance with the results of the biochemical investigations that the aqueous extract of SYZ even at moderate doses, significantly affects body organs, their enzymes as well as the various functions. LD(50) for both intraperitoneal and oral routes of SYZ were 263 and 2500 mg kg(-1) respectively. The present work has revealed the toxicity of sub chronic administration of SYZ, which suggests that its prolonged usage must be avoided.

Biochemical and toxicological studies of aqueous extract of syzigium aromaticum (l.) Merr. et Perry (myrtaceae) in Rodents

Abstract: The effects of long-term administration of boiled aqueous extract of Syzigium aromaticum (SYZ), commonly known as clove (which has been locally employed for treating gastrointestinal tract diseases and also used as food spices), on some biochemical indices, such as body weight, liver functions and blood parameters were studied in adult albino rats of both sexes. Selected doses of 300 and 700 mg kg-1 were given orally through cannular to groups of animals for a period of 90 days, while the control group received distilled water throughout the duration of study via the same route. Blood samples collected after therapy and assayed for activities of some liver enzymes recorded a significant (p<0.05) and prominent effect on ALP and AST. Measurement of haematological parameters also revealed significant effects (p<0.05; p<0.001) on Hb, RBC (p<0.05), PCV (p<0.001), platelets (p<0.001) and granulocytes (p<0.001). An insignificant reduction was recorded for total WBC. The histopathological study conducted was in consonance with the results of the biochemical investigations that the aqueous extract of SYZ even at moderate doses, significantly affects body organs, their enzymes as well as the various functions. LD50 for both intraperitoneal and oral routes of SYZ were 263 and 2500 mg kg-1 respectively. The present work has revealed the toxicity of sub chronic administration of SYZ, which suggests that its prolonged usage must be avoided

Gastrointestinal effects of Syzigium aromaticum (L) Merr. & Perry (Myrtaceae) in animal models.

BACKGROUND: Gastrointestinal disorders constitute one of the most common diseases world-wide and the treatment of some of them has since constituted a great challenge to health workers, which therefore calls for an urgent search into newer agents. In recent years, several efforts have been made through series of investigations on natural resources. OBJECTIVE: The plant Syzigium aromaticum (SYZ), commonly known as clove has since been employed locally to treat constipation. Attempt to complement the effort of other researchers called for its selection for laboratory investigation, in order to determine its possible effect on intestinal propulsion in rodents as well as its suspected gastrointestinal protective properties. METHODS: SYZ hot aqueous extract was investigated using selected doses in the various study models. Effect of the decoction on intestinal propulsion was studied by administering 300 and 700 mg kg(-1) hot extract to groups of overnight fasted mice, while using charcoal meal as a marker. The effect of the herbal drug was compared with other standard drugs and antagonists. In the same vein, the same doses of the extract were administered orally to groups of overnight fasted rats prior to challenge with different necrotizing agents-absolute ethanol (1 ml/rat), indomethacin (30 mg kg(-1)) and 70% ethanol in 150 mM HCl (1 ml/rat). Both negative and positive controls were similarly treated simultaneously with distilled water (10 ml kg(-1)) and standard antiulcer drugs (omeprazole 20.0 mg kg(-1), cimetidine 100.0 mg kg(-1) and misoprostol 0.2 mg kg(-1)), respectively. Lastly, the effect of SYZ was investigated on a segment of isolated rabbit ileum and subsequently compared with acetylcholine 5.5 x 10(-5) M. The effects of atropine (3.4 x 10(-6) M and 3.4 x 10(-5) M) on SYZ were also studied. RESULTS: The extract was found to increase the gut muscle propulsion similar to the standard drugs-carbachol and metoclopramide. When used together with atropine, SYZ produced a reduction in intestinal propulsion which suggested the involvement of cholinergic mechanisms in the action of the extract. In the ulcer models, the decoction reduced the ulcer number and ulcer area in the ethanol and HCl-ethanol models, with significant respective ulcer indices of 2.80 +/- 3.51 and 11.4 +/- 3.79 compared with controls (p < 0.05). In the indomethacin model, the extract, 700 mg kg(-1), compared favourably with misoprostol with an index of 0.20 +/- 0.11 which was also found to be significant compared with the control. In the in-vitro investigation on the rabbit ileum SYZ (200-6400 microg ml(-1)) contracted the tissue in a dose-dependent fashion but it was found to be less effective than acetylcholine (5.5 x 10(-5) M). Atropine sulphate 3.4 x 10(-6) M and 3.4 x 10(-5) M reduced gut contractility induced by SYZ, similar to the in-vivo observation. The latter could substantiate the earlier speculation of the herbal drug exerting its effect via cholinergic mechanism apart from the diverse possible activities of the various bioactive components that were identified through phytochemical testing of SYZ. CONCLUSION: The present findings explain the folkloric uses of SYZ as an antiulcer and a purgative agent as well as its possible mechanism of action.

