School of Pharmacy

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    Anticonvulsant Effect Of Ethanolic Leaf Extract Of Ehretia Cymosa Thonn (Boraginaceae) In Murine Models.
    (University Of Ghana, 2018-07) Nelson, L.R.
    Purpose: Ehretia cymosa is used locally in Ghana to treat epilepsy. To validate this anecdotal information with scientific data, the anticonvulsant effect of the ethanolic extract of the leaves of Ehretia cymosa was studied in murine models. Materials and Methods: The potential anticonvulsant activity of an ethanol extract of Ehretia cymosa (ECE) (30, 100, and 300 mg kg-1) was tested employing the acute pentylenetetrazole (PTZ)-, PTZ-induced kindling, picrotoxin-induced seizures and maximal electroshock (MES) in mice. The extract‘s effect on motor co-ordination and nociception was also tested using the rota-rod and the hot plate tests respectively. Acute and sub-chronic toxicity tests were also done to ascertain how safe the extract is in rodents. Results: This study showed that, the ethanolic extract of ECE possesses anticonvulsant effects in the various seizure threshold models used, except in the maximal electroshock seizure model. The latencies to the first myoclonic jerks were increased by ECE while both the duration and frequencies of seizures reduced significantly. There was however no effect on motor coordination even when highest dose of 300 mg kg-1 was used. No mortalities were recorded in the animals used during the period of this study. The ECE also did not have any significant effect on any of the serum biochemical parameters after the study. Conclusions: The ethanolic extract of the leaves of the Ehretia cymosa was found to possess anticonvulsant properties, and possibly acts through the GABAergic transmission pathway but has no muscle relaxant properties. The findings from this study, therefore, give scientific credence to the traditional use of Ehretia cymosa to manage epilepsy. The 10-week oral administration of the extract of Ehretia cymosa under the prevailing laboratory conditions was found to be relatively safe in male Sprague–Dawley rats.
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    Anticonvulsant and Sedative Effects of the Hydro-Ethanolic Whole Plant Extract of Cleome Rutidosperma (Dc.) (Cleomeceae) in Mice.
    (University of Ghana, 2019-07) Tabariyeng, N.J.
    BACKGROUND: Cleome rutidosperma (DC.) (Family: Cleomeceae) is a low-growing herb used for the treatment of epilepsy in African traditional medicine. This study presents the anticonvulsant, sedative effects and safety profile of the hydro-ethanolic extract of the whole plant of Cleome rutidosperma (CRE) in murine experimental models. METHODS: Preliminary phytochemical screening of the extract was conducted using standard colorimetric assays. The general effect of the extract, CRE (10, 30, 100, 300, 1000 and 3000 mg kg-1 p.o.) on the central nervous system of mice was assessed using the Irwin test. The anticonvulsant screening of CRE (100, 300 and 1000 mg kg-1 p.o.) utilized four murine models of experimental epilepsy; pentylenetetrazole (PTZ)-, picrotoxin (PIC)-, maximal electroshock (MES)- induced seizures and pentylenetetrazole-induced kindling. Phenobarbitone and carbamazepine were used as reference anticonvulsant agents in the anticonvulsant screening experiments. The duration, frequency and latency to seizures were measured for each treated animal. The extract’s ability to induce sedation was also investigated using the thiopental sleeping time test. Acute and subacute toxicity studies were conducted to determine the safety of the extract in mice. RESULTS: Preliminary phytochemical screening indicated the presence of flavonoids, alkaloids, glycosides, phytosterols and saponins. In the Irwin test, the extract produced sedation as its major effect. In the acute seizure models, the extract caused significant increase in the latency to seizure (P< 0.0001) and a significant reduction in the duration of tonic-clonic convulsions (P< 0.0001) in PTZ- induced seizure model. Also, the extract significantly decreased duration of seizures (P< 0.0001) and increased the latency to seizure in the PIC- induced seizure model (P< 0.0001). In the MES test, the extract did not significantly reduce the duration of hind limb tonic extension (P= 0.6446) and it did not increase the latency to hind limb tonic extension (P= 0.3257). In PTZ-induced kindling test, the extract significantly (P=0.0002) reduced the percentage severity of seizures in the mice and prevented the animals from being fully kindled. The extract (30, 100, 300 and 1000 mg kg-1 p.o.) dose-dependently and significantly decreased the latency to sleep (P< 0.0001) and increased significantly the duration of sleep (P< 0.0001) induced by thiopental sodium. There were no deaths recorded in the acute toxicity studies even at a dose of 3000 mg kg-1 thus the LD50 was estimated to be more than 3000 mg kg-1. The relative organ to body weight ratio for both control and treatment groups were not significantly different in both acute (P= 0.9987) and subacute (P= 0.9887) toxicity studies. Histopathological examination of the brain, and heart showed no prominent abnormalities in the extract-treated group. However, the histopathological examination of the kidney and liver showed tubular dilatation with erythrocyte infiltration and hepatocellular oedema respectively. CONCLUSIONS: The hydro-ethanolic extract of the whole plant of Cleome rutidosperma produces anticonvulsant and sedative effects in mice. The extract was relatively safe in the acute and sub-acute toxicity investigations in mice, with an LD50 greater than 3000 mg kg-1.
