Ethnobotanical Study of Medicinal Plants Used by Traditional Healers to Treat Cancer-Like Symptoms in Eleven Districts, Ethiopia

Ethnobotanical study of medicinal plants in Dibatie district, Metekel zone, Benishangul Gumuz Regional State, western Ethiopia

BACKGROUND

Herbal medicine has been used for the treatment of human and livestock ailments since ancient times. Numerous rural and urban communities in Ethiopia practice traditional medicine and transfer the knowledge verbally from generation to generation. Thus, this study was conducted to document the traditional medicinal plants and associated indigenous knowledge in Dibatie district, Metekel zone, Benishangul Gumuz Regional State, western Ethiopia.

METHODS

Three hundred seventy-four (374) informants from 11 kebeles (the smallest administrative units) were selected and participated in the data delivery. The ethnobotanical data collection was carried out using semi-structured interviews, preference ranking, direct matrix ranking, field observation, market surveys, and focus group discussions, including voucher specimen collections. The ethnobotanical data were analyzed using descriptive statistics (frequency and percentage), ranking, comparison, and quantitative ethnobotanical techniques such as informant consensus factor, fidelity level index, Jaccard's coefficient of similarity, and use value index.

RESULTS

A total of 170 plant species were recorded to treat 79 human and 29 livestock ailments. Fabaceae (with 20 species) and Asteraceae (with 18 species) were the most dominant medicinal plant families in the area. Most remedial plants were herbs (61 species, 35.88%), followed by shrubs (39 species, 22.94%). The majority (135 species, 79.41%) of medicinal plants were harvested from wild sources and mainly possessed multiple remedy parts (41.17%) that are usually prescribed in fresh form (60.13%). The most commonly reported human ailment was snake venom, while blackleg was mostly reported among livestock diseases. The herbal medicines were mostly administered orally (52.20%), followed by dermal (17.62%) application. Embelia schimperi Vatke, Glinus lotoides L., Haplosciadium abyssinicum Hochst., Mucuna melanocarpa Hochst. ex A. Rich., and Phragmanthera macrosolen (Steud. ex A. Rich.) M.G.Gilbert had the highest fidelity level values (100%) against the corresponding ailments.

CONCLUSION

The study area is rich in a diversity of potential medicinal plants and associated indigenous knowledge. Thus, appropriate conservation actions and careful utilization are essential to counteract the rise of anthropogenic threats and to ensure the continuity of plants with the related indigenous knowledge. Additionally, the medicinal plants should be validated through experimentation to integrate local knowledge with modern medications.

Traditional ethnobotanical knowledge and ethnomedicinal use of plants in the Tropical Rift Valley of Ethiopia

Introduction

A wide range of floral resources are used in Ethiopia for primary healthcare. Unfortunately, due to inadequate documentation and the fact that they were verbally passed down from one generation to the next, these indigenous medicinal practices are being forgotten. The study's goal was to identify and record indigenous peoples' traditional knowledge of plant usage in the Abala Abaya District of Wolaita, Ethiopia.

Methods

The collection of ethnobotanical data used a cross-sectional research design involving focus group discussions and semistructured questionnaires between January 2021 and April 2022. From each selected kebele (ward; smallest administrative unit), 50 informants (a total of 200) were selected as representative sample using a systematic random sampling technique.

Results

More than 50 different human and animal illnesses have been documented to be treated by seventy-two species of plants grouped in thirty-two families. The most abundant families were Poaceae and Asteraceae (8 taxa in each). The two most often used plant parts were leaf (29%) and herbs (54%), respectively. Oral administration was the most typical mode of delivery (75%). For treating stomachache in the category of gastrointestinal illnesses, Hagenia abyssinica (Bruce) J.F.Gmel got the greatest fidelity level scores (FL = 100%).

Conclusions

In Abala Abaya District, there is broad access to traditional medicinal plants that can treat ailments in both humans and animals. This study, therefore, might be a baseline piece of information for further botanical related studies in the region. Plants with the highest FL values are highly recommended for novel drug discovery.

