Unleashing the Potential of Medicinal Plants in Benin: Assessing the Status of Research and the Need for Enhanced Practices

Medicinal plants play a crucial role in the primary health care of the population in developing countries such as Benin. The national universities of Benin conduct research on the pharmacological, toxicological, and phytochemical properties of these plants, but the resulting knowledge often does not lead to the development of phytomedicines for the improvement of public health. This study aims to assess the current status of research on medicinal plants in Benin. A literature review was conducted using various search engines, and the collected data was analyzed. The results indicate that research on the biological properties of medicinal plants is still in its early stages, with limited and inadequate methodological approaches. These limitations highlight the urgent need to enhance research practices and facilitate the development of effective and safe phytomedicines.


Introduction
In many developing countries, including Benin, traditional medicine plays a crucial role in providing primary health care to the population. The abundant use of medicinal plants in traditional medicine and the transmission of this knowledge from generation to generation highlights the importance of preserving and utilizing this resource in a sustainable manner.
Benin is a country in West Africa with a rich tradition of herbal medicine. Many plants are used by the population of Benin for various purposes, including medicinal, culinary, and spiritual uses. Here are some of the most commonly used plants in Benin [1]: -Aloe vera: Aloe vera is a succulent plant that is commonly used for medicinal purposes. In Benin, it is used to treat various ailments, including skin conditions, digestive problems, and infections. -Neem: Neem is a tree that is widely used in Benin for its medicinal properties. It is used to treat a variety of conditions, including fever, malaria, and skin diseases. -Hibiscus: Hibiscus is a plant that is used in Benin to make a popular drink known as bissap. The drink is made by steeping the leaves of the hibiscus plant in hot water  Table 1 highlights the main limitations and areas for improvement in research practices in the field of medicinal plants. Most antimicrobial activities are studied through the in vitro susceptibility testing of microbial strains with disc diffusion methodologies. There is a lack of advanced studies that examine the mechanism of action of the antimicrobial effect and its in vivo efficacy. Additionally, there is sometimes a lack of proper implementation of protocols. Furthermore, the studies conducted thus far only cover microbial growth inhibition, and research on the anti-virulence properties of the medicinal plants has not been carried out.
Regarding antioxidant activity, research on the antioxidant potential of medicinal plant extracts is commonly conducted using in vitro free radical scavenging tests such as the DPPH assay. Limitations in these studies include the lack of multiple tests to confirm the radical scavenging activity, ignorance of other modes of possible antioxidant effect, and a lack of investigation into the in vivo effectiveness of the antioxidant effect.  Table 1 highlights the main limitations and areas for improvement in research practices in the field of medicinal plants. Most antimicrobial activities are studied through the in vitro susceptibility testing of microbial strains with disc diffusion methodologies. There is a lack of advanced studies that examine the mechanism of action of the antimicrobial effect and its in vivo efficacy. Additionally, there is sometimes a lack of proper implementation of protocols. Furthermore, the studies conducted thus far only cover microbial growth inhibition, and research on the anti-virulence properties of the medicinal plants has not been carried out.
Regarding antioxidant activity, research on the antioxidant potential of medicinal plant extracts is commonly conducted using in vitro free radical scavenging tests such as the DPPH assay. Limitations in these studies include the lack of multiple tests to confirm the radical scavenging activity, ignorance of other modes of possible antioxidant effect, and a lack of investigation into the in vivo effectiveness of the antioxidant effect.
Few scientific studies have confirmed the anti-inflammatory activity of medicinal plants by researching inflammation mediators. This highlights the need for further research in this area to fully understand the anti-inflammatory effects of these plants. [  Acaricidal activity In vitro test on the survival of ticks exposed to various concentrations of an extract. [125,126]  Capacity building on the conduct of field and laboratory testing of insecticidal activity.
No details on the volume of extract sprayed.
Capacity building on the conduct of field and laboratory testing of insecticidal activity. [170,171] Antihypertensive activity In vivo test on Wistar rats with the exploration of few relevant parameters.
Advanced study with the consideration of several parameters to elucidate the mechanism of action.
Capacity building on adapted models to elucidate the mechanism of action.
In-vivo testing on rats by the induction of metabolic disorder and the administration of extract concentrations and an evaluation of the effects.
Advanced study via more adapted models to elucidate the anti-diabetic effect of medicinal plants. Use of old model methods at the expense of more advanced methods.
Advanced study via more adapted models.
Training on advanced tests to explore the analgesic effect. [162]