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    Effect of Cellgevity®, a Glutathione-Enhancer Dietary Supplement, on Streptozotocin-Induced Type-2 Diabetes and Nephrotoxicity in Rat
    (University of Ghana, 2019-07) Asare, B.A.
    Background: Diabetic nephropathy (DN), a diabetes-induced nerve damaging effect on the kidney structure and function due to hyperglycaemia is a major microvascular complication. Hyperglycaemia causes uremia, hypercreatininemia, declined glomerular filtration rate, and decreased levels of serum protein and albumin. This condition leads to progressive decline in renal function resulting in renal insufficiency and End-Stage Renal Disease. The prevalence of DN in Africa has increased significantly in recent years, emphasising the importance of developing new preventive and treatment therapies. Despite the fact that there are different medications used to manage DN, most of these drugs are associated with serious unwanted side effects that contributes to the many complications observed in DN patients. This has paved way for the search for newer and better therapeutic agents that can better manage the disease and, at the same time, causing very less side effects. It was hypothesised that Cellgevity® could provide protection from diabetes and its complications. Aim: To evaluate the hypoglycaemic and nephroprotective potentials of Cellgevity® in healthy and type-2 diabetic nephropathy rat models. Methods: Seventy (70) male Sprague-Dawley rats with an average weight of 200 g were grouped into10 groups of seven rats each (n = 7). All rats were subjected to an overnight fast for 12 hours after which type-2 diabetes mellitus (T2DM) was induced using streptozotocin (STZ) (60 mg/kg b.wt) and nicotinamide (NA) (110 mg/kg b.wt). After 24-hours of STZ-NA injection, rats with fasting blood glucose (FBG) greater than 11.1 mmol/L were considered diabetic and divided into 8 groups. Group 1 of the diabetic rats received distilled water (diabetic negative control). Groups 2, 3, and 4 were orally administered with varying doses of Cellgevity® (40 mg/kg b.wt; 80 mg/kg b.wt; 160 mg/kg b.wt respectively); Group 5 and 6 received 15 mg/kg b.wt and 20 mg/kg b.wt of glibenclamide (Glib) and captopril (Cap) respectively. Group 7 and 8 of the diabetic rats received combinations of either Cellgevity® and Glib or Glib and Cap. Two additional groups (non-diabetic rats) served as normal controls. Blood samples were taken by tail snip and FBG were measured at specific days (1, 3, 6, 9, 12, 15, 22 and 29) following induction of T2DM. At the end of the experiment (29th day), the animals were sacrificed, and their blood, kidneys and pancreas harvested for haematological, biochemical, and histological studies. Results: Diabetic rats showed a significant increase in FBG (30.33 mmol/L, p<0.001), serum creatinine (81.20%) and urea (110%) with a corresponding decrease in total protein (47.94%) and albumin (75.46%) when compared to the normal control rats. The Cellgevity® doses, 40 mg/kg b.wt and 80 mg/kg b.wt significantly decreased (p<0.001) FBG from 30.33 to 17.33±3.69 mmol/L and 17.35±9.07 mmol/L respectively. The Glib dose (15 mg/kg b.wt) reduced levels of FBG from 30.33 to 9.85±3.96 mmol/L within the 28-day treatment period. Also, there was a significant increase (p<0.01) in serum albumin (ALB, 176.52%), total proteins (T.PROT, 79.13%) and white blood cell count (WBC, 154.98%) in diabetic rats administered with Cellgevity® when compared to the diabetic control rats. Serum ALB levels in diabetic rats administered with single therapy of Glib and combined form (Glib plus Cap) increased significantly (p<0.01) by 109.30% and 210.83% respectively in comparison with the diabetic control rats. Furthermore, Glib and Glib plus Cap markedly increased T.PROT by 27.10% and 61.87% respectively when compared to the diabetic control. Administration of Cellgevity® (low dose) resulted in 68.78% and 55.87% decrease in serum CREA and urea respectively. Similarly, the groups that were administered with Glib and Glib plus Cap had a decrease in serum CREA by 56.61% and 58.69% respectively in comparison with diabetic control rats. Kidney histological sections (40X) showed noticeable alterations (shrank glomeruli tuft, ballooned bowman space) in the diabetic control rat in comparison with the diabetic positive control rats. Conclusion: The study demonstrated that administration of Cellgevity® (40, 80 mg/kg b.wt) reduces FBG level and protects against nephrotoxicity in STZ-NA induced type-2 diabetic rats. This study could justify the use of Cellgevity® in the management of nephropathy in diabetic patients. Further study (clinical trial) should be conducted in humans to confirm this finding.