Aqueous Extract of Leaves and Flowers of Acmella caulirhiza Reduces the Proliferation of Cancer Cells by Underexpressing Some Genes and Activating Caspase-3

The increasing prevalence of cancers and the multiple side effects of cancer treatments have led researchers to constantly search for plants containing bioactive compounds with cell death properties. This work aimed at evaluating the antiproliferative effect of an Acmella caulirhiza extract. After evaluation of the in vitro antioxidant potential of the three extracts of Acmella caulirhiza (aqueous (AE-Ac), hydroethanolic (HEE-Ac), and ethanolic (EE-Ac)) through the scavenging of DPPH● and NO● radicals, the extract with the best antioxidant activity was selected for bioactive compound assessment and antiproliferative tests. Subsequently, the cytotoxic activity was evaluated on the viability of breast (MCF-7), brain (CT2A, SB-28, and GL-261), colon (MC-38), and skin (YUMM 1.7 and B16-F1) cancer lines using the MTT method. Then, the line where the extract was the most active was selected to evaluate the expression of certain genes involved in cancerogenesis by RT-PCR and the expression of cleaved caspase-3 involved in cell death mechanism by western blot. The AE-Ac showed the best scavenging activity with IC50s of 0.52 and 0.02 for DPPH● and NO●, respectively. This AE-Ac was found to contain alkaloids, flavonoids, and tannins and was more active on YUMM 1.7 cells (IC50 = 149.42 and 31.99 μg/mL for 24 and 48 h, respectively). Results also showed that AE-Ac downregulated the expression of inflammation (IL-1b (p = 0.017) and IL-6 (p = 0.028)), growth factors (PDGF (p = 0.039), IGF (p = 0.034), E2F1(p = 0.038), and E2F2(p = 0.016)), and antiapoptotic protein genes (Bcl-2 (p = 0.028) and Bcl-6 (p = 0.039)). The cleaved caspase-3 was positively modulated by the AE-Ac inducing thus cell death by apoptosis. AE-Ac showed inhibitory effects on the expression of genes involved in cancer progression making it a potential health intervention agent that can be exploited in cancer therapy protocols.

Review of Medicinal Plants Traditionally Used to Treat Diarrhea by the People in the Amhara Region of Ethiopia

Background

Diarrheal illness is the second-most common cause of death in under-five children. Worldwide, it results in about 1.7 billion illnesses and 525,000 deaths among under-five children annually. It is the leading cause of malnutrition among under-five children. Different people use medicinal plants to treat diarrhea. The present study aimed to review the medicinal plants used to treat diarrhea by the people in the Amhara region and to diagnose whether the antidiarrheal activities of the medicinal plants have been confirmed by studies using animal models.

Methods

The author searched 21 articles from worldwide databases up to December 2022 using Boolean operators ("AND" and "OR") and the terms "ethnobotanical studies," "ethnobiology," "traditional medicine," "ethnobotanical knowledge," and "Amhara region."

Results

From the 21 studies reviewed, 50 plant species grouped into 28 families were reported to treat diarrhea by the people in the Amhara region. The top most used families were Lamiaceae (12%), Fabaceae (8%), Asteraceae, Cucurbitaceae, Euphorbiaceae, and Poaceae (6% each). The modes of administration of the plant parts were orally 98.88% and topically 1.12%. The different extracts of 18 (or 36%) of the medicinal plants traditionally used to treat diarrhea by the people in the Amhara region have been proven experimentally in animal models.

Conclusions

The people in the Amhara region use different medicinal plants to treat diarrhea. Most of them take the medicinal plants orally. The traditional claim that 60% of medicinal plants are antidiarrheal has been confirmed in in vitro studies.

Chemopreventive Activity of 80% Methanol Leaf Extract of Vernonia auriculifera Hiern (Asteraceae) Against Dimethylhydrazine-Induced Colorectal Carcinogenesis in Rats

Background

Vernonia auriculifera Hiern (Asteraceae) is among Ethiopian herbal medicines that are traditionally used to treat skin and gastrointestinal cancers. In this study, the chemopreventive potential of Vernonia auriculifera leaf extract in dimethylhydrazine (DMH)-induced colorectal carcinogenesis in rats was investigated.

