In Vivo Antimalarial Activity of 80% Methanol and Aqueous Bark Extracts of Terminalia brownii Fresen. (Combretaceae) against Plasmodium berghei in Mice

Terminalia brownii Fresen: Stem Bark Dichloromethane Extract Alleviates Pyrogallol-Induced Suppression of Innate Immune Responses in Swiss Albino Mice

Terminalia brownii is widely used in folklore medicine and has diverse biological activities. However, its effect on the immune system is yet to be studied. Therefore, our study evaluated the immunomodulatory effect of T. brownii on nonspecific immunity. Innate immunity is the initial defence phase against pathogens or injuries. Dichloromethane plant extracts were tested on female Swiss albino mice and Wister rats. The effect of the extract on innate immunity was assessed via total and differential leukocyte counts, tumor necrosis factor-alpha, and nitric oxide production by mouse macrophages. The 3-(4, 5-dimethyl thiazolyl-2)-2, 5-diphenyltetrazolium bromide assay was employed for viability testing. Phytochemical profiling was carried out using gas chromatography-mass spectrometry, while toxicity studies were carried out following the Organization for Economic Cooperation and Development guidelines. Our results demonstrated that administration of T. brownii stem bark dichloromethane extract to pyrogallol-immuno compromised mice significantly (p < 0.05) increased total and differential leukocyte counts compared with the control. The extract showed no adverse effect on the viability of Vero cells and macrophages and significantly (p < 0.05) augmented tumor necrosis factor-alpha and nitric oxide production. Hexadecanoic acid, linoleic acid, octadecanoic acid, squalene, campesterol, stigmasterol, and β-sitosterol, all of which stimulate, were identified in the extract. The extract did not cause any death or toxic signs in rats. In conclusion, T. brownii dichloromethane extract has an immunoenhancing effect on innate immune responses and is not toxic. The observed immunoenhancing impact of the extract was attributed to the presence of the identified compounds. The results of this study provide crucial ethnopharmacological leads towards the development of novel immunomodulators for managing immune-related disorders.

In vitro antiplasmodial activity-directed investigation and UPLC-MS fingerprint of promising extracts and fractions from Terminalia ivorensis A. Chev. and Terminalia brownii Fresen

ETHNOPHARMACOLOGICAL SIGNIFICANCE

Medicinal plants from the Terminalia genus are widely used as remedies against many infectious diseases, including malaria. As such, Terminalia ivorensis A. Chev. and Terminalia brownii Fresen. are famous due to their usefulness in traditional medicines to treat malaria and yellow fever. However, further information is needed on the extent of anti-Plasmodium potency of extracts and fractions from these plants and their phytochemical profile.

AIM OF THE STUDY

This study was designed to investigate the in vitro antiplasmodial activity and to determine the chemical profile of promising extracts and fractions from T. ivorensis and T. brownii stem bark.

MATERIALS AND METHODS

Crude aqueous, ethanolic, methanolic, hydroethanolic and ethyl acetate extracts were prepared by maceration from the stem barks of T. brownii and T. ivorensis. They were subsequently tested against chloroquine-sensitive (Pf3D7) and multidrug-resistant (PfDd2) strains of P. falciparum using the parasite lactate dehydrogenase (PfLDH) assay. Extracts showing very good activity on both plasmodial strains were further fractionated using column chromatography guided by evidence of antiplasmodial activity. All bioactive extracts and fractions were screened for their cytotoxicity on Vero and Raw cell lines using the resazurin-based assay and on erythrocytes using the hemolysis assay. The phytochemical profiles of selected potent extracts and fractions were determined by UPLC-QTOF-MS analysis.