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    Antinociceptive Activity of the Hydro-Ethanolic Extract of the Leaves of Mallotus Oppositifolius (Geiseler) Mull. Arg. in Acute and Chronic Pain Models
    (University of Ghana, 2019-07) Addai, E.O.
    BACKGROUND: Mallotus oppositifolius is a medicinal plant commonly used in folk medicine to treat disorders involving pain and inflammation, among other ailments. However, the potential of this herb for the treatment of pain has only rudimentary scientific validation. The study sought to investigate the analgesic activity of the hydro-ethanolic extract of the leaves of M. oppositifolius (MOE) in order to provide detailed scientific justification for its traditional folkloric use. METHODS: Preliminary phytochemical screening was conducted on the MOE. Antinociceptive activity of MOE (30, 100 and 300 mg/kg) in acute pain models was evaluated using the formalin test, the acetic acid-induced writhing assay and the hot plate test. The mechanism of antinociception was evaluated by employing various antagonists in the formalin test including naloxone (2 mg/kg), glibenclamide (8 mg/kg), theophylline (10 mg/kg), ondansetron (0.5 mg/kg), yohimbine (3 mg/kg), nifedipine (10 mg/kg) and atropine (5 mg/kg). For the chronic pain model, peripheral neuropathy was induced in ICR mice using paclitaxel (2 mg/kg, i.p.) for 5 days and the effect of the extract on paclitaxel-induced peripheral neuropathy was evaluated daily for 5 days post induction using the Randall-Selitto test for mechanical hyperalgesia, hot plate test for thermal hyperalgesia and cold water at 4℃ for cold allodynia with pregabalin (10, 30 and 100 mg/kg) as the positive control. Sub-chronic toxicity study was carried out with male Sprague-Dawley rats divided into four groups; group 1 received vehicle p.o. while groups 2-4 were orally treated with MOE daily at 30, 100 and 300 mg/kg for 90 days consecutively. At the end of the test mice were sacrificed for their organs for histopathological analysis and their whole blood and serum for haematological and biochemical analysis respectively. RESULTS: Phytochemical screening confirmed the presence of secondary metabolites including saponins, alkaloids, flavonoids, glycosides, sterols, tannins and reducing sugars. MOE together with morphine and diclofenac (positive controls) showed significant (P<0.05) and dose-dependent decrease in the nociceptive scores in the formalin test, the acetic acid induced writhing assay and an increase in antinociceptive scores in the hot plate test. Naloxone, theophylline, ondansetron, glibenclamide, atropine, yohimbine and nifedipine failed to block the antinociceptive effects of MOE (100 mg/kg) in the formalin test. The extract significantly (P<0.05) and dose-dependently increased the paw withdrawal latencies to mechanical and thermal hyperalgesia after the 5–day induction of neuropathy with paclitaxel in mice. In the 90-day sub-chronic toxicity study, data analysis of mortality, body weight gain, clinical observations, haematology, biochemistry, organ weights and histopathological findings did not show significant differences between control and treated groups. CONCLUSION: The oral administration of a hydro-ethanolic leaf extract of Mallotus oppositifolius produces dose-dependent antinociceptive effects in formalin, acetic acid-induced and thermal acute pain tests, and also significantly inhibited mechanical and thermal hyperalgesia in paclitaxel-induced peripheral neuropathy in mice. There was no extracttreatment related toxicity in rats following a 90-day daily oral administration. The findings support the traditional uses of the plant in alleviating pain.
