Genotoxicity study of Ethiopian medicinal plant extracts on HepG2 cells.

BACKGROUND: Most of herbal medicines are used without any standard safety and toxicological trials although common assumption is that these products are nontoxic. However, this assumption is incorrect and dangerous, so toxicological studies should be done for herbal drugs. Although Pterolobium stellatum, Otostegia integrifolia and Vernonia amygdalina root extracts are frequently used in Ethiopian traditional medicine, there are no evidences of their active toxic compounds. Therefore, we made an effort to assess probable genotoxic effect of these plant extracts on DNA of human hematoma (HepG2) cells using alkaline comet assay. METHODS: Genotoxic effects of extracts were evaluated using single cell gel electrophoresis (SCGE) method on HepG2 cell. Regarding comet data, the average mean tail intensities (TI) from each individual experiment and treatment (usually at least 3 cultures/treatment) were pooled and the average mean TI was used as an indicator of DNA damage and the standard error of mean (SEM) as the measure of variance. RESULTS: DNA damage in the form of comet tail has been observed for 1 and 0.5 mg/ml P. stellatum chloroform and 80% methanol extracts on HepG2 cells, respectively. The chloroform extract of P. stellatum showed increased tail DNA percentage in a concentration dependent manner. Comet tail length in the chloroform P. stellatum extract treated cells (1 mg/ml) was significantly higher by 89% (p < 0.05) compared to vehicle treated controls. The rest of test extracts seemed to be without genotoxic effect up to a concentration of 0.5 mg/ml. CONCLUSIONS: Our findings show that two extracts from one plant evaluated have a genotoxic potential in vitro which calls for a more thorough safety evaluation. Such evaluation should include other end-points of genotoxicity apart from DNA damage, and possibly also pure compounds.

Evaluation of the antimycobacterial activity of crude extracts and solvent fractions of selected Ethiopian medicinal plants.

BACKGROUND: Tuberculosis (TB) is a global health problem complicated by drug resistance and human immunodeficiency virus that has dramatically increased active TB. Several medicinal plants are used traditionally to treat TB in Ethiopia and investigating these plants is required as plants are an alternative source for development of new anti-TB drugs. The purpose of this study was to investigate antimycobacterial activity of crude extract of Carissa edulis, Otostegia integrifolia, Persea americana, Pterolobium stellatum and Vernonia amygdalina as well as fractions of the most active crude extract. METHODS: The effect of various doses of the crude extracts as well as solvent fractions on M. tuberculosis H37Rv and/or MDR-TB clinical isolate was determined using broth microdilution and microtiter resazurin assay methods. Minimum inhibitory concentration was determined by CFU count and resazurin color change observation. RESULTS: Chloroform and 80% methanol extracts of P. stellatum and O. integrifolia as well as 80% methanol and acetone extracts of P. americana had significant antimycobacterial activity (p < 0.001) against M. tuberculosis H37Rv. Chloroform extract of V. amygdalina and C. edulis didn't, however, show any significant activity compared to negative controls. P. stellatum chloroform extract was the most active on M. tuberculosis H37Rv (MIC 0.039 mg/ml) and AOZ8W-4 (MDR-TB clinical isolate) (MIC = 0.078 mg/ml). Ethyl acetate fraction of P. stellatum chloroform extract was the most active fraction. CONCLUSION: P. stellatum, O. integrifolia and P. americana were found to be endowed with antimycobacterial activity. However, P. stellatum appears to be the most promising plant based on criteria set by different studies. Ethyl acetate fraction of P. stellatum was found to be the most active and future studies should involve this fraction.

Evaluation of wound healing and anti-inflammatory activity of hydro-alcoholic extract and solvent fractions of the leaves of Clerodendrum myricoides (Lamiaceae) in mice.

