In vitro antiplasmodial activity and cytotoxicity of 33 West African plants used for treatment of malaria

The dichapetalins and dichapetalin-type compounds: structural diversity, bioactivity, and future research perspectives

Covering mainly from 2013 up to 2023 with relevant references to work done before 2013First reported in 1995, the dichapetalins and analogous compounds constitute a novel class of natural dammarane-type merotriterpenoids characterized by their unique 2-phenylpyrano moiety annellated to ring A of the dammarane skeleton. They have been reported from only two genera: Dichapetalum (Dichapetalaceae) and Phyllanthus (Phyllanthaceae). About 100 novel dichapetalins and dichapetalin-type compounds, including the acutissimatriterpenes and their antitumour and other bioactivities have been reported. In the present review, we cover the distribution, ethnobotanical and medicinal importance and the diversity of secondary metabolites reported from the two genera Dichapetalum and Phyllanthus from 2013 to date, with appropriate reference to relevant information prior to 2013. We also propose and discuss possible biosynthetic pathways, antitumour activity against a broad range of human and murine cancer cell lines, structure activity relationships, and other biological activities and mechanisms of action. Finally, the review deals with future perspectives which include expansion of the structural diversity and bioactivity scope, possible simplification of the structural complexity of the compounds to enhance their drug-likeness, in silico studies, and continuation of the search for new dichapetalins and dichapetalin-type compounds from the over 200 Dichapetalum and over 1200 Phyllanthus species yet to be investigated. It is envisaged that the present review will stimulate further multidisciplinary and interdisciplinary studies.

The ethnomedicine, phytochemistry, and pharmacological properties of the genus Bersama: current review and future perspectives

Bersama (Melianthaceae) has been used in traditional medicine for a wide range of ailments, including blood purifier, immune booster, psychotropic medication, and treatment for malaria, hepatitis, infertility, diabetes, impotency, meningitis, and stroke. This review gathers fragmented information from the literature on ethnomedicinal applications, phytochemistry, pharmacology, and toxicology of the Bersama genus. It also explores the therapeutic potential of the Bersama genus in ethnophytopharmacology, allowing for further investigation. All the available information published in the English language on Bersama genus was compiled from electronic databases such as Academic Journals, Ethnobotany, Google Scholar, PubMed, Science Direct, Web of Science, and library search using the following keywords: "Bersama genus," "traditional use," "phytochemistry," "pharmacological effects," and "toxicology". The ethnomedical applications of the Bersama genus have been recorded, and it has been used traditionally for more than 30 different types of ailments. Thus far, more than 50 compounds have been isolated from the genus. Cardiac glycosides and terpenoids are the main compounds isolated from the Bersama genus. Different plant parts of Bersama genus extracts demonstrated a wide range of pharmacological properties, including antioxidant, antimalarial, antidiabetic, antiviral, anti-inflammatory, and cytotoxic activity. Exemplary drug leads from the genus include mangiferin and quercetin-3-O-arabinopyranoside, both of which have antioxidant activities. Bersama genus has long been used to cure a wide range of ailments. Bersama genus extracts and phytochemicals have been found to have promising pharmacological activities. Further study on promising crude extracts and compounds is required to develop innovative therapeutic candidates.

Evaluation of packaging, labels, and some physicochemical properties of herbal antimalarial products on the Ghanaian market

Introduction

Malaria is a parasitic disease that is endemic in tropical areas and can be life-threatening. There has been a decrease in the prevalence of malaria in Ghana but the burden of the disease is still high in the country. Many Ghanaians depend on herbal products for malaria treatment. This study aimed to survey and evaluate commercial herbal antimalarials in the Volta Region of Ghana.

Methods

A survey of finished herbal antimalarials was done at herbal shops, pharmacies, and over-the-counter medicine seller shops. Products available on shelves were purchased and their details were recorded, after which they were examined using a visual inspection tool. The density, pH, and extract weight per dose of each sample were also determined.

Results

Thirty-four liquid formulations (A-1-34) containing 1-9 different herbs were found. The majority of the product labels had errors in consumer age classifications. Unconventional ways of stating doses were found on two products (A-13, "tot"; A-19, cupful). Six products did not have dosing devices. No duration of treatment was indicated on 24 products. Dose errors were found on A-14 and A-22. Samples A-17 and A-28 did not have registration or batch numbers. Product A-28 did not have its herbs listed on it and was indicated for persons aged 3-8 years at a dose of 45 mL. The relative density range for the products was 0.997-1.015. From the pH investigation, no product was extremely erosive; however, 10 samples were deemed erosive (pH, 3.0-3.99), whereas 24 were minimally erosive (pH, ≥4.0). The extract weight per dose volume (20-90 mL) was 0.048-1.766 g, indicating that unit dose capsules or tablets could be formulated from the products.

Conclusion

The findings clearly show that Ghanaian authorities responsible for regulating herbal products must enforce guidelines for the formulation, label details, and sale of antimalarial products. Additionally, the unpleasant taste of liquid herbal mixtures can affect patient compliance and dosing convenience; therefore, it is recommended that oral solid dosage forms of herbal antimalarials are produced as alternatives to the liquid mixtures.

Unleashed Treasures of Solanaceae: Mechanistic Insights into Phytochemicals with Therapeutic Potential for Combatting Human Diseases

Plants that possess a diverse range of bioactive compounds are essential for maintaining human health and survival. The diversity of bioactive compounds with distinct therapeutic potential contributes to their role in health systems, in addition to their function as a source of nutrients. Studies on the genetic makeup and composition of bioactive compounds have revealed them to be rich in steroidal alkaloids, saponins, terpenes, flavonoids, and phenolics. The Solanaceae family, having a rich abundance of bioactive compounds with varying degrees of pharmacological activities, holds significant promise in the management of different diseases. Investigation into Solanum species has revealed them to exhibit a wide range of pharmacological properties, including antioxidant, hepatoprotective, cardioprotective, nephroprotective, anti-inflammatory, and anti-ulcerogenic effects. Phytochemical analysis of isolated compounds such as diosgenin, solamargine, solanine, apigenin, and lupeol has shown them to be cytotoxic in different cancer cell lines, including liver cancer (HepG2, Hep3B, SMMC-772), lung cancer (A549, H441, H520), human breast cancer (HBL-100), and prostate cancer (PC3). Since analysis of their phytochemical constituents has shown them to have a notable effect on several signaling pathways, a great deal of attention has been paid to identifying the biological targets and cellular mechanisms involved therein. Considering the promising aspects of bioactive constituents of different Solanum members, the main emphasis was on finding and reporting notable cultivars, their phytochemical contents, and their pharmacological properties. This review offers mechanistic insights into the bioactive ingredients intended to treat different ailments with the least harmful effects for potential applications in the advancement of medical research.

The SARS-CoV-2 Mpro Dimer-Based Screening System: A Synthetic Biology Tool for Identifying Compounds with Dimerization Inhibitory Potential

The COVID-19 endemic remains a global concern. The search for effective antiviral candidates is still needed to reduce disease risk. However, the availability of high biosafety level laboratory facilities for drug screening is limited in number. To address this issue, a screening system that could be utilized at lower biosafety levels remains essential. This study aimed to develop a novel SARS-CoV-2 main protease (Mpro) dimer-based screening system (DBSS) utilizing synthetic biology in Escherichia coli BL21(DE3). We linked the SARS-CoV-2 Mpro with the DNA-binding domain of AraC regulatory protein, which regulates the reporter gene expression. Protein modeling and molecular docking showed that saquinavir could bind to AraC-Mpro both in its monomer and dimer forms. The constructed DBSS assay indicated the screening system could detect saquinavir inhibitory activity at a concentration range of 4-10 μg/mL compared to the untreated control (P ≤ 0.05). The Vero E6 cell assay validated the DBSS result that saquinavir at 4-10 μg/mL exhibited antiviral activity against SARS-CoV-2. Our DBSS could be used for preliminary screening of numerous drug candidates that possess a dimerization inhibitor activity of SARS-CoV-2 Mpro and also minimize the use of a high biosafety level laboratory.

Exploring the biomedical potential of a novel modified glass ionomer cement against the pandrug-resistant oral pathogen Candida albicans SYN-01

Dental caries is an infectious disease that is a major concern for dentists. Streptococci and Lactobacilli were long thought to be the primary etiology responsible for caries. Candida albicans with acidogenic and aciduric characteristics has recently been implicated in the onset and progression of cariogenic lesions. Moreover, due to the increased resistance to common antimicrobials, the discovery of innovative candidates is in high demand. Therefore, our study might be the first report that explores the efficacy of glass ionomer cement (GIC) incorporated with a newly modified carboxylated chitosan derivative (CS-MC) against multidrug-resistant (MDR) and/or pandrug resistant (PDR) C. albicans isolated from the oral cavity. In this work, four CS-MC-GIC groups with different concentrations were formulated. Group four (CS-MC-GIC-4) gave a significant performance as an anticandidal agent against selected PDR Candida strain, with an obvious decrease in its cell viability and high antibiofilm activity. It also, enhanced all the mechanical properties and supports cell viability of Vero cells as a nontoxic compound. Moreover, CS-MC-GIC-4 inhibited neuraminidases completely, which might provide a novel mechanism to prevent dental/oral infections. Thus, findings in this study open up new prospect of the utilization of CS-MC-GIC as a novel dental filling material against oral drug-resistant Candida.

