Pathogenic microorganisms and oxidative stress have continuously threatened the wellbeing of humans. In this study, we determined the Minimum Inhibitory Concentration (MIC) and Minimum Bacteriocidal Concentration (MBC)/ Minimum Fungicidal Concentration (MFC) of extracts of Eugenia uniflora, Cassia sieberiana, Laportea aestuans and Dysoxylum lenticellare against methicillin resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Candida albicans. The antioxidant activities of these extracts were also evaluated. The 50% methanol extracts were obtained by maceration at room temperature (26-33 ºC). The antimicrobial test was carried out by broth dilution assay using Streptomycin and Ketoconazole as positive controls while 50% methanol was used as the negative control. The antioxidant activities were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP) and Total Antioxidant Capacity (TAC) assays with ascorbic acid used as positive control. In antibacterial studies, E. uniflora was active against all test organisms. C. sieberiana had the lowest MIC against B. subtilis and MRSA. Dysoxylum lenticellare was only active against B. subtilis. In antifungal studies, E. uniflora and C. sieberiana were the only extracts active against C. albicans. In antioxidant studies, E. uinflora was the most active for DPPH and FRAP assays while C. sieberiana was the most active for TAC. In all antioxidant evaluations, E. uniflora was the most active followed by C. siebariana while L. aestuans was the least active. Eugenia uniflora had the best antimicrobial and antioxidant activities justifying its ethnomedicinal use in the treatment of microbial infections and free radical-induced conditions such as influenza, digestive disorders, and inflammations.

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There are evidences that free radicals mediated damages play important role in the aetiology of several diseases necessitating search for  antioxidants especially from natural origin. Free radical scavenging activities of Laportea aestuans (Urticaceae) is well documented, therefore this study aims at evaluating the safety of L. aestuans and isolating free radical scavenging compound(s) from the plant extract. The aerial (leaves, stem and inflorescence) parts of L. aestuans were collected together and extracted with 80% methanol. The toxicity of the plant extract was evaluated using brine shrimp lethality assay and acute toxicity study while Thin Layer Chromatography (TLC) bioautography with 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH•) radical as detection reagent was used to guide the isolation of compounds from the plant extract. The LC50 of L. aestuans extract was 4276.87 µg/mL, suggesting that the extract is nontoxic. This was further confirmed by the healthiness of study rats following administration of the extract at 5000 mg/kg b.wt in the acute toxicity study. TLC bioautography showed that hexane fraction had the most pronounced radical scavenging activities. Three compounds identified as hexadecanoic acid butyl ester, heptadecanoic and octadecane were characterized using IR, 1H, 13C NMR, ESI – MS and GC – MS analysis.

Background: Increased exposure to pathogens and free radicals contributed to the high incidence and mortality rate of various cancers in Nigeria and globally. Promotion of scientific research on medicinal plants in collaboration with traditional health practitioners to validate claims made on safety, efficacy and quality of traditional medicinal plants in the treatment of cancer is imperative. This study aims at screening extracts of selected Nigerian medicinal plants used traditionally for cancer treatment for antioxidant, antimicrobial and cytotoxic activities towards identification of potential source of new anticancer agents.Methods: Twenty-one extracts from sixteen medicinal plants species were screened for their cytotoxicity on RD, HeLa and Hep-2 cancer cell lines using MTT assay. The DPPH radical scavenging activity of the extracts as well as their Total Phenolic Content (TPC) were evaluated. The extracts were also evaluated for their antimicrobial activity using spectrophotometric growth inhibition method. Results: Extracts of Tetrapleura tetrapleura and Xylopia aethiopica showed high DPPH inhibitory activity and phenolic content. Extracts of X. aethiopica and Anchomanes difformis showed broad spectrum of antibacterial activities while root extracts of Crotolaria retusa and T. tetraptera exhibited antifungal activities comparable (P<0.05) to Ketoconazole. Extracts of Capcicum frutescens, Aspilia africana, X. aethiopica, T. tetraptera and C. retusa showed broad spectrum of cytotoxic activities.Conclusions: Extracts of T. tetraptera and X. aethiopica demonstrated satisfactory activities in all the biological tests which could be linked to their high phenolic contents. The findings support the ethno-medicinal uses of most of the tested medicinal plants.

Malaria is a deadly disease that continues to pose a threat to children and maternal well-being. This study was designed to identify the chemical constituents in the ethanolic fruit extract of Azadirachta indica, elucidate the pharmacological potentials of identified phytochemicals through the density functional theory method and carry out the antimalarial activity of extract using chemosuppression and curative models. The liquid chromatography-mass spectrometry (LC-MS) analysis of the ethanolic extract was carried out, followed by the density functional theory studies of the identified phytochemicals using B3LYP and 6-31G (d, p) basis set. The antimalarial assays were performed using the chemosuppression (4 days) and curative models. The LC-MS fingerprint of the extract led to the identification of desacetylnimbinolide, nimbidiol, O-methylazadironolide, nimbidic acid, and desfurano-6α-hydroxyazadiradione. Also, the frontier molecular orbital properties, molecular electrostatic potential, and dipole moment studies revealed the identified phytochemicals as possible antimalarial agents. The ethanolic extract of A indica fruit gave 83% suppression at 800 mg/kg, while 84% parasitaemia clearance was obtained in the curative study. The study provided information about the phytochemicals and background pharmacological evidences of the antimalarial ethnomedicinal claim of A indica fruit. Thus, isolation and structure elucidation of the identified phytochemicals from the active ethanolic extract and extensive antimalarial studies towards the discovery of new therapeutic agents is recommended for further studies.