In vivo anti-inflammatory effect and toxicological screening of Maytenus heterophylla and Maytenus senegalensis extracts

The effect of an anti-malarial herbal remedy, Maytenus senegalensis, on electrocardiograms of healthy Tanzanian volunteers

BACKGROUND

The emergence of resistance to artemisinin-based combination therapy necessitates the search for new, more potent antiplasmodial compounds, including herbal remedies. The whole extract of Maytenus senegalensis has been scientifically investigated for potential biological activities both in vitro and in vivo, demonstrating strong antimalarial activity. However, there is a lack of data on the electrocardiographic effects of M. senegalensis in humans, which is a crucial aspect in the investigation of malaria treatment. Assessing the electrocardiographic effects of M. senegalensis is essential, as many anti-malarial drugs can inadvertently prolong the QT interval on electrocardiograms. Therefore, the study's objective was to evaluate the electrocardiographic effects of M. senegalensis in healthy adult volunteers.

METHODS

This study is a secondary analysis of an open-label single-arm dose escalation. Twelve healthy eligible Tanzanian males, aged 18 to 45, were enrolled in four study dose groups. A single 12-lead electrocardiogram (ECG) was performed at baseline and on days 3, 7, 14, 28, and 56.

RESULTS

No QTcF adverse events occurred with any drug dose. Only one volunteer who received the highest dose (800 mg) of M. senegalensis experienced a moderate transient change (△QTcF > 30 ms; specifically, the value was 37 ms) from baseline on day 28. There was no difference in maximum QTcF and maximum △QTcF between volunteers in all four study dose groups.

CONCLUSIONS

A four-day regimen of 800 mg every 8 h of M. senegalensis did not impact the electrocardiographic parameters in healthy volunteers. This study suggests that M. senegalensis could be a valuable addition to malaria treatment, providing a safer alternative and potentially aiding in the battle against artemisinin-resistant malaria. The results of this study support both the traditional use and the modern therapeutic potential of M. senegalensis. They also set the stage for future research involving larger and more diverse populations to explore the safety profile of M. senegalensis in different demographic groups. This is especially important considering the potential use of M. senegalensis as a therapeutic agent and its widespread utilization as traditional medicine. Trial registration ClinicalTrials.gov, NCT04944966. Registered 30 June 2021-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04944966?term=kamaka&draw=2&rank=1.

Ethnobotanical study of medicinal plants used by the people of Mosop, Nandi County in Kenya

Background: Throughout the history, nature has provided mankind with most of their basic needs, which include food, shelter, medicine, clothes, flavours, scents as well as raw materials. Given that they are an integral part of cultural heritage, medicinal plants have played a significant role in human healthcare systems around the world. Investigating various biological resources for use as medicines requires ethnomedicinal studies. Methods: Data on utilization of ethnomedicinal plants from local healers in Kenya's Mosop Sub-County in Nandi County was documented through open-ended, semi-structured questionnaires. A number of quantitative indices, such as the Use Citation (UC), Informant Consensus Factor (ICF), Use Value (UV), Frequency of Citation (FoC) and Relative Frequency of Citation (RFC) were used to convey the potential medical benefits, vitality and variety of the ethnomedicine. Results: 102 informants provided information on 253 ethnomedicinal plant species, classified into 74 families. There were 249 native plant species identified, along with few exotic species: Senegalia senegal (L.) Britton, Persea americana Mill, Carica papaya L. and Solanum betaceum Cav. Of all recorded species, 32% and 27% were herbs and trees, respectively. Among plant parts, leaves were most frequently utilized (27%) and roots (26%), while decoctions (21%) were the most widely used formulations. The dominant family was Asteraceae, with 28 species, followed by Lamiaceae, with 19 species. The highest ICF value was 0.778 for a number of parasitic and infectious illnesses, including ringworms, athlete's foot rot, tetanus, typhoid, intestinal parasites, abscesses, malaria, and amoebiasis. The study's data validates the region's widespread use of traditional medicinal plant remedies. Conclusion: The current study will lay a foundation of knowledge for future research investigations. The abundance of knowledge regarding ethnomedicinal species and their medicinal applications will stimulate further phytochemical and pharmacological research, which could lead to the discovery of potentially significant pharmaceuticals.