BACKGROUND: Wounds significantly affect people's quality of life and the clinical and financial burden of healthcare systems around the world. Many of the current drugs used to treat wounds have problems such as; allergies and drug resistance. Hence, the exploration of new therapeutic agents from natural origin may avert this problem. Clerodendrum myricoides have long been used to treat wounds in Ethiopia. Despite this, nothing has so far been reported about the wound healing and anti-inflammatory activity of C. myricoides. This study aimed to evaluate the wound healing and anti-inflammatory activity of 80% methanol extract and solvent fractions of C. myricoides leaves in mice. METHODS: Leaves of C. myricoides were extracted using the maceration technique. The extract was formulated as 5% and 10% w/w ointments. The wound healing activity of the extract was evaluated using excision, incision, and burn wound models whereas the healing activities of solvent fractions were evaluated using the excision wound model. A carrageenan-induced paw edema model was used for the anti-inflammatory test. RESULTS: In the dermal toxicity test, 2000 mg/kg of 10% extract was found to be safe. In excision and burn wound models, treatment with 10% and 5% extract showed a significant (p<0.001) wound contraction. Solvent fractions of the extract significantly reduced wound contraction. A significant reduction in periods of epithelialization and favorable histopathology changes were shown by extract ointments. In incision wounds, 10% (p<0.001) and 5% (p<0.01) extracts significantly increase skin-breaking strength. After one hour of treatment, 400 mg/kg (p<0.001) and 200 mg/kg (p<0.05) showed significant reduction in paw edema. CONCLUSION: Results of this study indicate that 80% methanol extract and the solvent fraction of the leaves of C. myricoides possess wound-healing and anti-inflammatory activity and support traditional claims.

The Role of Pharmacogenomics Studies for Precision Medicine Among Ethiopian Patients and Their Clinical Implications: A Scoping Review.

Background: Pharmacogenomics research is currently revolutionizing treatment optimization by discovering molecular markers. Medicines are the cornerstone of treatment for both acute and chronic diseases. Pharmacogenomics associated treatment response varies from 20% to 95%, resulting in from lack of efficacy to serious toxicity. Pharmacogenomics has emerged as a useful tool for therapy optimization and plays a bigger role in clinical care going forward. However, in Africa, in particular in Ethiopia, such studies are scanty and not generalizing. Therefore, the objective of this review was to outline such studies, generating comprehensive evidence and identify studied variants' association with treatment responses in Ethiopian patients. Methods: The Joanna Briggs Institute's updated 2020 methodological guidelines for conducting and guidance for scoping reviews were used. We meticulously adhered to the systemic review reporting items checklist and scoping review meta-analyses extension. Results: Two hundred twenty-nine possibly relevant studies were searched. These include: 64, 54, 21, 48 and 42 from PubMed, Scopus, Google Scholar, EMBASE, and manual search, respectively. Seventy-seven duplicate studies were removed. Thirty-nine papers were rejected with justification, whereas 58 studies were qualified for full-text screening. Finally 19 studies were examined. The primary pharmacogene that was found to have a significant influence on the pharmacokinetics of efavirenz was CYP2B6. Drug-induced liver injury has frequently identified toxicity among studied medications. Conclusion and Future Perspectives: Pharmacogenomics studies in Ethiopian populations are less abundant. The studies conducted focused on infectious diseases, specifically on HAART commonly efavirenz and backbone first-line anti-tuberculosis drugs. There is a high need for further pharmacogenomics research to verify the discrepancies among the studies and for guiding precision medicine. Systematic review and meta-analysis are also recommended for pooled effects of different parameters in pharmacogenomics studies.

Evaluation of Wound Healing and Anti-Inflammatory Activities of 80% Methanol Crude Extract and Solvent Fractions of Trichilia dregeana Sond (Meliaceae) Leaves in Mice.