Biological Activities Methodology Limitations-Prospects Improvement of Research Practice References
Antidifferentiation or anticancer activity of liver cells In vivo test on Wistar rats with methodological deficiencies.
Advanced study via more adapted models.
Training on advanced tests to explore the anticancer effect of medicinal plants. [195][196][197][198] Anti-anemic activity Lack of precision on the justification of the doses used.
Advanced study on the research of the mechanism of action of the antidiabetic effect.
Capacity building on advanced studies to investigate the mechanism of action of the anti-diabetic effect. [110,161,[205][206][207][208] In vivo test on normal rats without diabetes induction.
The experimental design is not consistent with the anti-diabetic effect being explored.
Capacity building on appropriate tests for diabetes induction and the exploration of the antidiabetic effects of plant extracts. [209,210] Insecticidal and repellent activity Test on the pest D. porcellus. [211] Larvicidal activity In vitro test on larvae. [212][213][214] Anti-coughing activity In vivo test on guinea pigs using the citric acid method. [215] Aphrodisiac activity In vivo test with exploration of the parameters related to the aphrodisiac effect.
[ [216][217][218] Diuretic activity -In vivo test with little data on some important aspects of pharmacology. -No exploration of enzymatic parameters.
Advanced study on the most suitable models.
Training on advanced study via more suitable models.
[ 219,220] Hemostatic activity In vitro (anti-coagulation) and in vivo test to stop bleeding. [221][222][223][224] Hepatoprotective activity In vivo test on Wistar rats after the induction of liver damage, followed by an evaluation of enzymatic and histological parameters.
Advanced study on adapted models allowing the elucidation of the mechanism of action. No assay of inflammation markers.
Training on advanced study via more suitable models. Capacity building on in-vivo tests for inflammation markers. [194,225,226]  Advanced study on the elucidation of the mechanism of action. [227] Spasmolytic activity Tested on isolated rat trachea in combination with an aqueous extract of Afromomum melegueta. [228] Spermatogenic activity In vivo test on Wistar Rats, followed by assessment of reproductive parameters.
Advanced study on other models allowing the elucidation of the mechanism of action.
Training on advanced study via other models to elucidate the mechanism of action. [229,230] Normoglycemic activities In vivo test on Wistar rats, followed by blood glucose determination.
Advanced study via more adapted models to elucidate the anti-diabetic effect of medicinal plants.
Capacity building on advanced studies using more suitable models to elucidate the anti-diabetic effect of medicinal plants. [182] Lipid-lowering activity In-vivo test on rats by forced administration of 2 ml of pork fat and sugar water.
More suitable models should be considered.
Capacity building on the design and execution of the research protocol in pharmacology. [231] Antipyretic

Toxicological Studies
A total of 107 scientific studies have explored the toxicity of the medicinal plants identified. Most of the studies focused on larval cytotoxicity, followed by acute oral toxicity (Figure 2).
Limitations and opportunities for improving research practices for toxicology studies are presented in Table 2 below. The limitations identified in these studies point to needs for capacity building in advanced toxicity testing of natural substances.

Phytochemical Study
One hundred thirty-eight (138) phytochemical studies were identified among the published reports on medicinal plants. Most of them are related to the sole qualitative profiling by the method of staining and precipitation (Figure 3).
The main limitations of these techniques (Table 3) are related to the frequent use of a preliminary test (Cytotoxicity larceny) without a real deepening. The lack of cytotoxicity assays applied to in vitro cultures of mammalian cell lines limits the ability to predict the toxic potential in the context of human use and necessitates the use of rodents and chicks. This highlights the need to use more advanced methods for the identification and characterization of bioactive molecules.  Limitations and opportunities for improving research practices for toxicology studies are presented in Table 2 below. The limitations identified in these studies point to needs for capacity building in advanced toxicity testing of natural substances.  [3,44,53,63,11 3,146,182,189, 200,236,240,2 43-252] Cellular toxicity test HepG2 cell test.
No limit noted.

