Piperine Enhances Antimalarial Activity of Methyl Gallate and Palmatine Combination

PURPOSE

Artemisinin combination therapies, the first-line antimalarials in Nigeria, have reportedly suffered multiple failures in malaria treatment, hence the search for novel combination of other compounds. Methyl gallate and palmatine have been reported to exhibit antiplasmodial activities but the antimalarial activity of their combination has not been evaluated. Therefore, the evaluation of the combination of methyl gallate and palmatine for antimalarial activity in vitro and in vivo in the presence of piperine was carried out.

MATERIALS AND METHODS

The inhibitory potential of methyl gallate and palmatine combination on β-hematin (hemozoin) formation was studied in vitro. Also, the antimalarial activity of methyl gallate and palmatine combination with/without a bioenhancer (piperine) was evaluated in Plasmodium berghei NK65-infected mice.

RESULTS

Methyl gallate and palmatine in the ratio 3:2 acted synergistically in vitro and had the highest inhibitory effect (IC50 = 0.73 µg/mL) on β-hematin (hemozoin) formation. The 3:2 combination of methyl gallate and palmatine exhibited no antimalarial activity in vivo in the absence of piperine but caused reduction in parasitemia that exceeded 40% in the presence of piperine at the dose of 25 mg/kg body weight on days 6 and 8 post-inoculation in mice.

CONCLUSION

The 3:2 combination of methyl gallate and palmatine in the presence of piperine exhibited antimalarial activity in vivo, possibly by synergistic inhibition of hemozoin formation which may cause accumulation of haem within the food vacuole of Plasmodium spp. and its death.

Potentials of Terpenoids as Inhibitors of Multiple Plasmodium falciparum Protein Drug Targets

PURPOSE

The resistance of parasite to readily affordable antimalarial drugs, the high cost of currently potent drugs, and the resistance of vector mosquitoes to insecticides threaten the possibility of malaria eradication in malaria endemic areas. Due to the fact that quinine and artemisinin were isolated from plants sources, researchers have been encouraged to search for new antimalarials from medicinal plants. This is especially the case in Africa where a large percentage of the population depends on medicinal plant to treat malaria and other ailments.

METHOD

In this study, we evaluated previously characterized Plasmodium-cidal compounds obtained from the African flora to identify their likely biochemical targets, for an insight into their possible antimalarial chemotherapy. Molecular docking study was first conducted, after which remarkable compounds were submitted for molecular dynamic (MD) simulations studies.

RESULTS

From a total of 38 Plasmodium-cidal compounds docked with confirmed Plasmodium falciparum protein drug targets [plasmepsin II (PMII), histo-aspartic protein (HAP) and falcipain-2 (FP)], two pentacyclic triterpene, cucurbitacin B and 3 beta-O-acetyl oleanolic acid showed high binding affinity relative to artesunate. This implies their capacity to inhibit the three selected P. falciparum target proteins, and consequently, antimalarial potential. From the MD simulations studies and binding free energy outcomes, results confirmed that the two compounds are stable in complex with the selected antimalarial targets; they also showed excellent binding affinities during the 100 ns simulation.

CONCLUSION

These results showed that cucurbitacin B and 3 beta-O-acetyl oleanolic acid are potent antimalarials and should be considered for further studies.

Identification of potential inhibitors of cholinergic and β-secretase enzymes from phytochemicals derived from Gongronema latifolium Benth leaf: an integrated computational analysis