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    Genetic Polymorphisms Affecting Tacrolimus Dose Requirements in Ghanaian Patients with End-Stage Renal Disease
    (University of Ghana, 2019-07) Otabil, M.K.
    Background: ESRD is the irreversible damage of a person’s kidney, affecting it normal physiological functions and rendering it fatal if not managed by dialysis or transplantation. In Ghana, ESRD is managed primarily by hemodialysis until the patient can afford kidney transplantation. However, transplants are accompanied with an immune response by the host immune system resulting in a high probability of organ rejection. Immunosuppressant dosing in combination with other immune regulatory medications are required to prevent transplant rejection. Tacrolimus is a first-line immunosuppressant; however, it has a narrow therapeutic range. Tacrolimus is a known substrate of CYP3A5, CYP3A4 enzymes and an efflux pump, P-glycoprotein. The differences in expression level of the substrates are a contributory factor to the individual variations of the pharmacokinetics of Tacrolimus. General Aim: To determine the genetic polymorphisms in CYP3A5, CYP3A4 and MDR1 genes in Ghanaian patients with End Stage Renal Disease. Method: This is a cross-sectional study that involved 87 ESRD patients, out of which 5 were transplant recipients and 82 were on dialysis. Clinical and demographic data were recorded and the genomic DNA isolated. Samples were genotyped for specific SNPs in CYP3A5*3 6986 A>G rs776746, CYP3A4*1B -290 A>G rs2740574, MDR1_Ex12 1236 C˃T rs1128503, MDR1_Ex26 3435 C>T rs1045642, MDR1_Ex21 2677 G>A rs2032582 and MDR1_Ex21 2677 G˃T rs2032582 using PCR-RFLP. The genetic frequencies of the transplant recipients were analyzed against the patients’ Tacrolimus dose and trough levels. Outcome: The mean age of study participants was recorded as 46 years ±14.39. The etiologies of ESRD were mostly hypertension and diabetes. The frequency of CYP3A5*3 (6986 A˃G) genes expressed showed that 4.6% were mutant. This mutant gene was expressed only among the dialysis patients. The frequency of CYP3A4*1B (-290 A˃G) genes expressed showed that 79.31% were mutant, out of which 80% were from the transplant recipients. A wild-type genotypic frequency of 100% was recorded in the participants for the MDR1_Ex12 (1236 C˃T) gene. Also, a 100% wild-type genotypic frequency was recorded in the participants for the MDR1_Ex21 (2677 G˃A) genes. No homozygous mutant genotype was expressed for MDR1_Ex21 (2677 G˃T) genes, however, 1.15% expressed the heterozygous genotype. None of the participants expressed the mutant genotype TT which affects the level of expressed P-glycoprotein in the transmembrane region of cells. The frequency of MDR1_Ex26 (3435 C˃T) genes expressed showed that 1.15% were mutant genotype. From the Tacrolimus trough level and genotype analysis, four transplant recipients expressing the homozygous variant CYP3A4*1B/*1B recorded significantly lower Tacrolimus trough level (average of 5.95± 1.8 ng/ml) compared to the fifth recipient (10.3ng/ml). There was no clear correlation between the expressed genes of the MDR1 haplotype genes and Tacrolimus trough level.
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    Effect of 30-Day Administration of Cellgevity® On Selected Rat Liver Cyp450 Enzyme Activity and Possible Interaction with Carbamazepine
    (University of Ghana, 2019-07) Akandawen, M.