Biochemical and molecular docking-based strategies of Acalypha indica and Boerhavia diffusa extract by targeting bacterial strains and cancer proteins

Antibiotic-resistant microbes have emerged around the world, presenting a risk to health. Plant-derived drugs have become a potential source for the production of antibiotic-resistant drugs and cancer therapies. In this study, we investigated the antibacterial, cytotoxic and antioxidant properties of Acalypha indica and Boerhavia diffusa, and conducted in silico molecular docking experiments against EGFR and VEGFR-2 proteins. The metabolic extract of A. indica inhibited Streptococcus iniae and Staphylococcus sciuri with inhibition zones of 21.66 ± 0.57 mm and 20.33 ± 0.57 mm, respectively. The B. diffusa leaf extract produced inhibition zones of 20.3333 ± 0.5773 mm and 20.33 ± 0.57 mm against Streptococcus iniae and Edwardsiella anguillarum, respectively. A. indica and B. diffusa extracts had toxicities of 162.01 μg/ml and 175.6 μg/ml, respectively. Moreover, B. diffusa (IC50 =154.42 µg/ml) leaf extract exhibited moderately higher antioxidant activity compared with the A. indica (IC50 = 218.97 µg/ml) leaf extract. Multiple interactions were observed at Leu694, Met769 and Leu820 sites for EGFR and at Asp1046 and Cys1045 sites for VEGFR during the molecular docking study. CID-235030, CID-70825 and CID-156619353 had binding energies of -7.6 kJ/mol, -7.5 kJ/mol and -7.6 kJ/mol, respectively, with EGFR protein. VEGFR-2 protein had docking energies of -7.5 kJ/mol, -7.6 kJ/mol and -7.3 kJ/mol, respectively, for CID-6420353, CID-156619353 and CID-70825 compounds. The MD simulation trajectories revealed the hit compound; CID-235030 and EGFR complex, CID-6420353 and VEGFR-2 exhibit stable profile in the root mean square deviation (RMSD), radius of gyration (Rg), solvent accessible surface area (SASA), hydrogen bond and root mean square fluctuation (RMSF) and the binding free energy by MM-PBSA method. This study indicates that methanol extracts of A. indica and B. diffusa may play a crucial role in developing antibiotic-resistant and cancer drugs.Communicated by Ramaswamy H. Sarma.

Examining the disparities of anti-malarial drug consumption among children under the age of five: a study of 5 malaria-endemic countries

BACKGROUND

Malaria is one of the most prominent illnesses affecting children, ranking as one of the key development concerns for many low- and middle-income countries (LMICs). There is not much information available on the use of anti-malarial drugs in LMICs in children under five. The study aimed to investigate disparities in anti-malarial drug consumption for malaria among children under the age of five in LMICs.

METHODS

This study used recent available cross-sectional data from the Malaria Indicator Survey (MIS) datasets across five LMICs (Guinea, Kenya, Mali, Nigeria, and Sierra Leone), which covered a portion of sub-Saharan Africa. The study was carried out between January 2, 2023, and April 15, 2023, and included children under the age of five who had taken an anti-malarial drug for malaria 2 weeks before the survey date. The outcome variable was anti-malarial drug consumption, which was classified into two groups: those who had taken anti-malarial drugs and those who had not.

RESULTS

In the study of LMICs, 32,397 children under five were observed, and among them, 44.1% had received anti-malarial drugs. Of the five LMICs, Kenya had the lowest (9.2%) and Mali had the highest (70.5%) percentages of anti-malarial drug consumption. Children under five with malaria are more likely to receive anti-malarial drugs if they are over 1 year old, live in rural areas, have mothers with higher education levels, and come from wealthier families.

CONCLUSION

The study emphasizes the importance of developing universal coverage strategies for anti-malarial drug consumption at both the national and local levels. The study also recommends that improving availability and access to anti-malarial drugs may be necessary, as the consumption of these drugs for treating malaria in children under the age of five is shockingly low in some LMICs.

Porphyrin-derived carbon dots for an enhanced antiviral activity targeting the CTD of SARS-CoV-2 nucleocapsid

BACKGROUND

Since effective antiviral drugs for COVID-19 are still limited in number, the exploration of compounds that have antiviral activity against SARS-CoV-2 is in high demand. Porphyrin is potentially developed as a COVID-19 antiviral drug. However, its low solubility in water restricts its clinical application. Reconstruction of porphyrin into carbon dots is expected to possess better solubility and bioavailability as well as lower biotoxicity.

METHODS AND RESULTS

In this study, we investigated the antiviral activity of porphyrin and porphyrin-derived carbon dots against SARS-CoV-2. Through the in silico analysis and assessment using a novel drug screening platform, namely dimer-based screening system, we demonstrated the capability of the antivirus candidates in inhibiting the dimerization of the C-terminal domain of SARS-CoV-2 Nucleocapsid. It was shown that porphyrin-derived carbon dots possessed lower cytotoxicity on Vero E6 cells than porphyrin. Furthermore, we also assessed their antiviral activity on the SARS-CoV-2-infected Vero E6 cells. The transformation of porphyrin into carbon dots substantially augmented its performance in disrupting SARS-CoV-2 propagation in vitro.

CONCLUSIONS

Therefore, this study comprehensively demonstrated the potential of porphyrin-derived carbon dots to be developed further as a promisingly safe and effective COVID-19 antiviral drug.

Curcumin-derived carbon-dots as a potential COVID-19 antiviral drug

Even entering the third year of the COVID-19 pandemic, only a small number of COVID-19 antiviral drugs are approved. Curcumin has previously shown antiviral activity against SARS-CoV-2 nucleocapsid, but its poor bioavailability limits its clinical uses. Utilizing nanotechnology structures, curcumin-derived carbon-dots (cur-CDs) were synthesized to increase low bioavailability of curcumin. In-silico analyses were performed using molecular docking, inhibition of SARS-CoV-2 nucleocapsid C-terminal domain (N-CTD) and antiviral activity were assessed in dimer-based screening system (DBSS) and in vitro respectively. Curcumin bound with the N-CTD at ΔG = -7.6 kcal/mol, however modifications into cur-CDs significantly improved the binding affinity and %interaction. Cur-CDs also significantly increased protection against SARS-CoV-2 in both DBSS and in vitro at MOI = 0.1. This study demonstrated the effect of post-infection treatment of curcumin and novel curcumin-derived carbon-dots on SARS-CoV-2 N-CTD dimerization. Further investigation on pre-infection and in-vivo treatment of curcumin and cur-CDs are required for a comprehensive understanding on the carbon-dots enhanced antiviral activity of curcumin against SARS-CoV-2.

Liver cancer antiproliferative activity of a new nor-cucurbitacin from Mareya micrantha Müll. Arg

Mareya micrantha Müll. Arg. (Euphorbiaceae) is a plant used in the Ivorian traditional medicinal system for various medical properties such as laxative, oxytocic, intestinal infectious diseases, malaria, etc. Six cucurbitacin derivatives (tetracyclic triterpenoids) are isolated from the leaves, stem barks or root barks of M. micrantha. Among these compounds, 29-nor-2β,15α,20β-trihydroxy-16α-acetyl-3,1,22-trioxo-cucurbita-4,23-diene (1) is a new nor-cucurbitacin isolated from the leaves; 29-nor-1,2,3,4,5,10-dehydro-3,15α,20β-trihydroxy-16α-acetyl-11,22-dioxo-cucurbita-23-ene 2-O-β-D-glucopyranoside (2) and 29-nor-2β,15α,20β-trihydroxy-16α-acetyl-3,11,22 trioxo-cucurbita-4,23-diene 2-O-β-D glucopyranoside (3) are new nor-cucurbitacins recently discovered by us in leaves and isolated again for this study while dihydro-epi-isocucurbitacin D (4), tetrahydro-cucurbitacin I (5) and cucurbitacin L (6) are known cucurbitacins but newly isolated from the stem barks and the root barks of M. micrantha. Their chemical structures are established according to spectral data (UV, IR, MS and 1H, 13C NMR). Their antiproliferative activity is explored in vitro on the chemo-resistant human hepatocarcinoma cell line Hep3B. Compound 1 showed a strong and selective antiproliferative activity against this cancer cell line (IC50 value of 0.12 ± 0.05 μM) when compared to normal hepatocytes HepaRG.

A review of efficacy and safety of Ugandan anti-malarial plants with application of RITAM score

BACKGROUND

Malaria, a treatable disease mainly caused by Plasmodium falciparum has remained a health challenge in Africa, a continent that accounted for 96% of total global cases and deaths in 2021. Uganda, a malaria endemic country is experiencing malaria parasite resistance to some of the drugs used in the artemisinin-based combination therapy (ACT). In an effort to prioritize herbal medicines for new product development, this review synthesized the available safety and efficacy literature on the Ugandan anti-malarial plants to suggest most effective herbal plants.

METHODS

Literature was exhaustively searched using engines and databases, such as Google scholar, Pubmed, and Scopus-indexed journals during the period of June 2020-December 2021. In the first phase, information on ethnobotanical uses of anti-malarial plants in Uganda was gathered and synthetized to generate a list of plants, followed by data on anti-malarial efficacy (both in vitro and in vivo) on each listed plant. Minimum inhibitory concentrations (µg/ml), and % parasite suppression for every plant were scored using The Research Initiative on Traditional and Antimalarial Methods (RITAM) scoring system. The best twenty (20) plants were evaluated for acute safety (LD₅₀) data in rat model, plant parts used, ease of cultivation, presence of clinical studies and other relevant factors for suggesting the best three (3) plants for future anti-malarial product development.

RESULTS

Over one hundred twenty-six (126) plant species are used in Uganda for treatment of malaria in local communities. Out of these, about 33% (41) have been studied for efficacy and safety, with Artemisia annua and Vernonia amygdalina being the most extensively studied and among the best twenty (20) anti-malarial plants in Uganda. Both are limited by parasite recrudescence in clinical studies. Microglossa pyrifolia, a very potent plant (IC50 = 0.03 - 0.05 µg/ml has potential to penetrate the liver and could ameliorate the challenge of recrudescence if combined with A. annua and V. amygdalina in a polyherbal formulation.

CONCLUSION

There are many plants with promising potential for malaria treatment in Uganda and a herbal combination of A. annua, V. amydalina and M. pyrifolia could offer the next herbal ACT if carefully studied and developed.

