scholarly journals Antimalarial Efficacy and Toxicological Assessment of Extracts of Some Ghanaian Medicinal Plants

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Michael Konney Laryea ◽  
Lawrence Sheringham Borquaye

The economic costs associated with morbidity and mortality due to malaria and malaria associated complications in many sub-Saharan countries and other malaria endemic regions of the world are huge. Reports of emergence of parasite resistance to current malaria drugs have complicated malaria treatment and require the development of new therapeutic agents. The folkloric use of medicinal plants for the management of malaria is well documented. This work evaluated the antiplasmodial activities and toxicity of some medicinal plants used to treat malaria and malaria-like symptoms in Ghana. Plant extracts were obtained by cold maceration in 70% ethanol. Antiplasmodial efficacies were assessed in vitro against 3 strains of Plasmodium falciparum strains (FCM, W2, and CAM06) and in vivo via the 4-day suppressive test in Plasmodium berghei infected mice. Cytotoxicity and acute toxicity were assessed in mammalian cells and mice, respectively. All extracts were active against at least one of the Plasmodium falciparum strains in in vitro evaluations with IC50’s in the range of 4–116 μg/mL, whereas Bidens pilosa extracts, with a chemosuppression rate of 75%, was the most active plant in the in vivo experiments. All plant extracts displayed very weak to no cytotoxicity against the mammalian cell line used and exhibited very good selectivity towards the Plasmodium parasites. Syzygium guineense and Parinari congensis extracts were the most toxic in the acute toxicity tests. Altogether, the results indicate that the medicinal plants do possess impressive antiplasmodial properties and provide scientific basis for their use in traditional herbal medicine.

2014 ◽  
Vol 59 (3) ◽  
pp. 1620-1626 ◽  
Author(s):  
Osmar N. Silva ◽  
Isabel C. M. Fensterseifer ◽  
Elaine A. Rodrigues ◽  
Hortência H. S. Holanda ◽  
Natasha R. F. Novaes ◽  
...  

ABSTRACTThe rapid increase in the incidence of multidrug-resistant infections today has led to enormous interest in antimicrobial peptides (AMPs) as suitable compounds for developing unusual antibiotics. In this study, clavanin A, an antimicrobial peptide previously isolated from the marine tunicateStyela clava, was selected as a purposeful molecule that could be used in controlling infection and further synthesized. Clavanin A wasin vitroevaluated againstStaphylococcus aureusandEscherichia colias well as toward L929 mouse fibroblasts and skin primary cells (SPCs). Moreover, this peptide was challenged here in anin vivowound and sepsis model, and the immune response was also analyzed. Despite displaying clearin vitroantimicrobial activity toward Gram-positive and -negative bacteria, clavanin A showed no cytotoxic activities against mammalian cells, and in acute toxicity tests, no adverse reaction was observed at any of the concentrations. Moreover, clavanin A significantly reduced theS. aureusCFU in an experimental wound model. This peptide also reduced the mortality of mice infected withE. coliandS. aureusby 80% compared with that of control animals (treated with phosphate-buffered saline [PBS]): these data suggest that clavanin A prevents the start of sepsis and thereby reduces mortality. These data suggest that clavanin A is an AMP that could improve the development of novel peptide-based strategies for the treatment of wound and sepsis infections.


Author(s):  
J Kolarova ◽  
J Velisek ◽  
Z Svobodova

The use of in vitro (fish cell lines) is a cost-effective, very rapid, and informative tool for toxicological assessments. Using the neutral red (NR) assay, we compared the in vitro acute toxicity (20hEC50) of twenty-six chemical substances on a rainbow trout gonad cell line (RTG-2) with their in vivo acute toxicity to Barbados Millions Poecilia reticulata (48hLC50, OECD 203) and crustacean Daphnia magna (48hEC50, OECD 202). The 20hEC50 values obtained by the NR assay were higher in nearly all the cases when compared to the 48hLC50 in P. reticulata and the 48hEC50 in D. magna, indicating that the sensitivity of the RTG-2 cell line was lower compared to P. reticulata and D. magna. A high (r = 0.89) and significant (P < 0.001) correlation was recorded between the 20hEC50 values of the RTG-2 and the 48hEC50 values of D. magna. The correlation between the 20hEC50 values of the RTG-2 and the 48hLC50 values of P. reticulata was lower (r = 0.65; P < 0.001), but also significant. The authors recommend use of the NR assay on the RTG-2 cell lines as a screening protocol to evaluate the toxicity of xenobiotics in aquatic environments to narrow the spectrum of the concentrations for the fish toxicity test.