    Background: There is considerable evidence that many patients concurrently take conventional drugs with dietary supplements or herbal products. One such supplement, with an amalgam of extracts, is Cellgevity®. There is, however, a dearth of information on the effect of this supplement on drug metabolizing enzymes, and on the pharmacokinetics of conventional drugs. Aim: To determine the effect of Cellgevity® on the activity of rat liver CYP1A1/2, CYP3A4, CYP2B1/2, CYP2C9 and CYP2D6 enzymes, and potential effect on the pharmacokinetics of carbamazepine. Methodology: Male and female Sprague-Dawley rats (Hsd:SD strain), weighing 150-200 g and 6-8 weeks old were put into five groups (3 males and 3 females per group). Group 1 was administered with the vehicle (distilled water), that was, solvent used in dissolving Cellgevity® (negative control). Groups 2, 3 and 4 were administered a suspension of Cellgevity® by oral gavage at a low dose (38.63 mg/kg), medium dose (77.25 mg/kg) and high dose (154.50 mg/kg) daily, respectively. Group 5 was administered phenobarbital (15 mg/kg) as positive control. After a 30-day administration period, the animals were sacrificed and livers harvested. Microsomal preparations from rat livers were made by homogenization and differential centrifugation. The substrates of each specific CYP was added to microsomal preparation in phosphate buffer (pH 7.4) and incubated at 37oC and their metabolites measured using fluorometric and chromatographic assays for CYP3A4, CYP2B1/2, CYP1A1/2, CYP2C9 and CYP2D6. Modulation of enzymes by Cellgevity® treatment was determined by comparing enzyme activity of Cellgevity®-treated animals with enzyme activity of negative control animals. The effect of Cellgevity® on the pharmacokinetics of carbamazepine in healthy male SD rats was also investigated. Rats were put into 2 groups consisting of 5 rats in each group. Group 1 was given only Cellgevity® (77.25 mg/kg, po) with normal saline and Group 2 was administered with Cellgevity® (77.25 mg/kg, po) and carbamazepine (80 mg/kg po) concurrently. Treatment was done for 14 days and blood sampled at 0.5, 1, 4, 12 and 24 h from each rat on the 15th day. Blood samples were centrifuged, and serum obtained. Analyses for the levels of carbamazepine in serum (pooled) corresponding to each time point for each group were done by Fluorescence Polarization Immunoassay. Non-compartmental pharmacokinetic analysis was used to estimate pharmacokinetic parameters for the 2 groups. The pharmacokinetic parameters: Cmax, Tmax, AUC, Ke and t1/2 estimation was done by non-compartmental analysis using GraphPad Prism 8.0. Results: Data from the current study showed that on a whole Cellgevity® increased activity of rat liver CYP3A4, CYP2B1/2, CYP1A1/2, CYP2C9 and CYP2D6. However, the increase in enzyme activity of CYP1A1/2, CYP2C9 and CYP2D6 by Cellgevity® was found to be statistically significant. Amongst treatment groups with statistically significant increase in enzyme activity, it was found that, CYP activity modulation by Cellgevity® was dose dependent for female groups of CYP1A1/2, CYP2C9 and CYP2D6, and combined sex group of CYP2C9. The pharmacokinetic parameters for SD rats administered carbamazepine with Cellgevity® vis-a-vis rats administered carbamazepine with normal saline were as follows: Cmax; 20 μmol/L vrs 11 μmol/L, AUC0→24; 347 μmol.h/L vrs 170 μmol.h/L, Ke; 0.3 h-1 vrs 0.4 h-1, and t1/2; 2.3 h vrs 1.7 h, respectively. Conclusion: A 30-day treatment period with Cellgevity® among rats led to a significant increase in the enzyme activity of CYP1A1/2, CYP2C9 and CYP2D6. From the study, it was evident that Cellgevity® altered the pharmacokinetics of carbamazepine in SD rats.
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    Antinociceptive Activity of the Hydro-Ethanolic Extract of the Leaves of Mallotus Oppositifolius (Geiseler) Mull. Arg. In Acute and Chronic Pain Models
    (University of Ghana, 2019-07) Addai, E.O.