Neurodegenerative disorders (NDDs) are associated with increased activities of the brain acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and β-secretase enzyme (BACE1). Inhibition of these enzymes affords therapeutic option for managing NDDs such as Alzheimer's disease (AD) and Parkinson's disease (PD). Although, Gongronema latifolium Benth (GL) has been widely documented in ethnopharmacological and scientific reports for the management of NDDs, there is paucity of information on its underlying mechanism and neurotherapeutic constituents. Herein, 152 previously reported Gongronema latifolium derived-phytochemicals (GLDP) were screened against hAChE, hBChE and hBACE-1 using molecular docking, molecular dynamics (MD) simulations, free energy of binding calculations and cluster analysis. The result of the computational analysis identified silymarin, alpha-amyrin and teraxeron with the highest binding energies (-12.3, -11.2, -10.5 Kcal/mol) for hAChE, hBChE and hBACE-1 respectively as compared with those of the reference inhibitors (-12.3, -9.8 and - 9.4 for donepezil, propidium and aminoquinoline compound respectively). These best docked phytochemicals were found to be orientated in the hydrophobic gorge where they interacted with the choline-binding pocket in the A-site and P-site of the cholinesterase and subsites S1, S3, S3' and flip (67-75) residues of the pocket of the BACE-1. The best docked phytochemicals complexed with the target proteins were stable in a 100 ns molecular dynamic simulation. The interactions with the catalytic residues were preserved during the simulation as observed from the MMGBSA decomposition and cluster analyses. The presence of these phytocompounds most notably silymarin, which demonstrated dual high binding tendencies to both cholinesterases, were identified as potential neurotherapeutics subject to further investigation.

Antioxidant activities of artesunate-procyanidin hybrid compound in erythrocyte and liver of Plasmodium berghei NK65-infected mice

Resistance of malaria parasites to conventionally used antimalarial drugs has necessitated the search for new potent antimalarials, especially those that can also ameliorate oxidative stress-mediated secondary complications. This has led to the synthesis of an antimalarial artesunate-procyanidin hybrid compound (PC14), but it has not been evaluated for its antioxidant activity. This study was carried out to evaluate the antioxidant activities of PC14 in the erythrocyte and liver of Plasmodium berghei NK65-infected mice. A hundred mice were randomly divided into 10 equal groups (A-J). Mice in Groups B-J were inoculated with P. berghei NK65 while group A mice were not inoculated. Starting from Day 3 post-inoculation, dimethyl sulfoxide (DMSO) (5%) was administered to mice in Groups A and B (normal and negative controls, respectively), while various doses of chloroquine, artesunate, procyanidin, and PC14 were administered to their respective groups for 3 days. Thereafter, antioxidant parameters were determined in the erythrocyte and liver on Days 6 and 10 post-inoculation. A significant increase (P < 0.05) was observed in malondialdehyde levels in the erythrocyte and liver of negative control on Day 10 post-inoculation compared to normal controls. Significant reduction (P < 0.05) was observed in activities of liver catalase and superoxide dismutase and erythrocyte glutathione peroxidase and glutathione-S-transferase of negative control on Days 6 and 10 compared to normal controls. However, PC14 at various doses significantly (P < 0.05) reversed these alterations. The results suggest that PC14 possesses antioxidant activity, and it enhanced antioxidant defense in the erythrocyte and liver of P. berghei-infected mice.

Pharmacoinformatic study of inhibitory potentials of selected flavonoids against papain-like protease and 3-chymotrypsin-like protease of SARS-CoV-2

Background

Inhibition of papain-like protease (PLpro) and 3-chymotrypsin-like protease (3CLpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is projected to terminate its replication. Hence, these proteases represent viable therapeutic targets.

Methods

Sixty-one flavonoids with reported activities against other RNA viruses were selected and docked in PLpro and 3CLpro. Flavonoids with better binding energies compared to reference inhibitors (lopinavir and ritonavir) in their interaction with PLpro and 3CLpro were selected for drug-likeness and ADMET analysis. The best representative flavonoid for each protease from the ADMET filtering analysis was subjected to molecular dynamics simulations (MDS) and clustering analysis of the trajectory files.

Results

Licorice, ugonin M, procyanidin, silymarin, and gallocatechin gallate had better binding energies (-11.8, -10.1, -9.8, -9.7 and -9.6 kcal/mol respectively) with PLpro compared to lopinavir and ritonavir (-9.1 and -8.5 kcal/mol respectively). Also, isonymphaeol B, baicalin, abyssinone II, tomentin A, and apigetrin had better binding energies (-8.7, -8.3, -8.2, -8.1, and -8.1 kcal/mol respectively) with 3CLpro compared to lopinavir and ritonavir (-7.3 and -7.1 kcal/mol respectively). These flavonoids interacted with the proteases via hydrogen and non-hydrogen bonding. Of these flavonoids, silymarin and isonymphaeol B demonstrated most favourable combination of attributes in terms of binding energies, compliance with Lipinski rule for drug-likeness and favourable pharmacokinetics in silico. These two flavonoids exhibited appreciable degree of structural stability, maintaining strong interaction with residues in the different representative clusters selected during the MDS run.