RESULTS

Of the ten extracts obtained from both plant species, nine showed inhibitory activity against both P. falciparum strains (Pf3D7 and PfDd2), with median inhibitory concentration (IC₅₀) values ranging from 0.13 μg/ml to 10.59 μg/ml. Interestingly, the aqueous extract of T. ivorensis (Ti^W) and methanolic extract of T. brownii (Tb^M) displayed higher antiplasmodial activities against both strains (IC₅₀ 0.13-1.43 μg/ml) and high selectivity indices (SI > 100). Their fractionation led to two fractions from T. ivorensis and two from T. brownii that showed very promising antiplasmodial activity (IC₅₀ 0.15-1.73 μg/mL) and SI greater than 100. The hemolytic assay confirmed the safety of crude extracts and fractions on erythrocytes. UPLC-MS-based phytochemical analysis of the crude aqueous extract of T. ivorensis showed the presence of ellagic acid (1) and leucodelphidin (2), while analysis of the crude methanol extract of T. brownii showed the presence of ellagic acid (1), leucodelphinidin (2), papyriogenin D (3), dihydroactinidiolide (4) and miltiodiol (5).

CONCLUSIONS

The extracts and fractions from T. ivorensis and T. brownii showed very good antiplasmodial activity, thus supporting the traditional use of the two plants in the treatment of malaria. Chemical profiling of the extracts and fractions led to the identification of chemical markers and the known antimalarial compound ellagic acid. Further isolation and testing of other pure compounds from the active fractions could lead to the identification of potent antiplasmodial compounds.

Medicinal plants used in traditional treatment of malaria in Ethiopia: a review of ethnomedicine, anti-malarial and toxicity studies

Background

Malaria is extremely common in Ethiopia, and it is one of the country's most serious public health and economic problems. Traditional medicines have long been utilized in Ethiopia by people of various ethnic groups. As a result, the goal of this study is to record the use of Ethiopian medicinal herbs that have been used to treat malaria. Also, a critical review of the literature on the therapeutic properties of these and other Ethiopian medicinal plants that have been tested against Plasmodium spp. parasites was conducted with the goal of highlighting neglected studies and fostering further research in this area.

Methods

A comprehensive literature search was performed in Scopus, Web of Science Core Collection, PubMed, Science Direct, Google Scholar, and Scientific Electronic Library Online (SciELO) from August 2021 to October 2021. The study databases included original articles published in peer reviewed journals covering anti-malarial plants, dated until October 2021.

Results

The review looked at 51 plant species (28 families) that have been used to treat malaria in Ethiopia. The most often used ethnobotanical plant species for the treatment of malaria were Allium sativum, Croton macrostachyus, Carica papaya, and Lepidium sativum. Leaves were used more frequently as a therapeutic preparation than other parts. Plant extracts were found to have very good, good, and moderate anti-malarial activity in mice with rodent Plasmodium species. The most active species were Ajuga remota and Capsicum frufescens, which suppressed parasitaemia by 77.34% and 72.65%, respectively, at an oral dose of 100 mg/kg and an LD50 of above 2000 mg/kg. The compound Aloinoside reported from Aloe macrocarpa leave latex was the most potent; it suppressed parasitaemia by 100% at 400 mg/kg oral dose of Plasmodium berghei infected mice, and its LD50 was above 2000 mg/kg. Toxicity was shown to be safe in 84% of the plant extracts.

Conclusion

In Ethiopia, medicinal plants have a significant part in reducing the severity of malaria due to their widespread use. As a result, more studies are needed to identify and develop effective novel drugs that could be employed in broader malaria eradication efforts.

Antimalarial Efficacy of Hydromethanolic Root Extract and Solvent Fractions of Urtica simensis Hochst. ex. A. Rich. (Urticaceae): An Experimental Study on Plasmodium berghei-Infected Mice

Background

Despite modern therapeutic armamentariums, malaria remains a 21st century public health menace. The issue of combating malaria is the ever-growing resistance to high-tech medications in which novel phytomedicines are highly demanding, a rapidly expanding research avenue. In Ethiopian folklore medicine, Urtica simensis has been used to treat malaria by drinking its juice after the dry roots have been mashed and combined with water. Hitherto, no in vivo study has been reported in the literature so far. To substantiate this folkloric claim, the present work herein was done.