Introduction: The leaves of Trichilia dregeana Sond are traditionally used to treat wounds. Even though there have been in vitro studies and claims supporting wound healing, there are no scientific data on in vivo wound healing and anti-inflammatory activities of the leaves of T. dregeana. Objective: This study aimed to evaluate wound healing and anti-inflammatory activity of 80% methanol crude extract and solvent fractions of T. dregeana in mice. Method: The leaves of T. dregeana were dried, ground, and macerated with 80% methanol three times successively. The crude extract was fractioned by water, ethyl acetate, and hexane separately. The acute dermal and oral toxicity tests were done by applying 2000 mg/kg of 10% (w/w) crude extract ointment (CEO) topically and 2000 mg/kg of crude extract orally, respectively. The wound healing activity of the crude extract was evaluated on excision, incision, and burn wound models while the fractions were evaluated only on excision wound model. The anti-inflammatory activity of the crude extract was evaluated on xylene-induced ear edema and cotton pellet granuloma tests. Result: Both acute dermal and oral toxicity tests were found to be safe after topical application of 2000 mg/kg of 10% (w/w) CEO and oral administration of 2000 mg/kg of crude extract suspension, respectively. Both 5% and 10% (w/w) CEO produced significant (p < 0.001) wound contraction and period of epithelialization from day 4 onwards as compared to simple ointment (SO) on both excision and burn wounds. The tensile strength was increased significantly (p < 0.001) for the CEO-treated mice as compared to both untreated and SO groups. The crude extract also showed anti-inflammatory activity at 100, 200, and 400 mg/kg by inhibiting ear edema, exudate, and granuloma formation as compared to the SO group. Conclusion: The increase in wound contraction, reduction in period of epithelialization, and increase in tensile strength support the traditional claims of T. dregeana for wound healing.

Evaluation of Antidiabetic and Antioxidant Activity of Leaf Extract and Solvent Fractions of Hypoestes forskaolii (Val) (Acanthaceae) in Mice.

BACKGROUND: Currently, there is a demand for new antidiabetic drugs from natural therapeutic agents, and diabetes mellitus disease is global epidemic. The leaf of Hypoestes forskaolii has been used in the traditional health system for the management of diabetes mellitus in Ethiopia and Eritrea. The aim of this study was to evaluate in vivo antidiabetic, antihyperlipidemic and in vitro antioxidant activity of leaf extract and solvent fractions of the leaf of H. forskaolii (Vahl) in mice. METHODS: The blood glucose-lowering activities of leaf extract and solvent fractions of the leaf of H. forskaolii were screened in the normoglycemic, glucose loaded, and streptozotocin-induced diabetic mice models. In the treatment of streptozotocin-induced diabetic mice with leaf extract and solvent fractions, weight and lipid profile was measured. Antioxidant activity of the plant leaf extract was determined using DPPH assay. RESULTS: The leaf extract of H. forskaolii showed significant blood glucose reduction in the normoglycemic model and glucose loaded test at doses of 200 mg/kg (34.1%, p < 0.001 and 55.5%, p < 0.001), respectively, as compared to the normal control. In the streptozotocin-induced diabetic model, extract and solvent fractions significantly (p < 0.001) reduced blood glucose level at all tested doses (100mg/kg, 200mg/kg and 400mg/kg) on the 14th day as compared to diabetic control. In addition, a significant reduction (p < 0.001) of serum TC, VLDL, LDL, TG was observed. In the antioxidant activity test, the IC50 values of extract and a standard drug (ascorbic acid) were 4.87µg/mL and 15.7µg/mL, respectively. CONCLUSION: The present study showed that the methanolic leaf extract and solvent fractions of H. forskaolii have antidiabetic, and antioxidant activity that provides a scientific support for the local use of the plant leaves in the treatment of diabetes.

Pesticide Residue Analysis of Khat Leaves and Health Risks among Khat Chewers in the Amhara Region, Northwestern Ethiopia.

Introduction: Farmers use a large number of pesticides to increase the productivity of Khat cultivation. Since Khat is consumed by many Ethiopians as a habit, there may be a significant concentration of pesticide residues in Khat leaves which result in adverse effects among the exposed population. Excess use of pesticides in Khat causes cancer, genotoxicity, and endocrine disturbances. The current study aimed to determine the concentration of selected pesticide residues on Khat leaves samples and to estimate the possible health risk on consumers. Methods: Thirty Khat samples were collected from Khat cultivators in the Amhara region, Ethiopia. Pesticide residue extraction and cleanup of Khat samples were performed using the QuEChERS method. Data were also collected about personal variables and Khat consumption habits. The pesticide concentrations were determined and the health risks were estimated. Results: Profenofos, dimethoate, and chlorpyrifos were detected in 6 (20%), 24 (80%), and 28 (93.3%) Khat samples, respectively. However, diazinon was detected in two samples and endosulfan I was not detected. The average concentration of chlorpyrifos, dimethoate, profenofos, and diazinon in Khat samples was 75.39 ± 20.26, 130 ± 48.94, 242.45 ± 119.79, and 81.5 ± 21.0 µg/kg, respectively. The HQ for diazinon was greater than 1 which shows the chronic health risks associated with intake of diazinon among Khat chewers. The acute health risks associated with intake of profenofos and diazinon were minimal. Discussion. Pesticide residue exposure is a risk factor for cardiac complications, reduction in antioxidant defense system, and developing neurological symptoms. All the pesticides were higher than the European Union Maximum Residue Levels (EU-MRL). Diazinon has the potential to cause higher chronic health risks. Chronic Khat chewers in the region may face potential health risks from pesticide residues. Awareness creation among people in the study area is necessary to avoid the adverse health effects of pesticide residues.