    BACKGROUND: Mallotus oppositifolius is a medicinal plant commonly used in folk medicine to treat disorders involving pain and inflammation, among other ailments. However, the potential of this herb for the treatment of pain has only rudimentary scientific validation. The study sought to investigate the analgesic activity of the hydro-ethanolic extract of the leaves of M. oppositifolius (MOE) in order to provide detailed scientific justification for its traditional folkloric use. METHODS: Preliminary phytochemical screening was conducted on the MOE. Antinociceptive activity of MOE (30, 100 and 300 mg/kg) in acute pain models was evaluated using the formalin test, the acetic acid-induced writhing assay and the hot plate test. The mechanism of antinociception was evaluated by employing various antagonists in the formalin test including naloxone (2 mg/kg), glibenclamide (8 mg/kg), theophylline (10 mg/kg), ondansetron (0.5 mg/kg), yohimbine (3 mg/kg), nifedipine (10 mg/kg) and atropine (5 mg/kg). For the chronic pain model, peripheral neuropathy was induced in ICR mice using paclitaxel (2 mg/kg, i.p.) for 5 days and the effect of the extract on paclitaxel-induced peripheral neuropathy was evaluated daily for 5 days post induction using the Randall-Selitto test for mechanical hyperalgesia, hot plate test for thermal hyperalgesia and cold water at 4℃ for cold allodynia with pregabalin (10, 30 and 100 mg/kg) as the positive control. Sub-chronic toxicity study was carried out with male Sprague-Dawley rats divided into four groups; group 1 received vehicle p.o. while groups 2-4 were orally treated with MOE daily at 30, 100 and 300 mg/kg for 90 days consecutively. At the end of the test mice were sacrificed for their organs for histopathological analysis and their whole blood and serum for haematological and biochemical analysis respectively. RESULTS: Phytochemical screening confirmed the presence of secondary metabolites including saponins, alkaloids, flavonoids, glycosides, sterols, tannins and reducing sugars. MOE together with morphine and diclofenac (positive controls) showed significant (P<0.05) and dose-dependent decrease in the nociceptive scores in the formalin test, the acetic acid induced writhing assay and an increase in antinociceptive scores in the hot plate test. Naloxone, theophylline, ondansetron, glibenclamide, atropine, yohimbine and nifedipine failed to block the antinociceptive effects of MOE (100 mg/kg) in the formalin test. The extract significantly (P<0.05) and dose-dependently increased the paw withdrawal latencies to mechanical and thermal hyperalgesia after the 5–day induction of neuropathy with paclitaxel in mice. In the 90-day sub-chronic toxicity study, data analysis of mortality, body weight gain, clinical observations, haematology, biochemistry, organ weights and histopathological findings did not show significant differences between control and treated groups. CONCLUSION: The oral administration of a hydro-ethanolic leaf extract of Mallotus oppositifolius produces dose-dependent antinociceptive effects in formalin, acetic acid-induced and thermal acute pain tests, and also significantly inhibited mechanical and thermal hyperalgesia in paclitaxel-induced peripheral neuropathy in mice. There was no extracttreatment related toxicity in rats following a 90-day daily oral administration. The findings support the traditional uses of the plant in alleviating pain.
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    Effect of Swedish Bitters on Selected Rat Cytochrome P450 Enzyme Activity and Hepatic Antioxidant Levels
    (University of Ghana, 2019-07) Aning, A.