Safety and Tolerability of an Antimalarial Herbal Remedy in Healthy Volunteers: An Open-Label, Single-Arm, Dose-Escalation Study on Maytenus senegalensis in Tanzania

BACKGROUND

Though Maytenus senegalensis is one of the medicinal plants widely used in traditional medicine to treat infectious and inflammatory diseases in Africa, there is a lack of safety data regarding its use. Therefore, the study aimed to asselss the safety and tolerability of the antimalarial herbal remedy M. senegalensis.

MATERIAL AND METHODS

The study design was an open-label, single-arm, dose-escalation. Twelve eligible male healthy Tanzanians aged 18 to 45 years were enrolled in four study dose groups. Volunteers' safety and tolerability post-investigational-product administration were monitored on days 0 to 7,14, and 56.

RESULTS

There were no deaths or serious adverse events in any of the study groups, nor any adverse events that resulted in premature discontinuation. The significant mean changes observed in WBC (p = 0.003), Neutrophils (p = 0.02), Lymphocytes (p = 0.001), Eosinophils (p = 0.009), Alanine aminotransferase (p = 0.002), Creatinine (p = 0.03) and Total bilirubin (p = 0.004) laboratory parameters were not associated with any signs of toxicity or clinical symptoms.

CONCLUSIONS

M. senegalensis was demonstrated to be safe and tolerable when administered at a dose of 800 mg every eight hours a day for four days. This study design may be adapted to evaluate other herbal remedies.

Medicinal plants utilized in the management of epilepsy in Ethiopia: ethnobotany, pharmacology and phytochemistry

Epilepsy is a common central nervous system (CNS) disorder that affects 50 million people worldwide. Patients with status epilepticus (SE) suffer from devastating comorbidities and a high incidence of mortalities. Antiepileptic drugs (AEDs) are the mainstream treatment options for the symptomatic relief of epilepsy. The incidence of refractory epilepsy and the dose-dependent neurotoxicity of AEDs such as fatigue, cognitive impairment, dizziness, attention-deficit behavior, and other side effects are the major bottlenecks in epilepsy treatment. In low- and middle-income countries (LMICs), epilepsy patients failed to adhere to the AEDs regimens and consider other options such as complementary and alternative medicines (CAMs) to relieve pain due to status epilepticus (SE). Plant-based CAMs are widely employed for the treatment of epilepsy across the globe including Ethiopia. The current review documented around 96 plant species (PS) that are often used for the treatment of epilepsy in Ethiopia. It also described the in vivo anticonvulsant activities and toxicity profiles of the antiepileptic medicinal plants (MPs). Moreover, the phytochemical constituents of MPs with profound anticonvulsant effects were also assessed. The result reiterated that a lot has to be done to show the association between herbal-based epilepsy treatment and in vivo pharmacological activities of MPs regarding their mechanism of action (MOA), toxicity profiles, and bioactive constituents so that they can advance into the clinics and serve as a treatment option for epilepsy.

Monoaminergic system involvement in the antidepressant-like and anxiolytic-like properties of novel β-dihydroagarofuran sesquiterpene alkaloid and triterpenes isolated from Gymnosporia heterophylla aerial parts in mice

