Selected Antihypertensive Agents and Their Fixed-Dose Combinations Effectively Ameliorate Trastuzumab-Mediated Cardiac Dysfunction In Rats.

This study evaluates the therapeutic potentials of selected antihypertensive drugs [valsartan, amlodipine, lisinopril and their fixed-dose combinations (amlodipine + lisinopril) and (valsartan + lisinopril)] in ameliorating trastuzumab (TZM)­induced cardiac dysfunctions in experimental rats. After an ethical clearance for the study was obtained, in-bred young adult female Wistar rats were randomly allotted into 10 groups of 6 rats per group. Group I rats were treated with 10 ml/kg/day sterile water p.o. and 1 ml/kg/day sterile water i.p.; Group II, III and IV rats were orally treated with 5 mg/kg/day VAL and 1 ml/kg/day sterile water i.p., 0.25 mg/kg/day ADP and 1 ml/kg/day sterile water i.p., 0.035 mg/kg/day LSP and 1 ml/kg/day sterile water i.p., respectively. Group V rats were orally pretreated with 10 ml/kg/day of sterile water before i.p. 2.25 mg/kg/day of TZM. Groups VI-VIII rats were equally pretreated with 5 mg/kg/day VAL, 0.25 mg/kg/day ADP, and 0.035 mg/kg/day LSP before i.p. 2.25 mg/kg/day TZM treatment, respectively. Also, Groups IX and X rats were orally pretreated with the fixed-dose combinations of 0.25 mg/kg/day ADP + 0.035 mg/kg/day LSP in dissolved in sterile water and 5 mg/kg/day VAL + 0.035 mg/kg/day LSP before 2.25 mg/kg/day TZM treatment for 7 days. Blood pressure parameters [systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MAP)] and electrocardiogram (ECG) of the treated rats were measured using non-invasive procedures on days 1 and 7 of the experiment, following which the treated rats were sacrificed humanely under light inhaled diethyl ether and histopathological examination was conducted on all treated rat hearts. Results show that repeated TZM treatment significantly (p<0.05) raised SBP, DBP and MAP values from 115.0 ± 17.1 mmHg, 85.1 ± 15.1 mmHg     and      94.7 ± 15.5 mmHg, respectively on day 1      to 127.7 ± 27.8 mmHg, 87.4 ± 27.3 mmHg       and 100.5 ± 26.4 mmHg, respectively, on day 7. Oral pretreatments with VAL, ADP, LSP and their fixed-dose combinations significantly (p<0.05) attenuated increases in the SBP, DBP and MAP values with the most significant attenuation mediated by the fixed-dose VAL + LSP combination at the SBP, DBP and MAP values of 103.8 ± 20.6        mmHg, 65.5 ± 18.8 mmHg, and 77.9 ± 18.7 mmHg, respectively. TZM treatment also profoundly (p<0.05) prolonged the QT and corrected QT intervals from 85.0 ± 11.5 ms and         161.6 ± 20.3 ms, respectively, on day 1 to 110.2 ± 21.5 ms and 226.5 ± 41.5 ms, respectively, on day 7. However, these QT and corrected QT interval prolongations were effectively and profoundly attenuated by oral pretreatments with VAL, ADP, LSP and their fixed-dose combinations. In addition, TZM cardiotoxicity was characterized by marked vascular and cardiomyocyte congestion and coronary artery microthrombi formation. However, these histopathological changes were reversed with oral pretreatments with ADP, LSP, VAL and fixed-dosed [(ADP + LSP) and (VAL + LSP)] combinations although fixed-dose VAL + LSP was associated with histopathological lesions of coronary arterial wall cartilaginous metaplasia. Overall, this study revealed the promising therapeutic potentials of VAL, ADP, LSP and their fixed-dose combinations as repurposed drugs for the prevention of TZM-mediated cardiac dysfunctions.

In vivo Safety Evaluation of a Nigerian Polyherbal Mixture in Female Wistar Rats.