Methods

An acute oral toxicity study was conducted as per the standard protocol. To rule out, the extract's inherent potential effects on bodyweight, basal body To, and PCV changes were tracked for two weeks. A four-day suppressive model and a curative assay model were utilized to investigate the antimalarial activity of the plant. Percent parasitemia suppression, packed cell volume, mean survival date, bodyweight, and rectal body temperature were used to determine antimalarial activity.

Result

An acute toxicity study reveals that Urtica simensis was atoxic at a dose of 2000 mg/kg. It also affirms that U. simensis is free from intrinsic potential effects of interfering with bodyweight, temperature, and packed cell volume evolution. Both crude extract and its solvent fractions at all test doses exerted significant (P < 0.001) inhibition of parasitemia as compared to the control group. CF400 mg/kg provided the greatest chemosuppressive effect (79.24%). In a curative experiment, crude extract and CF were able to prevent the cardinal indications of P. berghei-induced malaria, such as weight loss, hypothermia, parasitemia, and anemia. Both crude extracts and their solvent fractions prolong survival dates.

Conclusion

The antimalarial activity of the crude extract and its solvent fractions was promising, confirming previous assertions. As a result, more research studies into chemical entities may be required.

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.

Sida acuta Burm.f. leaves ethanol extract ameliorates haematological and biochemical alterations induced by Plasmodium berghei ANKA-65 in mice

Background

Malaria has continued to be a threat to man and his wellbeing, especially Africans and Asians. New antimalarial drugs are urgently needed to mitigate malaria treatment failure due to resistant Plasmodium species. Medicinal plants used by indigenous Nigerians for treating fever and malaria such as Sida acuta Burm.f. (Malvaceae) could be a promising source of lead compounds for developing new generations of antimalarial drugs. The effects of ethanol extract of S. acuta leaves (EESAL) on malaria parasitemia, haematological and biochemical status of P. berghei-infected mice were investigated, using the 4-day curative test.

Methodology

EESAL was prepared by maceration method. The phyto-constituents and acute toxicity profile of the extract were evaluated using standard protocols. In addition, malaria parasitemia and chemo-suppression, and indicators of haematological and biochemical status of P. berghei-infected mice treated with EESAL were assessed.

Results

At 200, 400 and 600 mg/kg/d b.w., p.o doses for 4 consecutive days, EESAL significantly (p < 0.05) decreased parasitaemia and suppressed malaria parasite by 89.64%, 95.95% and 97.38%, respectively comparable to negative control. The reduction in percentage malaria parasitemia by EESAL is comparable to Artemether (140 mg/kg/d b.w., p.o) used as standard antimalarial drug in this study. The packed cell volume (PCV), haemoglobin (Hb) concentration, and red blood cell (RBC) and white blood cell (WBC) counts of negative control are significantly (p < 0.05) higher than normal control. However, parasitized-EESAL-treated mice have significantly (p < 0.05) higher PCV value, Hb concentration and RBC and WBC counts than negative control. Similarly, treatment of parasitized mice with EESAL restored some indicators of the antioxidant, lipid peroxidation, lipid profile and liver status altered by malaria. In addition, EESAL was tolerable up to 5000 mg/kg b.w., p.o.

Conclusion

These results indicate that the EESAL possesses antimalarial activity and normalizes alterations in haematological and biochemical status of malaria-infected mice.

Antiplasmodial Activity of the Crude Extract and Solvent Fractions of Stem Barks of Gardenia ternifolia in Plasmodium berghei-Infected Mice

Background

The evolution of resistance to currently used malaria medicines together with the severe economic burden of malaria initiates the search for novel antimalarial drugs. Thus, the present experiment was intended to assess the in vivo antiplasmodial effect of Gardenia ternifolia based on the traditional claims and in vitro antimalarial effect of the plant.