Methods

Rats were assigned to nine groups (normal, positive, and negative control groups, and three pre- and three post-initiation groups). Except for the normal control group (administered with 1 mL/100 g distilled water), the remaining eight groups were given DMH (20 mg/kg) intraperitoneally (ip) for 15 consecutive weeks to induce colorectal tumours. The extract was given orally to the pre-initiation and post-initiation groups at doses of 100, 200, and 400 mg/kg before and after the induction of cancer, respectively. The positive control group was treated with aspirin (60 mg/kg/day) orally for the whole experimental period. Parameters including body weight, average tumour number, size, progression, incidence, total cholesterol, serum total protein, and triglyceride levels were determined. The cytotoxic activity of the extract in Caco-2 cells was evaluated using the MTT assay, and the antioxidant activity of the extract was also assessed using 2.2-diphenyl-1-picrylhydrazine (DPPH) and reducing power methods. Moreover, total phenol and flavonoid contents were determined using appropriate methods.

Results

Rats treated with the extract showed a lower incidence of up to 50% in the pre-initiation higher dose, average number (p<0.05),and size (p<0.05) of tumours compared to untreated rats. It also inhibited colorectal cancer-associated increases in serum total cholesterol and triglycerides. The extract's IC50 value in the MTT assay was found to be higher than 200 µg/mL. The extract had an IC50 of 74.88 ± 0.86 µg/mL and 84.69 ± 2.02 µg/mL in the reducing power and DPPH assays, respectively. Total flavonoid and phenol contents were 14.51 ± 0.41 mg quercetin acid equivalent/gm and 47.37 ± 0.72 mg gallic acid equivalent/gm of the crude extract, respectively.

Conclusion

The findings collectively indicated that the leaves of V. auriculifera possess chemopreventive activity, probably mediated through antioxidant mechanisms, which supports the traditional claim.

Anti-Convulsant Activity of Soxhlet Leaf Extracts of Ajuga Integrifolia Buch.-Ham. Ex D.Don (Lamiaceae) in Mice

Background

The leaves of Ajuga integrifolia Buch.-Ham. ex D.Don (Lamiaceae) have long been used as an anti-convulsant remedy in Ethiopian traditional medicine. However, the evidence supporting their use is sparse in the literature. This study was conducted to add to the existing body of knowledge about the anti-convulsant activity of the plant.

Methods

The anti-convulsant activity of the extract was investigated in both acute (pentylenetetrazol [PTZ], 80 mg/kg; and maximal electroshock [MES]) and chronic (PTZ, 35 mg/kg) kindling seizure models. For the experimental paradigms, various doses of the extract (100, 200, and 400 mg/kg) were administered. Positive controls received sodium valproate (200 mg/kg) for the PTZ model and phenytoin (25 mg/kg) for the MES model. Parameters including the onset of clonus and duration of hindlimb tonic extension were recorded and compared with controls. Moreover, the total alkaloid, flavonoid, and phenol contents of the extracts were determined.

Results

Ethyl acetate extract produced a superior effect among all solvent extracts in both the PTZ and MES models. At all doses, it significantly delayed the mean onset of clonus (p<0.01) in the PTZ test compared to controls. It also significantly reduced (p<0.001) the mean duration of hindlimb tonic extension in the MES model. Treatment of mice with 200 mg/kg (p<0.01) and 400 mg/kg (p<0.001) of ethyl acetate extract significantly protected against PTZ-induced kindling compared to controls. The leaf was found to contain 10.002±0.119 mg atropine equivalent per gram of dry extract of alkaloids, 9.045±0.8445 mg quercetin equivalent per gram of dry extract of flavonoids, and 21.928±1.118 mg gallic acid equivalent per gram of dry extract of phenols.

Conclusion

This study indicated that the plant A. integrifolia has anti-convulsant activity in both acute and chronic models of seizure. This plant represents a potential source for the development of a new anti-epileptic drug for pharmacoresistant epilepsy.