The present study evaluates the oral safety and oral toxicity reversibility of a Nigerian Polyherbal Mixture (NPM) in female Wistar rats. In this study, acute oral toxicity was conducted on 20 female Wistar rats using the limit dose test of Up-And-Down Procedure of the OECD Acute Oral Toxicity Testing 425 guidelines at 5000 mg/kg of NPM. Additionally, 40 female Wistar rats (120-150 g) were divided into 4 groups (n=10) and orally treated with 10ml/kg of distilled water, 82 mg/kg, 410 mg/kg and 2050 mg/kg of NPM, respectively, for 90 days. Five rats from each group were sacrificed while the remaining rats in each group were kept for another 14 days for oral toxicities reversibility test. Blood samples and vital organs were obtained for biochemical, hematological and histological changes. Results showed that acute oral toxicity testing of NPM caused no death in any of the three sequentially treated rats and its estimated LD50 value was greater than 5000 mg/kg. Chronic oral treatment with 82-2050 mg/kg NPM caused significant elevations in the serum urea and creatinine and full blood count parameters (except differential WBC counts). The elevated renal function parameters were corroborated by dose-related histological changes of renal tubular congestions. also caused profound thrombocytosis and histopathological changes of pulmonary interstitial widening and gastritis. In conclusion, NPM may not be considered safe for consumption on prolonged use and at a high dose due to its profound tendencies to cause pulmonary fibrosis, nephrotoxicity, gastritis and thrombo-embolism. However, all the biochemical and hematological but histopathological alterations induced by NPM were reversed 14 days after the treatment cessation.

Chemopreventive Effect of Tadalafil in Cisplatin-Induced Nephrotoxicity in Rats.

Nephrotoxicity remains a common untoward effect of cisplatin therapy with limited effective chemopreventive options available till date. This study aims to evaluate the possible chemopreventive effect and mechanism(s) of action of 2 mgkg-1 and 5 mgkg-1 of Tadalafil in cisplatin-induced nephrotoxic rats. In this study, twenty-five male Wistar rats were randomly divided into five groups (n = 5 rats per group) and daily pretreated with oral doses of distilled water (10 mLkg-1), ascorbic acid (100 mgkg-1), Tadalafil (2 mgkg-1 and 5 mgkg-1) for 7 days before cisplatin (5 mgkg-1, intraperitoneal) was administered. 72 hours post-cisplatin injections, rats were sacrificed humanely and blood samples for serum electrolytes, urea and creatinine and renal tissues for reduced glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malonialdehyde dehydrogenase (MAD) assays and histopathology were collected. Results showed that cisplatin injection caused significant decreases in the serum sodium (Na+), potassium (K+), bicarbonate (HCO3-), calcium (Ca2+), phosphate (PO42-) and concomitant significant increases in the serum urea and creatinine levels. In addition, there were significant decreases in the renal tissue GSH, SOD, CAT and increased MAD and GSH-Px levels which were corroborated by histopathological features of tubulonephritis. However, these histo-biochemical alterations were significantly attenuated by ascorbic acid and Tadalafil pretreatments. Overall, results of this study showed the chemopreventive potential of Tadalafil against cisplatin-induced nephrotoxicity which was possibly mediated via antioxidant and anti-lipoperoxidation mechanisms.

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.

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.

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

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.

Hypoglycemic and hypolipidemic effects of methanol seed extract of Citrus paradisi Macfad (Rutaceae) in alloxan-induced diabetic Wistar rats.