Author(s):  
Meseret Tadelo ◽  
Tamirat Wato ◽  
Tilahun Negash

Background: Tomato (Lycopersicon esculentum Mill.) belongs to the family Solanaceae. In Ethiopia, control of early blight is largely dependent on fungicidal application. There is a research need to identify effective botanical extracts to control Alternaria solani that cause early blight of tomato and for evaluation of plant extracts through different solvents on the target pathogen. Methods: In vitro experiment was conducted to evaluate the effectiveness of crude extracts of 16 selected medicinal plants against Alternaria solani. Thus, crude extracts were extracted from medicinal plants with different solvents (methanol, ethanol and petroleum at (25%, 50% and 100%) concentrations. The Alternaria solani was isolated from infected tomato leaves showing early blight symptoms. Evaluation of plant extracts was carried out against Alternaria solani using food poisoned technique on PDA. Result: Results showed that most of the methanolic extract plants were showed significant inhibition of the mycelial growth as compared to ethanolic and petroleum ether extracts. A higher rate of mycelial reduction was recorded by ethanol extracts of Allium sativum at all concentrations (100%) followed by methanol extracts of Allium sativum at 25%, 50%, 100% concentration (90.02%, 97.01%, 100% respectively). The effectiveness of extracts against Alternaria solani depends on use at the higher concentrations and various solvents. For crude extracts that have shown higher inhibitory effects against Alternaria solani in vitro conditions, actual chemical compounds should be identified. Furthermore, it is also important to evaluate these plants on other microbes, study to test in vivo and to assess their real potential field condition wherever early blight is an important disease of tomato.


2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Angel Josabad Alonso-Castro ◽  
María del Carmen Juárez-Vázquez ◽  
Nimsi Campos-Xolalpa

A literature review was undertaken by analyzing distinguished books, undergraduate and postgraduate theses, and peer-reviewed scientific articles and by consulting worldwide accepted scientific databases, such as SCOPUS, Web of Science, SCIELO, Medline, and Google Scholar. Medicinal plants used as immunostimulants were classified into two categories: (1) plants with pharmacological studies and (2) plants without pharmacological research. Medicinal plants with pharmacological studies of their immunostimulatory properties were subclassified into four groups as follows: (a) plant extracts evaluated forin vitroeffects, (b) plant extracts with documentedin vivoeffects, (c) active compounds tested onin vitrostudies, and (d) active compounds assayed in animal models. Pharmacological studies have been conducted on 29 of the plants, including extracts and compounds, whereas 75 plants lack pharmacological studies regarding their immunostimulatory activity. Medicinal plants were experimentally studiedin vitro(19 plants) andin vivo(8 plants). A total of 12 compounds isolated from medicinal plants used as immunostimulants have been tested usingin vitro(11 compounds) andin vivo(2 compounds) assays. This review clearly indicates the need to perform scientific studies with medicinal flora from Mexico, Central America, and the Caribbean, to obtain new immunostimulatory agents.


2021 ◽  
Author(s):  
Latha Damle ◽  
Hrishikesh Damle ◽  
Shiban Ganju ◽  
C Chandrashekar ◽  
BR Bharath

