Effects of commercial soils on germination, early growth, and chlorophyll content of Aspilia africana, a medicinal plant

Denis Okello,Richard Komakech,김용구(Yong-Goo Kim),Endang Rahmat,정유성(Yuseong Chung),Francis Omujal,강영민(Youngmin Kang) 한국식물생명공학회 2021 JOURNAL OF PLANT BIOTECHNOLOGY Vol.48 No.2

Aspilia africana (Pers) C.D.Adams, a plant used for centuries in many African countries to treat diseases such as osteoporosis, malaria, tuberculosis, and diabetes, is of great pharmaceutical interest, yet there is limited scientific literature on its germination and growth. This research paper describes the effects of different commercial soils on the germination, growth, and chlorophyll content of A. africana. The germination parameters assessed included final germination percentage (FGP), mean germination time (MGT), and germination index (GI). Shoot length, leaf number, and fresh and dry weights were some of the parameters used to assess A. africana growth. The FGP was low and did not vary significantly; the MGT was 7 ~ 10 days; and the GI was significantly higher in PPS soil at 4.61 ± 0.332 days. Aspilia africana plants in HS:PPS soil showed the best overall growth, producing the highest mean leaf number (18.00 ± 1.129), longest mean shoot length (202.43 ± 13.451 mm), and highest mean fresh and dry weights (7.08 ± 1.061 g and 0.629 ± 0.112 g, respectively). The highest chlorophyll content in leaves of A. africana under HS:PPS conditions suggested a higher photosynthetic potential of plants in this soil. The best growth performance of A. africana in the HS:PPS soil could be attributed to a higher amount of certain mineral nutrients such as nitrogen, potassium, and phosphorus in the HS:PPS soil compared to the other soil categories. It is unclear why the FGP of A. africana was low and we recommend an exclusive study to investigate this further.

Comparative antiplasmodial activity, cytotoxicity, and phytochemical contents of Warburgia ugandensis stem bark against Aspilia africana wild and in vitro regenerated tissues

Okello Denis,Gathirwa Jeremiah,Wanyoko Alice,Komakech Richard,Chung Yuseong,Gang Roggers,Omujal Francis,Kang Youngmin 한국식물생명공학회 2023 JOURNAL OF PLANT BIOTECHNOLOGY Vol.50 No.2

Malaria remains to be one of the most severe global public health concerns. Traditionally, Aspilia africana and Warburgia ugandensis have been used to treat malaria in several African countries for millennia. In the current study, A. africana calli (AaC), A. africana in vitro roots (AaIR), A. africana wild leaf (AaWL), and W. ugandensis stem bark (WuSB) were dried and pulverized. Fourier transform near-infrared spectroscopy was used to analyze the powdered samples, while 80% ethanolic extracts of each sample were assayed for antiplasmodial activity (against Plasmodium falciparum strains DD2 (chloroquine-resistant) and 3D7 (chloroquine-sensitive)) and cytotoxicity. WuSB showed the highest antiplasmodial activity (IC50 = 1.57 ± 0.210 µg/ml and 8.92 ± 0.365 µg/ml against P. falciparum 3D7 and DD2, respectively) and selectivity indices (43.90 ± 7.914 and 7.543 ± 0.051 for P. falciparum 3D7 and DD2, respectively). The highest total polyphenolic contents (total phenolic and flavonoid contents of 367.9 ± 3.55 mg GAE/g and 203.9 ± 1.43 mg RUE/g, respectively) were recorded for WuSB and the lowest were recorded for AaC. The anti- plasmodial activities of the tested plant tissues correlated positively with total polyphenolic content. The high selectivity indices of WuSB justify its traditional applications in treating malaria and present it as a good candidate for discovering new antimalarial compounds. We recommend elicitation treatment for AaIR, which showed moderate antiplasmodial activity against P. falciparum DD2, to increase its secondary metabolite production for optimal antimalarial activity.

Comparative antiplasmodial activity, cytotoxicity, and phytochemical contents of Warburgia ugandensis stem bark against Aspilia africana wild and in vitro regenerated tissues

Denis Okello,Jeremiah Gathirwa,Alice Wanyoko,Richard Komakech,Yuseong Chung,Roggers Gang,Francis Omujal,Youngmin Kang The Korean Society of Plant Biotechnology 2023 JOURNAL OF PLANT BIOTECHNOLOGY Vol.50 No.2