In vitro Anti-Leishmanial Activities of Methanol Extract of Brucea antidysenterica J.F. Mill Seeds and Its Solvent Fractions

Introduction

Leishmaniasis is one of the neglected tropical diseases, threatening lives of about 350 million people globally. Brucea antidysenterica seeds are used for the treatment of cutaneous leishmaniasis in the traditional medicine in Ethiopia.

Objective

This study aimed to evaluate Brucea antidysenterica seeds' anti-leishmanial activity in vitro.

Methods

The crude (80% methanol) extract of Brucea antidysenterica seeds and its fractions were evaluated for their anti-leishmanial activities against promastigotes and intracellular amastigotes of Leishmania donovani and Leishmania aethiopica, and for their cytotoxic effects against mammalian cells. The quantitative estimations of total phenolic compounds (TPCs), flavonoids (TFCs) and alkaloids (TACs) were determined, spectrophotometrically. Median inhibitory concentration (IC50) and median cytotoxic concentration (CC50) of the extract and its solvent fractions were calculated using GraphPad Prism 9.1.0 computer software. Data was presented as mean ± standard error of the mean (SEM).

Results

The crude extract and its hexane, ethyl acetate and butanol fractions showed anti-leishmanial activities, with IC50 values of 4.14-60.12 µg/mL against promastigotes, and 6.16-40.12 µg/mL against amastigotes of both Leishmania species. They showed moderate cytotoxicity against Vero cell lines and peritoneal mice macrophages, with CC50 values of 100-500 µg/mL, but >1600 µg/mL against red blood cells. Selectivity indices ranged from 7.97 to 30.97. The crude extract, and its ethyl acetate and hexane fractions possessed 54.78-127.72 mg of gallic acid equivalent TPC, 18.30-79.21 mg of quercetin equivalent TFC, and 27.62-97.22 mg of atropine equivalent TAC per gram of extracts.

Conclusion

The seeds of the plant possessed anti-leishmanial activities against L. aethiopica and L. donovani that might provide a scientific justification for its use in the treatment of leishmaniasis by traditional healers. Future works are recommended to isolate, purify and identify the possible secondary metabolites attributed to the anti-leishmanial activity.

Analgesic and Anti-Inflammatory Activities of 80% Methanol Extract and Solvent Fractions of Ehretia cymosa Thonn (Boraginaceae) Leaves in Rodents

Background

Ethnobotanical studies in various districts of Ethiopia reported that Ehretia cymosa (E. cymosa) is used for the management of headache, abdominal pain, arthritis and rheumatism. However, there is no scientific investigation done so far to confirm these traditional claims. Thus, the aim of this study was to assess the analgesic and anti-inflammatory effects of the 80% methanol extract and fractions of E. cymosa leaves.

Methods

The dried and pulverized leaves of E. cymosa were soaked with 80% methanol to obtain a crude extract. Fractionation was done using chloroform, ethyl acetate and water by a soxhlet apparatus. The analgesic effects of the crude extract and solvent fractions were assessed using acetic acid-induced writhing and hot plate tests whereas anti-inflammatory activities were investigated using carrageenan-induced paw edema and cotton-pellet-induced granuloma models.

Results

In all the tested doses, the 80% methanol extract and solvent fractions revealed substantial (p < 0.001) analgesic activities in acetic acid induced writhing test. In the hot plate method, all the tested doses of E. cymosa crude extract and the solvent fractions produced significant analgesic activities (p < 0.05). In the carrageenan-induced acute inflammation model, all tested doses of the crude extract and solvent fractions resulted in a significant decline in paw edema. The 80% methanol extract and solvent fractions of E. cymosa at all the tested doses significantly reduced inflammatory exudates and granuloma mass formations (p < 0.001).

Conclusion

From the results of this investigation, it can be stated that 80% methanol extract, aqueous, ethyl acetate and chloroform fractions of E. cymosa exhibited considerable analgesic and anti-inflammatory activities, supporting the plant's traditional use as a remedy for a variety of painful and inflammatory conditions.