In vitro Antioxidant and in vivo Wound Healing Activities of the 80% Methanol Extract and Solvent Fractions of Seeds of Brassica carinata A. Braun (Brassicaceae) in Mice.

BACKGROUND: Brassica carinata is one of the traditional medicinal plants used in Ethiopia for the treatment of wounds and other diseases. However, the plant has not been scientifically validated, and thus the present study evaluated the in vitro anti-oxidant and the in vivo wound healing activity of the crude extract and solvent fractions of B. carinata seeds in mice. MATERIALS AND METHODS: The crude extract was prepared by maceration using 80% methanol and formulated as 5% and 10% w/w ointments for topical application. The acute dermal toxicity was performed in female albino rats based on Organization for Economic Cooperation and Development (OECD) guideline number 434. Excision and incision wound healing models were used to evaluate the wound healing activities of crude extract and solvent fractions ointments in mice. Wound healing parameters such as wound area contraction and the period of epithelialization were determined in an excision model, whereas tensile strength was determined in an incision model. Moreover, the crude extract and solvent fractions were evaluated for the free radical scavenging activities in DPPH assay. RESULTS: The acute dermal toxicity test showed that a limit dose of 2,000 mg/kg of 10% w/w crude extract ointment did not cause dermal toxicity in mice. In the excision wound model, the data revealed that 10% w/w ointment exhibited a significant wound contraction (from day 6 to 16, P<0.001) effect with a significant decrease in epithelization period (at day 14, P<0.001). In addition, 5% ointment of the crude extract showed a significant effect in wound contraction (from day 8 onwards, P<0.01) and epithelization period (at day 16, P<0.01). Despite all fractions being shown to promote wound healing, 10% w/w aqueous and ethyl acetate fractions showed a significant wound contraction (P<0.001) effect starting from the 4th day onwards. Besides, the maximum antioxidant activity was seen in the aqueous fraction with an IC50 value of 3.45±0.12 mg/mL. CONCLUSION: The present study demonstrated that the 80% methanol extract and solvent fractions of the seeds of B.carinata possess potential wound healing and anti-oxidant effects, supporting the traditional use of the plant for wound management.

Survey on Polypharmacy and Drug-Drug Interactions Among Elderly People with Cardiovascular Diseases at Yekatit 12 Hospital, Addis Ababa, Ethiopia.

BACKGROUND: Elderly people are most commonly associated with cardiac disease. Cardiovascular diseases are interlinked with co-morbidities which require multiple drug therapy in addition to cardiovascular drugs. This results to polypharmacy which carries a high risk of potential drug-drug interactions. Elderly patients are at a particular risk of drug related problems because of increased level of polypharmacy and the physiological changes which accompany aging. This study was aimed to assess polypharmacy and potential drug-drug interactions (DDIs) among elderly people with cardiovascular diseases at Yekatit 12 hospital. METHODOLOGY: A retrospective cross-sectional study using patients chart review was conducted on all elderly people with cardiovascular diseases at Yekatit 12 hospital in the period between March 2018 and March 2019. The types, seriousness and level of potential DDIs were checked using Medscape online drug interaction checker. RESULTS: The mean number of drugs per prescription was 4.25 ± 1.754 and the prevalence of polypharmacy (concurrent use of 5 and more drugs) was 42.7%. Polypharmacy and potential DDIs were significantly associated with polymorbidity (P = 0.000), being hospitalized (P = 0.047) and congestive heart failure (P = 0.016). A total of 850-potential DDIs were identified, the mean number of potential DDIs was 3.37 per prescription. The potential DDIs were mainly significant (73.29%) in nature and pharmacodynamics (73.06%) in mechanism. The prevalence of total and serious potential DDIs were 84.3% and 17.3%, respectively. Most commonly interacting drug combination was aspirin + enalapril (30.2%). CONCLUSION: A higher incidence of polypharmacy and increased risk of potential DDIs in elderly people with cardiovascular disease are major therapeutic issues at Yekatit 12 hospital.

