Botanical features and ethnopharmacological potential of Leonotis nepetifolia (L.) R. Br: a review

Roggers Gang,강영민 한국식물생명공학회 2022 JOURNAL OF PLANT BIOTECHNOLOGY Vol.49 No.1

Leonotis nepetifolia (L.) R. Br, commonly called dagga, klip dagga, or lion’s ear, has been used to effectively treat various diseases and other health problems for a long time because of its antimicrobial, anti-inflammatory, antioxidant, and analgesic activities. Several studies have attributed these biological activities to L. nepetifolia’s constituent secondary metabolites, such as alkaloids, phenolics, flavonoids, tannins, steroids, glycosides, coumarins, anthocyanins, and saponins. This review aims to examine the evidence-based ethnopharmacological uses of L. nepetifolia in the treatment of bronchial asthma, diarrhea, skin diseases, malaria, burns, cancer, diabetes mellitus, and rheumatism. However, although L. nepetifolia has great potential to treat these diseases, further isolation and identification of its therapeutic phytochemical constituents are required. In addition, the performance of its extracts and phytochemicals should be thoroughly tested in preclinical and clinical trials in order to ascertain their safety and efficacy, which will prove valuable in developing new medicines.

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.

Changes in Fungal Community and Gene Expression of Specific Ligninolytic Enzymes in Response to Wood Decay

이민,Rahmat Endang,Lynn Prewitt,Roggers Gang,반영준,강창호,강영민 한국생물공학회 2023 Biotechnology and Bioprocess Engineering Vol.28 No.5

Microbial communities, particularly Basidiomycota fungi, play crucial roles in ecosystem functioning, including wood decay and the recycling of carbon and nutrients. However, the relationship between fungal diversity and wood decomposition remains poorly understood. This study investigated the effect of fungal community, gene expression, and activity of specific ligninolytic enzymes on wood decay in pine, cedar, and alkaline copper quaternary (ACQ)-treated pines for 30 months. The fungal community and gene expression levels were characterized using DNA sequencing and RT–qPCR, respectively. The Azure-B assay and phenol red test were conducted to determine enzyme activity. The results showed that non-wood-decaying fungi dominated early in the decay process, whereas true wooddecaying fungi, such as Trametes sp., dominated later. Visual decay ratings and modulus of elasticity data implied that pine deteriorated more than cedar and that ACQ treatment helped prevent deterioration of pine. The gene expression levels of lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lcc) produced by the predominant fungus, T. elegans, varied depending on the wood type. LiP expression was the highest in ACQ-treated pines after 10 months of treatment. MnP expression was higher in both decay-resistant woods (cedar- and ACQtreated pines) than in untreated pines. No Lcc expression was detected. Moreover, the specific activity of these enzymes was generally higher in untreated pine than in the decay-resistant wood. This study contributes to the understanding of the role of fungal communities in wood decay and the impact of preservation treatments on the gene expression and activity of wood decay enzymes.

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.

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.