European Journal of Medicinal Plants

Aim: Medicinal plants have played an important role in the treatment of different ailments including malaria in developing countries particularly in Africa. This study has evaluated the antimalarial activities of Azadirachta indica A. Juss (Meliaceae), Cymbopogon citratus Stapf. (Poaceae), Moringa oleifera Lam. (Moringaceae), Tithonia diversifolia (Hemsl) A. Grey (Asteraceae) and Vernonia amygdalina Del. (Asteraceae) which are commonly-used for malaria treatment in Uganda.

Study Design: This is an experimental laboratory report on antimalarial activities of some Ugandan medicinal plants for subsequent profiling in an herbal pharmacopoeia and eventual drug development.

Place and Duration of Study: The Animal Research Facility and the Clinical and Research Laboratory, Faculty of Medicine, Mbarara University of Science and Technology, Uganda, between July 2019 and March 2020.

Methodology: The antimalarial activity of the hot infusion of each leaf was evaluated on chloroquine-sensitive Plasmodium berghei ANKA-infected mice using 4-day test at 100 – 400 mg/kg with chloroquine (10 mg/kg) and artemether-lumefantrine (4 mg/kg) as positive controls; and distilled water as negative control. The observed haematological responses of the animals were determined with an automated haematometer.

Results: The results showed dose-dependent activities in the animals treated with the extract of each plant leaf in varying degrees. Thus, V. amygdalina and T. diversifolia showed the highest antimalarial activities with the chemosuppression values of 75% and 66% at 400 mg/kg, respectively. The results of V. amygdalina, T. diversifolia and M. oleifera, extracts gave the lowest ED₅₀ of 141, 195 and 231 mg/kg, respectively being significantly different from A. indica (ED₅₀ 319 mg/kg) and C. citratus (ED₅₀ 346 mg/kg) with V. amygdalina as the most potent extract among the five plant leaves.

Conclusion: The observed activities of the five plants have therefore supported their folkloric uses as antimalarial remedies by the Ugandan traditional medicine practitioners with obvious potentials for drug development.

Tea is a popular drink all over the world and has been attracting attention for its beneficial health effects. We developed a fermented tea by processing it with an exopolysaccharides-producing lactic acid bacterium, Lactococcus lactis subsp. cremoris, in order to manufacture high-quality tea with a physiological function. Lactococcus lactis subsp. cremoriswas added to tea leaves (Camellia sinensis) and fermented for two weeks. To examine the progress of fermentation, we determined the change in pH as well as the contents of ascorbic acid and folic acid in the extract of leaves. Decreases in ascorbic and folic acids were identified, but pH only slightly changed during fermentation, showing a slower development of fermentation with lactic acid bacteria. Furthermore, we analyzed the extract’s components, such as catechins, amino acids, including theanine as the major amino acid, and caffeine. Although there were some fluctuations in contents, no significant change was seen over a period of two weeks. Fermentation had no effect on the degradation of these components, suggesting that they may be relatively stable. To investigate a potential physiological function, antioxidant activity was measured using 1,1-Diphenyl-2-picryl-hydrazyl, (DPPH). Consequently, the results showed that the activity of the extracts was unaffected by fermentation until the seventh day, when it began to increase. Our results suggested that the fermented tea developed in this study, which maintained its key components of catechins, theanine and caffeine, exhibit a physiological function as a processed tea and a novel food material.

Maytenus ilicifolia Mart. Ex Reissek, was first studied in the 60s, but only in the 80s and 90s were the studies were driven by scientific research that attributed medicinal properties to the plant, such as healing actions for human gastric diseases. In this work, a study was carried out on the characterization of the chemical composition of M. ilicifolia at different stages of development, using spectroscopic techniques of sustainable character, which do not require toxic solvents as previous preparations. Extracts from cotyledons, seedlings that have never been researched in the literature and leaf/stem were lyophilized to characterize the compounds present in this plant using photoacoustic and spectroscopy techniques in the Infrared spectroscopy using Fourier Transform-FTIR with ATR. The photoacoustic results show that there is a differentiation of development stages in the plant due to the greater presence of chlorophylls and terpenes in the seedlings and their absence in the cotyledon, which is characterized as the reserve part in the germination phase of the plant. The range of bands the literature reports for epigallocatechin and friedelin, the possible agents responsible for the medicinal effects of the plant were mainly seen in the cotyledon, thus demonstrating the use of the seedling in its initial stage, to extract and obtain these active components.

Aim: To evaluate the nephroprotective property of Cnidoscolus chayamansa aqueous leaf extract in diabetic rats.

Study Design: Rats were randomly divided into five groups with group 1 as the normal control. Diabetic was induced in groups 2-4. Group 2 was used as the test control while groups 3 and 4 were treated with different concentrations of the leaf extract; group 5 was treated with the standard drug, glipizide.

Place and Duration of Study: Departments of Biochemistry and Anatomy, University of Jos, Nigeria, between August to November, 2019.

Methodology: Fourty (40) male albino Wistar rats were grouped into five groups. The rats were treated for fourteen days and then sacrificed by decapitation after anaesthesia. Blood was collected for biochemical parameters; kidney was excised and stored in formaldehyde until required for histopathological study. Serum urea, creatinine, uric acid, sodium, potassium, chloride and bicarbonate were determined using appropriate methods.

Results: The test control had a significant (P < .05) decrease in the concentrations of Na⁺, Cl^- and HCO₃^- ions; significant (P < .05) increases in serum K⁺ ion, urea, uric acid and creatinine. Treatments of the test groups with the different doses of the leaf extract and the standard drug increased the concentration of Na⁺ ion which was not significantly (P < .05) different from the test control. On the other hand, the concentration of Cl^- and HCO^- ions  were significantly (P < .05) increased; the concentrations of K⁺, urea, uric acid and creatinine were significantly (P < .05) decreased. The histochemistry of the kidneys revealed that the injury brought about under diabetic condition was ameliorated with the treatments with the low and high doses of the leaf extract, and the standard drug.

Conclusion: The results show that the aqueous leaf extract has nephroprotective property.

Drug-resistant pathogenic and opportunistic bacteria pose a global health threat. Plants, particularly those employed in traditional (folk) medicine, may provide a source of antimicrobials compounds possessing novel mechanisms of action with which to combat current and emerging infectious diseases. However, experimental designs in ethnobotanical investigations of this type are complicated by several factors. Among these are chemotype variations among plants and plant parts, and potential antagonistic, additive or synergistic effects between plant compounds. These efforts are further hindered by a lack of standardized applicable chemical extraction methods in the field, which makes assessment and comparison of experimental results difficult. This overview thus seeks to provide insight into these complicating factors, give a brief historical survey of ancient investigations into antibiotics, and identify some of the strengths and weaknesses of the various modern methods and techniques routinely employed in ethnobotanical antibiotic research.

The liver, despite its crucial role in metabolism is prone to several metabolic injuries and insults manifesting as liver damage. Thus, liver diseases arise from multiple aetiologies. In Nigeria, chronic liver diseases are rampant and constitute a significant cause of morbidity. Globally, medicinal plants play crucial roles in healthcare. Several Nigerian medicinal plants are used in the management of various liver disorders. This review focuses on medicinal plants that are used in the management of liver diseases in Nigeria. The search for novel active principles from plants must be sustained due to increasing prevalence of various liver ailments, challenges associated with liver transplantation and poor healthcare funding. The identification, isolation and characterization of active compounds from Nigerian medicinal plants could lead to the potential development of affordable and effective drugs for the management of liver diseases.