Studies on the mitochondrial, immunological and inflammatory effects of solvent fractions of Diospyros mespiliformis Hochst in Plasmodium berghei-infected mice.

The use of medicinal plants in the treatment of malaria is gaining global attention due to their efficacy and cost effectiveness. This study evaluated the bioactivity-guided antiplasmodial efficacy and immunomodulatory effects of solvent fractions of Diospyros mespiliformis in mice infected with a susceptible strain of Plasmodium berghei (NK 65). The crude methanol extract of the stem of D. mespiliformis (DM) was partitioned between n-hexane, dichloromethane, ethyl acetate and methanol. Male Swiss mice (20 ± 2 g) infected with P. berghei were grouped and treated with vehicle (10 mL/kg, control), Artemether lumefantrine (10 mg/kg), 100, 200 and 400 mg/kg of n-hexane, dichloromethane, ethyl acetate and methanol fractions of D. mespiliformis for seven days. Blood was obtained for heme and hemozoin contents while serum was obtained for inflammatory cytokines and immunoglobulins G and M assessments. Liver mitochondria were isolated for mitochondrial permeability transition (mPT), mitochondrial F1F0 ATPase (mATPase) and lipid peroxidation (mLPO) assays. The GC-MS was used to identify the compounds present in the most potent fraction. The dichloromethane fraction had the highest parasite clearance and improved hematological indices relative to the drug control. The heme values increased, while the hemozoin content significantly (P < 0.05) decreased compared with the drug control. The highest dose of HF and MF opened the mPT pore while the reversal effects of DF on mPT, mATPase and mLPO were dose-dependent. The levels of IgG, IgM and TNFα in the DF group were significantly higher than the drug control, while the IL-1ß and IL-6 values did not vary linearly with the dose. Lupeol and Stigmastan-3,5-diene were the most abundant phytochemicals in the DF. The outcome of this study showed that the DF has immunomodulatory effects in infected mice, reduced proliferation of the malaria parasite and thus protect liver cells.

In vitro antiplasmodial activity and prophylactic potentials of extract and fractions of Trema orientalis (Linn.) stem bark.

BACKGROUND: Trema orientalis (T. orientalis Linn) has been used in the management of malaria in the western part of Nigeria and despite its application in ethnomedicine, there is dearth of scientific evidence to justify the acclaimed prophylactic antimalarial usage of the plant. The aim of this study is to assess the in vitro antiplasmodial cell-free assay and chemopreventive efficacy of the methanol extract of the stem bark of T. orientalis and its fractions as a prophylactic regimen for malaria prevention. Also, the antimicrobial activities of the extract and the fractions were investigated. METHOD: Vacuum liquid chromatography was used to obtain dichloromethane, ethylacetate and methanol fractions from the methanol extract of T. orientalis. The fractions were tested for their prophylactic and cell-free antimalarial activity using murine models and ß-hematin formation assay respectively. Disc diffusion method was used to determine the antibacterial activity of the extract and its fractions against both Gram-positive and Gram-negative bacteria. RESULTS: In the prophylactic experiment, dichloromethane (DCMF), methanol fraction (MF) and extract (ME) (in this order) showed significant chemopreventive effects against P. berghei invasion of the red blood cells when compared with both Sulfadoxine-Pyrimethamine (SP) and untreated controls. Results of the in vitro study showed that the DCMF had the highest effect in preventing the formation of ß-hematin when compared with other fractions. The DCMF also had the highest percentage inhibition of ß-hematin formation when compared with chloroquine. The extract and fractions showed a concentration dependent antibacterial activity. Methanol extract had a pronounced inhibitory effect on Enterobacter cloaca ATCC 13047 and Enterococcus faecalis ATCC 29212. Serratia mercescens ATCC 9986 and Pseudomonas aeruginosa ATCC 19582 were the most susceptible bacteria. CONCLUSION: The results obtained showed that both extract and fractions of T. orientalis possessed antiplasmodial and antimicrobial activity.

Histopathological changes induced in an animal model by potentially pathogenic Enterococcus faecalis strains recovered from ready-to-eat food outlets in Osun State, Nigeria.

Enterococci have been implicated as an emerging important cause of several diseases and multiple antibiotic resistance. However, there is little information about the prevalence of pathogenic and/or antibiotic-resistant Enterococcus faecalis in ready-to-eat foods in Nigeria. Here we report the pathogenic potential of three selected antibiotic-resistant E. faecalis strains isolated from food canteens and food outlets with different virulence determinant genes, including EFC 12 (with gel (+), esp (+), cylA (+), and asa1 (+)), EFT 148 (with gel (+), ace (+), and asa1 (+)), and EFS 18 (with esp (+) and cylA (+)) in an animal model. Enterococcemia, hematological parameters, and histopathological changes in organ tissues were examined in experimental animals. The results showed differences in enterococcemia and hematological parameters between the control group and experimental animal group. Enterococcemia was observed for 7 days, and the animal group infected with EFC 12 showed the highest growth rate, followed by EFT 148, with the lowest growth rate seen in the EFS 18-infected group. White blood cell count, packed cell volume, and platelets were significantly reduced (P<0.05) in the experimental animals compared with the controls. White blood cells decreased drastically during the study period in rats challenged with EFC 12 (from 7,800 to 6,120 per mm(3)) but levels remained higher in the control group (from 9,228 to 9,306 per mm(3)). Histopathological changes included areas of pronounced hemorrhage, necrosis, and distortion in liver tissues, which were more marked in rats infected with EFC 12, followed by EFT 148, then EFS 18. The results of this study suggest the presence of potentially pathogenic E. faecalis strains in food canteens and food outlets; hence, there is a need for strict adherence to good hygiene practices in the study area owing to the epidemiological significance of foods.