Ethnomedicinal survey and mutagenic studies of plants used in Accra metropolis, Ghana

The Composition and Biochemical Properties of Strophantus (Apocynaceae), with a Focus on S. sarmentosus

The genus Strophantus belongs to the Apocynaceae family of flowering plants which grows primarily in tropical Africa. The plants are widely used in traditional herbal medicine. S. sarmentosus, in particular, is used for the treatment of, e.g., joint pain and rheumatoid arthritis, wound infections, head lice, diarrhea, snake bite, and eye conditions. Despite its widespread use, dedicated research characterizing its bioactive plant components is scarce. Investigations have focused mainly on its cardenolides because of their cardioactivity and historical use as cardiotonic. There are also studies concerning the antibacterial, antioxidant, and anti-inflammatory activity of plant extracts. This review summarizes the present knowledge surrounding the biochemical and analytical research on Strophantus, in general, and S. sarmentosus, in particular, and describes the current state of the field based on the available scientific literature.

Ethnopharmacological Study of Medicinal Plants Used for the Treatment of Cardiovascular Diseases and Their Associated Risk Factors in sub-Saharan Africa

Cardiovascular diseases (CVDs) are the leading cause of global mortality, including deaths arising from non-communicable diseases in sub-Saharan Africa (SSA). Consequently, this study aimed to provide details of medicinal plants (MPs) employed in SSA for the treatment of CVDs and their related risk factors to open new avenues for the discovery of novel drugs. The extensive ethnopharmacological literature survey of these MPs in 41 SSA countries was based on studies from 1982 to 2021. It revealed 1,085 MPs belonging to 218 botanical families, with Fabaceae (9.61%), Asteraceae (6.77%), Apocynaceae (3.93%), Lamiaceae (3.75%), and Rubiaceae (3.66%) being the most represented. Meanwhile, Allium sativum L., Persea americana Mill., Moringa oleifera Lam., Mangifera indica L., and Allium cepa L. are the five most utilised plant species. The preferred plant parts include the leaves (36%), roots (21%), barks (14%), fruits (7%), and seeds (5%), which are mostly prepared by decoction. Benin, Mauritius, Nigeria, South Africa, and Togo had the highest reported use while most of the investigations were on diabetes and hypertension. Despite the nutraceutical advantages of some of these MPs, their general toxicity potential calls for caution in their human long-term use. Overall, the study established the need for governments of SSA countries to validate the efficacy/safety of these MPs as well as provide affordable, accessible, and improved modern healthcare services.

Anti-HCV Tannins From Plants Traditionally Used in West Africa and Extracted With Green Solvents

Millions of people are still infected with hepatitis C virus (HCV) nowadays. Although recent antivirals targeting HCV proteins are very efficient, they are not affordable for many people infected with this virus. Therefore, new and more accessible treatments are needed. Several Ivorian medicinal plants are traditionally used to treat “yellow malaria”, a nosological category including illness characterized by symptomatic jaundice such as hepatitis. Therefore, some of these plants might be active against HCV. An ethnobotanical survey in Côte d’Ivoire allowed us to select such medicinal plants. Those were first extracted with methanol and tested for their anti-HCV activity. The most active ones were further studied to specify their IC50 and to evaluate their toxicity in vitro. Greener solvents were tested to obtain extracts with similar activities. Following a phytochemical screening, tannins of the most active plants were removed before re-testing on HCV. Some of these tannins were identified by UPLC-MS and pure molecules were tested against HCV. Out of the fifteen Ivorian medicinal plants selected for their putative antiviral activities, Carapa procera DC. and Pericopsis laxiflora (Benth. ex Baker) Meeuwen were the most active against HCV (IC50: 0.71 and 0.23 μg/ml respectively) and not toxic for hepatic cells. Their crude extracts were rich in polyphenols, including tannins such as procyanidins A2 which is active against HCV. The same extracts without tannin lost their anti-HCV activity. Replacing methanol by hydro-ethanolic solvent led to tannins-rich extracts with similar antiviral activities, and higher than that of aqueous extracts.