BACKGROUND: Alcohol decoction of Citrus paradisi Macfad (Rutaceae) seed is reputed for the local management of array of human diseases including, anemia, diabetes mellitus and obesity by some Yoruba herbalists (SouthWest, Nigeria). Despite its historic use, scientific evaluation of its folkloric use in the management of diabetes mellitus is scarce. OBJECTIVES: The present study was designed at investigating the glucose and lipid lowering effects of methanol seed extract of Citrus paradisi Macfad (MECP) in alloxan-induced diabetic rats. In addition, the phytochemical analysis of the extract was also conducted using standard procedures. METHODS: Young adult, male, alloxan-induced diabetic rats were randomly divided into groups I - VI with 12 rats in each group. Group I rats were the normal untreated rats while group II rats served as the diabetic untreated rats while Rats in groups III - VI served as diabetic rats treated with 100, 300 and 600 mg/kg/day MECP and 20 mg/kg/ day metformin, respectively, for 30 days. On the 15th and respectively, 31st day, blood samples from the fasted rats were obtained for fasting plasma glucose (FPG), plasma triglycerides (TG), total cholesterol (TC), high density lipoprotein- cholesterol (HDL-c), low density lipoprotein-cholesterol (LDL-c) and very low density lipoprotein-cholesterol (VLDL-c) from the sacrificed rats. RESULTS: Oral treatment with 100 - 600 mg/kg/day MECP, for 30 days, resulted in significant (p < 0.05, p < 0.01, p < 0.001) reductions in FPG, TG, TC, LDL-c, VLDL-c in the diabetic rats, effects which were comparable to that of metformin. The extract also caused significant (p < 0.05, p < 0.01) rise in HDL-c values in the alloxan diabetic rats. Phytochemical result showed the presence of alkaloids, flavonoids, cardiac glycosides, tannins and saponin in varying concentrations. The biological effects recorded for the extract could be due to any or a combination of these phytochemical constituents. CONCLUSION: Results of this study lend support to the traditional use of grapefruit seeds in the management of type 1 diabetic patients and may suggest a role in orthodox management of the disease.

Hypoglycemic and hypolipidemic effects of the aqueous fresh leaves extract of Clerodendrum capitatum in Wistar rats.

Diabetes mellitus, the most common endocrine disorder of carbohydrate metabolism, is treated in the African traditional phytotherapies with the cold water decoction of Clerodendrum capitatum (CC). In the current study, the hypoglycemic and hypolipidemic effects of fresh leaves aqueous extract of CC were studied in four groups of six adult Wistar rats per group and weighting 120-150 g, by administering graded oral doses (100, 400 and 800 mg/kg/day) of the extract for 14 days. On the 15th day, the fasted rats were anesthetized under inhaled halothane and blood samples obtained through cardiac puncture. Phytochemical analysis of CC extract was conducted using standard procedures while the preliminary acute oral toxicity study was also conducted using limit dose test of Up and Down Procedure at a limit dose of 5000 mg/kg body weight/oral route. Results of the study showed CC to cause significant (p<0.05, p<0.001) dose dependent hypoglycemic and hypolipidemic effects but had no effect on the pattern of weight gain in the treated rats. Although no lethal effect was recorded with CC oral administration for up to 5000 mg/kg body weight/oral route, but there was an associated transient somatomotor and behavioral toxicities. Phytochemical results revealed the presence of saponins, flavonoids, alkaloids, tannin, glycosides and reducing sugars in the extract. Thus, the folkloric use of Clerodendrum capitatum in the treatment of suspected type 2 diabetics has a positive correlation with scientific data generated in this study.

Hypoglycemic and antidiabetic activities on the stem bark aqueous and ethanol extracts of Musanga cecropioides in normal and alloxan-induced diabetic rats.

Daily oral administration of the aqueous and ethanolic extracts of Musanga cecropioides stem bark in normal and diabetic rats at doses of 250, 500 and 1000 mg/kg/day, for 14 days significantly lowered the fasting plasma glucose levels in normal and alloxan-induced diabetic rats in dose-dependent fashion. The ethanol extract induced more significant antidiabetic effect than the aqueous extract.

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.

Oral metformin-ascorbic acid co-administration ameliorates alcohol-induced hepatotoxicity in rats.