Antidiarrheal Activity of Hydromethanolic Root Extract and Solvent Fractions of Clutia abyssinica Jaub. & Spach. (Euphorbiaceae) in Mice.

INTRODUCTION: Diarrheal diseases are associated with an estimated 1.3 million deaths annually, with most occurring in resource-limited countries; up to 25% of deaths in young children living in Africa and southeast Asia are attributable to acute gastroenteritis. Due to limitations associated with various treatments available, the need for developing newer drugs is imperative. OBJECTIVE: This study was aimed to evaluate the antidiarrheal activity of root extract and fractions of C. abyssinica Jaub. & Spach. (Euphorbiaceae) in mice. METHODS: After plant extraction and subsequent fractionation of the crude extract, the antidiarrheal activity was screened in castor oil induced diarrhea, castor oil induced enteropooling, and gastrointestinal motility test models accordingly. RESULT: The root extract of C. abyssinica produced neither visible signs of toxicity nor death at a single dose of 2000 mg/kg, suggesting the LD50 > 2000 mg/kg. In the castor oil induced diarrheal model, the highest dose of the extract (400 mg/kg) showed a maximal inhibition in the onset (158.00 ± 14.64, p < 0.01, in minutes) of wet feces as compared to the negative control. In the enteropooling model, 400 mg/kg treated mice showed a significant reduction in volume (0.47 ± 0.02 ml, p < 0.01) and weight (0.50 ± 0.02 g, p < 0.05) of intestinal content as compared to the vehicle treated group. In the gastrointestinal motility test, the hydromethanolic root extract of C. abyssinica significantly inhibited the intestinal transit of charcoal meal at 400 mg/kg. In addition, chloroform and n-butanol fractions significantly reduced the distance moved by charcoal at doses of 200 mg/kg and 400 mg/kg, whereas aqueous fraction showed a significant effect at all test doses. The highest antidiarrheal index was observed at the maximal dose of extract and each fraction. CONCLUSION: The results obtained showed that the findings provide scientific support for the folkloric repute of C. abyssinica roots as treatment of diarrhea.

Depression, Anxiety, Stress, and Associated Factors among Khat Chewers in Amhara Region, Northwest Ethiopia.

Individuals with substance use disorder are prone to develop different psychiatric disorders. Substance abuse and associated problems are of current global concern that leads to mental health disorders which contributed about 14% of the global burden of the disease. It has become an epidemic in some parts of the African region with adolescents being the main victims of the ill health and social effects of substance use. This study is aimed at assessing the prevalence of depression, anxiety, and stress and associated factors among khat chewers in the Amhara region, 2019. A community-based cross-sectional study was done from February 14 to April 15, 2019. A purposive sampling technique was used to enroll the subjects. Data was collected using the face-to-face interview technique using the Depression Anxiety Stress Scale 21 (DASS-21) questionnaire. Descriptive statistics and bivariate and multivariate logistic regression were used to summarize the results. p value < 0.05 was considered statistically significant. A total of 478 participants were enrolled in the study with a response rate of 94.1%. The overall prevalence of depression, anxiety, and stress was 27.4%, 40.6%, and 18.8%, respectively. Around 43% of the respondents develop dependency from khat chewing. Working in a private sector, being self-employed, being jobless, spending 90 to 180 minutes and more, chewing 51-100 g and more, and chewing khat more than once per week were positively associated with stress. On the other hand, being a private sector worker, being jobless, completing secondary education, earning 1001-5000 ETB per month, chewing khat more than once per week, being khat dependent, and the presence of chronic illness were positively associated with anxiety. History of chronic illness and being khat dependent were positively associated with depression. The prevalence of depression, anxiety, and stress was high among khat chewers in the Amhara region. Special attention has to be given to khat chewers since khat chewing will double the burden of mental illness. Proper awareness and evaluation activities will reduce the impact of the problem.