Conclusion

Silymarin and isonymphaeol B are proposed for further studies as compounds with potential activities against SARS-CoV-2.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40816-022-00347-y.

• Flavonoids displayed varying affinities for PLpro and 3CLpro of SARS-CoV-2

• They interacted via hydrogen and non-hydrogen bonds; nine and twenty-seven flavonoids had better binding affinities for PLpro and 3CLpro respectively than lopinavir and ritonavir

• Silymarin and isonymphaeol B demonstrated most favourable combination of attributes in terms of binding energies, compliance with Lipinski rule for drug-likeness and favourable pharmacokinetics.

• Silymarin and isonymphaeol B exhibited appreciable degree of structural stability, maintaining strong interaction with residues in the different representative clusters selected during the MDS run.

Studies on Activities and Chemical Characterization of Medicinal Plants in Search for New Antimalarials: A Ten Year Review on Ethnopharmacology

Malaria is an endemic disease that affected 229 million people and caused 409 thousand deaths, in 2019. Disease control is based on early diagnosis and specific treatment with antimalarial drugs since no effective vaccines are commercially available to prevent the disease. Drug chemotherapy has a strong historical link to the use of traditional plant infusions and other natural products in various cultures. The research based on such knowledge has yielded two drugs in medicine: the alkaloid quinine from Cinchona species, native in the Amazon highland rain forest in South America, and artemisinin from Artemisia annua, a species from the millenary Chinese medicine. The artemisinin-based combination therapies (ACTs), proven to be highly effective against malaria parasites, and considered as “the last bullet to fight drug-resistant malaria parasites,” have limited use now due to the emergence of multidrug resistance. In addition, the limited number of therapeutic options makes urgent the development of new antimalarial drugs. This review focuses on the antimalarial activities of 90 plant species obtained from a search using Pubmed database with keywords “antimalarials,” “plants” and “natural products.” We selected only papers published in the last 10 years (2011–2020), with a further analysis of those which were tested experimentally in malaria infected mice. Most plant species studied were from the African continent, followed by Asia and South America; their antimalarial activities were evaluated against asexual blood parasites, and only one species was evaluated for transmission blocking activity. Only a few compounds isolated from these plants were active and had their mechanisms of action delineated, thereby limiting the contribution of these medicinal plants as sources of novel antimalarial pharmacophores, which are highly necessary for the development of effective drugs. Nevertheless, the search for bioactive compounds remains as a promising strategy for the development of new antimalarials and the validation of traditional treatments against malaria. One species native in South America, Ampelozyzyphus amazonicus, and is largely used against human malaria in Brazil has a prophylactic effect, interfering with the viability of sporozoites in in vitro and in vivo experiments.

Dietary stigmastane-type saponins as promising dual-target directed inhibitors of SARS-CoV-2 proteases: a structure-based screening

Despite the development of COVID-19 vaccines, at present, there is still no approved antiviral drug against the pandemic. The SARS-CoV-2 3-chymotrypsin-like proteases (S-3CLpro) and papain-like protease (S-PLpro) are essential for the viral proliferation cycle, hence attractive drug targets. Plant-based dietary components that have been extensively reported for antiviral activities may serve as cheap sources of preventive nutraceuticals and/or antiviral drugs. A custom-made library of 176 phytochemicals from five West African antiviral culinary herbs was screened for potential dual-target-directed inhibitors of S-3CLpro and S-PLpro in silico. The docking analysis revealed fifteen steroidal saponins (FSS) from Vernonia amygdalina with the highest binding tendency for the active sites of S-3CLpro and S-PLpro. In an optimized docking analysis, the FSS were further docked against four equilibrated conformers of the S-3CLpro and S-PLpro. Three stigmastane-type steroidal saponins (vernonioside A2, vernonioside A4 and vernonioside D2) were revealed as the lead compounds. These compounds interacted with the catalytic residues of both S-3CLpro and S-PLpro, thereby exhibiting dual inhibitory potential against these SARS-CoV-2 cysteine proteases. The binding free energy calculations further corroborated the static and optimized docking analysis. The complexed proteases with these promising phytochemicals were stable during a full atomistic MD simulation while the phytochemicals exhibited favourable physicochemical and ADMET properties, hence, recommended as promising inhibitors of SARS-CoV-2 cysteine proteases.