AbstractBackgroundIn the absence of a specific drug for COVID 19, treatment with plant extracts could be an option worthy of further investigation.PurposeTo screen the phytochemicals for Anti-SARS-CoV-2 in silico and evaluate their safety and efficacy in vitro and in vivo.MethodThe phytochemicals for Anti-SARS-CoV-2 were screened in silico using molecular docking. The hits generated from in silico screening were subjected for extraction, isolation and purification. The anti-SARS-CoV-2 activity of plant extracts of Z. piperitum (ATRI-CoV-E1), W. somnifera (ATRI-CoV-E2), C. inophyllum (ATRI-CoV-E3), A. paniculata (ATRI-CoV-E4), and C. Asiatica (ATRI-CoV-E5). The in vitro safety and anti-SARS-CoV-2 activity of plant extracts were performed in VeroE6 cells using Remdesivir as positive control. The acute and sub-acute toxicity study was performed in Wistar male and female rats.ResultsThe percentage of cell viability for ATRI-COV-E4, ATRI-COV-E5 and ATRI-COV-E2 treated VeroE6 cells were remarkably good on the 24th and 48th hour of treatment. The in vitro anti-SARS-CoV-2 activity of ATRI-COV-E4, ATRI-COV-E5 and ATRI-COV-E2 were significant for both E gene and N gene. The percentage of SARS-CoV-2 inhibition for ATRI-COV-E4 was better than Remdesivir. For E gene and N gene, Remdesivir showed IC50 of 0.15 µM and 0.11 µM respectively, For E gene and N gene, ATRI-CoV-E4 showed IC50 of 1.18 µg and 1.16 µg respectively. Taking the clue from in vitro findings, the plant extracts A. paniculata (ATRI-COV-E4), W. somnifera extract (ATRI-COV-E5) and C. asiatica extract (ATRI-COV-E2) were combined (ATRICOV 452) and evaluated for acute and sub-acute toxicity in Wistar male and female rats. No statistically significant difference in haematological, biochemical and histopathological parameters were noticed.ConclusionThe study demonstrated the Anti-SARS-CoV-2 activity in vitro and safety of plant extracts in both in vitro and in vivo experimental conditions.


2003 ◽  
Vol 31 (2) ◽  
pp. 89-89 ◽  
Author(s):  
Willi Halle ◽  
Marlies Halder ◽  
Andrew Worth ◽  
Elke Genschow

This is a translation of a report on the Registry of Cytotoxicity (RC), originally published in German in 1998. The report presented an advanced in vitro method, which can significantly reduce the number of animals needed for the toxicity testing of a broad range of compounds/xenobiotics. With the RC method, it was possible to predict the oral or intravenous acute toxicity (LD50) — which is a regulatory requirement for newly developed pharmaceuticals and industrial and household chemicals — from the cytotoxicity data (mean IC50 = IC50X) obtained with mammalian cells. The RC method can be used before the in vivo test, and it does not pose any additional harm or suffering to laboratory animals. The RC method is of broad practical use: it can be applied, for example, in the pharmaceutical industry or the chemical industry in regulatory testing or in research. It is ready for validation, and could then be incorporated into OECD guidelines, thus reducing the total number of animals needed for regulatory toxicity testing. The RC method is based on the comparison of the IC50X values and the LD50 values by using linear regression analysis. With the RC method, it was possible to predict, within a predefined dose range, the acute oral LD50 for 252 of 347 xenobiotics, and the intravenous LD50 for rats and/or mice for 117 of 150 xenobiotics. Comparative studies showed that these results are highly reproducible.


1993 ◽  
Vol 12 (4) ◽  
pp. 301-303 ◽  
Author(s):  
O.E. Orisakwe ◽  
N. Obi

The in vitro and in vivo adsorption of diazinon to two brands of activated charcoal and locally produced carbon black (N220) has been studied. Solutions of diazinon 10, 20 and 40 μg ml-1 were prepared in distilled water and different quantities of adsorbent added. Diazinon-adsorbent slurries were vortex mixed, centrifuged and analysed for free diazinon spectrophotometrically at 241 nm. Small quantities of activated charcoal (AC) and carbon black (CB) showed little or no adsorption of diazinon, while 1000 mg of either AC or CB was able to take up more than 70% at all concentrations of diazinon tested. In acute toxicity tests in mice the optimal adsorbent: diazinon ratio was 8:1 when the animals were treated with 45 mg kg-1 diazinon after immediate, 1, and 3 h post administration of the adsorbent.


1996 ◽  
Vol 15 (9) ◽  
pp. 702-735 ◽  
Author(s):  
J. Ashby ◽  
L. Kier ◽  
Age Wilson ◽  
T. Green ◽  
PA Lefevre ◽  
...  