Evaluation of Antimalarial Activity of Hydromethanolic Crude Extract and Solvent Fractions of the Leaves of Nuxia congesta R. Br. Ex Fresen (Buddlejaceae) in Plasmodium berghei Infected Mice.

BACKGROUND: In Ethiopia, malaria control has been complicated due to resistance of the parasite and its vectors to the current drugs. Therefore, new drugs are required to avert the problem posed by drug-resistant Plasmodium strains. There is need to investigate alternative sources of antimalarial agents and plants are potential source of antimalarial drugs. This study aimed to investigate the antimalarial activity of the leaves of N. congesta crude extract (hydromethanolic extract) and solvent fractions (n-hexane, chloroform, and aqueous fractions of crude extract) traditionally used to treat malaria in many parts of Ethiopia. METHODS: Acute oral toxicity of the leaves of N. congesta extract was assessed in mice up to a dose of 5,000 mg/kg body weight. Antiplasmodial activities of crude extract and solvent fractions were assessed in P. berghei infected female Swiss albino mice models using the Peter's 4-day suppressive test. The curative activities of crude extract and fractions were evaluated using Rane's test. RESULTS: Plant extract exhibited no signs of toxicity on mice at a dose of 5,000 mg/kg body weight. Crude extract showed significant parasitemia suppressions at doses of 500 mg/kg (P<0.05), 750 mg/kg (P<0.01), and 1,000 mg/kg (P<0.001) as compared to negative control in the Peter's 4-day suppressive test, but failed to reach a significant level at 500 mg/kg and 750 mg/kg in the curative test (Rane's test). Aqueous fraction showed significant parasitemia suppression at a dose of 400 mg/kg (P<0.05) in curative test and 600 mg/kg (P<0.05) in Peter's 4-day suppressive and curative tests. Maximum suppressive effects of extract (58.13%) and aqueous fraction (44.9%) were observed at the highest doses administered. CONCLUSION: Hydromethanolic leaf extract of N. congesta and its aqueous fraction exhibited antimalarial activities. The antimalarial activity and lack of acute toxicity are suggested to uphold the earlier claims made by the Ethiopian traditional practitioners.

Antidiabetic and Antihyperlipidemic Activities of the Leaf Latex Extract of Aloe megalacantha Baker (Aloaceae) in Streptozotocin-Induced Diabetic Model.

BACKGROUND: Diabetes mellitus has become a major public health and economic problem across the globe. The inadequacies, as well as serious adverse effects associated with conventional medicines, led to a determined search for alternative natural therapeutic agents. The leaf latex extract of Aloe megalacantha has been used for the management of diabetes mellitus in Ethiopian folk medicine. This study aimed to evaluate the antidiabetic and antihyperlipidemic effects of the leaf latex extract of A. megalacantha in streptozotocin- (STZ-) induced diabetic model. METHODS: The experimental diabetes was induced in Swiss albino mice by the administration of a single dose of STZ (150 mg/kg), intraperitoneally. The leaf latex extract of A. megalacantha at three different doses (100, 200, and 400 mg/kg) was administered for a period of 14 days. Fasting blood glucose levels (BGLs) were measured by glucose-oxidase and peroxidase reactive strips. After fourteen days, mice from all groups fasted and the blood was collected through puncturing the retroorbit of the eyes under mild anesthetic condition. The collected blood sample was used to determine serum biochemical parameters such as total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), and high-density lipoprotein (HDL) cholesterol. The statistical analysis of results was carried out using one-way analysis (ANOVA) followed by post hoc multiple comparison tests. RESULTS: Oral administration of A. megalacantha leaf latex extract at doses of 100, 200, and 400 mg/kg daily for 14 days results in a significant (p < 0.05) decrease in fasting BGL as compared to negative control STZ-induced diabetic mice. The leaf latex has significantly reduced the level of TC, TG, and LDL, VLDL cholesterol while a significant (p < 0.05) HDL cholesterol increment was observed. CONCLUSIONS: The findings of the present investigation indicated that the leaf latex of A. megalacantha possessed significant antihyperglycemic and antihyperlipidemic potential which may prove the claimed use of the plant in amelioration of diabetes and associated complications in Ethiopian folk medicine.