Experience of patients with breast cancer with traditional treatment and healers' understanding of causes and manifestations of breast cancer in North Shewa zone, Ethiopia: a phenomenological study

OBJECTIVES

Despite a high number of traditional healers (THs) who treat patients with cancer in Ethiopia, there is limited evidence that explored the lived experience of patients with breast cancer (BC) with traditional treatment and healers' understanding of the causes and manifestations of BC.

DESIGN

A phenomenological study design was employed.

SETTING

This study was conducted in the North Shewa zone in Ethiopia.

PARTICIPANTS

Eight in-depth interviews were conducted; four of which were with patients with BC and four with THs. Semistructured interviewing techniques were used to collect data from the two groups of respondents. All interviews were audio-recorded. The recorded data were transcribed verbatim. Coding and marking were then performed to make the raw data sortable. The marked codes were then summarised and categorised into themes.

RESULTS

In this study, some of THs were unaware of the main risk factors or causes of BC. They did not mention the lifestyle risk factors of BC such as smoking cigarettes, consuming alcohol and eating habits. The most common clinical manifestations noted by THs were lumps at the breast, discharge from the nipples and weakness. All of the THs got their knowledge of BC treatment from their families and through experience. Regarding the lived experience of treatment, some patients with BC perceived that traditional medicines were safer and more effective than modern treatments and they eventually referred themselves to the THs.

CONCLUSIONS

Although THs were unaware of the causes of BC, they were familiar with basic signs and symptoms of the disease. Patients with BC referred themselves to the THs because they preferred traditional therapies to modern ones. In order to better satisfy the unmet needs of Ethiopian women with BC, due consideration should be given to traditional treatments.

A comprehensive review of the ethnomedicine, phytochemistry, pharmacological activities of the genus Kniphofia

CONTEXT

Kniphofia (Asphodelaceae) is found mainly in South Africa and Tropical Africa. Malaria, hepatitis B, blood purifier, cancer, eczema, and female infertility have all been traditionally treated using this genus.

OBJECTIVE

The current review provides a complete and up-to-date compilation of documented traditional medicinal uses, phytochemicals, and pharmacological activities of the genus.

METHOD

Relevant literature was collected by searching the major electronic scientific databases including PubMed, Science Direct, Web of Science, and Google Scholar using appropriate keywords ethnomedicinal studies, phytochemical investigations, and pharmacological activities of Kniphofia species. The search strategy included all articles with descriptors that were available until November 30, 2021. Only published works in English were used for this study. The data were collected using textual descriptions of the studies, tabulation, grouping, and figures.

RESULT

At present, more than 40 compounds have been isolated from different parts of Kniphofia species. The major compounds isolated from the Kniphofia species are monomeric anthraquinones and dimeric anthraquinones. Pharmacologically the extracts and isolated compounds showed antioxidant, antimalarial, antiproliferative, anti-HIV-1, anti-leukotriene, and cytotoxic activity. The genus afforded exemplary drug leads such as knipholone and knipholone anthrone with anti-HIV-1, antimalarial and cytotoxicity activity.

CONCLUSIONS

Kniphofia species have traditionally been used to treat a variety of diseases. Pharmacological actions of phytochemicals were shown to be promising. Despite this, considering the genus's inclusion on the red data list of South Africa, it deserves more attention. In order to find novel drug candidates, more studies on promising crude extracts and compounds are needed.

Endemic medicinal plants of Ethiopia: Ethnomedicinal uses, biological activities and chemical constituents

ETHNOPHARMACOLOGICAL RELEVANCE

Around 80% of Ethiopians rely on traditional medicinal plants to treat a variety of ailments, and the country is home to a number of endemic plants, making it part of East Africa's hotspot of biodiversity. Despite widespread acceptance of endemic medicinal plants among the local community, comprehensive documentation of their therapeutic uses and phytochemistry is lacking. This review thus provides the first comprehensive appraisal of traditional use, pharmacological properties and phytochemistry of Ethiopian endemic medicinal plants. By storing and preserving indigenous and scientific knowledge about the medicinal benefits of the plants, such documentation generates information database for the future. It also aids the conservation of key medicinal plants along with translational research to accelerate the development of pharmaceuticals.