A serum metabolomics study based on LC-MS: Chemosensitization effects of Rauvolfia vomitoria Afzel. combined with 5- fluorouracil on colorectal cancer mice

Colorectal cancer (CRC) is one of the malignant tumors with high incidence, and is mainly treated by chemotherapy at present. However, during CRC treatment, long-term use of traditional chemotherapeutic drugs will reduce the sensitivity of chemotherapy. Our previous studies have shown that Rauvolfia vomitoria total alkaloids (RVA) played an important role in 5-fluorouracil (5-FU) chemosensitization in CRC therapy, but its intervention mechanism has not been clarified completely in the metabolic level. Therefore, in this study, LC-MS based metabolomics was employed to explore the mechanism of 5-FU chemosensitization in CRC induced by the combination of RVA and conventional chemotherapeutic with 5-FU. The results showed that the final tumor weight of the high-dose combined group was significantly different from that of the 5-FU alone group. To evaluate the chemosensitization effects of RVA, serum samples collected from six groups (six mice in each group) with different administration methods were analyzed by HPLC-Q-Exactive Orbitrap/MS. After multivariate statistical analysis and metabolites identification, 25 different metabolites were identified between the 5-FU treatment group and combined high-dose treatment group, among which lipid and fatty acid metabolism pathways were mostly affected. These results suggest that RVA may sensitize traditional chemotherapeutic drug 5-FU and exert anti-tumor activity through influencing lipid metabolism and cell energy metabolism. Metabolomics provided a new insight into estimate of the therapeutic effect and dissection of the potential mechanisms of traditional Chinese medicine in treating colorectal cancer.

Genus Rauvolfia: A review of its ethnopharmacology, phytochemistry, quality control/quality assurance, pharmacological activities and clinical evidence

ETHNOPHARMACOLOGICAL RELEVANCE

The plants are from the genus Rauvolfia Plum. ex L. (Apocynaceae), which is represented by 74 species with many synonyms, and distributed worldwide, especially in the Asian, and African continents. Traditionally, some of them are used for the treatment of various disorders related to the central nervous system (CNS), cardiovascular diseases (CVD), and as an antidote due to the presence of monoterpene indole alkaloids (MIAs) such as ajmaline (144), ajmalicine (164) serpentine (182), yohimbine (190) and reserpine (214).

AIM

The present review provides comprehensive summarization and critical analysis of the traditional to modern applications of Rauvolfia species, and the major focus was to include traditional uses, phytochemistry, quality control, pharmacological properties, as well as clinical evidence that may be useful in the drug discovery process.

MATERIALS AND METHODS

Information related to traditional uses, chemical constituents, separation techniques/analytical methods, and pharmacological properties of the genus Rauvolfia were obtained using electronic databases such as Web of Science, Scopus, SciFinder, PubMed, PubChem, ChemSpider, and Google Scholar between the years 1949-2021. The scientific name of the species and its synonyms were checked with the information of The Plant List.

RESULTS

A total of seventeen Rauvolfia species have been traditionally explored for various therapeutic applications, out of which the roots of R. serpentina and R. vomitoria are used most commonly for the treatment of many diseases. About 287 alkaloids, seven terpenoids, nine flavonoids, and four phenolic acids have been reported in different parts of the forty-three species. Quality control (QC)/quality assurance (QA) of extracts/herbal formulations of Rauvolfia species was analyzed by qualitative and quantitative methods based on the major MIAs such as compounds 144, 164, 182, 190, and 214 using HPTLC, HPLC, and HPLC-MS. The various extracts of different plant parts of thirteen Rauvolfia species are explored for their pharmacological properties such as antimicrobial, antioxidant, antiprotozoal, antitrypanosomal, antipsychotic, cardioprotective, cholinesterase inhibitory, and hepatoprotective. Of which, clinical trials of herbal formulations/extracts of R. serpentina and MIAs have been reported for CVD, CNS, antihypertensive therapy, antidiabetic effects, and psoriasis therapy, while the extracts and phytoconstituents of remaining Rauvolfia species are predominantly significant, owning them to be additional attention for further investigation under clinical trials and QC/QA.

CONCLUSION

The present communication has provided a comprehensive, systematic, and critically analyzed vision into the traditional uses, phytochemistry, and modern therapeutic applications of the genus Rauvolfia are validated by scientific evidence. In addition, different plant parts from this genus, especially raw and finished herbal products of the roots of R. serpentina have been demonstrated for the QC/QA.

Antiplasmodial, Antitrypanosomal, and Cytotoxic Effects of Anthonotha macrophylla, Annickia polycarpa, Tieghemella heckelii, and Antrocaryon micraster Extracts

Malaria and trypanosomiasis are protozoan diseases which pose a devastating challenge to human health and productivity especially, in Africa where their respective vectors (female Anopheles mosquito and tsetse fly) abound. Various medicinal plants are used to treat these parasitic diseases. However, the scientific basis of their use and toxicological profiles have not been assessed. We have, therefore, evaluated the antiplasmodial, antitrypanosomal, and cytotoxic activities of four African medicinal plant extracts namely, Anthonotha macrophylla leaf (AML), Annickia polycarpa leaf (APLE), Tieghemella heckelii stem bark (THBE), and Antrocaryon micraster stem bark (AMSBE) extracts in vitro against P. falciparum (W2mef laboratory strain), T. brucei (GUTat 3.1 strain), and mammalian RAW 264.7 macrophage cell line, respectively. The most active antiplasmodial extract was AML (IC50 = 5.0 ± 0.08 μg/mL with SI of 21.9). THBE also, produced the most effective antitrypanosomal activity (IC50 = 11.0 ± 0.09 μg/mL and SI of 10.2) among the extracts. In addition, none of the extracts produced toxic effect in the RAW 264.7 macrophage cell line except APLE which was moderately cytotoxic and also produced the least SI in both antitrypanosomal and antiplasmodial assays. These results suggest that AML and THBE could offer safe and alternative therapy for malaria and trypanosomiasis. This is the first study to report the antitrypanosomal and in vitro antiplasmodial activities of these four plants/plant parts. The cytotoxicity of the plant parts used is also being reported for the first time except for the T. heckelii stem bark.

Health benefits and biological activities of spiny monkey orange (Strychnos spinosa Lam.): An African indigenous fruit tree

ETHNOPHARMACOLOGICAL RELEVANCE

Spiny monkey orange (Strychnos spinosa Lam.) is an African endemic fruit tree that is widely consumed by humans and animals for its nutritional value. In folk medicine, different parts of S. spinosa are widely used for the management of the health and well-being of humans and livestock.

AIM

We provide a critical appraisal on the ethnobotanical uses, nutritional and pytochemical as well as the biological activities of S. spinosa.

METHODS

Articles were mined from online databases such as Google Scholar, PubMed, Science Direct, SciELO and SpringerLink. We captured research outputs that aligned with the scope of the review.

RESULTS

Strychnos spinosa remains a commonly consumed fruit due to its high nutritional (e.g. carbohydrates, crude protein and fats) content and energy. In folk medicine, different parts of S. spinosa are prescribed as remedy for diverse medical conditions especially for treating malaria, diabetes, snakebites, skin-related conditions and sexually transmitted infections in humans as well as sleeping sickness in livestock. Together with essential oils, more than 25 compounds have been profiled using Gas chromatography-mass spectrometry (GC-MS), and approximately 45 compounds have been isolated and structurally elucidated using diverse spectroscopic techniques such as UV-visible, Infrared (IR), Nuclear Magnetic Resonance (NMR) and mass spectroscopy (MS). Strychnos spinosa exerts varying degrees of biological activities against different microorganisms (bacteria and fungi) and parasites (plasmodia, trypanosomes and ticks) responsible for many diseases in humans and livestock. Furthermore, low to moderate enzyme-inhibitory effects of S. spinosa extracts suggest its ability to mitigate pains, inflammations and diabetics as well as snakebite venom. Increasing evidence from the in vivo studies support the use of the plant as a popular remedy for managing diabetics in folk medicine. The low cytotoxic effect of the plant extracts against different cell lines could be an indication of its relative safety.

CONCLUSION

Strychnos spinosa exhibits various health-promoting benefits due to its diverse nutritional and phytochemical constituents. Given that the majority of the existing evidence on these aforementioned therapeutic properties and safety are in vitro-based, the clinical significance of these results remain limited.

Preclinical Trial of Traditional Plant Remedies for the Treatment of Complications of Gestational Malaria

Background: Most pregnant women living in high malaria endemic regions of Nigeria use herbal remedies for the management of malaria-in-pregnancy, rather than the commonly prescribed drugs. Remedies common to this area involve a suspension of A. indica (AI) leaves and in some cases, a suspension containing a mixture of AI and D.edulis (PS). Aim: This study examined the therapeutic efficacies of AI, PS, or a combination of AI and PS in a pregnant rat model for exoerythrocytic stages of Plasmodium falciparum parasite. Method: A predetermined sample size of 30 dams was used (for a power level and confidence interval of 95%), and divided equally into six groups made up of non-malarous dams, untreated malarous dams, and malarous dams either treated exclusively with 1 mL of 3000 mg/kg b.w AI, 1000 mg/kg b.w PS, AI + PS (50% v/v), or 25 mg/kg b.w CQ. Result: No maternal mortality was recorded. AI significantly improved maternal weight gain from 32.4 to 82.2 g and placental weight from 0.44 to 0.53 g. In the curative test, AI and AI + PS significantly reduced the average percentage parasitemia (APP) in the pregnant rats from >80% to <20%. No significant difference in the APP was found between the pregnant rats treated with any of CQ or AI during the suppressive test. Results for the prophylactic test of the study groups showed that the APP was significantly reduced from 24.69% to 3.90% when treated with AI and 3.67% when combined with PS. AI + PS reduced diastolic blood pressure from 89.0 to 81.0 mm/Hg and compared with that of the non malarous dams. AI or AI + PS significantly increased the platelet counts (103 µL) from 214.1 to 364.5 and 351.2, respectively. AI and AI + PS improved birth weight from 2.5 to 3.9 g and crown rump length from 2.6 to 4.1 cm. For biomarkers of preeclampsia, combining AI and PS led to the reversal of the altered levels of creatine kinase, lactate dehydrogenase, cardiac troponin, soluble Fms-Like Tyrosine Kinase-1, and placental growth factor. Conclusions: This study validates the use of A. indica for the treatment of gestational malaria due to its antiplasmodial and related therapeutic effects and in combination with pear seeds for the management of malaria-in-pregnancy-induced preeclampsia.