Gymnosporia heterophylla (synonym Maytenus) is widely used in folk medicine for the treatment of various illness including neurological diseases. This study presents the antidepressant-like and anxiolytic-like effects of novel bioactive constituents; 3,4-seco-1-hydroxy-21-oxoolean-3,11-olide (A2), 1β,2β-diacetoxy-9β-benzoyloxy-6α-nicotinoyloxy-β-dihydroagarofuran (A5) as well as known 3-acetoxy-1β-hydroxyLupe-20(29)-ene (selective COX-2; A4) from the aerial parts of G. heterophylla. The antidepressant-like effect was studied using the forced swim test (FST) while the elevated plus maze test (EPMT) and open field test (OFT) were employed for anxiolytic-like effect. Acute treatment with A4 and A5 (0.5, 5 or 10 mg/kg) significantly reduced the duration of immobility and immobile episodes with prolongation of immobility latency in the FST with peak effects observed at 10 and 0.5 mg/kg, respectively. Moreover, antidepressant-like effect of A4 and A5 were relatively better than that of fluoxetine. Conversely, the pretreatment of mice with prazosin (1 mg/kg, α₁-adrenoceptor antagonist), yohimbine (1 mg/kg; α₂-adrenoceptor antagonist), or sulpiride (50 mg/kg; dopamine D₂-receptor antagonist) reversed antidepressant-like effect of A4 and A5 but not WAY 100635 (10 mg/kg, i.p., selective 5-HT_1A receptor antagonist), GR 127935 (5 mg/kg, i.p., selective 5-HT_1B receptor antagonist), metergoline (4 mg/kg, i.p, non-selective 5-HT₂ receptor antagonist), ketanserin (5 mg/kg, i.p., a selective 5-HT_2A receptor antagonist) or p-chlorophenylalanine (pCPA) (100 mg/kg, i.p., tryptophan hydroxylase inhibitor) in the FST. Interestingly, A2, A4 and A5 significantly increased the time spent in the open arms of the EPM suggestive of anxiolytic-like action. Findings from this study showed that the novel β-dihydroagarofuran sesquiterpene alkaloid and triterpenes possesses antidepressant-like and anxiolytic-like effects through enhancement of monoaminergic signaling.

A review on anti-peptic ulcer activities of medicinal plants used in the formulation of Enterica, Dyspepsia and NPK 500 capsules

Peptic ulcer disease affects many people globally. With the increasing resistance to some orthodox antibiotics such as Clarithromycin and Metronidazole, it is important that new acceptable, safer and effective therapies are developed to manage this disease. Various herbal medicines have been used traditionally for the remedy of peptic ulcer disease (PUD), however scientific information with regards to their anti-peptic ulcer both in-vivo and in-vitro as well as clinical studies supporting their use is still inadequate. The Centre for Plant Medicine Research, (CPMR) Mampong-Akuapem, Ghana manufactures three herbal Products namely Enterica, Dyspepsia and NPK 500 capsules which are currently used for the remedy of PUD as a triple therapy at its out-patient clinic with promising effects. The aim of this review is to gather information from literature on the anti-ulcer properties, pharmacological, phytochemical constituents and related activities of herbal plants used at the CPMR for formulation of the triple herbal therapy. This review may, provide some scientific bases for the use of Enterica, Dyspepsia and NPK 500 capsules in the management of Peptic ulcer at the CPMR out-patient clinic.

METHODS

Organization for the review involved the on and/or offline search for information from available literature using electronic data and scientific research information resources such as PubMed, Science Direct and Google scholar.

RESULTS

In this review, fifteen ethno-medicinal plants used for the formulation of Enterica, Dyspepsia and NPK capsules have been discussed, presenting the description of the plants, composition and pharmacological activity.

INTERPRETATION

Tables with the summary of reviewed medicinal plants with their anti-ulcer models and inference on possible mechanisms of action were drawn up. The mechanism(s) of action of individual plants and products (Enterica, Dyspepsia and NPK 500 capsules) must be further investigated and established experimentally in-vitro in addition to in-vivo pharmacological and clinical activity studies to confirm their use in the remedy of PUD.