AIM OF THE REVIEW

The aims of this review are to collect and document current information on the ethnopharmacological uses, phytochemistry, and biological activities of Ethiopian endemic medicinal plants, identify research gaps, and provide perspectives and suggestions for future research on the plants as potential sources of pharmaceuticals.

MATERIALS & METHODS

A comprehensive literature review using electronic databases such as Medline, Web of Science, Google Scholar, ScienceDirect, SpringerLink, and Wiley Online Library was conducted for collecting relevant information. The World Flora Online (WFO) database and the International Plant Names Index (IPNI) were utilized to authenticate the taxonomic information of the plants. Chemical structures were drawn using ChemBioDraw Ultra 12.1 and verified via PubChem.

RESULTS

The present review has identified 412 Ethiopian endemic plants. Out of the 412 endemic plants species recorded for Ethiopia 44 are medicinally valuable to mitigate a myriad of diseases, and nine (27.3%) of them are endangered. Our literature survey also found out that a total of 74 compounds were isolated and characterized from the endemic plants, with phenolics accounting for the majority of them (66.2%). The plants exhibited antimalarial, antimicrobial, anticancer, anthelmintic, mosquitocidal, antidiabetic, antioxidant, and anti-inflammatory properties.

CONCLUSION

The work has resulted in an up-to-date inventory of Ethiopia's endemic flora, as well as the identification of species with traditional medicinal uses. The pharmacological activity and phytochemistry of numerous endemic plants with various traditional therapeutic claims are yet to be researched scientifically. Scientific validation of the herbal remedies, including evidence-based safety and efficacy studies are, therefore, crucial. The endangered medicinal plants must be conserved in order for local communities to have access to them in the future.

A Review on Medicinal Plants Used in the Management of Respiratory Problems in Ethiopia over a Twenty-Year Period (2000–2021)

This review is aimed at assessing and compiling the different ethnomedicinal studies in different parts of Ethiopia used to treat respiratory diseases. The data were collected from different published research papers through searching the web sources such as PubMed, Science Direct, Google Scholar, and other related websites. The important search terminologies included ethnobotany, respiratory diseases, medicinal plants, and Ethiopia. For this, a total of 65 articles of recent publications (from 2000 to May 2021 years) that provided full information about the use of medicinal plant species to treat respiratory disorder diseases in Ethiopia were consulted. Based on this, a total of 96 medicinal plants belonging to 57 families were reviewed. The commonly recorded families used to manage respiratory problems were Asteraceae, Lamiaceae, Solanaceae, and Fabaceae. Herbs and shrubs were the dominant plant growth forms. Due to the easiest form of their preparation for treating respiratory disorders, leaves are the most cited plant parts followed by roots. Crushing and pounding are useful methods of remedy preparation to treat respiratory diseases. This review concluded that different medicinal plants have a significant contribution in combating serious respiratory problems in Ethiopia. Hence, the complied review of medicinal plants on the treatment of respiratory problems would play a great role in further pharmacological and phytochemical investigations in developing new drugs used for the treatment of respiratory problems and in the conservation of these important medicinal plants.

Attitude and practice toward traditional medicine among hypertensive patients on follow-up at Mizan–Tepi University Teaching Hospital, Southwest Ethiopia

Introduction:

Traditional medicine has been used for the management of common mild conditions such as headache, diarrhea, and common cold as well as in the treatment of chronic diseases including hypertension. The usage of this medicine is regarded as acceptably safe with most Ethiopian people. Attitude and practices toward traditional medicine are crucial elements of hypertension control and its favorable outcome expectation. This study aimed at assessing the attitude and practice toward traditional medicine among hypertensive patients on follow-up at Mizan–Tepi University Teaching Hospital, Southwest Ethiopia.

Method:

Facility-based cross-sectional study was conducted from 1^st December 2020 to 30^th December 2020 among 173 hypertensive patients. A consecutive sampling technique was used to select study participants. Data were collected through interviewer-administered structured questionnaire and analyzed using Statistical Package for the Social Sciences software version 23. Multivariable logistic regression analysis was done to identify the independent predictors of patients’ attitude toward traditional medicine and their traditional medicine use at a p value ⩽0.05.