BACKGROUND: Alcoholic liver disease remains a major cause of liver failure worldwide with no available curative or prophylactic therapy as at present. High dose metformin is reported to ameliorate liver injuries in both human and animal models of acute and chronic alcoholic liver injuries. OBJECTIVES: The aim of the present in vivo animal study was to determine whether metformin-ascorbic acid co-administration also prevents alcoholic hepatotoxicity in chronic alcohol exposure. METHODS: In the present study, ameliorating effect of 200 mg/ kg/day of ascorbic acid (Asc), 500 mg/kg/day of metformin (Met) and their co-administration (Met-Asc) were investigated in 5 groups of 50% ethanol-treated male Wistar rats for 2 weeks of the experiment. The body weight of each rat was taken on days 1, 7, and 14 of the experiment, respectively. On day 15, fasted blood samples for plasma lipids and liver enzyme markers were collected via cardiac puncture from the rats under diethyl ether anaesthesia. RESULTS: Results showed that administration of graded oral doses of 50% ethanol for 14 days significantly (p<0.001) elevated the plasma liver enzymes--aspartate aminotransferase (AST), alanine aminotansferase (ALT) and alkaline phosphatase (ALP). Two weeks of ethanol treatment also induced alterations in the plasma triglycerides (PTG), total cholesterol (PTC), high density lipoprotein (HDL-c), and low density lipoprotein (LDL-c). However, these elevations were significantly (p<0.05) attenuated by Asc, Met, and Met-Asc after 14 days of oral treatment, with Met-Asc having higher significant (p<0.001) ameliorating effect than Asc alone but with comparative effect to that of Met alone. CONCLUSION: High dose metformin-ascorbic acid co-administration protected the liver against the deleterious effects of chronic high dose alcohol and the hepatoprotective effect of Met-Asc appeared to be due mainly to the metformin molecule of the drug combination. However, further studies would be required to evaluate the mechanisms underlying the observed effects.

Hypoglycemic and hypocholesterolemic activities of the aqueous leaf and seed extract of Phyllanthus amarus in mice.

The effect of the aqueous leaf and seed extracts of Phyllanthus amarus at oral dose of 150, 300 and 600 mg/kg was investigated for their antidiabetic and anti-lipidemic potentials. The extract produced a dose-dependent decrease in the fasting plasma glucose and cholesterol, and reduction in weights in treated mice. The results suggest that the extract could be enhancing peripheral utilization of glucose but the mechanisms on how this works remain unclear.

Preliminary toxicity and phytochemical studies of the stem bark aqueous extract of Musanga cecropioides in rats.

These studies were designed to determine the preliminary oral toxicity profile of the crude aqueous stem bark extract of Musanga cecropioides (MCW) in adult Sprague-Dawley rats and its active chemical constituents by way of phytochemistry. The acute oral toxicity study was conducted using limit dose test of Up and Down Procedure according to the OECD/OCDE Test Guidelines on Acute Oral Toxicity (AOT425statPgm, version: 1.0) at a limit dose of 3,000 mg/kg body weight/oral route. Repeat dose oral toxicity studies were conducted by daily oral dosing of 750 mg/kg body weight of MCW dissolved in 1 ml of 0.9% saline and 1 ml of 0.9% saline to rats in the test and control groups, respectively, for 28 days. On day 29, blood samples for bioassays were collected by cardiac puncture under diethyl ether anesthesia. The phytochemical analysis was conducted using standard procedures. The LD(50) estimate of the extract was calculated to be greater than 3,000 mg/kg body weight/oral route. The extract caused a significant (P<0.05) decrease in weight gain, differential eosinophil count and increase in serum creatinine but did not affect the organ weights, other serum electrolytes (Na(+), K(+), HCO(3)(-)), liver enzymes and other hematological indices in test rats. Its phytochemical analysis showed it contains saponins, flavonoids, alkaloids, tannins, phlobatannins, glycosides, reducing sugars and anthraquinones. These results show that the aqueous extract of Musanga cecropioides is relatively safe toxicologically when administered orally. Thus, its use in folkloric medicine as an oral antihypertensive is relatively safe when used over the tested period.