Comprehensive toxicological studies of the herbicide acetochlor are presented and discussed. Although it gave a negative profile of responses in the many toxicity tests conducted there were some findings that prompted further investigation. First, although non-mutagenic in the Sal monella assay, acetochlor was clastogenic to mammalian cells treated in vitro. This clastogenic potential was not expressed in vivo in four rodent cytogenetic assays (bone marrow and germ cells). Second, although acetochlor gave a negative response in rat liver UDS assays when tested at the acute MTD, gavage administration of a single, supra- MTD dose (2000 mg/kg) gave a weak positive assay response. This dose-level (2000 mg/kg) was necrotic to the liver, depressed hepatic glutathione levels by up to ∼80%, altered the metabolism of acetochlor, and was associated with up to 33% lethality. In contrast, reference liver genotoxins such as DMN, DMH and 2AAF were shown to elicit UDS in the absence of such effects, and at ∼400 x lower dose-levels. Finally, microscopic nasal polypoid adenomas were induced in the rat when acetochlor was administered for two years at the maximum tolerated dose (MTD). The tumours were not life-threatening, they did not metastasize, and no DNA damage was induced in the nasal cells of rats maintained on a diet containing the MTD of acetochlor for either 1 or 18 weeks (comet assay). In order to probe the mechanism of action of these high dose toxicities a series of chemical and genetic toxicity studies was conducted on acetochlor and a range of structural analogues. These revealed the chloroacetyl sub structure to be the clastogenic species in vitro. Although relatively inert, this substituent is preferentially reactive to sulphydryl groupings, most evidently, to glutathione (GSH). Similar chemical reactivity and clastogenicity in vitro was observed for two related chemicals bearing a chloroacetyl group, both of which have been defined as non-carcinogens in studies reported by the US NTP. These collective observations indicate that the source of the clastogenicity of acetochlor in vitro is also the source of its rapid detoxification in the rat in vivo, via reaction with GSH. Metabolic studies of acetochlor are described which reveal the formation of a series of GSH-associated biliary metabolites in the rat that were not produced in the mouse. The metabolism of acetochlor in the rat changes with increasing dose-levels, probably because of depletion of hepatic GSH. It is most likely that a rat-specific metabolite is responsible for the rat nasal tumours observed uniquely at elevated dose-levels. The absence of genetic toxicity to the nasal epithelium of rats exposed acutely or sub- chronically to acetochlor favours a non-genotoxic me chanism for the induction of these adenomas. The observation of a time- and dose-related increase in S- phase cells in the nasal epithelium is consistent with this conclusion. Despite some confusion caused by the early use of peri- lethal gavage administrations of acetochlor to rodents, and supra-MTD dietary concentrations in some of the chronic studies, the available MTD data are consistent with acetochlor not posing a genetic or carcinogenic hazard to humans.


2021 ◽  
Author(s):  
Yeweynshet Tesera ◽  
Asnake Desalegn ◽  
Ashenif Tadele ◽  
Abebe Mengesha ◽  
Birhanu Hurisa ◽  
...  

Abstract Background: Rabies, endemic in most African and Asian countries, is a viral zoonosis that causes an estimated 59,000 human deaths a year, despite the existence of safe and effective vaccines. In most developing countries people believe to cure rabies with different traditional and religious treatment rather than seeking effective post exposure prophylaxis. Purpose: To investigate the phytochemical constituents, acute toxicity and antirabies activity of crude extracts of the leaves of Justicia schimperiana and Ricinus communis and the stem bark of Croton macrostachyus. Methods: To test the presence of various phytochemicals, standard procedures were used. For the determination of acute toxicity and in vivo antirabies activities, Organization for Economic Corporation and Development (OECD) Guideline No.423 was used. Different concentrations of extracts (0.4, 0.8, 1.6, 3.2, 6.4 and 12.8 mg/ml) were tested for their cytotoxic effect on Vero cells through 3-(4, 5-Dimethylthiazol-2-yl)-2, 5Diphenyltetrazolium Bromide (MTT) assay. The in vitro antirabies assay was carried out based on the minimal cytotoxic concentration of extracts. Results: The phytochemical screening result has revealed the presence of alkaloids, flavonoids, phenols, steroids, tannins and terpenoids in all plant extracts screened but lack saponins. All the extracts were slightly toxic in Swiss albino mice model but non cytotoxic in Vero cell lines. The antirabies assay result showed that all plant extracts had a moderate to good antirabies potential. The methanol extracts exhibited higher antirabies activity compared to the other extracts under investigation. Conclusion: The present study concluded that the studied plants have possessed different phytochemicals that helps in their antirabies potential. Utilization of these pharmacological properties involves further investigation of these active ingredients by implementation techniques of extraction, purification, separation, crystallization and identification.


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