Morinda lucida Benth (Rubiaceae): A review of its ethnomedicine, phytochemistry and pharmacology

ETHNOMEDICINAL RELEVANCE

Natural products derived from plants have served the primary healthcare needs of millions of indigenous people for centuries, many of which have been documented and scientifically validated. Morinda lucida Benth (Rubiaceae), also referred to as brimstone tree, is an ethnomedicinal plant which has been widely used in traditional medicine for several decades, particularly in the African continent. Various parts of the plant, including stem bark, leaves and root, have been applied in traditional medicine for the management of various pathological conditions such as malaria, diabetes, hypertension, inflammation, typhoid fever, cancer, cognitive disorders, sickle cell disease, trypanosomiasis, onchocerciasis and various fevers. In this review, we critically evaluated the relationship between traditional uses, laboratory pharmacological activities and clinical studies on M. lucida so as to unveil opportunities for the development of relevant therapeutic agents against diseases that threaten mankind.

MATERIALS AND METHODS

A search for relevant data on M. lucida was done using scientific databases (Google Scholar, Mendeley, ScienceDirect, PubMed, Asian Science Citation Database, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, Chinese Scientific Journal Database, Chinese Science Citation Database, other web sources (such as The Plant List and PROTA), books and other literature sources.

RESULTS

A hundred compounds have been isolated from M. lucida. Many of the reported secondary metabolites include alkaloids, tannins, anthraquinones, sterols, saponins, polyphenols, terpenoids, phenols and cardiac glycosides. The in vitro and in vivo experimental studies on various extracts, fractions and isolated compounds of M. lucida support the acclaimed pharmacological activities of the plant, such as antimalarial, antidiabetic, hypotensive, anti-inflammatory, immunostimulatory, antioxidant, antimicrobial, antiproliferative, cognitive-enhancement, anti-sickling, anti-trypanosomal, anti-onchocercal, muscle relaxant, antifungal and anti-leishmanial activities. These evidence-based scientific reports lend credence to their traditional uses. However, the safety of extracts of M. lucida is a cause for concern following reported toxicities such as antispermatogenic effect, genotoxicity and in vitro inhibition of human cytochrome P450 3A subfamily.

CONCLUSION

Documented evidence suggests that M. lucida remains a rich source of extracts and chemical compounds with diverse bioactivities that are of therapeutic benefit to man and this justifies its traditional uses for the primary healthcare needs of indigenous populations across tropical Africa. Due to the fact that M. lucida extracts may not be safe at some reported doses, more in-depth studies on their toxicities are required to better understand safer approaches to their traditional uses. In addition, mechanistic studies on the isolated compounds with known pharmacological activities are quite limited, thus necessitating future research efforts to be focused on the mechanisms of action of these active principles in order to facilitate their potential enlistment for rational drug design.

Structure-based virtual screening suggests inhibitors of 3-Chymotrypsin-Like Protease of SARS-CoV-2 from Vernonia amygdalina and Occinum gratissimum