Zanthoxylum Species: A Review of Traditional Uses, Phytochemistry and Pharmacology in Relation to Cancer, Infectious Diseases and Sickle Cell Anemia

The health benefits and toxicity of plant products are largely dependent on their secondary metabolite contents. These compounds are biosynthesized by plants as protection mechanisms against environmental factors and infectious agents. This review discusses the traditional uses, phytochemical constituents and health benefits of plant species in genus Zanthoxylum with a focus on cancer, microbial and parasitic infections, and sickle cell disease as reported in articles published from 1970 to 2021 in peer-reviewed journals and indexed in major scientific databases. Generally, Z. species are widely distributed in Asia, America and Africa, where they are used as food and for disease treatment. Several compounds belonging to alkaloids, flavonoids, terpenoids, and lignans, among others have been isolated from Z. species. This review discusses the biological activities reported for the plant species and their phytochemicals, including anticancer, antibacterial, antifungal, antiviral, anti-trypanosomal, antimalarial and anti-sickling properties. The safety profiles and suggestions for conservation of the Z. species were also discussed. Taken together, this review demonstrates that Z. species are rich in a wide range of bioactive phytochemicals with multiple health benefits, but more research is needed towards their practical application in the development of functional foods, nutraceuticals and lead compounds for new drugs.

Antiplasmodial, antimalarial activities and toxicity of African medicinal plants: a systematic review of literature

BACKGROUND

Malaria still constitutes a major public health menace, especially in tropical and subtropical countries. Close to half a million people mainly children in Africa, die every year from the disease. With the rising resistance to frontline drugs (artemisinin-based combinations), there is a need to accelerate the discovery and development of newer anti-malarial drugs. A systematic review was conducted to identify the African medicinal plants with significant antiplasmodial and/or anti-malarial activity, toxicity, as wells as assessing the variation in their activity between study designs (in vitro and in vivo).

METHODS

Key health-related databases including Google Scholar, PubMed, PubMed Central, and Science Direct were searched for relevant literature on the antiplasmodial and anti-malarial activities of African medicinal plants.

RESULTS

In total, 200 research articles were identified, a majority of which were studies conducted in Nigeria. The selected research articles constituted 722 independent experiments evaluating 502 plant species. Of the 722 studies, 81.9%, 12.4%, and 5.5% were in vitro, in vivo, and combined in vitro and in vivo, respectively. The most frequently investigated plant species were Azadirachta indica, Zanthoxylum chalybeum, Picrilima nitida, and Nauclea latifolia meanwhile Fabaceae, Euphorbiaceae, Annonaceae, Rubiaceae, Rutaceae, Meliaceae, and Lamiaceae were the most frequently investigated plant families. Overall, 248 (34.3%), 241 (33.4%), and 233 (32.3%) of the studies reported very good, good, and moderate activity, respectively. Alchornea cordifolia, Flueggea virosa, Cryptolepis sanguinolenta, Zanthoxylum chalybeum, and Maytenus senegalensis gave consistently very good activity across the different studies. In all, only 31 (4.3%) of studies involved pure compounds and these had significantly (p = 0.044) higher antiplasmodial activity relative to crude extracts. Out of the 198 plant species tested for toxicity, 52 (26.3%) demonstrated some degree of toxicity, with toxicity most frequently reported with Azadirachta indica and Vernonia amygdalina. These species were equally the most frequently inactive plants reported. The leaves were the most frequently reported toxic part of plants used. Furthermore, toxicity was observed to decrease with increasing antiplasmodial activity.

CONCLUSIONS

Although there are many indigenous plants with considerable antiplasmodial and anti-malarial activity, the progress in the development of new anti-malarial drugs from African medicinal plants is still slothful, with only one clinical trial with Cochlospermum planchonii (Bixaceae) conducted to date. There is, therefore, the need to scale up anti-malarial drug discovery in the African region.

In vitro antiplasmodial activity, cytotoxicity, and gas chromatography - flame ionization detector metabolites fingerprint of extracts and fractions from Tetrorchidium didymostemon

Background

Tetrorchidium didymostemon is used as an antimalarial remedy in southern Nigeria.

Objective(s)

This study was aimed at providing scientific validation for the use of T. didymostemon in the treatment of malaria in Nigeria.

Materials and methods

Plasmodium falciparum 3D7 (Pf3D7) strain was cultured and maintained in fresh O⁺ human erythrocytes. Standard methods were used to evaluate in vitro antiplasmodial activity, cytotoxic effect on Vero cell line, phytochemical screening, and antioxidant capacity. Gas Chromatography – Flame Ionization Detector (GC-FID) metabolite fingerprinting of the most potent fraction was carried out.

Results

The methanol leaf extract had higher antiplasmodial activity (IC₅₀Pf3D7 = 25 ± 0.21 μg/mL) in comparison with the stem bark extract (SBE) (IC₅₀Pf3D7 = 50 ± 0.94 μg/mL). The n-hexane fraction of the leaf extract had the best antiplasmodial activity (IC₅₀Pf3D7 = 3.92 ± 0.46 μg/mL) and selectivity index. This was followed by the dichloromethane (IC₅₀Pf3D7 = 12.5 ± 1.32 μg/mL), ethyl acetate (IC₅₀Pf3D7 = 35.0 ± 4.80 μg/mL), and hydromethanol fraction which was inactive (IC₅₀Pf3D7 > 100 μg/mL). All extracts and fractions were not toxic on Vero cell line (CC₅₀ > 1000 μg/mL). The n-hexane and dichloromethane fractions had the highest amount of phytochemicals. GC-FID analysis revealed high amounts of kaempferol, α-pinene, camphor, humulene, azulene, and β-caryophyllene in the n-hexane fraction.

Conclusion

The results of our study validate the traditional use of T. didymostemon in the treatment of malaria in southern Nigeria. They also suggest that the phytoconstituent(s) responsible for the antiplasmodial activity of this plant may be more extractable in non-polar solvents.

Survey of ethnobotanical cocktails commonly used in the treatment of malaria in southwestern Nigeria

Background

Combination of different antimalarials has become the popular method of care for malaria morbidity in conventional and traditional treatment approaches due to the need to increase the efficacy and reduce the selection of drug resistance. A worrisome concern is the critical gaps with regards to the information available on antimalarial herbal cocktails. This study presents cocktail herbal remedies in ethnomedicinal approaches to malaria treatment in Oyo and Ogun states, South West Nigeria. Ethnobotanical information on indigenous antimalarials used in combination remedies was collected from herbal practitioners using a semi-structured questionnaire.

Results

Findings showed majority of respondents treat malaria with combination herbal remedies. They sighted their beliefs and customs, the efficacy, affordability and availability of these herbs as reasons for their adoption of herbal medicines as their preferred mode of treating malaria. Enquiry revealed 26 sets of cocktail antimalarials from a variety of plant species. The plants and ingredients are extracted and used as decoction, infusion or steam baths. Oral route was the most popular mode of administration. Respondents reported they drink one to two medium-sized cups of the recipe on an average of two times daily within a duration of about 10 days.

Conclusions

Herbal antimalarial remedies continue to be the popular treatments option in our localities. This study provides knowledge of the diverse ways respondents combine medicinal herbs and other local ingredients for malaria treatment. Pharmacological screening is urgently needed to validate their safety and efficacy in order to protect the health of our locals heavily relying on them to combat high burdens of malaria.

Zanthoxylum Species: A Comprehensive Review of Traditional Uses, Phytochemistry, Pharmacological and Nutraceutical Applications

Zanthoxylum species (Syn. Fagara species) of the Rutaceae family are widely used in many countries as food and in trado-medicinal practice due to their wide geographical distribution and medicinal properties. Peer reviewed journal articles and ethnobotanical records that reported the traditional knowledge, phytoconstituents, biological activities and toxicological profiles of Z. species with a focus on metabolic and neuronal health were reviewed. It was observed that many of the plant species are used as food ingredients and in treating inflammation, pain, hypertension and brain diseases. Over 500 compounds have been isolated from Z. species, and the biological activities of both the plant extracts and their phytoconstituents, including their mechanisms of action, are discussed. The phytochemicals responsible for the biological activities of some of the species are yet to be identified. Similarly, biological activities of some isolated compounds remain unknown. Taken together, the Z. species extracts and compounds possess promising biological activities and should be further explored as potential sources of new nutraceuticals and drugs.

Phenylpropanoid conjugated iridoids with anti-malarial activity from the leaves of Morinda morindoides

Two phenylpropanoid-conjugated iridoids, deglucosyl gaertneroside (1) and morindoidin (2), were isolated from the leaves of Morinda morindoides (Rubiaceae) by activity-guided fractionation using an anti-malarial activity assay. The known related iridoids molucidin (3) and prismatomerin (4), two lignans, abscisic acid, two megastigmanes, and two flavonol glycosides were also identified. The structures of isolated compounds were elucidated using spectroscopic analysis. The isolated compounds were evaluated for anti-malarial activity against the chloroquine/mefloquine-sensitive strains of Plasmodium falciparum together with cytotoxicity against adult mouse brain cells. Potent anti-malarial activity of 3 and 4 (IC₅₀ of 0.96 and 0.80 μM, CC₅₀ of 1.02 and 0.88 μM, and SI of 1.06 and 1.10, respectively) was shown, while new iridoids 1 and 2 and pinoresinol (5) displayed moderate activity (IC₅₀ of 40.9, 20.6, and 24.2 μM) without cytotoxicity (CC₅₀ > 50 μM). These results indicate that 1-5 may be promising lead compounds for anti-malarial drugs. In addition, our results imply the necessity of the quality control of the extract of M. morindoides leaves based on the contents of 1-5 in terms of the safety and efficacy.