    Background: The use of herbal products has gained popularity especially in developing countries. A number of patients are known to take these herbal products concurrently with conventional drugs. Concomitant use of herbal preparations and conventional drugs may result in herb-drug interactions, often via modulation of drug metabolizing enzymes, in particular, Cytochrome P450 (CYP) enzymes. Swedish bitters is one of such herbal preparations on the market which may be concomitantly administered with other conventional drugs because of its use as a digestif. Aims: The aims of the current study were to determine the effect of Swedish bitters on the activities of rat liver microsomal CYP1A2, CYP3A4, CYP2B6, CYP2C9 and CYP2D6 enzymes, and also its effect on hepatic antioxidant levels. The effect of Swedish bitters on rat hematological and biochemical parameters was also assessed. Methods: Male Sprague-Dawley rats 6-8 weeks old were put into 5 groups (5 rats/group). The groups consisted of a positive control (15 mg/kg/day of phenobarbital), a negative control (distilled water), and low (5 mL/kg/day), medium (10 mL/kg/day) and high (20 mL/kg/day) doses of Swedish bitters, respectively. After a 7-day administration period of the aforementioned treatments, the rats were euthanized and blood obtained by cardiac puncture. The livers were isolated, immediately placed on ice and stored at -80oC until use. Microsomal preparations were obtained from harvested livers by homogenization and differential centrifugation. The substrates of each specific CYP was added to microsomal preparations in phosphate buffer (pH 7.4) at 37oC and their metabolites measured using spectrophotometric and chromatographic assays. Effect of Swedish bitters on enzyme activity was determined based on metabolite levels. Antioxidant levels/reactions such as Glutathione (GSH), Lipid peroxidation (LPO), Superoxide Dismutase (SOD) and Catalase (CAT) were evaluated in liver cytosol using standard methods. Additionally, hematological and biochemical parameters in the various groups from blood collected were determined using automated analyzers. Results: Results showed that Swedish bitters increased the activities of CYP2B1/2B2, CYP3A4, CYP2C9 and CYP2D6; with CYP2C9 significantly increased (p < 0.01). The activity of CYP1A1/1A2 did not differ significantly compared to the non-treated groups. There was a marginal increase in CYP1A2 activity in treatment groups, however, this was not statistically significant. Furthermore, with antioxidant levels/reactions assayed in liver cytosol, there was a dose dependent decrease in GSH levels and increase in SOD activity, however, both were not statistically significant. Catalase activity was found to have decreased dose-dependently, with the rats that received high dose of Swedish bitters showing a significant decrease compared to the untreated group. Lipid peroxidation did not alter significantly in treated groups compared to the untreated group. For hematological and biochemical parameters, monocytes and alkaline phosphatase (ALP) levels decreased significantly in the rats that received high doses of Swedish bitters. Conclusion: Swedish bitters increased the activity of rat CYP2C9 significantly. Swedish bitters also altered the levels of catalase enzyme activity and reduced ALP levels, significantly. Findings suggest that Swedish bitters may interact with other drugs that are metabolized by these CYPs especially when taken over longer periods.
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    Antinociceptive Activity of the Hydro-Ethanolic Extract of the Leaves of Mallotus Oppositifolius (Geiseler) Mull. Arg. In Acute And Chronic Pain Models
    (University of Ghana, 2019-07) Addai, E.O.
    BACKGROUND: Mallotus oppositifolius is a medicinal plant commonly used in folk medicine to treat disorders involving pain and inflammation, among other ailments. However, the potential of this herb for the treatment of pain has only rudimentary scientific validation. The study sought to investigate the analgesic activity of the hydro-ethanolic extract of the leaves of M. oppositifolius (MOE) in order to provide detailed scientific justification for its traditional folkloric use. METHODS: Preliminary phytochemical screening was conducted on the MOE. Antinociceptive activity of MOE (30, 100 and 300 mg/kg) in acute pain models was evaluated using the formalin test, the acetic acid-induced writhing assay and the hot plate test. The mechanism of antinociception was evaluated by employing various antagonists in the formalin test including naloxone (2 mg/kg), glibenclamide (8 mg/kg), theophylline (10 mg/kg), ondansetron (0.5 mg/kg), yohimbine (3 mg/kg), nifedipine (10 mg/kg) and atropine (5 mg/kg). For the chronic pain model, peripheral neuropathy was induced in ICR mice using paclitaxel (2 mg/kg, i.p.) for 5 days and the effect of the extract on paclitaxel-induced peripheral neuropathy was evaluated daily for 5 days post induction using the Randall-Selitto test for mechanical hyperalgesia, hot plate test for thermal hyperalgesia and cold water at 4℃ for cold