The malaria co-infection challenge: An investigation into the antimicrobial activity of selected Guinean medicinal plants

Malaria and Typhoid Fever Coinfection among Febrile Patients in Ngaoundéré (Adamawa, Cameroon): A Cross-Sectional Study

Background

Malaria and typhoid fever remain the major cause of morbidity and mortality in tropical and subtropical countries. It is common today to see patients being concurrently infected or treated for the two diseases.

Objective

The aim of the present study was to determine the prevalence of malaria, typhoid fever, and their coinfection among febrile patients at Ngaoundéré Regional Hospital, Adamawa, Cameroon. Methodology. A cross-sectional and descriptive study was conducted on 208 febrile patients coming for medical consultation at Ngaoundéré Regional Hospital and suspected for malaria and/or typhoid fever from September to November 2019. After receiving the consent of each patient, clinical and sociodemographic information were collected using a pretested semistructured questionnaire. Thereafter, blood samples were collected and subjected to (i) blood film examination for malaria detection and (ii) qualitative and semiquantitative Widal assay for typhoid fever detection.

Results

Plasmodium falciparum was the only species identified, and the prevalence of malaria was 50.0% (n = 104). The seroprevalence of typhoid fever was 64.3% (n = 133). The malaria and typhoid fever coinfection was 30.3% (n = 63). The coinfection between S. paratyphi (A, B, and C) and malaria was also observed with the prevalence ranging from 32.2 to 63.9%. Female group and children from 2 to 10 years old were the most affected groups by the two infectious agents.

Conclusion

Typhoid fever and malaria were more prevalent in Ngaoundéré City, particularly in children and women. Further studies should be done on the risk factors of malaria and typhoid fever coinfection in different study areas.

Icacinaceae Plant Family: A Recapitulation of the Ethnobotanical, Phytochemical, Pharmacological, and Biotechnological Aspects

Icacinaceae, an Angiospermic family comprising 35 genera and 212 accepted species, including trees, shrubs, and lianas with pantropical distribution, is one of the most outshining yet least explored plant families, which despite its vital role as a source of pharmaceuticals and nutraceuticals has received a meagre amount of attraction from the scientific community. Interestingly, Icacinaceae is considered a potential alternative resource for camptothecin and its derivatives, which are used in treating ovarian and metastatic colorectal cancer. However, the concept of this family has been revised many times, but further recognition is still needed. The prime objective of this review is to compile the available information on this family in order to popularize it in the scientific community and the general population and promote extensive exploration of these taxa. The phytochemical preparations or isolated compounds from the Icacinaceae family have been centrally amalgamated to draw diverse future prospects from this inclusive plant species. The ethnopharmacological activities and the associated endophytes and cell culture techniques are also depicted. Nevertheless, the methodical evaluation of the Icacinaceae family is the only means to preserve and corroborate the folkloristic remedial effects and provide scientific recognition of its potencies before they are lost under the blanket of modernization.

New Iron Twist to Chloroquine─Upgrading Antimalarials with Immunomodulatory and Antimicrobial Features

Herein, upgraded chloroquine (CQ) derivatives capable of overcoming Plasmodium resistance and, at the same time, suppressing excessive immune response and risk of concurrent bacteremia were developed. Twelve new ferrocene-CQ hybrids tethered with a small azathia heterocycle (1,3-thiazolidin-4-one, 1,3-thiazinan-4-one, or 5-methyl-1,3-thiazolidin-4-one) were synthesized and fully characterized. All hybrids were evaluated for their in vitro antiplasmodial, antimicrobial, and immunomodulatory activities. Additional assays were performed on selected hybrids to gain insights into their mode of action. Although only hybrid 4a was more potent than the parent drug toward CQ-resistant Dd2 Plasmodium falciparum strain, several other hybrids (such as 6b, 6c, and 6d) manifested substantially improved antimicrobial and immunomodulatory properties. Interesting structure-activity relationship data were obtained, hinting at future research for the development of new multitarget chemotherapies for malaria and other infectious diseases complicated by drug resistance, bacterial co-infection, and immune-driven pathology issues.