In vitro bioactivity of the fractions and isolated compound from Combretum elaeagnoides leaf extract against selected foodborne pathogens

ETHNOPHARMACOLOGICAL RELEVANCE

Combretum species are used traditionally for the treatment of diarrhoea, hookworm, fever, inflammation, pain and infectious diseases. Infections are commonly caused by the intake of food contaminated with foodborne pathogens. These are a significant concern in the food industry owing to their ability to form biofilms and cause food spoilage, despite the availability of modern food preservation techniques. Combretum elaeagnoides Klotzsch (Combretaceae) is used in southern African traditional medicine against infections and diarrhoea.

AIM OF THE STUDY

This study evaluated the antimicrobial ability of C. elaeagnoides leaf fractions and the isolated compound quercetin-3-O-rhamnoside against a panel of foodborne pathogens, and biofilms formed by them. The samples were also assessed for their antioxidant activity and cytotoxicity.

MATERIALS AND METHODS

Fractions prepared from the methanol extract of the leaves, and a bioactive compound (quercetin-3-O-rhamnoside) isolated from the ethyl acetate fraction were investigated for activity against nine reference and clinical strains of foodborne pathogens. The microdilution method was used to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the fractions and compound. The inhibition of biofilm formation and the crystal violet staining assays were used to determine the antibiofilm efficacy. The DPPH (2, 2-diphenyl-1-picrylhydrazyl) assay and the 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) electron reduction assay were used to determine the antioxidant potential of the fractions and compound. The cytotoxicity was assessed using the 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay against Vero African monkey kidney cells.

RESULTS

The fractions were active against all tested organisms, with MIC values ranging from 0.03 to 1.25 mg/mL. The best MBC was 0.63 mg/mL. All the fractions and the purified compound inhibited biofilm formation of Staphylococcus aureus and Salmonella Typhimurium, with percentage inhibition values greater than 50% at 1 mg/mL. The compound had very promising antibiofilm activity against Escherichia coli 1 (ATCC 25922) with percentage inhibition of >150%. The compound and fractions had good radical scavenging potential against the DPPH and ABTS radicals. Quercetin-3-O-rhamnoside and the fractions were relatively non-cytotoxic.

CONCLUSION

The ability of the fractions and compound to reduce and inhibit biofilm biomass and their promising antioxidant potential provide motivation to further investigate the use of plants to protect food products from contamination, as well as to treat infections characterized by bacterial biofilms.

In vitro cytotoxicity of Aspilia pluriseta Schweinf. extract fractions

OBJECTIVES

We and others have shown that Aspilia pluriseta is associated with various biological activities. However, there is a lack of information on its cytotoxicity. This has created an information gap about the safety of A. pluriseta extracts. As an extension to our recent publication on the antimicrobial activity and the phytochemical characterization of A. pluriseta root extracts, here we report on cytotoxicity of tested solvent fractions. We evaluated the potential cytotoxicity of these root extract fractions on Vero cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

RESULTS

We show that all solvent extract fractions (except methanolic solvent fractions) had cytotoxic concentration values that killed 50% of the Vero cells (CC50) greater than 20 µg/mL and selectivity index (SI) greater than 1.0. Taken together, we demonstrate that, A. pluriseta extract fractions' earlier reported bioactivities are within the acceptable cytotoxicity and selective index limits. This finding scientifically validates the potential use of A. pluriseta in the discovery of safe therapeutics agents.

Phytochemicals and Potential Therapeutic Targets on Toxoplasma gondii Parasite

Identification of drug target in protozoan T. gondii is an important step in the development of chemotherapeutic agents. Likewise, exploring phytochemical compounds effective against the parasite can lead to the development of new drug agent that can be useful for prophylaxis and treatment of toxoplasmosis. In this review, we searched for the relevant literature on the herbs that were tested against T. gondii either in vitro or in vivo, as well as different phytochemicals and their potential activities on T. gondii. Potential activities of major phytochemicals, such as alkaloid, flavonoid, terpenoids and tannins on various target sites on T. gondii as well as other related parasites was discussed. It is believed that the phytochemicals from natural sources are potential drug candidates for the treatment of toxoplasmosis with little or no toxicity to humans.

Antimicrobial activity, phytochemical characterization and gas chromatography-mass spectrometry analysis of Aspilia pluriseta Schweinf. extracts

Aspilia pluriseta is associated with various bioactivities, although with limited scientific justification. In this study, we evaluated the antimicrobial activity, and characterized the phytochemicals of root extracts of A. pluriseta aimed at validating its therapeutic potential. We used BACTEC MGIT™ 960 system to test for antitubercular activity, disc-diffusion together with the microdilution method to evaluate antimicrobial activities and qualitative phytochemical tests together with gas chromatography-mass spectrometry (GC-MS) analysis to determine the phytochemicals that associated with A. pluriseta extracts activity. We show that methanolic crude extract (at 1 g/mL) had high Mycobacterium tuberculosis (MTB) inhibitory activity (0 growth unit) and considerable potency against Escherichia coli (11.7 mm), Staphylococcus aureus (9.0 mm), and Candida albicans (7.7 mm). All the extract fractions exerted remarkable antimycobacterial activities with minimum inhibitory activity of between 6.26 – 25 μg/mL. The highest antimicrobial activity of petroleum ether and dichloromethane fraction was against E. coli at inhibition zone diameters of 8.3 mm, and 8.0 mm, respectively, while ethyl acetate fraction was against S. aureus with an inhibition zone of 8.7 mm. Methanolic fraction exhibited broad-spectrum activity against 87.5% of the tested microbes (inhibition zones 6.3–8.3 mm). Furthermore, we qualitatively detected terpenoids, alkaloids, and phenolics such as flavonoids, and anthraquinones in extract fractions. GC-MS analysis detected an abundance of fatty acid esters, 2-hydroxy-1-(hydroxymethyl) ethyl ester-hexadecanoic acid, and 2,3-dihydroxy propyl ester-octadecanoic acid and four alkanes. Taken together, we show that A. pluriseta extract fractions (especially ethyl acetate and methanolic fractions) have strong selective antitubercular activity, and thus, we scientifically validate the use of A. pluriseta as a potential source for the discovery of novel antitubercular agents.

A systematic review on COVID-19 pandemic with special emphasis on curative potentials of Nigeria based medicinal plants

Despite the frightening mortality rate associated with COVID-19, there is no known approved drug to effectively combat the pandemic. COVID-19 clinical manifestations include fever, fatigue, cough, shortness of breath, and other complications. At present, there is no known effective treatment or vaccine that can mitigate/inhibit SARS-CoV-2. Available clinical intervention for COVID-19 is only palliative and limited to support. Thus, there is an exigent need for effective and non-invasive treatment. This article evaluates the possible mechanism of actions of SARS-CoV-2 and present Nigeria based medicinal plants which have pharmacological and biological activities that can mitigate the hallmarks of the pathogenesis of COVID-19. SARS-CoV-2 mode of actions includes hyper-inflammation characterized by a severe and fatal hyper-cytokinaemia with multi-organ failure; immunosuppression; reduction of angiotensin-converting enzyme 2 (ACE2) to enhance pulmonary vascular permeability causing damage to the alveoli; and further activated by open reading frame (ORF)3a, ORF3b, and ORF7a via c-Jun N- terminal kinase (JNK) pathway which induces lung damage. These mechanisms of action of SARS-CoV-2 can be mitigated by a combination therapy of medicinal herbs based on their pharmacological activities. Since the clinical manifestations of COVID-19 are multifactorial with co-morbidities, we strongly recommend the use of combined therapy such that two or more herbs with specific therapeutic actions are administered to combat the mediators of the disease.

Modulation of inflammatory pathways, medicinal uses and toxicities of Uvaria species: potential role in the prevention and treatment of inflammation

The therapeutic efficacy of the contemporary anti-inflammatory drugs are well established; however, prolonged use of such can often lead to serious and life-threatening side effects. Natural product-based anti-inflammatory compounds with superior efficacy and minimum toxicity can serve as possible therapeutic alternatives in this scenario. Genus Uvaria is a part of Annonaceae family, while the majority of its species are widely distributed in tropical rain forest regions of South East Asia. Uvaria species have been used extensively used as traditional medicine for treating all sorts of inflammatory diseases including catarrhal inflammation, rheumatism, acute allergic reactions, hemorrhoids, inflammatory liver disease and inflamed joints. Phytochemical analysis of Uvaria species has revealed flavones, flavonoids, tannins, saponins, polyoxygenated cyclohexene and phenolic compounds as major phyto-constituents. This review is an attempt to highlight the anti-inflammatory activity of Uvaria species by conducting a critical appraisal of the published literature. The ethnopharmacological relevance of Uvaria species in the light of toxicological studies is also discussed herein. An extensive and relevant literature on anti-inflammatory activity of Uvaria species was collected from available books, journals and electronic databases including PubMed, ScienceDirect, Scopus, Proquest and Ovid. Extracts and isolates of Uvaria species exhibited significant anti-inflammatory activity through various mechanisms of action. 6,7-di-O-Methyl-baicalein, flexuvarol B, chrysin, (-)-zeylenol, 6-hydroxy-5,7-dimethoxy-flavone, and pinocembrin were the most potent anti-inflammatory compounds with comparable IC₅₀ with positive controls. Therefore, it is suggested that further research should be carried out to determine the pharmacokinetics, pharmacodynamics and toxicity of these therapeutically significant compounds, to convert the pre-clinical results into clinical data for drug development and design.

The In Vitro Antiplasmodial Activities of Aqueous Extracts of Selected Ghanaian Herbal Plants

Background

The asexual and sexual stages (gametocytes) of Plasmodium falciparum parasites are known to respond differently to antimalarial drugs. Herbal products with extended treatment regimens and inadequate dosing information are widely used to treat malaria in Ghana. This study set out to determine the in vitro activity of selected herbal extracts on the development of asexual and sexual stage malaria parasites.