Knowledge, Attitudes and Practices on the Use of Botanical Medicines in a Rural Caribbean Territory

The worldwide use of medicinal plant products has been steadily increasing over the past few decades, whereas the traditional knowledge and practices of these botanical medicines appears to be diminishing. Considering the need to conserve and document these traditions, the objective of this study was to understand the knowledge, attitudes, and practices of people who are familiar with botanical medicines, as well as any factors that may influence the perceptions and behaviours associated with the use of medicinal plants. A previously validated survey instrument assessing knowledge, attitudes, and practices on the use medicinal plants was randomly administered to residents of three rural Barbadian communities. The data was analyzed using descriptive statistics and cross tabulations (Chi-Square Test, Fisher’s Exact Test), with a confidence level of 95% and significance level of p < 0.05. One hundred and fifty-four participants completed the survey with a response rate of 96%. From participant responses we found that over 75% of the study population used botanical medicines. Key findings included a diverse repertoire of traditional knowledge on the use of medicinal plants, which included a total of 29 medicinal applications cited across 69 different plant species and 39 families. The most popular species among respondents (irrespective of use) were Pimenta racemosa (Mill.) J.W. Moore (FC = 30, RFC = 0.26), Momordica charantia L. (FC = 28, RFC = 0.24), Zingiber officinale Roscoe (FC = 22, RFC = 0.19) and Annona muricata L. (FC = 21, RFC = 0.18). The findings also show the persistence of medico-cultural concepts such as cleansing and cooling, and identified significant associations between the use of botanical medicines and related practices with demographic variables such as education (p = 0.05; Fisher’s Exact Test) and health insurance, χ² (1, n = 152) = 4.645, p = 0.003. The findings of this study can be used in the identification and archiving of the medicinal plant practices in Barbados and the wider Caribbean, as well as for the larger purposes of biocultural exploration, preservation and further scientific assessment of botanical medicine practices.

Antimicrobial Activity against Oral Pathogens Confirms the Use of Musa paradisiaca Fruit Stalk in Ethnodentistry

Background

Ethnodentistry is the use of indigenous oral cleansing agents such as plant parts by local folks not only to maintain oral hygiene but also to treat oral infections. Mostly, ethnodentistry is inspired by traditions and belief systems of local communities. Musa paradisiaca is extensively cultivated and used in many cultures for its nutritional and medicinal values. In Ghana, the fruit stalk of Musa paradisiaca is used as an oral cleansing agent to maintain oral hygiene; yet this folk claim remains to be ascertained scientifically.

Objective

The study assessed the antibacterial and antifungal effects of three extract fractions (aqueous, ethanol, and ethyl acetate fractions) of Musa paradisiaca fruit stalk against Lactobacillus acidophilus, Aggregatibacter actinomycetemcomitans, and Candida albicans, common oral pathogens implicated in dental caries and periodontitis.

Materials and Methods

Aqueous, ethanol, and ethyl acetate fractions of Musa paradisiaca fruit stalk were prepared by cold maceration and qualitatively screened for their phytochemical composition. Antimicrobial effects of the three extract fractions were assessed by using serial broth dilutions at increasing concentrations (62.5, 125, 250, 500, and 1000 µg/ml) and compared to standard antimicrobial agents (erythromycin, doxycycline, and fluconazole). Subsequently, the absorbances of the microbial suspensions treated with increasing concentrations of the extract fractions were measured at 450 nm, and the cell densities were determined.

Results

Except for the aqueous extract, which was less effective in decreasing microbial growth, the ethyl acetate and the ethanol extract fractions demonstrated antimicrobial efficacies comparable to those of the standard drugs. All three extract fractions demonstrated concentration-dependent growth inhibitory effects on the tested oral pathogens although not as effective as the standard drugs used.

Conclusion

Musa paradisiaca fruit stalk has demonstrated antimicrobial effects against Lactobacillus acidophilus, Aggregatibacter actinomycetemcomitans, and Candida albicans, common oral pathogens implicated in dental caries and periodontitis, and this finding confirms in part folk use of Musa paradisiaca fruit stalk as a traditional dental care agent. Thus, the fruit stalk of Musa paradisiaca could be explored for use as a cheap and readily available dental care agent for people entrapped in the poverty line.

Phytochemicals and Amino Acids Profiles of Selected sub-Saharan African Medicinal Plants' Parts Used for Cardiovascular Diseases' Treatment

For years, the focus on the lipid-atherosclerosis relationship has limited the consideration of the possible contribution of other key dietary components, such as amino acids (AAs), to cardiovascular disease (CVD) development. Notwithstanding, the potential of plant-based diets, some AAs and phytochemicals to reduce CVDs' risk has been reported. Therefore, in this study, the phytochemical and AA profiles of different medicinal plants' (MPs) parts used for CVDs' treatment in sub-Saharan Africa were investigated. Fourier-transform infrared analysis confirmed the presence of hydroxyl, amino and other bioactive compounds' functional groups in the samples. In most of them, glutamic and aspartic acids were the most abundant AAs, while lysine was the most limiting. P. biglobosa leaf, had the richest total branched-chain AAs (BCAAs) level, followed by A. cepa bulb. However, A. cepa bulb had the highest total AAs content and an encouraging nutraceutical use for adults based on its amino acid score. Principal component analysis revealed no sharp distinction between the AAs composition of MPs that have found food applications and those only used medicinally. Overall, the presence of medicinally important phytochemicals and AAs levels in the selected MPs' parts support their use for CVDs treatment as they might not add to the AAs (e.g., the BCAAs) burden in the human body.