Promising Antimycobacterial Activities of Flavonoids against Mycobacterium sp. Drug Targets: A Comprehensive Review

Tuberculosis (TB) caused by the bacterial pathogen Mycobacterium tuberculosis (Mtb) remains a threat to mankind, with over a billion of deaths in the last two centuries. Recent advancements in science have contributed to an understanding of Mtb pathogenesis and developed effective control tools, including effective drugs to control the global pandemic. However, the emergence of drug resistant Mtb strains has seriously affected the TB eradication program around the world. There is, therefore, an urgent need to develop new drugs for TB treatment, which has grown researchers’ interest in small molecule-based drug designing and development. The small molecules-based treatments hold significant potential to overcome drug resistance and even provide opportunities for multimodal therapy. In this context, various natural and synthetic flavonoids were reported for the effective treatment of TB. In this review, we have summarized the recent advancement in the understanding of Mtb pathogenesis and the importance of both natural and synthetic flavonoids against Mtb infection studied using in vitro and in silico methods. We have also included flavonoids that are able to inhibit the growth of non-tubercular mycobacterial organisms. Hence, understanding the therapeutic properties of flavonoids can be useful for the future treatment of TB.

Transmission-Blocking Strategies Against Malaria Parasites During Their Mosquito Stages

Malaria is still the most widespread parasitic disease and causes the most infections globally. Owing to improvements in sanitary conditions and various intervention measures, including the use of antimalarial drugs, the malaria epidemic in many regions of the world has improved significantly in the past 10 years. However, people living in certain underdeveloped areas are still under threat. Even in some well-controlled areas, the decline in malaria infection rates has stagnated or the rates have rebounded because of the emergence and spread of drug-resistant malaria parasites. Thus, new malaria control methods must be developed. As the spread of the Plasmodium parasite is dependent on the part of its life cycle that occurs in mosquitoes, to eliminate the possibility of malaria infections, transmission-blocking strategies against the mosquito stage should be the first choice. In fact, after the gametocyte enters the mosquito body, it undergoes a series of transformation processes over a short period, thus providing numerous potential blocking targets. Many research groups have carried out studies based on targeting the blocking of transmission during the mosquito phase and have achieved excellent results. Meanwhile, the direct killing of mosquitoes could also significantly reduce the probability of malaria infections. Microorganisms that display complex interactions with Plasmodium, such as Wolbachia and gut flora, have shown observable transmission-blocking potential. These could be used as a biological control strategy and play an important part in blocking the transmission of malaria.

The relationship between Indigenous and allopathic health practitioners in Africa and its implications for collaboration: a qualitative synthesis

BACKGROUND

There have been increasing calls for collaboration between Indigenous health practitioners (IHPs) and allopathic health practitioners (AHPs) in Africa. Despite this, very few successful systems exist to facilitate formal collaboration. Direct relationships between providers, and at a health systems level are crucial to successful collaboration, but the nature and extent of these relationships have yet to be adequately explored.

OBJECTIVE

To explore the relationship between IHPs and AHPs in Africa, and to discuss the implications of this for future collaboration.

METHODS

An interpretive qualitative synthesis approach, combining elements of thematic analysis, meta-ethnography, and grounded theory, was used to systematically bring together findings of qualitative studies addressing the topic of collaboration between Indigenous and allopathic health practitioners in Africa.

RESULTS

A total of 1,765 papers were initially identified, 1,748 were excluded after abstract, full text and duplicate screening. Five additional studies were identified through references. Thus, 22 papers were included in the final analysis. We found that the relationship between Indigenous and allopathic health practitioners is defined by a power struggle which gives rise to lack of mutual understanding, rivalry, distrust, and disrespect.

CONCLUSION

The power struggle which defines the relationship between IHPs and AHPs in Africa is a hindrance to their collaboration and as such could partly account for the limited success of efforts to foster collaboration to date. Future efforts to foster collaboration between IHPs and AHPs in Africa must aim to balance the power disparity between them if collaboration is to be successful. Since this would be a novel approach, decision-makers and organisations who trial this power balancing approach to facilitate collaboration should evaluate resultant policies and interventions to ascertain their feasibility and efficacy in fostering collaboration, and the lessons learnt should be shared.

Antimicrobial investigation of ethnobotanically selected guinean plant species

ETHNOPHARMACOLOGICAL RELEVANCE

In Guinea, medicinal plants play an important role in the management of infectious diseases including urinary disorders, skin diseases and oral diseases. This study was carried out to collect medicinal plant species employed for the treatment of these diseases and to investigate their antimicrobial potential.

MATERIALS AND METHODS

Based on an ethnobotanical investigation carried out in three Guinean regions, 74 traditional healers and 28 herbalists were interviewed and medicinal plants were collected. The most quoted plant species were evaluated for their antimicrobial activities against Staphylococcus aureus, Escherichia coli, Candida albicans, and in addition against Plasmodium falciparum.

