Charles Ansah

In Vivo Models Used for Evaluation of Potential Antigastroduodenal Ulcer Agents

Peptic ulcer is among the most serious gastrointestinal diseases in the world. Several orthodox drugs are employed for the treatment of the disease. Although these drugs are effective, they produce many adverse effects thus limiting their use. In recent years, there has been a growing interest in alternative therapies, especially those from plants due to their perceived relative lower side effects, ease of accessibility, and affordability. Plant medicines with ethnomedicinal use in peptic ulcer management need to be screened for their effectiveness and possible isolation of lead compounds. This requires use of appropriate animal models of various ulcers. The limited number of antiulcer models for drug development against gastric and duodenal ulcer studies has hindered the progress of targeted therapy in this field. It is, therefore, necessary to review the literature on experimental models used to screen agents with potential antigastroduodenal ulcer activity and explain their biochemical basis in order to facilitate their use in the development of new preventive and curative antiulcer drugs. Clinical trials can then be carried out on agents/drugs that show promise. In this paper, current in vivo animal models of ulcers and the pathophysiological mechanisms underlying their induction, their limitations, as well as the challenges associated with their use have been discussed.

DNA damage protecting activity and antioxidant potential of Launaea taraxacifolia leaves extract

Background: The leaf extract of Launaea taraxacifolia commonly known as African Lettuce is used locally to treat dyslipidemia and liver diseases, which are associated with oxidative stress. Methanol extract from L. taraxacifolia leaves was tested for its antioxidant activity and its ability to protect DNA from oxidative damage. Materials and Methods: In vitro antioxidant potential of the leaf extract was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO), and hydroxyl (OH) radical scavenging assays. Ferric reducing power, total antioxidant capacity (TAC), metal chelating, and anti-lipid peroxidation ability of the extract were also examined using gallic acid, ascorbic acid, citric acid, and ethylenediaminetetraacetic acid as standards. Results: L. taraxacifolia leaves extract showed antioxidant activity with IC50values of 16.18 μg/ml (DPPH), 123.3 μg/ml (NO), 128.2 μg/ml (OH radical), 97.94 μg/ml (metal chelating), 80.28 μg/ml (TAC), and 23 μg/ml (anti-lipid peroxidation activity). L. taraxacifolia leaves extract exhibited a strong capability for DNA damage protection at 20 mg/ml concentration. Conclusion: These findings suggest that the methanolic leaf extract of L. taraxacifolia could be used as a natural antioxidant and also as a preventive therapy against diseases such as arteriosclerosis associated with DNA damage.

In vitro H+/K+-ATPase Inhibition, Antiradical effects of a flavonoid-rich fraction of Dissotis rotundifolia, and In silico PASS Prediction of its isolated compounds

Background: Dissotis rotundifolia, commonly referred to as pink lady, has several medicinal uses including peptic ulcer. This study investigated the inhibitory effects of D. rotundifolia extract on H+/K+-ATPase and also assessed its antiradical activity. In silico study of some isolated compounds of this plant was also carried out to affirm the suspected binding properties of extract to H+/K+-ATPase enzyme. Materials and Methods: D. rotundifolia whole plant extract was obtained after extraction process and then assessed for its ability to scavenge free radicals in four in vitro test models. Its ability to inhibit the activity of H+/K+-ATPase enzyme was also evaluated. Molecular docking was carried out on phytoconstituents, namely, vitexin, isovitexin, orientin, and isoorientin reported to be present in the whole plant extract. Results: Data obtained indicated that D. rotundifolia extract (DRE) exhibits strong antioxidant activity. DRE also showed inhibitory effects on H+/K+-ATPase enzyme activity. Docking studies affirmed the in vitro binding effect of the extract to H+/K+-ATPase. Conclusion: These findings suggest that the plant extract possess antioxidant and antipeptic ulcer activity.