Methods

For the crude extraction of stem barks of G. ternifolia, a cold maceration method using hydromethanol as a solvent was employed. The hydroalcoholic extract was then fractionated by three solvents (chloroform, n-butanol, and aqueous solvent) with different polarity indexes. Swiss albino mice infected with the chloroquine-sensitive malaria parasite (Plasmodium berghei) were used in this study. Acute oral toxicity study was done according to standard protocols. Four-day suppressive (hydromethanolic crude extract and solvent fractions), Rane's (crude extract), and repository (crude extract) tests were used to examine the antiplasmodial effects of the study plant.

Results

The chemosuppressive study revealed that all doses of the crude extract and its fractions displayed a significant (P < 0.001) inhibition of parasitemia compared with the vehicle (negative control). The crude extract's highest dose (600 mg/kg) showed the maximum (57.84%) parasitemia suppression during the chemosuppressive test. The crude extract also produced significant (P < 0.001) curative and prophylactic effects at all doses in Rane's and repository tests compared with the negative control. In the 4-day test, the n-butanol fraction produced parasitemia suppression higher than the chloroform fraction but lower than the crude extract. Of these, water fractions demonstrated the lowest chemosuppressive effect. Anthraquinone, alkaloids, flavonoids, saponins, steroids, tannins, and terpenoids were qualitatively detected in the plant material.

Conclusion

The current results showed that the hydromethanolic extract and fractions of G. ternifolia stem barks have antiplasmodial action with a high curative effect. Chloroform and n-butanol fractions were more active among the fractions, indicating that the nonpolar and semipolar constituents of the plant are responsible for the antimalarial effects.

Evaluation of Antimalarial Activity of 80% Methanolic Root Extract of Dorstenia barnimiana Against Plasmodium berghei-Infected Mice

BACKGROUND

Due to resistance of parasites, costs, and safety issues with currently available drugs, there is a need to discover new antimalarials. Medicinal plants are one of the most important sources of new drugs. The purpose of this study was to evaluate the antimalarial activity of a methanolic root extract of Dorstenia barnimiana in Swiss albino mice infected with Plasmodium berghei.

METHODS

Four-day suppressive, curative, and prophylactic tests were performed on mice infected with P. berghei to evaluate the antimalarial activity of a methanolic root extract of the plant. Parasitemia suppression, survival time, body-weight change, rectal temperature change, and packed-cell volume were used to evaluate the activity of the extract. Data were analyzed using one-way ANOVA followed by Tukey's post hoc test for comparisons between and within groups, with P<0.05 considered statistically significant.

RESULTS

The D. barnimiana root extract showed significant (P<0.01) parasitemia-suppressive activities in all models compared to the negative control. The extract increased mean survival time and prevented weight loss, reduction in temperature, and anemia significantly in all tested doses in 4-day suppressive and curative tests.

CONCLUSION

Based on these findings, D. barnimiana root has promising antimalarial activity and can considered a potential source to develop new agents.

Medicinal plants as a fight against murine blood-stage malaria

OBJECTIVE

Malaria is an infectious parasitic disease affecting most of countries worldwide. Due to antimalarial drug resistance, researchers are seeking to find another safe efficient source for treatment of malaria. Since many years ago, medicinal plants were widely used for the treatment of several diseases. In general, most application is done first on experimental animals then human. In this article, medicinal plants as antimalarial agents in experimental animals were reviewed from January 2000 until November 2020.

MATERIALS AND METHODS

In this systematic review published articles were reviewed using the electronic databases NCBI, ISI Web of knowledge, ScienceDirect and Saudi digital library to check articles and theses for M.Sc/Ph.D. The name of the medicinal plant with its taxon ID and family, the used Plasmodium species, plant part used and its extract type and the country of harvest were described.

RESULTS AND CONCLUSION

The reviewed plants belonged to 83 families. Medicinal plants of families Asteraceae, Meliaceae Fabaceae and Lamiaceae are the most abundant for use in laboratory animal antimalarial studies. According to region, published articles from 33 different countries were reviewed. Most of malaria published articles are from Africa especially Nigeria and Ethiopia. Leaves were the most common plant part used for the experimental malaria research. In many regions, research using medicinal plants to eliminate parasites and as a defensive tool is popular.