RESULTS

A total of 112 plant species belonging to 102 genera distributed over 42 botanical families were inventoried. Among the selected plant species, promising activities against C. albicans were obtained for the methanolic extracts of the stem bark of Terminalia albida (IC₅₀ 1.2 μg/ml), the leaves of Tetracera alnifolia (IC₅₀ 1.6 μg/ml) and the root bark of Swartzia madagascariensis (IC₅₀ 7.8 μg/ml). The highest activity against S. aureus was obtained for the dichloromethane extracts of the leaves of Pavetta crassipes (IC₅₀ 8.5 μg/ml) and the root of Swartzia madagascariensis (IC₅₀ 12.8 μg/ml). Twenty one extracts, obtained from twelve plant species, were strongly active against Plasmodium falciparum, including the dichloromethane extracts of the root and stem bark of Terminalia albida root (IC₅₀ 0.6 and 0.8 μg/ml), the leaves of Landolphia heudelotii (IC₅₀ 0.5 μg/ml), the stem bark of Combretum paniculatum (IC₅₀ 0.4 μg/ml) and the leaves of Gardenia ternifolia (IC₅₀ 1.3 μg/ml).

CONCLUSION

The present study provides a comprehensive overview of medicinal plants employed by Guinean traditional healers for the treatment of various microbial diseases, including urinary disorders, skin diseases and oral diseases. Some of the studied plant species showed promising antimicrobial activity and could be considered as a potential source for the development of new antifungal and/or antimalarial agents.

Parasite-bacteria interrelationship

Parasites and bacteria have co-evolved with humankind, and they interact all the time in a myriad of ways. For example, some bacterial infections result from parasite-dwelling bacteria as in the case of Salmonella infection during schistosomiasis. Other bacteria synergize with parasites in the evolution of human disease as in the case of the interplay between Wolbachia endosymbiont bacteria and filarial nematodes as well as the interaction between Gram-negative bacteria and Schistosoma haematobium in the pathogenesis of urinary bladder cancer. Moreover, secondary bacterial infections may complicate several parasitic diseases such as visceral leishmaniasis and malaria, due to immunosuppression of the host during parasitic infections. Also, bacteria may colonize the parasitic lesions; for example, hydatid cysts and skin lesions of ectoparasites. Remarkably, some parasitic helminths and arthropods exhibit antibacterial activity usually by the release of specific antimicrobial products. Lastly, some parasite-bacteria interactions are induced as when using probiotic bacteria to modulate the outcome of a variety of parasitic infections. In sum, parasite-bacteria interactions involve intricate processes that never cease to intrigue the researchers. However, understanding and exploiting these interactions could have prophylactic and curative potential for infections by both types of pathogens.

Efficacy and Mechanisms of Flavonoids against the Emerging Opportunistic Nontuberculous Mycobacteria

Nontuberculous mycobacteria (NTM) are the causative agent of severe chronic pulmonary diseases and is accountable for post-traumatic wound infections, lymphadenitis, endometritis, cutaneous, eye infections and disseminated diseases. These infections are extremely challenging to treat due to multidrug resistance, which encompasses the classical and existing antituberculosis agents. Hence, current studies are aimed to appraise the antimycobacterial activity of flavonoids against NTM, their capacity to synergize with pharmacological agents and their ability to block virulence. Flavonoids have potential antimycobacterial effects at minor quantities by themselves or in synergistic combinations. A cocktail of flavonoids used with existing antimycobacterial agents is a strategy to lessen side effects. The present review focuses on recent studies on naturally occurring flavonoids and their antimycobacterial effects, underlying mechanisms and synergistic effects in a cocktail with traditional agents.

Tablet of Ximenia Americana L. Developed from Mucoadhesive Polymers for Future Use in Oral Treatment of Fungal Infections

The use of biocompatible polymers such as Hydroxypropylmethylcellulose (HPMC), Hydroxyethylcellulose (HEC), Carboxymethylcellulose (CMC), and Carbopol in solid formulations results in mucoadhesive systems capable of promoting the prolonged and localized release of Active Pharmaceutical Ingredients (APIs). This strategy represents a technological innovation that can be applied to improving the treatment of oral infections, such as oral candidiasis. Therefore, the aim of this study was to develop a tablet of Ximenia americana L. from mucoadhesive polymers for use in the treatment of oral candidiasis. An X. americana extract (MIC of 125 μg·mL-1) was obtained by turbolysis at 50% of ethanol, a level that demonstrated activity against Candida albicans. Differential Thermal Analysis and Fourier Transform Infrared Spectroscopy techniques allowed the choice of HPMC as a mucoadhesive agent, besides polyvinylpyrrolidone, magnesium stearate, and mannitol to integrate the formulation of X. americana. These excipients were granulated with an ethanolic solution 70% v/v at PVP 5%, and a mucoadhesive tablet was obtained by compression. Finally, mucoadhesive strength was evaluated, and the results demonstrated good mucoadhesive forces in mucin disk and pig buccal mucosa. Therefore, the study allowed a new alternative to be developed for the treatment of buccal candidiasis, one which overcomes the inconveniences of common treatments, costs little, and facilitates patients' adhesion.

