Antibacterial Activity Against Multidrug-Resistant Clinical Isolates of Nine Plants from Chencha, Southern Ethiopia.

Background: The diminishing efficacy of antibiotics currently in use and the emergence of multidrug-resistant bacteria pose a grave threat to public health worldwide. Hence, new classes of antimicrobials are urgently required, and the search is continuing. Methods: Nine plants were chosen for the current work, which are collected from the highlands of Chencha, Ethiopia. Plant extracts containing secondary metabolites in various organic solvents were checked for antibacterial activity against type culture bacterial pathogens and MDR clinical isolates. The broth dilution technique was used to evaluate the minimum inhibitory and minimum bactericidal concentrations of highly active plant extracts, and time-kill kinetic and cytotoxic assays were performed using the most active plant extract. Results: Two plants (C. asiatica and S. marianum) were highly active against ATCC isolates. The EtOAc extract of C. asiatica produced the highest zone of inhibition ranging between 18.2±0.8-20.7±0.7 and 16.1±0.4-19.2±1.4 mm against Gram-positive and Gram-negative bacteria, respectively. The EtOH extract of S. marianum displayed zones of inhibition in the range of 19.9±1.4-20.5±0.7 mm against the type culture bacteria. The EtOAc extract of C. asiatica effectively curbed the growth of six MDR clinical isolates. The MIC values of C. asiatica against the Gram-negative bacteria tested were 2.5 mg/mL, whereas the corresponding MBC values were 5 mg/mL in each case. The MIC and MBC values were the lowest in the case of Gram-positive bacteria, ie, 0.65 and 1.25 mg/mL, respectively. A time-kill assay showed the inhibition of MRSA at 4 × MIC and 8 × MIC within 2 hours of incubation. The 24 h LD50 values of C. asiatica and S. marianum corresponding to Artemia salina were 3.05 and 2.75 mg/mL, respectively. Conclusion: Overall results substantiate the inclusion of C. asiatica and S. marianum as antibacterial agents in traditional medicines.

Ethno-pharmacological investigations of Moringa stenopetala Bak. Cuf. and its production challenges in southern Ethiopia.

INTRODUCTION: Moringa stenopetala Bak. Cuf. is a native plant of Ethiopia with important nutraceutical applications. However, little is known about its nutritional, ethno-pharmaceutical and therapeutic properties. Hence, the present study sought to assess the nutraceutical applications of M. stenopetala among traditional healers in southern Ethiopia. METHODS: A community-based cross-sectional study was conducted on 50 selected administrative units in Gamo Gofa, Segen areas and south Omo zones of southern Ethiopia from May to June 2020. Data were gathered using a semi-structured interview, field observation, and group discussion. Both quantitative and qualitative data were analysed using Excel 2019 and open code version 4.03, respectively. The results were presented using descriptive statistics, with the fidelity level (FL)% used to distinguish the preferential use of various plant parts. RESULTS: A total of 120 individuals participated in the study, and the majority of them, 89 (74.2%), were male and farmers by occupation. Eight four (70%) of them were residents of the Gamo Gofa Zone. The fidelity level revealed that the leaf and root were the most commonly used parts for nutraceutical purposes. Remarkably, M. stenopetala is used to treat human ailments such as leprosy and kidney and liver infections via various modes of utilisation and administration. As a result, the most common methods of utilising plant products are chewing or consuming crushed plant parts, and the oral route is the much-preferred method of application. On the other hand, the larvae of Moringa moth Nurda blitealis, are a defoliating insect during the rainy season and have been identified as a limiting factor for its production. CONCLUSIONS: The nutraceutical aspects of M. stenopetala are extremely important to the rural community in southern Ethiopia. However, the defoliating moth larvae threaten its growth and biomass production, necessitating the need to manage and improve the plant's productivity and sustainable use. Additionally, conducting experimental studies to validate the plant's pharmacological potential correspond to a milestone in drug discovery.

Chemical Composition, Antioxidant, and Mosquito Larvicidal Activity of Essential Oils from Hyptis capitata Jacq.

