Antimicrobial Activity, Toxicity and Phytochemical Screening of Four Medicinal Plants Traditionally Used in Msambweni District, Kenya

This study was designed to evaluate the antimicrobial activity, toxicity and phytochemical composition of organic and aqueous crude extracts of Zanthoxylum chalybeum Engl. (Rutaceae), Adansonia digitata L. (Bombacaceae), Launaea cornuta (Hocht. ex Oliv. & Hern) C.Jeffrey (Compositae) and Grewia trichocarpa Hochst. ex A.Rich (Tiliaceae) traditionally used by local communities of Msambweni District in Kenya.  Aqueous and organic [Chloroform: Methanol (1: 1)] crude extracts were evaluated for their in vitro antimicrobial activity against Methicillin resistant Staphylococcus aureus (MRSA), Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans using broth dilution and disc diffusion methods. Toxicity was determined using Brine-shrimp larvae (Artemia salina L. nauplii) assay. The crude extracts were screened to determine the presence of flavonoids, alkaloids, saponins and sesquiterpene lactones using standard techniques. It was observed that the organic crude extracts from all the species tested except L. cornuta exhibited dose dependent activity against B. cereus, MRSA, P. aeruginosa and C. albicans. None of the crude extracts showed any inhibition against E. coli. Adansonia digitata and Grewia trichocarpa had LC50>1000 µg/ml and were shown to be non-toxic to Brine shrimp larvae unlike those of Z. chalybeum and L. cornuta which both had LC50<500 ug/ml and were considered to be toxic. Phytochemical screening of the crude extracts showed that alkaloids, flavonoids, sesquiterpene lactones and saponins were present in the four plants tested.The study has shown that A. digitata and Z. chalybeum possess promising antimicrobial activity against microbes of health importance and could lead to the isolation of new and potentially effective antimicrobial compounds. Keywords: Medicinal plants; Antimicrobial activity; Brine shrimp lethality test; Phytochemical analysis; Msambweni district; Kenya

Ethnodiagnostic Skills of the Digo Community for Malaria: A Lead to Traditional Bioprospecting

Malaria is a major public health problem that is presently complicated by the development of resistance by Plasmodium falciparum to the mainstay drugs. Thus, new drugs with unique structures and mechanism of action are required to treat drug-resistant strains of malaria. Historically, compounds containing a novel structure from natural origin represent a major source for the discovery and development of new drugs for several diseases. This paper presents ethnophytotherapeutic remedies, ethnodiagnostic skills, and related traditional knowledge utilized by the Digo community of the Kenyan Coast to diagnose malaria as a lead to traditional bioprospecting. The current study was carried out in three Digo villages of Diani sub-location between May 2009 and December 2009. Data was collected using semi-structured interviews, and open and close-ended questionnaires. A total of 60 respondents (34 men and 26 women) provided the targeted information. The results show that the indigenous knowledge of Digo community on malaria encompasses not only the symptoms of malaria but also the factors that are responsible for causing malaria, attributes favoring the breeding of mosquitoes and practices employed to guard against mosquito bites or to protect households against malaria. This knowledge is closely in harmony with scientific approaches to the treatment and control of the disease. The Digo community uses 60 medicinal plants distributed in 52 genera and 27 families to treat malaria. The most frequently mentioned symptoms were fever, joint pains, and vomiting while the most frequently mentioned practices employed to guard against mosquito bites and/or to protect households against malaria was burning of herbal plants such as Ocimum suave and ingestion of herbal decoctions and concoctions. The Digo community has abundant ethnodiagnostic skills for malaria which forms the basis of their traditional bioprospecting techniques

In silico exploration of Lycoris alkaloids as potential inhibitors of SARS-CoV-2 main protease (Mpro)