Oral toxicity studies of a Nigerian polyherbal health tonic tea extract in rats.

In the present study, acute and subchronic oral toxicity studies of an aqueous extract of a Nigerian Polyherbal Health Tonic (PHT) were investigated in adult Wistar rats of both sexes and weighing between 110-200 g. Acute toxicity study was conducted using limit dose test of Up and Down Procedure under computer guided statistical software program (AOT 425 StatPgm). The subchronic toxicity was evaluated in 4 groups of rats made up of six rats/group, administered single, daily oral doses of 10 ml/kg distilled water (DW), 125, 500 and 1500 mg/kg of PHT, respectively, for 90 days. On the 91st day, blood samples for haematological and biochemical assays were collected through cardiac puncture and selected vital organs harvested en bloc for histopathological examination under inhaled anaesthesia. Results showed PHT to be relatively safe on acute toxicity with an estimated LD50 value greater than 5000 mg/kg/oral route. On prolonged exposure, PHT induced initial weight gain in the 1st 6 weeks followed by significant (P < 0.05) dose related weight loss in the latter 6 weeks. The extract also caused significant (P < 0.05) dose related elevation of the full blood count parameters, dose unrelated elevation of serum urea, liver enzymes, serum proteins, albumin, total and conjugated bilirubin. On histology, PHT induced dose dependent gastric mucosal denudation, bile ductal lining distortion, diffuse pulmonary interstitial fibrous proliferation and diffuse splenic lymphocytic proliferation. Thus, our results showed that PHT use may be relatively safe on acute exposure but toxic on chronic exposure to high doses, although reversibility of these toxic effects was not studied in the present study.

Knowledge and management of malaria among non-medical Nigerian undergraduates.

AIMS AND OBJECTIVE: The present work investigated knowledge and management of malaria among non-medical students in two tertiary institutions in Lagos State, Nigeria, and aimed at evaluating the possible roles played by the human host in perpetuating the deadly disease, malaria, especially among those outside the health-sector. METHODS: Two tertiary institutions within Lagos metropolis were selected as study fields and a total population of 400 non-medical students was studied through random distribution of fixed-end and self-administered questionnaire. RESULTS: The study showed that most of the informants did not know much about malaria, in terms of its transmission, symptoms, prevention, management, morbidity and mortality, which could explain the disappointments that have been suffered in the fight against the parasite and its carrier even in the face of highly efficacious anti-malarias, since such individuals would not be able to manage the disease adequately. Some of the correct responses were found to be significant when compared with the incorrect options. Lastly, drugs other than anti-malarials were employed to treat the disease and conversely, most fevers were thought by the students to be due to malaria. CONCLUSION: The present work shows the massive gap in the knowledge of malaria between the health sector and other members of the society. If there must be any clue to the long-standing problems facing malaria therapy, it will come as a consequence of bridging the gap.

Effect of chronic co-administration of metformin and vitamin C on plasma glucose and lipid concentrations in normal rats.