Toxicity, mutagenicity and trace metal constituent of Termitomyces schimperi (Pat.) R. Heim (Lyophyllaceae) and kaolin, a recipe used traditionally in cancer management in Cote d'Ivoire

ETHNOPHARMACOLOGICAL RELEVANCE

Some local communities in Cote d'Ivoire use the mushroom Termitomyces schimperi combined with kaolin (TSK) to manage various cancers in patients. However, there is a paucity of data on toxicity, mutagenicity and trace metal constituent of TSK.

AIM OF THE STUDY

We sought to investigate the acute and sub-chronic toxicities, mutagenic potential, and trace metal constituents of TSK.

MATERIALS AND METHODS

To assess acute toxicity, single doses (1000, 3000 and 5000 mg/kg) of aqueous extract of TSK were administrated per os to Sprague Dawley (SD) rats on Day 1. The rats were then monitored for 13 consecutive days. Sub-chronic toxicity was evaluated by daily administration of 200 and 500 mg/kg of the extract per os for 90 consecutive days. SD rats used as control received distilled water. Signs of toxicity, changes in body weight and mortality were monitored. After the aforementioned monitoring processes, rats were sacrificed and blood collected for full blood count and biochemistry analysis. Animal organs were also collected for histopathological examination. The mutagenic potential of the aqueous extract of TSK (10000 μg/mL) on TA98 Salmonella typhimurium was estimated. Additionally, energy-dispersive X-ray fluorescence (ED-XRF) method was employed to determine trace metal constituents of TSK.

RESULTS

Single-dose administration of 5000 mg/kg of TSK did not cause any death in the SD rats; thus, LD50 was above 5000 mg/kg. Administration of 1000 and 3000 mg/kg of the aqueous extract of TSK did not cause any significant change in behaviour and body weight of SD rats during the 14-day monitoring period. However, the mean corpuscular volume and the mean corpuscular haemoglobin concentration increased significantly (p < 0.01) among rats administered 1000 and 3000 mg/kg of TSK. There was a significant increase (p < 0.0001) in alanine transaminase levels in rats administered 1000 and 3000 mg/kg of TSK extract compared with control. Conversely, there was a significant decrease (p=0.0122) in serum creatine level among rats administered 1000 and 3000 mg/kg of TSK extract compared with control. After 14 days, there were minimal changes with isolated organs of TSK-treated and control rats. Furthermore, 90-day treatment with extract of TSK caused no significant change in parameters assessed. TSK induced frameshift gene mutation in S. typhimurium before (p < 0.05) and after metabolic activation (p < 0.001). Elemental analysis of TSK revealed the presence of toxic (aluminium) or potentially toxic (silver, rabidium, titanium and zirconium) elements.

CONCLUSIONS

The aqueous extract of TSK showed no toxicity (acute and sub-chronic) at doses tested. These findings are consistent with the absence of heavy metals (i.e., cadmium) and potentially toxic elements (i.e., uranium) in TSK samples analysed. TSK showed some level of mutagenic potential. Further mutagenic and chronic toxicity studies on TSK are required.

Antiplasmodial and Genotoxic Study of Selected Ghanaian Medicinal Plants

Results

Five out of the eight plants, A. boonei stem bark, S; siamea Lam root, M. lucida Benth leaves, P. niruri, and A. hispidum DC whole plants, showed varying degrees of antiplasmodial activity against the asexual stage of the parasite. The most active extract against chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) P. falciparum strains is the A. hispidum extract which yielded a mean inhibitory concentration at 50% (IC₅₀) of 3.66 µg/ml and 3.71 µg/ml for 3D7 and Dd2, respectively. This was followed by S. siamea Lam with 3.95 µg/ml for 3D7 and 4.47 µg/ml for Dd2. The IC₅₀ values of the A. boonei extract against 3D7 and Dd2 P. falciparum parasites were 5.13 µg/ml and 3.62 µg/ml, respectively. For the M. lucida Benth extract, the least IC₅₀ value was 6.46 µg/ml. All five extracts exhibited dose-dependent antiplasmodial activity. Assessment of the genotoxic effects the A. hispidum extract by the comet assay revealed substantial damage to P. falciparum DNA.

Conclusion

This study demonstrates that the crude extract of A. hispidum DC, one of the plants used traditionally to treat malaria, inhibits the growth of P. falciparum in vitro and could be a potential source of antimalarial drug. The report has highlighted genotoxic and cytotoxic effects of the selected plant extracts on human leukocytes as well.