Contribution of Secondary Metabolites to the Gastroprotective Effect of Aqueous Extract of Ximenia americana L. (Olacaceae) Stem Bark in Rats

Ximenia americana L. (Olacaceae) is used in ethnomedicine as cicatrizant and for the treatment of gastric disorders. This study identified the chemical constituents of the aqueous extract of X. americana (XaAE) and evaluated its antiulcerogenic activity. After lyophilization, XaAE was analyzed by liquid chromatography-mass spectrometry (LC-MS) and its antiulcerogenic effect was evaluated in acute gastric lesions induced by ethanol, acidified ethanol, and indomethacin. Antisecretory action, mucus production and the participation of sulfhydryl groups (-SH) and nitric oxide (NO) were also investigated. The chromatographic analysis identified procyanidins B and C and catechin/epicatechin as major compounds. Oral administration of XaAE (100, 200 and 400 mg/kg) inhibited the gastric lesions induced by ethanol (76.1%, 77.5% and 100%, respectively), acidified ethanol (44.9%, 80.6% and 94.9%, respectively) and indomethacin (56.4%, 52.7% and 64.9%, respectively). XaAE reduced gastric contents and acidity (51.4% and 67.7%, respectively) but did not alter the production of gastric mucus. The reduction of the -SH and NO groups promoted by N-ethylmaleimide (NEM) and Nω-nitro-l-arginine-methyl-ester (L-NAME) respectively, reduced the gastroprotective effect of XaAE. In conclusion, XaAE has gastroprotective activity mediated in part by -SH, NO and antisecretory activity. This antiulcer action was initially correlated to its major constituents, procyanidins B and C and catechin/epicatechin.

Ethnopharmacology and Therapeutic Value of Bridelia micrantha (Hochst.) Baill. in Tropical Africa: A Comprehensive Review

Bridelia micrantha is traditionally used in tropical Africa to treat a wide range of human and animal diseases. The aim of this study was to summarise the research that has been done on the ethnomedicinal uses, phytochemistry and pharmacological properties of B. micrantha so as to understand its importance and potential value in primary healthcare systems. The literature search for information on ethnomedicinal uses and pharmacological activities of B. micrantha was undertaken using databases such as Web of Science, Scopus, Google Scholar, Science Direct, BioMed Central (BMC), PubMed and Springerlink. Other relevant literature sources included books, book chapters, websites, theses, conference papers and other scientific publications. This study showed that B. micrantha is used as herbal medicine in just over half (57.3%) of the countries in tropical Africa where it is indigenous. A total of 54 ethnomedicinal uses of B. micrantha have been recorded with a high degree of consensus on burns, wounds, conjunctivitis, painful eyes, constipation, gastric ulcers, cough, headache, rheumatism, painful joints, dysentery, ethnoveterinary medicine, malaria, sexually transmitted infections, stomach ache, tape worms and diarrhoea. Different plant parts, aqueous and organic extracts exhibited anthelmintic, antimicrobial, anticonvulsant and sedative, antidiabetic, antidiarrhoeal, antinociceptive, antioxidant, antiplasmodial, antischistosomal, hepatoprotective, insecticidal and β-lactamase inhibitory activities.

Ethnopharmacology, Chemistry and Biological Properties of Four Malian Medicinal Plants

The ethnopharmacology, chemistry and pharmacology of four Malian medicinal plants, Biophytum umbraculum, Burkea africana, Lannea velutina and Terminalia macroptera are reviewed. These plants are used by traditional healers against numerous ailments: malaria, gastrointestinal diseases, wounds, sexually transmitted diseases, insect bites and snake bites, etc. The scientific evidence for these uses is, however, limited. From the chemical and pharmacological evidence presented here, it seems possible that the use in traditional medicine of these plants may have a rational basis, although more clinical studies are needed.

Recent trends in phytochemistry, ethnobotany and pharmacological significance of Alchornea cordifolia (Schumach. & Thonn.) Muell. Arg

ETHNOPHARMACOLOGICAL RELEVANCE

Alchornea cordifolia (Schumach. & Thonn.) Muell. Arg. (Euphorbiaceae) (A. cordifolia) is widely distributed throughout tropical Africa, where it is used extensively in traditional medicine. Conditions for which the plant has enjoyed wide use are: coughs, gonorrhoea, infertility, prostatitis, bacterial infections, diarrhoea, ulcers, pain, inflammation, fever and bronchial troubles. This review summarizes the achievements of the investigations in traditional uses, ethnobotany, phytochemistry, biological activities and toxicological profile of A. cordifolia; this review also describes the shortcomings of studies on this herbal drug and thus serves as the basis of further scientific research and development of this traditional herbal drug.