Methods

The 72-hour SYBR Green 1-based in vitro drug assay was used to determine the asexual parasite growth inhibitory effects exhibited by aqueous extracts of Alchornea cordifolia, Polyalthia longifolia, Moringa oleifera, and Mangifera indica on the NF54, CamWT_C580Y, and IPC 4912 strains of Plasmodium falciparum. The effects of exposure of asexual and early-stage NF54 gametocytes to varying concentrations of the aqueous herbal extracts were assessed by microscopy after 7 days of continuous culturing in the presence of the herbal extract. Qualitative and quantitative phytochemical screening were also performed on the herbal extracts.

Results

In the SYBR Green 1 assay, aqueous extracts of Alchornea cordifolia exhibited moderate (IC₅₀ of 5.8, 17.4, and 15.8 μg/ml) and Mangifera indica exhibited low (IC₅₀ of 65.4, 96.7, and 81.7 μg/ml) activities against the NF54, Cam WT_C580Y, and IPC 4912 parasites, respectively, whilst Polyalthia longifolia and Moringa oleifera were inactive. Long-term treatment of NF54 parasites with 1 mg/ml of Polyalthia longifolia produced the highest densities of gametocytes and the least (56%) inhibition of asexual parasites on Day 7. Long-term treatment of NF54 parasites with 10 μg/ml Alchornea cordifolia resulted in complete parasite (asexual and gametocyte) clearance on Day 7. Conclusions. Alchornea cordifolia exhibited a ‘moderate' activity against the three parasites tested in the 72-hour SYBR Green 1 assay and also effectively cleared both asexual parasites and gametocytes. Long-term treatment of malaria parasites with herbal extracts mimics a treatment regimen and should be used to determine the antimalarial properties of herbal extracts.

Antimalarial Activity of Crude Extract and Solvent Fractions of the Leaves of Bersama abyssinica Fresen. (Melianthaceae) against Plasmodium berghei Infection in Swiss Albino Mice

Background

Treatment of malaria has been compromised by the emergence of drug-resistant parasites. Consequently, novel agents are urgently needed from different sources including from medicinal plants. Thus, the current study aimed at evaluating the antimalarial activity of crude extract and solvent fractions of the leaves of Bersama abyssinica (B. abyssinica) against Plasmodium berghei infection in Swiss Albino mice.

Method

A 4-day suppressive test was employed to evaluate the antimalarial effect of crude extract and solvent fractions against early infection. The curative and prophylactic effects of crude extract and fraction with the highest chemosuppression were further tested by Rane's test and residual infection procedure. Parasitemia, survival time, packed cell volume (PCV), body weight, and rectal temperature of mice were used as evaluation parameters. Windows SPSS version 20 was used to analyze the data and analysis of variance (ANOVA) followed by Tukey's post hoc test was used to compare data between groups.

Results

The crude extract and aqueous fraction significantly (P < 0.05 to 0.001) suppressed parasitemia followed by protection of PCV reduction resulting in prolonging the survival time but failed to protect body weight and rectal temperature reduction in all tested models. The ethyl acetate and chloroform fractions also showed significant chemosuppression and PCV protection in the 4-day suppressive test. The crude extract exhibited a chemosuppression of 49.51%, 57.94%, and 44.11% while the aqueous fraction showed suppression of 47.69%, 51.62%, and 37.07% in 4-day suppressive, curative, and prophylactic tests, respectively, at 400 mg/kg.

Conclusion

The crude extract and fractions showed fairly moderate antimalarial activity, and the finding supports the traditional claims and previous in vitro studies. Thus, this may call for further studies to isolate chemical entities for additional safety and efficacy tests.

Mining Sudanese Medicinal Plants for Antiprotozoal Agents

Neglected tropical diseases are major health hazards in developing countries. Annually, up to 30 million people are affected by either Chagas disease, African trypansomiasis or leishmaniasis, and more than 200 million by malaria. Most of the currently available drugs have drawbacks in terms of toxicity, limited oral availability, development of resistance, or non-affordability. Tropical plants of the arid zones are a treasure chest for the discovery of bioactive secondary metabolites. This study aims to compile Sudanese medicinal plants, validate their antiprotozoal activities, and identify active molecules. We have performed a survey of medicinal plants of Sudan and selected 62 that are being used in Sudanese traditional medicine. From these, we collected materials such as leaves, stem, bark, or fruit. The plant materials were extracted in 70% ethanol and further fractionated by liquid-liquid partitioning using solvents of increasing polarity. This resulted in a library of 235 fractions. The library was tested in vitro against Plasmodium falciparum (erythrocytic stages), Trypanosoma brucei rhodesiense (bloodstream forms), Trypanosoma cruzi (intracellular amastigotes), and Leishmania donovani (axenic amastigotes). Active fractions were also tested for cytotoxicity. Of the 235 fractions, 125 showed growth inhibitory activity >80% at 10 μg/ml, and >50% at 2 μg/ml against at least one of the protozoan parasites. Plasmodium falciparum was the most sensitive of the parasites, followed by T. b. rhodesiense and L. donovani. Only few hits were identified for T. cruzi, and these were not selective. Contrary to expectation based on phylogeny, but in agreement with previous results, a large number of extracts displayed mutual activity against T. brucei and P. falciparum. HPLC-based activity profiling for selected active extracts was performed to identify the bioactive principles. Active compounds identified by dereplication were guieranone A from Guiera senegalensis J.F.Gmel.; pseudosemiglabrin from Tephrosia apollinea (Delile) DC; ellagic acid and quercetin from Terminalia leiocarpa (DC.) Baill.; and catechin, ethyl gallate, and epicatechin gallate from Vachellia nilotica (L.) P.J.H.Hurter & Mabb. Also the extracts of Croton gratissimus var. gratissimus and Cuscuta hyalina Roth ex Schult. exhibited promising antitrypanosomatid activity. This assessment provides a comprehensive overview of Sudanese medicinal plants and supports the notion that they are a potential source of bioactive molecules against protozoan parasites.

LC-MS Analysis, 15-Lipoxygenase Inhibition, Cytotoxicity, and Genotoxicity of Dissotis multiflora (Sm) Triana (Melastomataceae) and Paullinia pinnata Linn (Sapindaceae)

This study aims to evaluate the anti-inflammatory, cytotoxicity, and genotoxicity activities of Dissotis multiflora (Sm) Triana and Paullinia pinnata Linn used traditionally in Cameroon to treat infectious diseases. Phytochemical screening was carried out using the LC-MS procedure. The ferrous oxidation-xylenol orange (FOX) assay was used to determine the 15-lipoxygenase (15-LOX) inhibitory activity of the plant samples. The tetrazolium-based colorimetric (MTT) assay was performed using Vero cells. The Ames test was carried out using Salmonella typhimurium TA98 and TA100 tester strains. LC-MS chromatogram of D. multiflora led to the identification of four known compounds, namely, 5-(3,5-dinitrophenyl)-2H-tetrazol (2), 2,2'-{[2-(6-amino-9H-purine-9-yl)ethyl]imino}diethanol (14), 1,2,5-oxadiazolo [3,4-b]pyrazine, 5,6-di (3,5-dimethyl-1-piperidyl) (19), and nimbolinin D (20) while four compounds were also identified in P. pinnata known as 2-hydroxycarbamoyl-4-methyl-pentanoic acid (2), pheophorbide A (16), 1-[4-({2-[(1-methyl-1H-indol-5-yl)amino]-4-pyrimidinyl}oxy)-1-naphthyl]-3-[1-(4 methylphenyl)-3-(2-methyl-2-propanyl)-1H-pyrazol-5-yl]urea (17), and nimbolinin D (18). D. multiflora and P. pinnata inhibited 15-LOX activity in concentration-dependent manner. The LC₅₀ (concentration that kills 50% of cells) values of the extracts ranged from 0.13 ± 00 to 1 ± 00 mg/mL for P. pinnata and D. multiflora, respectively. P. pinnata was cytotoxic at concentrations tested while D. multiflora was not. The selectivity index (SI) values ranged from 0.16 to 10.30 on Vero cell lines. No genotoxic effect was observed against both strains tested. These extracts are sources of compounds which can be used to control infectious diseases and associated inflammation. However, caution should be taken while using P. pinnata for medicinal purposes.

Food applications of Irvingia gabonensis (Aubry-Lecomte ex. O'Rorke) Baill., the 'bush mango': A review

Irvingia gabonensis, also known as 'bush mango', is a multipurpose fruit tree, native to tropical Africa. It is a priority indigenous fruit tree in western and central Africa since its wood is used for making utensils and fruits are mostly used as food and medicine. The objective of this work is to provide an updated review of the available knowledge about physicochemical characteristics of I. gabonensis fruit in order to evaluate its potential use in the food industry. The fruit mesocarp contains various phytochemicals and ascorbic acid concentration higher than some vitamin C rich fruits, then it is consumed fresh or dried, used to produce juice and wine, or as a flavourant. I. gabonensis fruit kernel is rich in oil (63%-69% crude fat), mainly composed of myristic and lauric acids. Its triacylglycerol composition and, resultantly, melting curve and polymorphism indicate an aptitude for diverse applications, as it is solid at room temperature. Forty-one phenolic compounds were identified in the seeds and derived extracts and supplements, being ellagic acid and its derivates the most present. This review enhances our knowledge about nutritional content and health benefits of I. gabonensis whole fruit, especially its pulp and seed, evidencing the need for safer and more efficient production of value-added products.

Terminalia bellirica fruit extracts: in-vitro antibacterial activity against selected multidrug-resistant bacteria, radical scavenging activity and cytotoxicity study on BHK-21 cells

Background

Identification of novel sources for developing new antibiotics is imperative with the emergence of antibiotic resistant bacteria. The fruits of Terminalia bellirica (Gaertn) Roxb., widely used in traditional medicine, were evaluated for antibacterial activity against multidrug-resistant (MDR) bacteria, antioxidant activity and cytotoxicity.