The hypotensive mechanisms for the aqueous stem bark extract of Musanga cecropioides in Sprague-Dawley rats.

The present study was designed to evaluate the hypotensive properties and the mechanisms of action of the stem bark aqueous extract of Musanga cecropioides R.Br. Apud Tedlie (MCW) in anesthetized rats of Sprague-Dawley strain, through an invasive direct blood pressure measuring procedure. Thirty adult rats, weighing 150-230 g, were grouped into five groups of six rats each. The effects of the intravenous graded doses (0.0005-0.05 mg/kg) of the extract on the blood pressure indices were investigated. Its underlying mechanisms were also studied using additional five groups of rats. The results showed that the extract caused a dose dependent fall in the systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure and heart rate of the rats. Bilateral carotid artery occlusion (BCO) caused a reflex increase in mean arterial pressure and heart rate which were significantly attenuated by the extract injection. Angiotensin Converting Enzyme (ACE) blockade with 5 mg/kg of Captopril and cholinergic blockade with 0.2 mg/kg of atropine significantly attenuated the hypotensive response to MCW. However, the pattern of MAP fall in rats pretreated with a combination of Promethazine (1 mg/kg) and Cimetidine (15 mg/kg) was not significant. The results of the study was able to demonstrate dose dependent hypotensive effect of MCW and that its vasorelaxant effects may be through inhibition of sympathetic, cholinergic control of the arterial pressure and most significantly through ACE blockade. However, the phytochemical, elemental and toxicological studies of this potential antihypertensive still needed to be investigated.

Willingness to seek HIV testing and counseling among pregnant women attending antenatal clinics in Ogun State, Nigeria.

HIV counseling and testing (CT) is slowly being introduced as one of several key components of the comprehensive package of HIV/AIDS prevention and care in Nigeria, particularly in the prevention of mother-to-child transmission of HIV (PMTCT). A cross-sectional survey of 804 women attending antenatal clinics (ANC) in Ogun State, Nigeria was done using questionnaires to assess their willingness to seek and undergo CT and know the determinants. Focus group discussions were also held in the general community: 84.3% of respondents believed in AIDS reality, while 24.3% thought they were at risk of HIV infection. Only 27% knew about MTCT, while 69.7% of 723 who had heard of HIV/AIDS did not know about CT. Only 71 (8.8%) had thought about CT and 33 (4.5%) mentioned HIV testing as one of antenatal tests. After health education on CT, 89% of the women expressed willingness to be tested. Their willingness for CT was positively associated with education (p < 0.05), ranging from 77% (no education) to 93% (post-secondary). More of those with self-perceived risk expressed willingness to test for HIV (p < 0.05). Those willing to be tested had a higher knowledge score on how HIV spreads than those not willing. Multiple regressions identified four key factors that were associated with willingness for CT: increasing educational level; not fearing a blood test; perception that the clinic offered privacy; and perceptions of higher levels of social support from relatives and peers. Those unwilling or undecided about CT expressed strong fear of social stigma/rejection if tested positive. The results provided insights for planning promotional programs and showed that not only are IEC efforts needed to boost knowledge about HIV/AIDS, but that change in clinic setting and community are imperative in creating supportive environment to encourage uptake of CT services.

Antidiarrhoeal activities of Ocimum gratissimum (Lamiaceae).

The antidiarrhoeal activities of leaf extracts of Ocimum gratissimum were investigated by disc diffusion and tube dilution methods. The extracts were active against Aeromonas sobria, Escherichia coli, Plesiomonas shigelloides, Salmonella typhi, and Shigella dysenteriae. The leaf extracts were most active against S. dysenteriae and least active against S. typhi. The sensitivity of the organisms measured in terms of zone of inhibition ranged from 8.00 to 19.50 mm. The minimum inhibitory concentrations were from 4.00 to 50.00 mg ml-1, while the minimum bactericidal concentration ranged from 8.00 to 62 mg ml-1. The potentials of the leaf extract for the treatment of diarrhoeal diseases is discussed.