Results:

Eighty-seven (50.29%) of the total 173 approached patients were found to have good attitude toward traditional medicine. Ninety-seven (56.07%) participants had used traditional medicine at least once in their lifetime and 45 (46.39%) patients used traditional medicine and modern medicine concomitantly. Participants’ residence (adjusted odds ratio = 2.79, confidence interval = 1.01–7.74, p-value = 0.049) and educational status (adjusted odds ratio = 1.76, confidence interval = 1.61–5.09, p-value = 0.032) had significant association with attitude toward traditional medicine, while patients’ age (adjusted odds ratio = 1.43, confidence interval = 1.32–4.96, p-value = 0.039), residence (adjusted odds ratio = 2.18, confidence interval = 1.10–4.32, p-value = 0.025), and occupation (adjusted odds ratio = 3.38, confidence interval = 1.55–7.38, p-value = 0.002) had significant association with their traditional medicine use.

Conclusion:

Half of the study participants had good attitude toward traditional medicine, and nearly, one-fourth of the participants had practiced traditional medicine along with modern medicine. Health service providers should be aware of traditional medicine use and advise patients on the dosing of traditional medicine.

Traditional and Phytochemical Bases of Herbs, Shrubs, Climbers, and Trees from Ethiopia for Their Anticancer Response

Ethiopia is one of Africa's six plant-rich countries, with around 60% of the plants being indigenous and most of them having medicinal properties. 80% of people in the country use these plants as a primary health care system to tackle different diseases, including cancer. This review is aimed at summarizing the evidence gained from diverse MPs in Ethiopia that have been used ethnobotanically and ethnopharmacologically for treatment of cancer. The primary data sources were Google Scholar, Web of Science, Science Direct, Scopus, PubMed, and other electronic scientific databases. This literature review showed that there are around 200 MPs used as anticancer. Seventy-four herbs, 39 trees, 77 shrubs, and 17 weed/climbers belonging to 56 families have been identified for their ethnobotanical anticancer potential, and 31 species were recognized for their pharmaceutically anticancer activities. The reviewed data also indicated that many Ethiopian MPs had been used to treat breast, lung, blood, and skin cancers and other tumors. Besides, the collected data showed that the leaves (36.76%), roots (27.2%), bark (12.5%), stem (5.1%), and fruit (7.35%) of plants are commonly used for the preparation of anticancer remedies. Among the reported plant species, Euphorbiaceae (10.71%), Acanthaceae (7.14%), and Asteraceae (7.1%) are the most prominent plant families being used to treat cancer ethnobotanically. Phytochemicals such as flavonoids (like xanthone, indirubin, flavopiridol, and silybin), alkaloids (like taxol, vincristine, evodiamine, and berberine), and physalin B, D, and F steroids exhibited anticancer activity on various cancer cell lines. The crude extracts of Aerva javanica, Vernonia leopoldi, Withania somnifera, Kniphofia foliosa, and Catharanthus roseus were powerful anticancer agents with an IC₅₀ value below 10 μg/mL. Although several Ethiopian plants possess anticancer potential, only a limited number of plants are scientifically studied. Therefore, more scientific studies on anticancer MPs should be carried out; it may lead to discovering and isolating cost-effective and safe anticancer drugs.

The Genetic Diversity of Enset (Ensete ventricosum) Landraces Used in Traditional Medicine Is Similar to the Diversity Found in Non-medicinal Landraces