Antiviral culinary plants are potential bioresources for preventive nutraceuticals and/or antiviral drugs in COVID-19. Structure-based virtual screening was undertaken to screen 173 compounds previously reported from Vernonia amygdalina and Occinum gratissimum for direct interaction with the active site of the 3-Chymotrypsin-Like Protease (3CL^pro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Based on docking scores and comparison with reference inhibitors, a hit-list of 10 top phytocompounds was defined, which also had strong interactions with the catalytic centre of 3CL^pro from three related strains of coronavirus (SARS-CoV, MERS-CoV, HKU4). Among these, six compounds (neoandrographolide, vernolide, isorhamnetin, chicoric acid, luteolin, and myricetin) exhibited the highest binding tendencies to the equilibrated conformers of SARS-CoV-2 3CL^pro in an in-depth docking analysis to 5 different representative conformations from the cluster analysis of the molecular dynamics simulation (MDS) trajectories of the protein. In silico drug-likeness analyses revealed two drug-like terpenoids viz: neoandrographolide and vernolide as promising inhibitors of SARS-CoV-2 3CL^pro. These structures were accommodated within the substrate-binding pocket; and interacted with the catalytic dyad (Cys¹⁴⁵ and His⁴¹), the oxyanion loop (residues 138-145), and the S1/S2 sub-sites of the enzyme active site through the formation of an array of hydrogen bonds and hydrophobic interactions. Molecular dynamics simulation and binding free energy calculation revealed that the terpenoid-enzyme complexes exhibit strong interactions and structural stability. Therefore, these compounds may stabilize the conformation of the flexible oxyanion loop; and thereby interfere with the tetrahedral oxyanion intermediate formation during the proteolytic activity of the enzyme.

Dual targeting of cytokine storm and viral replication in COVID-19 by plant-derived steroidal pregnanes: An in silico perspective

The high morbidity and mortality rate of Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection arises majorly from the Acute Respiratory Distress Syndrome and "cytokine storm" syndrome, which is sustained by an aberrant systemic inflammatory response and elevated pro-inflammatory cytokines. Thus, phytocompounds with broad-spectrum anti-inflammatory activity that target multiple SARS-CoV-2 proteins will enhance the development of effective drugs against the disease. In this study, an in-house library of 117 steroidal plant-derived pregnanes (PDPs) was docked in the active regions of human glucocorticoid receptors (hGRs) in a comparative molecular docking analysis. Based on the minimal binding energy and a comparative dexamethasone binding mode analysis, a list of top twenty ranked PDPs docked in the agonist conformation of hGR, with binding energies ranging between -9.8 and -11.2 kcal/mol, was obtained and analyzed for possible interactions with the human Janus kinases 1 and Interleukins-6 and SARS-CoV-2 3-chymotrypsin-like protease, Papain-like protease and RNA-dependent RNA polymerase. For each target protein, the top three ranked PDPs were selected. Eight PDPs (bregenin, hirundigenin, anhydroholantogenin, atratogenin A, atratogenin B, glaucogenin A, glaucogenin C and glaucogenin D) with high binding tendencies to the catalytic residues of multiple targets were identified. A high degree of structural stability was observed from the 100 ns molecular dynamics simulation analyses of glaucogenin C and hirundigenin complexes of hGR. The selected top-eight ranked PDPs demonstrated high druggable potentials and favourable in silico ADMET properties. Thus, the therapeutic potentials of glaucogenin C and hirundigenin can be explored for further in vitro and in vivo studies.

Enhancing the antimalarial activity of artesunate

The global challenge to the treatment of malaria is mainly the occurrence of resistance of malaria parasites to conventionally used antimalarials. Artesunate, a semisynthetic artemisinin compound, and other artemisinin derivatives are currently used in combination with selected active antimalarial drugs in order to prevent or delay the emergence of resistance to artemisinin derivatives. Several methods, such as preparation of hybrid compounds, combination therapy, chemical modification and the use of synthetic materials to enhance solubility and delivery of artesunate, have been employed over the years to improve the antimalarial activity of artesunate. Each of these methods has advantages it bestows on the efficacy of artesunate. This review discussed the various methods employed in enhancing the antimalarial activity of artesunate and delaying the emergence of resistance of parasite to it.

Influence of gender on the distribution of type 2 diabetic complications at the obafemi awolowo teaching hospital, Ile-Ife, Nigeria

Background

Sex specific differences appear particularly relevant in the management of type 2 DM.

Objective

We determined gender specific differences in cardio-metabolic risk, microvascular and macrovascular complications in patients with type 2 diabetes.

Methods

Four hundred type 2 diabetes patients, males and females, matched for age and disease duration were recruited from the diabetes clinic. Relevant clinical and laboratory information were obtained or performed.