Malaria remains to be one of the most severe global public health concerns. Traditionally, Aspilia Africana and Warburgia ugandensis have been used to treat malaria in several African countries for millennia. In the current study, A. africana calli (AaC), A. africana in vitro roots (AaIR), A. africana wild leaf (AaWL), and W. ugandensis stem bark (WuSB) were dried and pulverized. Fourier transform near-infrared spectroscopy was used to analyze the powdered samples, while 80% ethanolic extracts of each sample were assayed for antiplasmodial activity (against Plasmodium falciparum strains DD2 (chloroquine-resistant) and 3D7 (chloroquine-sensitive)) and cytotoxicity. WuSB showed the highest antiplasmodial activity (IC₅₀ = 1.57 ± 0.210 ㎍/ml and 8.92 ± 0.365 ㎍/ml against P. falciparum 3D7 and DD2, respectively) and selectivity indices (43.90 ± 7.914 and 7.543 ± 0.051 for P. falciparum 3D7 and DD2, respectively). The highest total polyphenolic contents (total phenolic and flavonoid contents of 367.9 ± 3.55 mg GAE/g and 203.9 ± 1.43 mg RUE/g, respectively) were recorded for WuSB and the lowest were recorded for AaC. The antiplasmodial activities of the tested plant tissues correlated positively with total polyphenolic content. The high selectivity indices of WuSB justify its traditional applications in treating malaria and present it as a good candidate for discovering new antimalarial compounds. We recommend elicitation treatment for AaIR, which showed moderate antiplasmodial activity against P. falciparum DD2, to increase its secondary metabolite production for optimal antimalarial activity.

Ethnomedicine and ethnopharmacology of medicinal plants used in the treatment of diabetes mellitus in Uganda

Gang Roggers,Matsabisa Motlalepula,Okello Denis,Kang Youngmin 한국응용생명화학회 2023 Applied Biological Chemistry (Appl Biol Chem) Vol.66 No.-

Diabetes mellitus (DM) is a global health problem owing to its high prevalence and increased morbidity and mortality. The prevalence of DM and impaired glucose tolerance in Uganda is approximately 4.1% and 6.6%, respectively. Medicinal plants are commonly used for the management of DM, especially in developing countries, such as Uganda. According to several ethnobotanical surveys conducted in Uganda, various medicinal plants are used in DM management. Meanwhile, ethnopharmacological studies have confirmed the anti-diabetic efficacy of various plants and plant-derived formulations from Uganda. However, these information remain highly fragmented without a single repository for plants used in the management and treatment of DM in Uganda, hindering further investigations. Therefore, this study aimed to comprehensively explore plants used for DM treatment in Uganda and retrieve relevant ethnopharmacological and ethnomedicinal information that can be used for DM therapy development. English peer-reviewed articles and books were searched in scientific databases, especially PubMed, Scopus, Google Scholar, Science Direct, SciFinder, and Medline, to retrieve information on medicinal plants used for DM treatment and management in Uganda. The databases were searched to obtain published literature on the anti-diabetic activities and safety of plants among the identified plants. The family name, plant parts used, anti-diabetic activities, dosage, and mechanisms of action of plant extracts were captured. In total, 46 species belonging to 26 families are used to treat DM in Uganda. Most species belonged to the Fabaceae (20%), Asteraceae (13%), and Solanaceae (7%) families. Anti-diabetic activities of 27 (59%) species have been scientifically investigated, whereas the rest have not been evaluated. This review indicated that various medicinal plants are used in the traditional treatment and management of DM across different regions in Uganda. Scientific investigations have revealed the anti-diabetic potential and safety of several of these plants. However, there is a need to validate the anti-diabetic potential of other unstudied plants. Additionally, isolating and characterizing active principles and elucidating the anti-diabetic mechanism of these plants and performing preclinical and clinical studies in the future could aid in the formulation of an effective and safe treatment for DM.

Assessment of anatomical characteristics of the medicinal plant African cherry (Prunus africana) for its accurate taxonomic identification

Richard Komakech,양선규,송준호,최고야,김용구,Denis Okello,Francis Omujal,Grace Nambatya Kyeyune,Motlalepula Gilbert Matsabisa,강영민 한국식물생명공학회 2022 JOURNAL OF PLANT BIOTECHNOLOGY Vol.49 No.2

The genus Prunus (family: Rosaceae) consists of over 400 plant species and exhibits vast biodiversity worldwide. Given the wide distribution of this genus, its taxonomic classification is important. Anatomical characteristics are conserved and stable and can therefore be used as an important tool for the taxonomic characterization of plants. Therefore, this study aimed to assess and document the anatomical characteristics of the leaf, stem, and seed of P. africana using micrographs and photographs for possible use in the identification, quality control, and phylogenetic analysis of the species. The anatomical sections of a young stem revealed a cortex consisting of isodiametric parenchyma cells, druse crystals, primary vascular bundles, and pith. The mature stem bark majorly consisted of the rhytidome, with the periderm densely arranged in multiple layers; a cluster of stone cells; and sclerenchyma. The leaf sections were hypostomatic, with stomata sizes ranging from 18.90- (22.34)-26.90 × 15.41-(18.40)-21.22 μm. The leaf sections showed the presence of characteristic druse crystals, vascular bundles, and mesophyll layers. The pericarp contained the epicarp, mesocarp, and endocarp, with their thickness being approximately 350-400, 300-350, and 30-50 μm, respectively. In addition, it contained a seed testa with a thickness of approximately 50-60 μm. The morphological and anatomical characteristics observed in P. africana leaves, stems, and seeds in this study could serve as useful data for the taxonomic identification of this species.