Enset (Ensete ventricosum) is a multipurpose crop extensively cultivated in southern and southwestern Ethiopia for human food, animal feed, and fiber. It has immense contributions to the food security and rural livelihoods of 20 million people. Several distinct enset landraces are cultivated for their uses in traditional medicine. These landraces are vulnerable to various human-related activities and environmental constraints. The genetic diversity among the landraces is not verified to plan conservation strategy. Moreover, it is currently unknown whether medicinal landraces are genetically differentiated from other landraces. Here, we characterize the genetic diversity of medicinal enset landraces to support effective conservation and utilization of their diversity. We evaluated the genetic diversity of 51 enset landraces, of which 38 have reported medicinal value. A total of 38 alleles across the 15 simple sequence repeat (SSR) loci and a moderate level of genetic diversity (He = 0.47) were detected. Analysis of molecular variation (AMOVA) revealed that only 2.4% of the total genetic variation was contributed by variation among the medicinal and non-medicinal groups of landraces, with an FST of 0.024. A neighbor-joining tree showed four separate clusters with no correlation to the use-values of the landraces. Except for two, all "medicinal" landraces with distinct vernacular names were found to be genetically different, showing that vernacular names are a good indicator of genetic distinctiveness in these specific groups of landraces. The discriminant analysis of the principal components also confirmed the absence of distinct clustering between the two groups. We found that enset landraces were clustered irrespective of their use-value, showing no evidence for genetic differentiation between the enset grown for 'medicinal' uses and non-medicinal landraces. This suggests that enset medicinal properties may be restricted to a more limited number of genotypes, might have resulted from the interaction of genotype with the environment or management practice, or partly misreported. The study provides baseline information that promotes further investigations in exploiting the medicinal value of these specific landraces.

Ethiopian Medicinal Plants Traditionally Used for the Treatment of Cancer; Part 3: Selective Cytotoxic Activity of 22 Plants against Human Cancer Cell Lines

Medicinal plants have been traditionally used to treat cancer in Ethiopia. However, very few studies have reported the in vitro anticancer activities of medicinal plants that are collected from different agro-ecological zones of Ethiopia. Hence, the main aim of this study was to screen the cytotoxic activities of 80% methanol extracts of 22 plants against human peripheral blood mononuclear cells (PBMCs), as well as human breast (MCF-7), lung (A427), bladder (RT-4), and cervical (SiSo) cancer cell lines. Active extracts were further screened against human large cell lung carcinoma (LCLC-103H), pancreatic cancer (DAN-G), ovarian cancer (A2780), and squamous cell carcinoma of the esophagus (KYSE-70) by using the crystal violet cell proliferation assay, while the vitality of the acute myeloid leukemia (HL-60) and histiocytic lymphoma (U-937) cell lines was monitored in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) microtiter assay. Euphorbia schimperiana, Acokanthera schimperi, Kniphofia foliosa, and Kalanchoe petitiana exhibited potent antiproliferative activity against A427, RT-4, MCF-7, and SiSo cell lines, with IC₅₀ values ranging from 1.85 ± 0.44 to 17.8 ± 2.31 µg/mL. Furthermore, these four extracts also showed potent antiproliferative activities against LCLC-103H, DAN-G, A2780, KYSE-70, HL-60, and U-937 cell lines, with IC₅₀ values ranging from 0.086 to 27.06 ± 10.8 µg/mL. Hence, further studies focusing on bio-assay-guided isolation and structural elucidation of active cytotoxic compounds from these plants are warranted.

Ethiopian Medicinal Plants Traditionally Used for the Treatment of Cancer, Part 2: A Review on Cytotoxic, Antiproliferative, and Antitumor Phytochemicals, and Future Perspective

This review provides an overview on the active phytochemical constituents of medicinal plants that are traditionally used to manage cancer in Ethiopia. A total of 119 articles published between 1968 and 2020 have been reviewed, using scientific search engines such as ScienceDirect, PubMed, and Google Scholar. Twenty-seven medicinal plant species that belong to eighteen families are documented along with their botanical sources, potential active constituents, and in vitro and in vivo activities against various cancer cells. The review is compiled and discusses the potential anticancer, antiproliferative, and cytotoxic agents based on the types of secondary metabolites, such as terpenoids, phenolic compounds, alkaloids, steroids, and lignans. Among the anticancer secondary metabolites reported in this review, only few have been isolated from plants that are originated and collected in Ethiopia, and the majority of compounds are reported from plants belonging to different areas of the world. Thus, based on the available bioactivity reports, extensive and more elaborate ethnopharmacology-based bioassay-guided studies have to be conducted on selected traditionally claimed Ethiopian anticancer plants, which inherited from a unique and diverse landscape, with the aim of opening a way forward to conduct anticancer drug discovery program.