Methods

Twelve solvent extracts of T. bellirica fruits were prepared by direct aqueous extraction and sequential extraction with dichloromethane, methanol and water using Soxhlet, bottle-shaker and ultrasound sonicator methods. Antibacterial activity of the extracts was tested against 16 strains MDR bacteria—methicillin-resistant Staphylococcus aureus (MRSA), extended spectrum β-lactamase (ESBL) producing Escherichia coli and MDR Acinetobacter spp., Klebsiella pneumoniae and Pseudomonas aeruginosa—and 4 control organisms, using the cut-well diffusion method. The minimum inhibitory concentration (MIC) was determined using an agar dilution method. The radical scavenging activity of six antibacterial extracts was screened against 2,2′-diphenyl-2-picrylhydrazyl (DPPH) and correlation was established between EC₅₀ (50% effective concentration) values and the total phenolic content (TPC). Cytotoxicity was determined for the most potent antibacterial extract on baby hamster kidney (BHK-21) cells by Tryphan Blue exclusion method. Statistical analysis was carried out by one-way analysis of variance at significant level p < 0.05 using “SigmaPlot 10” and “R 3.2.0” software.

Results

All aqueous and methanol extracts displayed antibacterial activity (MIC 0.25–4 mg/mL) against all strains of MRSA, MDR Acinetobacter spp. and MDR P. aeruginosa. The sequential aqueous extracts (MIC, 4 mg/mL) inhibited ESBL producing-E. coli. None of the extracts exhibited activity against MDR K. pneumoniae (MIC > 5 mg/mL). The sequential methanol extract (Soxhlet) recorded high antibacterial activity and the highest DPPH radical scavenging activity (EC₅₀, 6.99 ± 0.15 ppm) and TPC content (188.71 ± 2.12 GAE mg/g).

The IC₅₀ (50% inhibition concentration) values of the most potent antibacterial extract—the direct aqueous extract from reflux method—on BHK-21 cells were 2.62 ± 0.06 and 1.45 ± 0.08 mg/ml with 24 and 48 h exposure, respectively.

Conclusions

Results indicate that T. bellirica fruit is a potential source for developing broad-spectrum antibacterial drugs against MDR bacteria, which are non-toxic to mammalian cells and impart health benefits by high antioxidant activity.

Anti-Plasmodium falciparum Activity of Extracts from 10 Cameroonian Medicinal Plants

Background: In the midst of transient victories by way of insecticides against mosquitoes or drugs against malaria, the most serious form of malaria, caused by Plasmodium falciparum, continues to be a major public health problem. The emergence of drug-resistant malaria parasites facilitated by fake medications or the use of single drugs has worsened the situation, thereby emphasizing the need for a continued search for potent, safe, and affordable new antimalarial treatments. In line with this need, we have investigated the antiplasmodial activity of 66 different extracts prepared from 10 different medicinal plants that are native to Cameroon. Methods: Extracts were evaluated for their capacity to inhibit the growth of the chloroquine-sensitive (Pf3D7) and resistant (PfINDO) strains of P. falciparum using the SYBR green fluorescence method. The cytotoxicity of promising extracts against human embryonic kidney cells (HEK293T) mammalian cells was assessed by MTT assay. Results: The antiplasmodial activity (50% inhibitory concentration, IC50) of plant extracts ranged from 1.90 to >100 μg/mL against the two strains. Six extracts exhibited good activity against both Pf3D7 and PfINDO strains, including cold water, water decoction, and ethyl acetate extracts of leaves of Drypetes principum (Müll.Arg.) Hutch. (IC503D7/INDO = 4.91/6.64 μg/mL, 5.49/5.98 μg/mL, and 6.49/7.10 μg/mL respectively), water decoction extract of leaves of Terminalia catappa L. (IC503D7/INDO = 6.41/8.10 μg/mL), and water decoction extracts of leaves and bark of Terminalia mantaly H.Perrier (IC503D7/INDO = 2.49/1.90 μg/mL and 3.70/2.80 μg/mL respectively). These promising extracts showed no cytotoxicity against HEK293T up to 200 μg/mL, giving selectivity indices (SIs) in the range of >31.20⁻80.32. Conclusions: While providing credence to the use of D. principum, T. catappa, and T. mantaly in the traditional treatment of malaria, the results achieved set the stage for isolation and identification of active principles and ancillary molecules that may provide us with new drugs or drug combinations to fight against drug-resistant malaria.

Hydroethanolic Extracts of Erigeron floribundus and Azadirachta indica Reduced Plasmodium berghei Parasitemia in Balb/c Mice

Malaria is one of the most important infectious diseases in Africa especially in Cameroon. The nonaccessibility to current treatments for poor people and the appearance of drug-resistant Plasmodium falciparum parasites stimulate the search for alternative treatments. The aim of this study was to evaluate the antimalarial activity and the safety of hydroethanolic extracts from Erigeron floribundus and Azadirachta indica. The crude hydroethanolic extracts of E. floribundus (HEEF) and A. indica (HEAI) were prepared via maceration of the whole plant powder of E. floribundus and the leaves of A. indica in 70% ethanol. The antimalarial activity was determined according to Peter's 4-day suppressive test using the murine model Plasmodium berghei/Balb C mice, while the acute and subacute toxicity tests were assessed according to the OECD 425 and 407 guidelines, respectively. The results indicate a reduction of parasitemia ranging from 49.75 ± 3.64 to 69.28 ± 1.36% for HEAI and from 30.46 ± 4.30 to 62.36 ± 2.32% for HEEI. Overall, HEEF and HEAI at doses of 60, 120, and 240 mg/kg b.w. and 75, 150, and 300 mg/kg b.w., respectively, showed a significant (p≤0.001) parasitemia reduction on P. berghei infecting BALB/c mice. HEEF and HEAI caused a significant (p<0.001) attenuation of body temperature drop in mice compared to negative control, except for the 150 mg/kg b.w. dose in the female group. Moreover, there was no mice mortality observed with these extracts even at 5000 mg/kg, while the aspartate amino transferase (ASAT) level of mice treated with 300 mg/kg b.w. of HEAI extract increased when compared with the control. The results of this study support the traditional use of these plants species extracts against malaria infection in rural zones of Northern Cameroon, therefore confirming their potential as sources for the development of efficient phytomedicines for malaria-poverty disease alleviation.

Anti-infective activities of 11 plants species used in traditional medicine in Malaysia

Treatment of drug resistant protozoa, bacteria, and viruses requires new drugs with alternative chemotypes. Such compounds could be found from Southeast Asian medicinal plants. The present study examines the cytotoxic, antileishmanial, and antiplasmodial effects of 11 ethnopharmacologically important plant species in Malaysia. Chloroform extracts were tested for their toxicity against MRC-5 cells and Leishmania donovani by MTT, and chloroquine-resistant Plasmodium falciparum K1 strain by Histidine-Rich Protein II ELISA assays. None of the extract tested was cytotoxic to MRC-5 cells. Extracts of Uvaria grandiflora, Chilocarpus costatus, Tabernaemontana peduncularis, and Leuconotis eugenifolius had good activities against L. donovani with IC₅₀ < 50 μg/mL. Extracts of U. grandiflora, C. costatus, T. peduncularis, L. eugenifolius, A. subulatum, and C. aeruginosa had good activities against P. falciparum K1 with IC₅₀ < 10 μg/mL. Pinoresinol isolated from C. costatus was inactive against L. donovani and P. falciparum. C. costatus extract and pinoresinol increased the sensitivity of Staphylococcus epidermidis to cefotaxime. Pinoresinol demonstrated moderate activity against influenza virus (IC₅₀ = 30.4 ± 11 μg/mL) and was active against Coxsackie virus B3 (IC₅₀ = 7.1 ± 3.0 μg/mL). β-Amyrin from L. eugenifolius inhibited L. donovani with IC₅₀ value of 15.4 ± 0.01 μM. Furanodienone from C. aeruginosa inhibited L. donovani and P. falciparum K1 with IC₅₀ value of 39.5 ± 0.2 and 17.0 ± 0.05 μM, respectively. Furanodienone also inhibited the replication of influenza and Coxsackie virus B3 with IC₅₀ value of 4.0 ± 0.5 and 7.2 ± 1.4 μg/mL (Ribavirin: IC₅₀: 15.6 ± 2.0 μg/mL), respectively. Our study provides evidence that medicinal plants in Malaysia have potentials as a source of chemotypes for the development of anti-infective leads.

Zingiber Officinale Roscoe and Echinops Kebericho Mesfin Showed Antiplasmodial Activities against Plasmodium Berghei in a Dose-dependent Manner in Ethiopia

BACKGROUND

The emergence and spread of Plasmodium falciparum resistance to antimalarial drugs necessitated the search for new drugs from natural products. Zingiber officinal Roscoe and Echinops Kebericho Mesfin are traditional herbal medicines widely used for the treatment of malaria in Ethiopia. The aim of the study was to assess the toxicity profile and in vivo antiplasmodial activities of 70% methanol crude extracts of both plant materials against Plasmodium berghei.

METHODS

Healthy male Swiss Albino mice of age 4-5 weeks and weight 25-36 g were infected by P. berghei. The extracts were administered orally at doses 5000, 2500 and 1250 mg/kg for acute toxicity of E. kebericho Mesfin. Graded doses at 1000, 500 and 250 mg/kg used for four days suppressive studies. Parasitemia, body weight, packed cell volume (PCV) and survival time were determined. SPSS Version 20 was used for the analysis of data of parasitemia, body weight, PCV, and survival times. Statistical significance was determined by one-way ANOVA. Independent t-test was used to compare results. Results were presented as a mean ± standard error of the mean (M ± SEM). All data were analyzed at a 95% confidence interval (α= 0.05).

RESULTS

At the dose of 5000 mg/kg, E. kebericho Mesfin showed no toxic effects. The LD50 of extract could go beyond the dose used. In vivo antiplasmodial activity of extracts showed excellent chemo suppression at 500 and 1000 mg/kg in a dose dependent manner compared with the negative control. The chemo suppressions of the 1000 mg/kg of both plant extracts were 49.53 ± 1.90% and 32.83 ± 1.03%, respectively. The survival times of P. berghei infected mice were also a dose dependent manner while failed to prevent weight loss.

CONCLUSION

The extracts of both medicinal plants showed antiplasmodial activities against P. berghei. It confirmed the literature findings and their traditional uses.