Background: Mortality and morbidity associated with vector-borne diseases, particularly those caused by mosquitoes, are increasing and new means of controlling them, including bio-larvicides, are needed. Malaria is a serious threat in many countries of Africa and Asia, and eco-friendly vector preventing measures are very much essential. Plant-derived larvicides are of great importance in this context. Hyptis capitata is an aromatic medicinal plant which is widely distributed in tropical countries. The aim of the present study is to examine the chemical composition, antioxidant and mosquito larvicidal effects of essential oils of this plant, extracted by hydro-distillation. Methods: Chemical compositions of essential oils were analyzed using gas chromatography-mass spectrometry (GC-MS). Antioxidant activity was tested by the 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) assay and the mosquito larvicidal activity was checked against the fourth instar larvae of the malarial vector Anopheles stephensi. Fingerlings of Oreochromis mossambicus were used as a bio-model for toxicity studies. Results: A total of 48 constituents, inclusive of 44 (94.67%) from inflorescence and 19 (97.09%) from leaf oil were identified; δ-cadinene (14.68%) and linalool (6.99%) were the major constituents of the inflorescence oil, while leaf oil contained 1-octen-3-ol (34.08%), methyl linoleate (17.2%), and germacrene D (11.16%). Antioxidant analysis showed an effective concentration (EC50) value of 22.76 µg/mL for leaf oil and 26.18 µg/mL for the inflorescence oil, corresponding to 17.57 µg/mL of ascorbic acid. Both oils showed a respectable larvicidal effect and the lethal concentrations (LC50) are 39.08 µg/mL and 33.19 µg/mL for the inflorescence and leaf oil, respectively. Notably, both the inflorescence and leaf oils are not very toxic to fish with respect to the concentrations tested. Conclusion: This study showed that the essential oils extracted from the leaves and inflorescences of H. capitata are effective antioxidants and can act as inexpensive mosquito larvicidal agents.

Potato Peels Mediated Synthesis of Cu(II)-nanoparticles from Tyrosinase Reacted with bis-(N-aminoethylethanolamine) (Tyr-Cu(II)-AEEA NPs) and Their Cytotoxicity against Michigan Cancer Foundation-7 Breast Cancer Cell Line.

The synthesis of nanoparticles is most important in the context of cancer therapy, particularly copper nanoparticles, which are widely used. In this work, copper(II)-tyrosinase was isolated from potato peel powder. Copper nanoparticles (Tyr-Cu(II)-AEEA NPs) were synthesized via the reaction of tyrosinase with N-aminoethylethanolamine to produce Cu(II)-NPs and these were characterized by means of FT-IR, UV-Spectroscopy, XRD, SEM, TEM and a particle size analyzer. These Tyr-Cu(II)-AEEA NPs were tested as anticancer agents against MCF-7 breast cancer cells. Fluorescence microscopy and DNA fragmentation were also performed, which revealed the inhibiting potentials of Cu(II)-AEEA NPs and consequent cell death; Tyr-Cu(II)-AEEA NPs show potential cytotoxicity activity and this nano material could be contemplated as an anticancer medicament in future investigations.

Antibacterial Activity of Rosmarinus officinalis against Multidrug-Resistant Clinical Isolates and Meat-Borne Pathogens.

BACKGROUND: In developing countries, the prevalence of bacterial infections is quite rampant due to several factors such as the HIV/AIDS pandemic, lack of hygiene, overcrowding, and resistance to conventional antimicrobials. Hence the use of plant-based antimicrobial agents could provide a low-cost alternative therapy. Rosmarinus officinalis is reputed as a medicinal plant in Ethiopia; however, its antibacterial activity against many of the clinical isolates remains overlooked. METHODS: Tender foliage of R. officinalis was collected and extracted in ethanol (EtOH) and evaluated for their antimicrobial activity against ten multidrug-resistant (MDR) clinical isolates, human type culture pathogens, and meat-borne bacterial isolates by employing agar well diffusion assay. RESULTS: EtOH extract of R. officinalis efficiently subdued the growth of all tested MDR clinical isolates in varying degrees. Salmonella sp. and Staphylococcus aureus were found to be the most sensitive clinical isolates. Likewise, it efficiently repressed the growth of meat-borne pathogens, particularly, S. aureus and Salmonella sp. showing its potentiality to be used as a natural antibacterial agent in the meat processing industry. The mechanism of antibiosis of plant extract against meat-borne pathogens is inferred to be bactericidal. Chemical constituents of the crude plant extract were analysed by Gas Chromatography-Mass Spectroscopy (GC-MS), Fourier Transform Infrared (FT-IR), and UV-visible spectroscopy showing genkwanin (26%), camphor (13%), endo-borneol (13%), alpha-terpineol (12%), and hydroxyhydrocaffeic acid (13%) as the major compounds. CONCLUSION: Overall results of the present study conclude that R. officinalis could be an excellent source of antimicrobial agents for the management of drug-resistant bacteria as well as meat-borne pathogens.

In vitro antibacterial activity of medicinal plants against biofilm-forming methicillin-resistant Staphylococcus aureus: efficacy of Moringa stenopetala and Rosmarinus officinalis extracts.