Coronavirus disease 2019 (COVID-19) is a pandemic whose adverse effects have been felt all over the world. As of August 2022, reports indicated that over 500 million people in the world had been infected and the number of rising deaths from the disease were slightly above 6.4 million. New variants of the causative agent, SARS-CoV-2 are emanating now and then and some are more efficacious and harder to manage. SARS-CoV-2 main protease (Mpro) has essential functions in viral gene expression and replication through proteolytic cleavage of polyproteins. Search for SARS-CoV-2 Mpro inhibitors is a vital step in the treatment and management of COVID-19. In this study, we investigated whether alkaloids with antiviral and myriad other bioactivities from the genus Lycoris can act as SARS-CoV-2 Mpro inhibitors. We conducted a computer-aided drug design study through screening optimal ligands for SARS-CoV-2 Mpro from a list of over 150 Lycoris alkaloids created from online databases such as ChEMBL, PubChem, ChemSpider, and published journal papers. The In silico study involved molecular docking of Lycoris alkaloids to SARS-CoV-2 Mpro active site, absorption, distribution, metabolism, elimination and toxicity (ADMET) screening and finally molecular dynamic (MD) simulations of the most promising ligand-SARS-CoV-2 Mpro complexes. The study identified 3,11-dimethoxy-lycoramine, narwedine, O-demethyllycoramine and epilycoramine as drug-like and lead-like Lycoris alkaloids with favorable ADMET properties and are very likely to have an inhibition activity on SARS-CoV-2 Mpro and may become potential drug candidates. DOI: http://dx.doi.org/10.5281/zenodo.704180

Antimycobacterial and cytotoxic activity of selected medicinal plant extracts

AbstractEthnopharmacological relevanceTuberculosis (TB) caused by Mycobacterium tuberculosis remains an ongoing threat to human health. Several medicinal plants are used traditionally to treat tuberculosis in Ghana. The current study was designed to investigate the antimycobacterial activity and cytotoxicity of crude extracts from five selected medicinal plants.Material and methodsThe microplate alamar blue assay (MABA) was used for antimycobacterial studies while the CellTiter 96® AQueous Assay, which is composed of solutions of a novel tetrazolium compound [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt; MTS] and an electron coupling reagent (phenazine methosulfate) PMS, was used for cytotoxic studies. Correlation coefficients were used to compare the activity of crude extracts against nonpathogenic strains and the pathogenic Mycobacterium tuberculosis subsp.tuberculosis.ResultsResults of the MIC determinations indicated that all the crude extracts were active on all the three tested mycobacterial strains. Minimum inhibitory concentration values as low as 156.3µg/mL against M. tuberculosis; Strain H37Ra (ATCC® 25,177™) were recorded from the leaves of Solanum torvum Sw. (Solanaceae). Cytotoxicity of the extracts varied, and the leaves from S. torvum had the most promising selectivity index. Activity against M. tuberculosis; Strain H37Ra was the best predictor of activity against pathogenic Mycobacterium tuberculosis subsp.tuberculosis (correlation coefficient=0.8).ConclusionThe overall results of the present study provide supportive data on the use of some medicinal plants for tuberculosis treatment. The leaves of Solanum torvum are a potential source of anti-TB natural products and deserve further investigations to develop novel anti-TB agents against sensitive and drug resistant strains of M. tuberculosis

Palliative care in the homecare setting

This literature reviewed research was aiming at capturing the actual or predominant roles nurses play within the home care setting when caring for the terminally ill. The intended purpose is to summarize and produce evidence-based knowledge on the role that nurses play while taking care of the terminally ill patient. The design of the study utilizes three main electronic database search engines: Science Direct, EBSCO (academic search elite), and Saga journal. The authors used systematic inductive content analysis to analyze the 20 articles, that they retrieved from the database mentioned above. The study done prioritized the primary goal of our research, which was to get to know the actual role nurses play in palliative homecare. We used the Humanistic nursing theory (HNT) as our theoretical framework. Each of the 20 articles addresses the nurse’s role in palliative home care in their own way. The most predominant role which was addressed in most of the articles was Availability/Present while performing the basic tenet of nursing, Symptoms management (pain management inclusive), Patient Autonomy, and the spider in a web role. Among these four significant roles, Availability/Present, while performing the basic tenet of a nurse, was found to be superior, for most articles addressed it quite often and as many times compared to the other three roles. Symptoms management was second while spiders in the web role and patient Autonomy followed, respectively. The study found that caring for the critically ill requires training/education, which is lacking in most Finnish university nursing curriculum. Thus, the authors recommend that nursing programs in universities should incorporate palliative care in their plans, for it will go a long way to get nurses much more prepared in this field of work