Results

190(47.5%) were male and 210 (52.5%) were female respectively. The mean age of the study population was 60.6 + 9.93 years. Women had higher prevalence of hypertension (and obesity. Mean total cholesterol was significantly higher in women but men were more likely to achieve LDL treatment goals than women (69.5% vs 59.0%, p<0.05). More women (47.1% & 31.4%) reached glycaemic goals of <10mmol/l for 2HPP and HBA1c of <7.0%.

There were no gender differences in the distribution of microvascular and macrovascular complications (p>0.05) but women were more likely to develop moderate and severe diabetic retinopathy (p= 0.027).

Conclusion

Women with T2DM had worse cardiometabolic risk profile with regards to hypertension, obesity and lipid goals. Men achieved therapeutic goals less frequently than did women in terms of glycaemia. Microvascular and macrovascular complications occurred commonly in both sexes.

Cuprizone toxicity and Garcinia kola biflavonoid complex activity on hippocampal morphology and neurobehaviour

Cuprizone-induced neurotoxicity has been employed to study the biology of remyelination in experimental models of multiple sclerosis. This study was aimed at determining the role of kolaviron, a biflavonoid from Garcinia kola, in mitigating the damaging effects of cuprizone on behaviour and the hippocampus. Twenty-four male albino mice aged 6–8 weeks were categorised into 4 equal groups: Group A (Control) received regular diet; Group B received 200 mg/kg/d of kolaviron in addition to their regular diet; Group C received 0.2% cuprizone diet only, while Group D received both kolaviron and cuprizone diet. The treatment lasted for 35 days after which behavioural tests (Morris water maze, Y maze and open field tests) were conducted and brain tissues were processed for histology, histochemistry (Nissl staining), immunohistochemistry (glial fibrillary acidic protein) and biochemistry (malondialdehyde, superoxide dismutase and glutathione peroxidase). Results showed that cuprizone toxicity led to weight loss, impairment in memory and exploratory drive, oxidative stress, chromatolysis and reactive astrocytosis; meanwhile administration of kolaviron prevented cuprizone-induced weight loss, memory decline, oxidative stress and neuromorphological alterations. In conclusion, administration of kolaviron might be useful in limiting the effects of cuprizone toxicity on the morphology and functions of the hippocampus.

Effects of aqueous extract of Hibiscus sabdariffa on renal Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities in Wistar rats

OBJECTIVE

To investigate the effects of oral administration of aqueous extract of Hibiscus sabdariffa on renal Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities in rats.

METHODS

The 25 and 50 mg/(kg·d) of aqueous extracts of H. sabdariffa were respectively given to rats in the experimental groups for 28 d, and rats in the control group received an appropriate volume of distilled water as vehicle. Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities in the kidney were assayed by spectrophotometric method.

RESULTS

Administrations of 25 and 50 mg/(kg·d) of aqueous extract of H. sabdariffa significantly decreased the Ca(2+)-Mg(2+)-ATPase activity in the kidney of rats (P<0.05). However, the renal Na(+)-K(+)-ATPase activity of the experimental rats was not affected by either dose of the extract. And the plasma Na(+), K(+) and Ca(2+) levels of the experimental rats had no significant changes. Administration of either dose of the extract did not result in any significant changes in body and kidney weights, the concentrations of plasma albumin and total protein, and alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase activities. However, concentrations of creatinine and urea were significantly reduced by 50 mg/kg of the extract (P<0.05).

CONCLUSION

The present study indicates that oral administration of aqueous extract of H. sabdariffa may preserve the renal function despite a decreased renal Ca(2+)-Mg(2+)-ATPase activity.