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) is slowly rising in Ethiopia for the past few decades. Therefore, novel classes of antibiotics are indispensable to combat the increased incidence of newly emerging multidrug-resistant bacteria like MRSA. Terrestrial flora is considered as a reservoir of novel bioactive secondary metabolites as they have provided us with the largest array of natural products. In this background, the present study is intended to evaluate the in-vitro antibacterial efficacy of five medicinal plants (Ocimum lamiifolium Hochst. ex Benth., Rosmarinus officinalis L, Catharanthus roseus Linn., Azadirachta indica A. Juss and Moringa stenopetala Bac) against a panel of seven biofilm-forming MRSA. The leaves of the plants were extracted in organic solvents of varying polarity and the resultant crude extracts of respective medicinal plants were inspected for their antimicrobial activity by well diffusion technique. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of the plant extracts against MRSA were determined by the broth dilution method. Besides, an anti-biofilm assay of the most potent plant extract was also performed, after which its chemical constituents were delineated by combined Gas Chromatographic and Mass Spectroscopic profiling (GC-MS). The results revealed that, of the five plants, three species including M. stenopetala, R. officinalis, and O. lamifolium exhibited significant antibacterial activity. Organic solvents with high and medium polarity were excellent in extracting antimicrobials compared to nonpolar solvents. The broadest and highest rank of activity was observed in the crude ethanolic extract of M. stenopetala. Based on the MIC/MBC ratio, the crude ethanolic extract of M. stenopetala was determined to be bacteriostatic. Anti-biofilm assay showed that the extract of M. stenopetala fairly inhibited the growth of MRSA in the preformed biofilm matrix. The GC-MS analysis of M. stenopetala revealed the presence of twelve compounds with antimicrobial activity. The present study provides new insight into the development of novel drug leads to the management of MRSA.

In vitro Antibacterial Activity and Phytochemical Analysis of Nicotiana tabacum L. Extracted in Different Organic Solvents.

BACKGROUND: Controlling infectious disease using medicinal plants is the oldest healthcare known to mankind. Regardless of the enormous advances observed in modern medicine, medicinal plants are still playing vital roles. However, only a small proportion of medicinal plants are examined for bioactive compounds which may vary in different factors. This study aimed to evaluate phytochemical constituent and antimicrobial activities of Nicotiana tabacum L. extracted by different solvents against three set of bacteria. METHODS: Nicotiana tabacum L. was collected from the Western Ethiopia and extracted in seven organic solvents. An in-vitro anti-bacterial activity of plant extracts was carried out by agar well diffusion assay against microbial type culture collection of human pathogens, clinical bacterial isolates, and biofilm forming bacteria. Gas Chromatographic and Mass Spectroscopic (GC-MS) analysis was used to determine the phytochemical constituents. RESULTS: Antimicrobial activities of plant extract vary by extraction solvents; and ethyl acetate based extracts showed better antimicrobial activities. Of the experimental organisms, biofilm forming uropathogens were the most sensitive while clinical isolates were quite resistant. Analysis of the active ethyl acetate extract by GC-MS evinced a mixture of five volatile compounds; and Pyridine, 3-(1-methyl-2-pyrrolidinyl)-, (S) was the major compound detected. The overall results of the present study revealed that N. tabacum L extract has high antimicrobial activities against biofilm forming uropathogens. CONCLUSION: High antimicrobial activity was observed in ethyl acetate extract of N. tabacum against the biofilm forming bacteria whereas the clinically isolated bacteria were the most resistant group. The antibacterial property demonstrated could be due to Pyridine, 3-(1-methyl-2-pyrrolidinyl)-(S) with a broad spectrum of activity.

Potential in vitro antimicrobial efficacy of Holigarna arnottiana (Hook F).

OBJECTIVE: To explore the in vitro antimicrobial potential of Holigarna arnottiana (H. arnottiana) against human and shrimp pathogenic bacteria and use GC-MS analysis to elucidate its antimicrobial principles. METHODS: In the present study, organic extract of H. arnottiana was examined for in vitro antimicrobial potency against five clinical human pathogens, seven species of human type culture pathogens, six pathogenic Vibrio strains isolated from moribund tiger shrimp (Penaeus monodon) and seven type cultures (Microbial Type Culture Collection, MTCC) of prominent shrimp pathogens. RESULTS: The extraction of H. arnottiana with ethyl acetate yielded bioactive crude extract that efficiently repressed the growth of all tested pathogens. Among the pathogens tested, shrimp pathogens were the most susceptible organisms while clinical pathogens were found to be a little resistant. The chemical constituents of the H. arnottiana were analysed by GC-MS which revealed the presence of major compounds such as 3,7,11,15-tetramethyl-2-hexadecen-1-o1 (42.1%), 1-lodo-2-methylundecane (34.5%) and squalene (11.1%) which might have a functional role in the chemical defence against microbial invasion. CONCLUSIONS: Based on the finding it could be inferred that H. arnottiana would be a reliable source for developing shrimp and human bio-therapeutics in future.