A Review of the Toxicity and Phytochemistry of Medicinal Plant Species Used by Herbalists in Treating People Living With HIV/AIDS in Uganda

Introduction: Despite concerns about toxicity, potentially harmful effects and herb-drug interactions, the use of herbal medicines remains widely practiced by people living with HIV/AIDS (PLHIV) in Uganda. Objective: The objective of the paper was to comprehensively review the literature on the toxicity and chemical composition of commonly used medicinal plant species in treating PLHIV in Uganda. Methods: We reviewed relevant articles and books published over the last sixty years on ethnobotany, antiviral/anti-HIV activity, toxicity, phytochemistry of Vachellia hockii, Albizia coriaria, Bridelia micrantha, Cryptolepis sanguinolenta, Erythrina abyssinica, Gardenia ternifolia, Gymnosporia senegalensis, Psorospermum febrifugium, Securidaca longipendunculata, Warburgia ugandensis and Zanthoxylum chalybeum and their synonyms. We searched PubMed, Web of Science, Scopus, Science Direct and Google Scholar. Discussion: Most of the plant species reviewed apart from P. febrifugium, S. longipedunculata and C. sanguinolenta lacked detailed phytochemical analyses as well as the quantification and characterization of their constituents. Crude plant extracts were the most commonly used. However, purified/single component extracts from different plant parts were also used in some studies. The U87 human glioblastoma was the most commonly used cell line. Water, ethanol, methanol and DMSO were the commonest solvents used. In some instances, isolated purified compounds/extracts such as Cryptolepine and Psorospermin were used. Conclusion: Cytotoxicity varied with cell type, solvent and extract type used making it difficult for direct comparison of the plant species. Five of the eleven plant species namely, A. coriaria, C. sanguinolenta, G. ternifolia, P. febrifugium and Z. chalybeum had no cytotoxicity studies in animal models. For the remaining six plant species, the crude aqueous and ethanol extracts were mainly used in acute oral toxicity studies in mice. Herbalists reported only A. coriaria and W. ugandensis to cause toxic side effects in humans. However, selective cytotoxic plant extracts can potentially be beneficial as anticancer or anti-tumour drugs.

Cyclooxygenase inhibitory compounds from Gymnosporia heterophylla aerial parts

Gymnosporia heterophylla (Celastraceae) is an African medicinal plants used to treat painful and inflammatory diseases with partial scientific validation. Solvent extractions followed by repeated chromatographic purification of the G. heterophylla aerial parts led to the isolation of one new β-dihydroagarofuran sesquiterpene alkaloid (1), and two triterpenes (2-3). In addition, eight known compounds including one β-dihydroagarofuran sesquiterpene alkaloid (4), and six triterpenes (5-10) were isolated. All structures were determined through extensive analysis of the NMR an MS data as well as by comparison with literature data. These compounds were evaluated for the anti-inflammatory activities against COX-1 and -2 inhibitory potentials. Most of the compound isolated showed non selective COX inhibitions except for 3-Acetoxy-1β-hydroxyLupe-20(29)-ene (5), Lup-20(29)-ene-1β,3β-diol (6) which showed COX-2 selective inhibition at 0.54 (1.85), and 0.45 (2.22) IC₅₀, in mM (Selective Index), respectively. The results confirmed the presence of anti-inflammatory compounds in G. heterophylla which are important indicators for development of complementary medicine for inflammatory reactions; however, few could be useful as selective COX-2 inhibitor.

Botanical features for identification of Gymnosporia arenicola dried leaf

Gymnosporia arenicola Jordaan (Celastraceae) is a shrub or small tree, which naturally occurs in coastal sand dunes of Southern Mozambique and South Africa. Its dried leaf is often used in traditional medicine for the treatment of infectious and inflammatory diseases. Hereby, we present results of studies carried out according to the pharmacopoeia standards for the identification of herbal drugs, in the whole, fragmented, and powdered plant material. These results were complemented with scanning electron microscopy and histochemical techniques. The leaf microscopic analysis revealed a typical dorsiventral mesophyll with a corresponding spongy parenchyma-palisade parenchyma ratio of 0.60, anomocytic and paracytic stomata, papillate cells with a diameter of 4.00 ± 0.40 µm, multicellular uniseriate nonglandular trichomes with a length of 27.00 ± 4.10 µm and cristalliferous idioblasts containing calcium oxalate cluster crystals with a diameter of 23.04 ± 5.84 µm. The present findings demonstrate that the G. arenicola leaf has both nonglandular trichomes and hypoderm, features not previously described in the corresponding botanical section (Gymnosporia sect. Buxifoliae Jordaan). The establishment of these new botanical markers for the identification of G. arenicola leaf is essential for quality, safety and efficacy reasons.