MATERIALS AND METHODS

A. cordifolia-related information was collected from various resources including published articles in peer-reviewed journals, unpublished materials, textbooks, government survey reports and scientific databases such as Scifinder®, Pubmed, Science Direct, Wiley, Springer, ACS, Scielo, Web of Science and other web search instruments (Google, Yahoo), published on the subject from 1950 to 2016. 'The Plant List' (www.theplantlist.org) and 'Kew Royal Botanic Gardens' (mpns.kew.org) were used to validate the scientific name of the plant.

RESULTS

The literature revealed several reports on traditional uses, biological activities, chemical constituents and toxicological evaluation of A. cordifolia. The phytochemical information indicates identification of 95 compounds including fatty acids, terpenoids, flavonoids, phenolic acids, alkaloids, which exhibited various pharmacological activities such as wound healing, anti-inflammation, anticancer, antioxidant, immunomodulation, antidiarrhoeal, antimicrobial, antidepressant, hepatoprotective, antiplasmodial and anxiolytic. However, there are still significant gaps in the completeness of our understanding of A. cordifolia bioactivity, therapeutic value, and roles played by each of the numerous phytoconstituents.

CONCLUSIONS

The present review indicated that A. cordifolia is a valuable medicinal plant with multiple pharmacological effects. However, further research on the pharmacological mechanism of action of this plant is recommended in order to unravel the pharmacokinetics, pharmacodynamics, clinical relevance and toxicity of its extracts as well as constituents.

Cytotoxicity of 91 Kenyan indigenous medicinal plants towards human CCRF-CEM leukemia cells

ETHNOPHARMACOLOGICAL RELEVANCE

Plants from Kenyan flora are traditionally used against many ailments, including cancer and related diseases. Cancer is characterized as a condition with complex signs and symptoms. Recently there are recommendations that ethnopharmacological usages such as immune and skin disorders, inflammatory, infectious, parasitic and viral diseases should be taken into account when selecting plants that treat cancer.

AIM

The present study was aimed at investigating the cytotoxicity of a plethora of 145 plant parts from 91 medicinal plants, most of which are used in the management of cancer and related diseases by different communities in Kenya, against CCRF-CEM leukemia cell line.

MATERIALS AND METHODS

Extracts from different plant parts (leaves, stems, stem bark, roots, root barks, aerial parts and whole herb) were obtained by cold percolation using different solvent systems, such as (1:1v/v) dichloromethane (CH2Cl2) and n-hexane (1), methanol (MeOH) and CH2Cl2 (2); neat MeOH (3), 5% H2O in MeOH (4) and with ethanol (EtOH, 5); their cytotoxicities were determined using the resazurin reduction assay against CCRF-CEM cells.

RESULTS

At a single concentration of 10μg/mL, 12 out of 145 extracts exhibited more than 50% cell inhibition. These include samples from the root bark of Erythrina sacleuxii (extracted with 50% n-hexane-CH2Cl2), the leaves of Albizia gummifera, and Strychnos usambarensis, the stem bark of Zanthoxylum gilletii, Bridelia micrantha, Croton sylvaticus, and Albizia schimperiana; the root bark of Erythrina burttii and E. sacleuxii (extracted with 50% CH2Cl2-MeOH), the stem bark of B. micrantha and Z. gilletii (extracted using 5% MeOH-H2O) and from the berries of Solanum aculeastrum (extracted with neat EtOH). The EtOH extract of the berries of S. aculeastrum and A. schimperiana stem bark extract displayed the highest cytotoxicity towards leukemia CCRF-CEM cells, with IC50 values of 1.36 and 2.97µg/mL, respectively. Other extracts having good activities included the extracts of the stem barks of Z. gilletii and B. micrantha and leaves of S. usambarensis with IC50 values of 9.04, 9.43 and 11.09µg/mL, respectively.

CONCLUSIONS

The results of this study provided information related to the possible use of some Kenyam medicinal plants, and mostly S. aculeastrum, A. schimperiana, C. sylvaticus, Z. gilletii, B. micrantha and S. usambarensis in the treatment of leukemia. The reported data helped to authenticate the claimed traditional use of these plants. However, most plants are used in combination as traditional herbal concoctions. Hence, the cytotoxicity of corresponding plant combinations should be tested in vitro to authenticate the traditional medical practitioners actual practices.