Antiplasmodial, Cytotoxic and Acute Toxicity Activities of Vernonia lasiopus O. Hoffman

Background: Malaria continues to cause heavy morbidity and mortality and it is the fifth leading cause of death globally. The disease causes over one million deaths annually and affects many more, particularly due to increasing multi-drug resistant strains of Plasmodium falciparum. Sustained investigations in both curative and prophylactic interventions have supported the ethno-pharmacological approach to identify novel compounds as a major channel towards achieving a solution. Vernonia lasiopus has been used in traditional medicine for their antimalarial, antiviral and analgesic properties. Objective: To investigate the antiplasmodial activity and toxicity profile Vernonia lasiopus extracts. Methodology: Extraction of aerial parts and roots was done using dichloromethane:chloroform (1:1) and the resulting crude extracts each fractionated into six fractions by vacuum liquid chromatography using solvents of different polarities. The crude extract and fractions were investigated for antiplasmodial activity using the chloroquine (CQ) sensitive D6 and chloroquine (CQ) resistant W2 laboratory adapted Plasmodium falciparum strains. Cytotoxicity was evaluated on Vero 199 cells at starting concentrations of 100µg/ml, whereas acute toxicity (LD50) determined on healthy female Swiss mice (20±2 gm.). Selectivity index was used as an indicator of antiplasmodial viability. Results: The fractions of V. lasiopus roots showed higher activity combined than individually. The crude V. lasiopus root extract had an IC50 13.1 µg/ml and selectivity index >7.63. Fraction 1 of the crude root extract (VLR1) was the most viable fraction with an IC50 of 16.8 µg/ml and S.I >5.95. Both had CC50>100 µg/ml and LD50 >5000mg/kg. Conclusion: extracts of V. lasiopus aerial parts and roots were found to exhibit notable viable antiplasmodial effects, and had minimal acute toxicity in mice. Key words: Plasmodium falciparum, Vernonia lasiopus, antiplasmodial activity, toxicity, selectivity index

Organochlorine pesticide residues in farmed fish in Machakos and Kiambu counties, Kenya

This study was conducted to evaluate occurrence of organochlorine pesticide residues in Oreochromis niloticus fish reared by aquaculture in Kiambu and Machakos Counties. A total of 213 fish organ samples were analyzed for organochlorine pesticide residues from Kiambu and Machakos Counties in Kenya using gas–liquid chromatography. Overall, betahexachlorocyclohexane (BHC) group, the cyclodiens, aldrin, heptachlor, dieldrin, endrin and the Dichlodiphenyltrichloroethane (DDT) group of compounds were detected in fish samples. p,p′-DDT and its metabolite p,p′-DDD were detected in the muscle, liver and gonad and their concentration ranged between not detectable (ND) to 0.916 μg kg−1 for p,p′-DDT and ND to 1.684 μg kg−1 for p,p′-DDD. Brain had the highest concentration of DDT metabolites o, p′-DDT (2.098 ± 4.097 μg kg−1) and p′ p-DDD (1.684 ± 3.666 μg kg−1). Organochlorine pesticide residues were generally higher in Kiambu County compared to Machakos County but there was no significant difference. The residue levels of organochlorines in all fish samples analyzed were lower than the benchmark levels set by FAO, FDA, and NAS/NAE