In vivo antiplasmodial and toxicological effect of Maytenus senegalensis traditionally used in the treatment of malaria in Tanzania

Background

In Tanzania and elsewhere, medicinal plants, including Maytenus senegalensis, are still widely used in the treatment of malaria and other ailments. The aim of the present study was to investigate the in vivo antiplasmodial and toxic effects in mice.

Methods

Oral antiplasmodial and acute toxicity of the ethanolic root extract of M. senegalensis was evaluated in mice. The Peters 4-day in vivo antiplasmodial effect against early rodent malaria infection in chloroquine-sensitive Plasmodium berghei NK 65 strain in mice.

Results

The M. senegalensis extract was found non-toxic and the oral median lethal dose in mice was determined to be greater than 1,600 mg/kg body weight. The findings revealed a significant (P = 0.001) daily increase in the level of parasitaemia in the parasitized untreated groups and a significant (P < 0.001) dose dependent decrease in parasitaemia in the parasitized groups treated with varying doses ranging from 25 to 100 mg/kg body weight of M. senegalensis extract and the standard drug sulphadoxine/pyrimethamine at 25/1.25 mg/kg body weight. Overall, the dose dependent parasitaemia suppression effects were in the order of: 25/1.25 mg/kg body weight of sulphadoxine/pyrimethamine > 100 mg/kg > 75 mg/kg > 50 mg/kg > 25 mg/kg body weight of M. senegalensis extract.

Conclusion

The implications of these findings is that M. senegalensis ethanolic root bark extract possess potent antiplasmodial effect and may, therefore, serve as potential sources of safe, effective and affordable anti-malarial drugs. The displayed high in vivo antiplasmodial activity and lack of toxic effect render M. senegalensis a candidate for the bioassay-guided isolation of compounds which could develop into new lead structures and candidates for drug development programmes against human malaria.

Evaluation of pharmacological activities, cytotoxicity and phenolic composition of four Maytenus species used in southern African traditional medicine to treat intestinal infections and diarrhoeal diseases

BACKGROUND

Microbial infections and resulting inflammation and oxidative stress are common pathogenesis of gastrointestinal tract (GIT) disorders. In South Africa, several species of the genus Maytenus are used in traditional medicine to treat various infectious diseases. Most of the previous work on this genus was focused on nonpolar extracts from the root and bark. In this study, leaf extracts of polar extracts of Maytenus peduncularis, Maytenus procumbens, Maytenus senegalensis and Maytenus undata were evaluated for antimicrobial, anti-inflammatory and antioxidant activities to determine their efficacy as therapeutic agents in GIT disorders.

METHODS

Phenolic-enriched leaf extracts and fractions were prepared by extracting with acidified 70% methanol and solvent-solvent fractionation. The activities of the fractions against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis as well as clinical isolates of Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans were determined using a serial microplate dilution method. Antioxidant activities were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), hydroxyl (OH) radical scavenging and linoleic acid peroxidation inhibitory assays. The phenolic composition as well as the cytotoxicity against Vero cell lines of the crude extracts was evaluated using various standard protocols.