Potential antimalarials from Nigerian plants: a review

Malaria, caused by parasites of the genus Plasmodium, is one of the leading infectious diseases in many tropical regions, including Nigeria, a West African country where transmission occurs all year round. Many of the inhabitants use plants as remedies against fever and other symptoms of acute malaria, as reported herein. Some of these plants have their antimalarial efficacies scientifically demonstrated and the active compounds isolated with their probable mechanisms of action studied. Medicinal plants are used to treat diseases also where the biodiversity of plants occur in parallel with endemic transmission of malaria. This review focuses on medicinal plants which are used to treat malaria in Nigeria, and on antimalarial testing of extracts and purified compounds from plants. Some show intense activity against malaria parasites in vitro and in experimentally infected mice. The search for new drugs based on plants is important due to the emergence and widespread of chloroquine-resistant and multiple drug-resistant malaria parasites, which require the development of new antimalarials. An acquaintance with antimalarial plants may be a springboard for new phytotherapies that could be affordable to treat malaria, especially among the less privileged native people living in endemic areas of the tropics, mostly at risk of this devastating disease.

Ethanolic extract of Clerodendrum violaceum Gürke leaves enhances kidney function in mouse model of malaria

Evaluation of the effects of daily oral administration of ethanolic extract of C. violaceum leaves (13 mg/kg body weight) for 5 days on some kidney function indices of uninfected and Plasmodium berghei-infected mice was done on days 3, 8 and 14 post-infection. The indices studied include serum urea and creatinine concentrations with the specific activities of alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase in the kidney. Treatment of P. berghei-infected mice with ethanolic extract of C. violaceum leaves (13 mg/kg body weight) for 5 days was able to ameliorate significantly the alterations in the various parameters observed in infected untreated mice, comparing favourably with chloroquine treatment in most cases. Administration of extract to uninfected mice had no significant effect on both serum and kidney parameters compared to the uninfected control. The results suggest that the ethanolic extract of C. violaceum leaves does not adversely affect kidney function at the dose used in traditional medicine for the treatment of malaria but rather enhances it.

Haematological evaluation of ethanolic extract of Allium ascalonicum in male albino rats

The haematological effect of ethanolic extract of Allium ascalonicum was evaluated in male albino rats during a 21 day administration at the doses of 50, 100 and 200 mg/kg b.w, orally. Parameters evaluated include the serum lipids, red and white cell indices. The results showed that the extract administered decreased most of the parameters relating to red cell and increased most of those parameters relating to white cells. It also decreased the total cholesterol (TCH), high density lipoprotein cholesterol (HDL) and low density lipoprotein cholesterol (LDL) with no significant effect on the triglyceride levels.

Effect of ethanolic extract of Khaya senegalensis on some biochemical parameters of rat kidney

The effect of administration of ethanolic extract of Khaya senegalensis (2mg/kg body weight) on some biochemical parameters of rat kidney were investigated. Experimental animals were randomly divided into the control, those administered with the extract for 6 days and those administered with extract for 18 days, respectively. The prolonged administration of the extract resulted in significant reduction in the alkaline phosphatase activities of the kidney and its body weight ratio (P<0.05). In contrast, the same prolonged administration of the extract resulted in significant increase in the serum sodium ion concentration (P<0.05) while there was no significant difference in serum potassium ion concentration when compared to control (P>0.05). Administration of the extract for 6 days produced no significant difference from the control values in all the parameters investigated except in serum urea concentration which produced a significant increase (P<0.05). The available evidence in this study suggest that the ethanolic extract of Khaya senegalensis exerted more deleterious effect on the kidney when administered continuously over a prolonged period than a short one and this will adversely affect the functioning of the kidney.

Campylobacter jejuni as a bacterial cause of diarrhoea in Ile-Ife, NIgeria

A total of 495 diarrhoea and non-diarrhoea patients whose ages ranged between 5 and 39 years were examined for the presence of Campylobacter jejuni, Salmonella and Shigella species. About 12% of the specimens from diarrhoea patients were positive for Campylobacter jejuni compared with 6% and 10% for Salmonella and Shigella species. In contrast 2%, 0% and 1% of the samples from non-diarrhoea patients were positive for Campylobacter jejuni, Salmonella and Shigella species respectively. Most (62%) of the Campylobacter jejuni from diarrhoea patients were isolated from children under the age of 10 years. This compared with 26% and 37% for Salmonella and Shigella species in this age group. The frequency of isolation of Campylobacter jejuni in diarrhoea patients was highest during the dry months of the year. This study demonstrates the importance of Campylobacter jejuni as a major bacterial cause of diarrhoea in this part of the world.