In clinical setting, uncomplicated diabetes mellitus type 2 is managed with anti-oxidants (e.g. ascorbic acid, alpha-tocopherol, etc.) with standard oral hypoglycaemic agents, which is aimed at limiting its glucose auto-oxidation and lipid peroxidation complications. The current study is an experimental animal study aimed at investigating the effect of co-administration of metformin and ascorbic acid (Vitamin C) on plasma glucose and lipid levels in non-diabetic rats which could serve as a template for future studies in this area. The hypoglycaemic and hypolipidaemic activities of metformin, ascorbic acid, and metformin-ascorbic acid combination were studied in 4 groups consisting of 6 rats per group and weighing 120 - 155 g, by administering oral doses of 5, 10 and 15 (for co-administration) mg/kg/day of the drugs, respectively, for 30 days. The acute oral toxicity of the combination was also conducted using limit dose test of Up and Down Procedure of Acute Oral Toxicity test. Results of the study showed that metformin and metformin-ascorbic acid combination induced significant and comparable hypoglycaemia. The drug combination also lowered plasma total cholesterol, low density lipoprotein-cholesterol (LDL-c), very low density lipoprotein-cholesterol (VLDL-c) significantly but had no effect on plasma high density lipoprotein-cholesterol (HDL-c). The LD50 estimate of the drug combination was greater than 5000 mg/kg body weight/oral route. The results of this study suggest the drug combination could have hypoglycaemic and lipid-lowering effects.

A KAP study of the attitude and practice of traditional medicine in a contemporary Nigerian community.

OBJECTIVE: To study the knowledge, attitude and practice of traditional medicine among Nigerians in a contemporary selected community. DESIGN: Structured, fixed-alternative, self-administered questionnaires constituted the research instrument, which was randomly distributed among the sampled population of 320 respondents. SETTING: Agege Local Government Area located in Lagos State, Nigeria and consisting of diverse tribes, different social classes, religious beliefs and levels of literacy. Subjects above the age of 12 years were selected for the study. RESULTS: Out of the 320 copies of the questionnaire distributed, 300 were returned. It was observed that 134 (44.7%) had a knowledge of traditional medicine and what it entails. A total of 101 (33.7%) believed that every ailment has spiritual implications and that drugs alone are not adequate for therapy. Furthermore, the majority of the subjects considered traditional medicine unreliable when used alone. They would, therefore, combine it with orthodox drugs for better efficacy. However, only 8.3% advocated the replacement of western medicine by traditional medicine. There was an association between age, educational background and knowledge of traditional medicine (p < 0.01). CONCLUSION: The secrecy of practitioners has hampered access to the therapeutic benefit of the system of medicine to the general population. However, traditional medicine is still employed since it is a part of African cultures, and because of the unavailability of western medicine. Such employment of traditional medicine has resulted in misuse and consequently, adverse drug reactions.

Toxicological study of the extracts of anti-malarial medicinal plant Enantia chlorantha.

Acute and sub-acute toxicity studies of the medicinal plant Enantia chlorantha were carried out in mice. The oral and s.c. routes of administration of both the aqueous and ethanolic extracts were employed. All the animals reacted to the medicinal plant, when given by both routes, with itching leading to body scratching lasting about 10 minutes. Fatality was not recorded in mice given 0.2g kg-1 s.c. and 20.0g kg-1 orally of both the ethanolic and aqueous extracts of E. chlorantha but larger concentration of both extracts resulted in deaths. Mean lethal dose (LD50) of 0.7g kg-1 was recorded for ethanolic, while 43.65g kg-1 was for aqueous preparations. In the sub-acute toxicity in which the animals were given 3 x 10(3)-5 x 10(-3)g kg-1 of the aqueous extract to drink at will for five weeks, no fatality was recorded and no significant damage to the body organs was observed. These data indicate that the plant drug when taken is safe in diseased states.

The effects of extracts of Enantia chlorantha in malaria.

The aqueous extract of the plant Enantia chlorantha was found effective in suppressing Plasmodium yoelii infection in mice if given orally in drinking fluid at 0.2-150 mg ml-1, but not if given by oral cannulation or subcutaneously. The animals given the extract in their drinking fluid survived for over 60 days. The ethanolic extract also was found to be effective in eliminating the parasites when administered subcutaneously in doses of 0.05-0.5 mg g-1. The chemoprophylactic action of the aqueous extract given in drinks prior to infection gave protection for almost 96 hours, but the ethanolic extract administered parenterally gave no such protection. The aqueous and ethanolic extracts have ED50 values of 6.9 mg g-1 and 0.34 mg g-1, respectively, and are schizonticidal in action. Phytochemical analysis of the plant extracts revealed the presence of alkaloids, saponins and simple sugars.