Medicinal plants used by the people of Nsukka Local Government Area, south-eastern Nigeria for the treatment of malaria: An ethnobotanical survey

ETHNOBOTANICAL RELEVANCE

Malaria is a serious public health problem especially in sub-Saharan African countries such as Nigeria. The causative parasite is increasingly developing resistance to the existing drugs. There is urgent need for alternative and affordable therapy from medicinal plants which have been used by the indigenous people for many years.

AIM OF STUDY

This study was conducted to document the medicinal plant species traditionally used by the people of Nsukka Local Government Area in south-eastern Nigeria for the treatment of malaria.

METHODS

A total of 213 respondents, represented by women (59.2%) and men (40.8%), were interviewed using a semi-structured questionnaire. The results were analysed and discussed in the context of previously published information on anti-malarial and phytochemical studies of the identified plants.

RESULTS

The survey revealed that 50 plant species belonging to 30 botanical families were used in this region for the treatment of malaria. The most cited families were Apocynaceae (13.3%), Annonaceae (10.0%), Asteraceae (10.0%), Lamiaceae (10.0%), Poaceae (10.0%), Rubiaceae (10.0%) and Rutaceae (10.0%). The most cited plant species were Azadirachta indica (11.3%), Mangifera indica (9.1%), Carica papaya (8.5%), Cymbopogon citratus (8.5%) and Psidium guajava (8.5%).

CONCLUSION

The present findings showed that the people of Nsukka use a large variety of plants for the treatment of malaria. The identified plants are currently undergoing screening for anti-malarial, toxicity and chemical studies in our laboratory.

Indigofera oblongifolia regulates the hepatic gene expression profile induced by blood stage malaria

Malaria is still a major health problem worldwide. This study aimed to investigate the hepatoprotective role of Indigofera oblongifolia leaf extracts (ILE) against mice hepatic injury induced by Plasmodium chabaudi. Female C57BL/6 mice were treated with 100 mg/kg of ILE after infection with erythrocytes parasitized by P. chabaudi. On day 7 post-infection, the extract improved the histological alteration induced by the parasite. This was evidenced by the decreased histological index induced by ILE. Moreover, ILE was able to increase the hepatic antioxidant capacity and could significantly improve the decrease in erythrocyte count and hemoglobin content in mice blood plasma due to infection. ILE was also able to upregulate the expression of 24 genes related to metabolism and of 3 genes related to the immune response. Furthermore, the extract was able to downregulate the expression of 35 genes related to metabolism and of 82 genes related to immune response. Moreover, the microarray study showed that ILE regulated the change in gene expression induced by the parasite. Among these genes, we quantified the expression of cd209f, cyp7a1, Hsd3b5, Sult2a3, Lcn2, CcI8, Nos2, and saa3-mRNAs. These genes were regulated by ILE. Therefore, our results revealed the protective role of Indigofera oblongifolia against hepatic injury induced by blood stage malaria.

Mosquito control with green nanopesticides: towards the One Health approach? A review of non-target effects

The rapid spread of highly aggressive arboviruses, parasites, and bacteria along with the development of resistance in the pathogens and parasites, as well as in their arthropod vectors, represents a huge challenge in modern parasitology and tropical medicine. Eco-friendly vector control programs are crucial to fight, besides malaria, the spread of dengue, West Nile, chikungunya, and Zika virus, as well as other arboviruses such as St. Louis encephalitis and Japanese encephalitis. However, research efforts on the control of mosquito vectors are experiencing a serious lack of eco-friendly and highly effective pesticides, as well as the limited success of most biocontrol tools currently applied. Most importantly, a cooperative interface between the two disciplines is still lacking. To face this challenge, we have reviewed a wide number of promising results in the field of green-fabricated pesticides tested against mosquito vectors, outlining several examples of synergy with classic biological control tools. The non-target effects of green-fabricated nanopesticides, including acute toxicity, genotoxicity, and impact on behavioral traits of mosquito predators, have been critically discussed. In the final section, we have identified several key challenges at the interface between "green" nanotechnology and classic biological control, which deserve further research attention.

Traditional uses, phytochemistry and pharmacological properties of African Nauclea species: A review

ETHNOPHARMACOALOGICAL RELEVANCE

The genus Nauclea in Africa comprises seven species. Among them, N. latifolia, N. diderrichii and N. pobeguinii are widely used by the local population in traditional remedies. Preparation from various parts of plants (e.g. roots, bark, leaves) are indicated by traditional healers for a wide range of diseases including malaria, pain, digestive ailments or metabolic diseases.

MATERIALS AND METHODS

A literature search was conducted on African species of the genus Nauclea using scientific databases such as Google Scholar, Pubmed or SciFinder. Every document of ethnopharmacological, phytochemical or pharmacological relevance and written in English or French were analyzed.

RESULTS AND DISCUSSION

The Nauclea genus is used as ethnomedicine all along sub-Saharan Africa. Several local populations consider Nauclea species as a major source of remedies for malaria. In this regard, two improved traditional medicines are currently under development using extracts from N. latifolia and N. pobeguinii. Concerning the chemical composition of the Nauclea genus, indoloquinolizidines alkaloids could be considered as the major class of compounds as they are reported in every analyzed Nauclea species, with numerous structures identified. Based on traditional indications a considerable amount of pharmacological studies were conducted to ensure activity and attempt to link them to the presence of particular compounds in plant extracts.

CONCLUSION

Many experimental studies using plant extracts of the African species of the genus Nauclea validate traditional indications (e.g. malaria and pain). However, bioactive compounds are rarely identified and therefore, there is a clear need for further evaluations as well as for toxicity experiments. The sustainability of these plants, especially of N. diderrichii, a threatened species, should be kept in mind to adapt local uses and preparation modes of traditional remedies.

Medicinal properties of Ocotea bullata stem bark extracts: phytochemical constituents, antioxidant and anti-inflammatory activity, cytotoxicity and inhibition of carbohydrate-metabolizing enzymes

OBJECTIVE

This study evaluates the phytochemical constituents, antioxidant and anti-inflammatory activity, cytotoxicity, and inhibitory activity against carbohydrate metabolism of extracts from Ocotea bullata stem bark.

METHODS

Hexane, ethyl acetate, methanol and water were used to extract the air-dried sample. The phytochemical investigation and antioxidant assays were carried out on the extracts using standard procedures. The antidiabetic and anti-inflammatory potentials were evaluated using α-amylase, α-glucosidase and 5-lipoxygenase enzymes respectively. Vero cells were employed to determine the cytotoxicity of the extracts.

RESULTS

The ethyl acetate extract showed higher phenolic contents (8.97 mg/g gallic acid) while methanol displayed higher flavonoid (36.06 mg/g quercetin) and flavonol (153.44 mg/g rutin) contents than other extracts. Hexane extract had the greatest capacity to scavenge 1,1-diphenyl-2-picryl-hydrazyl (0.19 mg/mL), hydroxyl (25.77 mg/mL) and 2,2-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid (0.07 mg/mL) radicals, while ethyl acetate extract exhibited stronger inhibition (P < 0.05) against superoxide anion (0.41 mg/mL) and ferric ion-reducing power (2.36 mg/mL) compared to other extracts and standards. Aqueous extract (27.02 mg/mL) exhibited strong metal-chelating activity (P < 0.05) compared to other extracts and gallic acid. The aqueous extract demonstrated the greatest inhibition of α-glucosidase (1.45 mg/mL) and α-amylase (2.43 mg/mL) compared to other extracts and acarbose. There were no significant differences (P < 0.05) in half-maximum inhibitory concentration (IC₅₀) values of all tested extracts and indomethacin in the inhibition of 5-lipoxygenase activity. The aqueous extract was nontoxic to Vero cells with an IC₅₀ value of 0.38 mg/mL.

CONCLUSION

O. bullata stem bark contains active phytochemicals with diverse pharmacological potentials that could be beneficial in managing diabetes and inflammation.

A Review on Ethnopharmacological Applications, Pharmacological Activities, and Bioactive Compounds of Mangifera indica (Mango)

Mangifera indica (family Anacardiaceae), commonly known as mango, is a pharmacologically, ethnomedically, and phytochemically diverse plant. Various parts of M. indica tree have been used in traditional medicine for the treatment of different ailments, and a number of bioactive phytochemical constituents of M. indica have been reported, namely, polyphenols, terpenes, sterols, carotenoids, vitamins, and amino acids, and so forth. Several studies have proven the pharmacological potential of different parts of mango trees such as leaves, bark, fruit peel and flesh, roots, and flowers as anticancer, anti-inflammatory, antidiabetic, antioxidant, antibacterial, antifungal, anthelmintic, gastroprotective, hepatoprotective, immunomodulatory, antiplasmodial, and antihyperlipemic. In the present review, a comprehensive study on ethnopharmacological applications, pharmacological activities, and bioactive compounds of M. indica has been described.

Ethanol Extract of Blighia sapida Stem Bark Show Remarkable Prophylactic Activity in Experimental Plasmodium berghei-Infected Mice

This work explores the antiplasmodial potential of ethanol extract of Blighia sapida (Lin. Sapindaceae) in chloroquine (CQ)-resistant Plasmodium berghei (ANKA strain)-infected mice. Chloroquine-resistant (ANKA) strain of P berghei was inoculated intraperitoneally into Swiss albino mice. Mice were treated orally for 4 consecutive days, before and after inoculation (prophylactic, suppressive, and curative models) with graded doses of the plant extracts with Artemether-Lumefantrine (Coartem) as control. Prophylactically, the extract showed a remarkable activity in the chemosuppression of P berghei parasites (P < .01) ranging from 57% to 36.5% at doses of 200 to 800 mg/kg, respectively, whereas Coartem (10 mg/kg) produced 62.1% chemosuppression. No significant chemosuppression was observed in the curative and suppressive models. The plant extract appeared to be safe at the highest dose tested (5000 mg/kg) for acute toxicity, with no adverse effect on the different organs. The plant extract possesses prophylactic antimalarial activity, which supports its use in the prevention of malaria.