RESULTS

The antimicrobial activities were concentrated in the non-polar fractions of hexane, dichloromethane and ethyl acetate (MICs 19-312 μg/ml). The crude extracts and polar fractions (butanol and water) had moderate to poor antimicrobial activity (MICs 312 to above 2500 μg/ml). The crude extracts and polar fractions had good antioxidant activity (EC50 values varied from 1.22 to 607 μg/ml, 1.71 to 312 μg/ml and 23 to 284 μg/ml for DPPH, ABTS and OH respectively. Linoleic acid peroxidation inhibition EC50 values of the crude extracts ranged between 27 and 39 μg/ml with relatively low toxicity against Vero cell lines (IC50 values 87 to 187 μg/ml). Fractionation of a crude extract with low activity could lead to fractions with more potent activity.

CONCLUSION

This study justifies the traditional use of leaf crude extracts and fractions from these four plants to remedy gastrointestinal disorders resulting from infection, inflammation and oxidative stress complications. The study also provides rationale for the use of leaf extracts with same beneficial effects in place of unsustainable root and bark harvest.

Traditional use of medicinal plants in south-central Zimbabwe: review and perspectives

BACKGROUND

Traditional medicine has remained as the most affordable and easily accessible source of treatment in the primary healthcare system of resource poor communities in Zimbabwe. The local people have a long history of traditional plant usage for medicinal purposes. Despite the increasing acceptance of traditional medicine in Zimbabwe, this rich indigenous knowledge is not adequately documented. Documentation of plants used as traditional medicines is needed so that the knowledge can be preserved and the utilized plants conserved and used sustainably. The primary objective of this paper is to summarize information on traditional uses of medicinal plants in south-central Zimbabwe, identifying research gaps and suggesting perspectives for future research.

METHODS

This study is based on a review of the literature published in scientific journals, books, reports from national, regional and international organizations, theses, conference papers and other grey materials.

RESULTS

A total of 93 medicinal plant species representing 41 families and 77 genera are used in south-central Zimbabwe. These plant species are used to treat 18 diseases and disorder categories, with the highest number of species used for gastro-intestinal disorders, followed by sexually transmitted infections, cold, cough and sore throat and gynaecological problems. Shrubs and trees (38% each) were the primary sources of medicinal plants, followed by herbs (21%) and climbers (3%). The therapeutic claims made on medicinal plants documented in south-central Zimbabwe are well supported by literature, with 82.8% of the plant species having similar applications in other regions of Zimbabwe as well as other parts of the world and 89.2% having documented biological and pharmacological properties.

CONCLUSION

This study illustrates the importance of traditional medicines in the treatment and management of human diseases and ailments in south-central Zimbabwe. Traditional medicines still play an important role in meeting basic health care of local communities in Zimbabwe.

Medicinal plants traditionally used in Mali for dysmenorrhea

Dysmenorrhea is painful menstrual cramps, which negatively impacts the quality of life of a large percentage of the world's female population in reproductive age. The paper reviews the plants used in the Malian traditional medicine for the treatment of dysmenorrhea. Some medicinal plants were effective for treatments of dysmenorrhea with minimal side effects. Conventional therapy for dysmenorrhea, which usually includes non-steroidal anti-inflammatory drugs (NSAIDs), provides symptomatic relief, but presents increasing adverse effects with long-term use. This article is in the framework of a study supported by International Foundation for Science (IFS) on three medicinal plants used in the treatment of dysmenorrhea in Mali: Maytenus senegalensis Stereospermum kunthianum and Trichilia emetica.

Maytenus heterophylla and Maytenus senegalensis, two traditional herbal medicines

Maytenus heterophylla (Eckl. and Zeyh.) N.K.B. Robson and Maytenus senegalensis (Lam.) Exell are two African shrubs or trees that go under the common name of spike thorn, which belong to the Celastraceae family. Different plant parts of this species are largely used in traditional medicine for infectious and inflammatory diseases treatment. Several studies have been reported for both these species, but there are no recent review articles focusing microscopic, phytochemistry and pharmacological studies. The aim of this review is to summarize the information about these two African traditional medicines. Such kind of data can be applied in future experimental work and may guide future studies, namely in the field of validation of traditional medicine.