Discussion
The aim of this study was to document the current state of scientific research practices regarding the evaluation of the biological, pharmacological, toxicological, and phytochemical properties of medicinal plants in Benin flora. The data obtained indicate that studies conducted in Benin cover priority areas such as pharmacology, toxicology, chemistry, microbiology, etc. In the scientific literature, a study that integrated data from different countries on several other continents documented that these fields constitute the areas in which many studies of medicinal plants are conducted [278]. This finding suggests that the study of medicinal plants in Benin, as well as in other countries outside Africa, primarily focuses on the above-mentioned areas.
The results obtained from this study demonstrate that the scientific studies in Benin concerning these aspects of medicinal plants are still in an embryonic or preliminary stage. In general, there is a lack of scientific research oriented toward more in-depth studies. The current data highlight the character, which is preliminary even at best, of the evidence of confirmation of the therapeutic usefulness of medicinal plants through the study of their biological activity. This situation explains the low availability of phytomedicines resulting from research of a sufficient depth to contribute effectively to the improvement of the health status of the population, more than 80% of whom depend on traditional medicine for their health needs. In this context, scientific elites should fully assume their leadership role by establishing a long-term roadmap to improve the quality of scientific research on medicinal plants and the modes of cooperation between academic staff and traditional medicine practitioners. However, despite their willingness, local research institutions lack adequate technical facilities to work in conditions that allow them to produce quality research results. In Benin, scientific research remains underfunded, with less than 1% of the gross domestic product devoted to it [279].
Furthermore, the results obtained demonstrate that the researchers from the University of Abomey-Calavi were the most active in the scientific investigations mentioned above. This is easily explained by the fact that the University of Abomey-Calavi is the oldest public university in Benin, and its multidisciplinarity is favorable to this state of affairs. At this university, among the biological activities of the medicinal plants explored, antimicrobial activities have been very frequent in both human and animal health. Benin, similar to other developing countries in Africa, has a strong culture in which the population is very attached to the ancestral tradition, which is based on the use of medicinal plants against all kinds of diseases. Thus, among the diseases most targeted by the studies reviewed, infectious diseases ranked in the first position. A similar observation was reported by Salmerón-Manzano et al. [278]. In their study, these authors reported that parasitic diseases were the most frequent in African regions, particularly in Cameroon. These observations can be explained by the fact that infectious diseases constitute one of the deadliest diseases worldwide [280]. In addition, the issue of antimicrobial resistance is a major public health concern at present as it further complicates the management of infectious diseases [281]. The World Health Organization has strongly recommended the exploration of several alternatives to contribute to the effective control of infectious diseases [282], and medicinal plants are among the most-explored alternatives. Therefore, this could justify the commitment of Beninese researchers, particularly those at the University of Abomey-Calavi, to invest in scientific studies examining the antimicrobial potential of medicinal plants.
The impact and interest of a study on the current status of research on medicinal plants at the national universities of Benin is then significant in several ways: Overall, the study can have a positive impact on public health, the economy, and scientific research in Benin, and it could be of interest to researchers, healthcare providers, policymakers, and other stakeholders in the region.

Materials and Methods
The data collection and analysis were conducted over a 4-month period (September to December 2022) via a literature review. The process was organized in three main steps: - The first step was to search the following search engines (Google Scholar, Pubmed, Sciencedirect, and FreeFullPDF) for scientific information on the medicinal plants studied in Benin, using the following expressions or word groups: "Biological activities"; "Pharmacological activities"; "Toxicity"; "Phytochemistry" "Phytochemical screening", and "Quantitative screening". This search was performed in both French and English. The information was collected according to each of the four major universities of Benin (the University of Abomey-Calavi, University of Parakou, National University of Agriculture of Kétou, and the National University of Science, Technology, Engineering and Mathematics of Abomey). - The second step consisted of a critical analysis of the methodological approach of each of the scientific studies identified in order to identify the main limitations of the methodologies used and to propose possible actions to improve research practices. For the scientific articles whose authors were in collaboration via several research institutions, the authorship of the article was defined by considering the corresponding author from one of the national universities of Benin. - The last step consisted of making a synthesis of the information collected about the different pharmacological, toxicological, and phytochemical activities by university.
The Table 4 presents the description of the articles included in the study. Table 4. Update on the scientific articles included in this study.

Total Number of Articles Included in This Study 272
Year range 2001-2022

Conclusions
Faced with this alarming situation, it is urgent that Beninese researchers implement mechanisms for the real development of science in Benin. Opportunities for North-South and other partnerships are desired more than ever to strengthen the technical capacities of research structures and to strengthen the skills of teacher-researchers on the methodological approaches currently accepted in the biomedical field, especially in those of the development of plant-based remedies and standardized phytomedicines. Funding: This study was supported by the Global Innovation Network for Teaching and Learning (GINTL) collaboration funding in Africa, China and India for the application round in spring/summer 2022, provided by the Finnish Ministry of Education and Culture, under the project entitled "Education for sustainable and rational approaches to the use of medicinal plants in Benin: Co-constructive pedagogical strategy, research, and dissemination of good practices". Data Availability Statement: All data generated and/or analyzed during the current study are included in this published article. The datasets used and/or analyzed during this study are also available from the corresponding author upon reasonable request.