Terminalia ivorensis A. Chev. Ethanolic Stem Bark Extract Protects Against Gentamicin-Induced Renal and Hepatic Damage in Rats -

The aim of present study was to investigate the possible protective effects of an ethanolic stem bark extract of Terminalia ivorensis on gentamicin – induced nephrotoxicity and hepatotoxicity in male Sprague-Dawley rats. Groups of animals received either gentamicin alone or in combination with 100, 300 or 1000 mg/kg of extract for a period of 14 days. On the 15 th day, the modulatory effect of Terminalia ivorensis was examined by assessing biochemical and renal markers of hepatic and renal damage. Markers of oxidative injury including reduced glutathione, superoxide dismutase, catalase and lipid peroxidation were assessed. Histology of the kidneys and the liver were also processed for analysis. The extract at a dose of 100-1000 mg/kg significantly reduced elevations in creatinine, urea and serum enzymes evokedby gentamicin. Additionally, the low levels of reduced glutathione and the antioxidant enzymes from the gentamicin treatment were significantly improved in the extract-treated animals. The results correlated well with the histopathological findings as the extract reversed the severe architectural distortions of the kidneys and liver caused by gentamicin. We conclude from the study that, the ethanolic stem bark extract of Terminalia ivorensis protects the liver and the kidneys against gentamicininduced renal and hepatic damage.

Erratum to: Synergistic anti-malarial action of cryptolepine and artemisinins

© 2016 Forkuo et al. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Erratum to: Malar J (2016) 15:89 DOI 10.1186/s12936‐016‐1137‐5 After publication of the original article [1], the authors found that there was an error in the first sentence of the ‘Conclusions’ section: “The combination of CPE with the artemisinins showed a synergistic effect both in vivo and in vitro against P. falciparum 3D7 and P. berghei NK-65, respectively.” Within this sentence, the appearance of ‘P. falciparum 3D7’ and ‘P. berghei NK-65’ should have been reversed. The sentence in the original article has been corrected to read as follows: “The combination of CPE with the artemisinins showed a synergistic effect both in vivo and in vitro against P. berghei NK-65 and P. falciparum 3D7, respectively.”

Assessment of an ethanolic seed extract of Picralima nitida ([Stapf] Th. and H. Durand) on reproductive hormones and its safety for use.

Background: Picralima nitida seed extract (PNE) has aphrodisiac and contraceptive effect. Aim: To investigate the effect of PNE on reproductive hormones. Materials and Methods: The size and length of the combs of white leghorn day-old chicks treated with testosterone (0.5-1.5 mg/kg), cyproterone (3-30 mg/kg), or PNE (50-500 mg/kg) for 7 days, as well as cyproterone (10, and 30 mg/kg) on PNE-induced, and PNE (50-500 mg/kg) on testosterone-induced comb growth, were measured in the chick comb test. The effect of PNE the percentage change in an oviduct-chick weight ratio of Rhode Island Red layer day-old chicks treated with 17-β-estradiol (0.1-0.9 µg), PNE (30-300 mg/kg) or vehicle, for 6 days, was determined in the chick uterotrophic assay. Liver and kidney function was well lipid, and hematological profile tests were conducted to assess safety. Results: 7-day treatment with PNE and testosterone increased significantly (P ≤ 0.01-0.001) while cyproterone significantly decreased (P ≤ 0.001) comb growth dose-dependently. Qualitatively, testosterone and PNE treatment resulted in relatively brighter red combs. Cyproterone caused significant inhibition (P ≤ 0.001) of both testosterone and PNE-induced comb growth. Co-administration of testosterone and PNE suppressed comb growth significantly (P ≤ 0.001). Administration of 17-β estradiol and PNE increased (P ≤ 0.001) oviduct-chick weight ratio dose-dependently. No significant changes were observed in assessing liver and kidney function, lipid profile, and hematological parameters. Conclusion: PNE exhibits both androgenic (partial testosterone agonist) and estrogenic activity. It has no detrimental effects on the blood, liver, and kidney tissue with prolonged use.