allodynia with pregabalin (10, 30 and 100 mg/kg) as the positive control. Sub-chronic toxicity study was carried out with male Sprague-Dawley rats divided into four groups; group 1 received vehicle p.o. while groups 2-4 were orally treated with MOE daily at 30, 100 and 300 mg/kg for 90 days consecutively. At the end of the test mice were sacrificed for their organs for histopathological analysis and their whole blood and serum for haematological and biochemical analysis respectively. University of Ghana http://ugspace.ug.edu.gh xiii RESULTS: Phytochemical screening confirmed the presence of secondary metabolites including saponins, alkaloids, flavonoids, glycosides, sterols, tannins and reducing sugars. MOE together with morphine and diclofenac (positive controls) showed significant (P<0.05) and dose-dependent decrease in the nociceptive scores in the formalin test, the acetic acid induced writhing assay and an increase in antinociceptive scores in the hot plate test. Naloxone, theophylline, ondansetron, glibenclamide, atropine, yohimbine and nifedipine failed to block the antinociceptive effects of MOE (100 mg/kg) in the formalin test. The extract significantly (P<0.05) and dose-dependently increased the paw withdrawal latencies to mechanical and thermal hyperalgesia after the 5–day induction of neuropathy with paclitaxel in mice. In the 90-day sub-chronic toxicity study, data analysis of mortality, body weight gain, clinical observations, haematology, biochemistry, organ weights and histopathological findings did not show significant differences between control and treated groups. CONCLUSION: The oral administration of a hydro-ethanolic leaf extract of Mallotus oppositifolius produces dose-dependent antinociceptive effects in formalin, acetic acid-induced and thermal acute pain tests, and also significantly inhibited mechanical and thermal hyperalgesia in paclitaxel-induced peripheral neuropathy in mice. There was no extracttreatment related toxicity in rats following a 90-day daily oral administration. The findings support the traditional uses of the plant in alleviating pain.
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    Pharmacokinetic Evaluation of Chitosan Coated Hydroxypropylmethyl Cellulose (HPMC) Microparticles of Levodopa and Carbidopa
    (University of Ghana, 2019-07) Dankyi, B.O.
    Background: Levodopa, a prodrug of dopamine, remains the gold standard in the treatment of Parkinson’s disease. Current levodopa drugs are formulated in combination with an aromatic amino acid decarboxylase inhibitor, carbidopa, to prevent peripheral metabolism of levodopa. However, chronic use of levodopa is associated with potentially disabling motor complications and side effects, which arise from variable plasma concentration of the drug. Several attempts have been made to improve the formulation and drug delivery of levodopa with the aim of providing constant plasma levels in order to improve the drug’s efficacy. Microparticluate drug delivery systems have shown potentiality to deliver drugs at their target sites over a long of period of time while maintaining constant plasma concentrations. The aim of this study was to formulate and evaluate the pharmacokinetics of chitosan coated hydroxypropylmethyl cellulose (HPMC) microparticles of levodopa and carbidopa using in vitro and in vivo models. Methodology: Microparticles were formulated by encapsulating levodopa/carbidopa powders in HPMC using the spray-drying method. The levodopa microparticles were evaluated for size, drug content, percentage drug loading capacity, encapsulation efficiency and in vitro release profile. For pharmacokinetic evaluation, Sprague Dawley rats were administered either levodopa/carbidopa powder, levodopa/carbidopa microparticles or Sinemet CR (a controlled release formulation of levodopa/carbidopa). Blood samples were collected after predetermined times after the third dose. Plasma was obtained from blood and levodopa levels determined by high performance liquid chromatography. Pharmacokinetic parameters; maximum plasma concentration (Cmax), the time it takes to achieve this peak (Tmax), area under the curve (AUC) and half-life (t1/2) of were estimated from concentration-time curves. Results: The particle size obtained ranged between 0.04 μm to 6 μm with a mean size of 0.2 μm. Of the expected 20% drug loading, the actual drug loading capacity of the microparticles was found to be 19.1%, giving an encapsulation efficiency of 95.6%. The in vitro release kinetics showed a controlled and sustained drug release profile of levodopa microparticles with 80% drug release occurring at 12 h. In vivo pharmacokinetic studies showed a kinetic profile of levodopa/carbidopa microparticles as compared to the conventional control release formulation. The AUC (704.5 ± 85.37), and Cmax (262.4 μg/mL) of levodopa/carbidopa microparticles were relatively higher than Sinemet CR (AUC 252.7 ± 33.88 and Cmax 128.8 μg/mL). Conclusion: Findings from the study suggest that levodopa/carbidopa microparticles may give adequate levels of levodopa plasma concentration over a period of time.