Biosynthesis, Characterization and Antimicrobial Activity of Silver Nanoparticles Using Cell Free Lysate of Bacillus Subtilis: A Biotechnology Approach

Present study was aimed at the bio-synthesis and characterization of silver nanoparticles (AgNPs) using bacterial cell free lysate of Bacillus specie isolated from iron-rust contaminated soil sample from the Niger Delta region of Nigeria. This method was cost effective, eco-friendly and an alternative to chemical synthesis which is hazardous and requiring tedious synthetic manipulation. This study also evaluated the antimicrobial effect of the synthesized silver nanoparticles. Silver nanoparticles produced by reacting cell-free lysate of Bacillus subtilis and 1 mM of aqueous silver nitrate solution were characterized by Ultraviolet-visible spectroscopy, Transmission electron microscopy (TEM) and Photon correlation microscopy (Zeta sizer). The UV-Visible spectrophotometric result revealed an absorption maxima corresponding to peaks near 428 nm, depicting reduction of ionic silver (Ag+) to silver atom (Ag0). It has already been reported that nitrate reductase enzymes are implicated in metal ion reduction reactions. The Transmission electron microscopy analysis revealed that the AgNPs size ranged between 58.24 ± 1.04 nm and 72.20 ± 2.10 nm complementing the result obtained from Photon correlation microscopy (76.86 ± 1.14 nm). The antibacterial activity of AgNPs gave highest inhibition zone diameter of 26 mm on Pseudomonas aeruginosa at the dose of 0.10 mg/ml and 14 mm on tested Candida albicans. The synthesized silver nanoparticles were found to produce a dose dependent antimicrobial inhibitory effect while surface adsorption and lysis were implicated as the mode of action

Antioxidant evaluation and bio-guided isolation from methanol leaf extract of Acalypha godseffiana

Acalypha godesffiana is a plant used in conventional medicine for fungal-related illnesses. The plant‘s extracts were investigated in this study, antioxidant, and antimicrobial studies were conducted. Different models were employed in the antioxidant assay; serial dilution was utilized to determine the minimum inhibitory concentration (MIC). The extract from A. godseffiana was purified and characterized by chromatographic and spectroscopic techniques, respectively. Three biologically active compounds, 3, 5-dihdroxylbenzoic acid (1), 3, 4, 5-trihydroxybenzoic acid (2), as well as Di-(2-ethylhexyl) phthalate (3), were identified for the first time in A. godseffiana. The extract and fractions exhibited varying scavenging capacities on different anti-oxidative models. The DPPH of MeOH (IC50= 0.51 mg mL^-1) was comparable with silymarine (SLY) IC50= 0.52 mg mL^-1 and better than gallic acid (GAL) IC50=1.95 mg mL^-1; the ABTS.+ of EtOAc column fraction (ACF, IC50=0.46 mg mL^-1) was comparable with standard SLY, IC50 = 0.47 mg mL^-1; and an OH radical of DCM, IC50= 0.10 mg mL^-1, was better than both standards (SLY, IC50= 6.30 mg mL^-1, GAL: IC50= 1.93 mg mL^-1). ACF showed superior antifungal activities (0.02 mg mL^-1) against Cryptococcus neoformans and Candida albicans, compared to ketoconazole (MIC of 0.250 mg mL^-1). Compounds (1-3) from A. godseffina reportedly displayed antioxidant and other activities. This study validated the antifungal potentials of A. godseffiana leaves and identified bioactive compounds. The extracts should be further investigated, and the compounds should be added to the existing library for further investigation of possible leads.

Biological activity of plant extracts and isolated compounds from Alchornea laxiflora: Anti-HIV, antibacterial and cytotoxicity evaluation

This study was designed to assess the cytotoxicity, anti-HIV and antibacterial efficacy of various solvent extracts of roots, stem and leaves of Alchornea laxiflora, as well as five compounds isolated from its methanolic stem extract viz.; ellagic acid (1); 3-O-methyl-ellagic acid (2), 3-O-β-d-glucopyranosyl-β-sitosterol (3), 3-O-acetyl-oleanolic acid (4) and 3-O-acetyl-ursolic acid (5). The tested crude extracts were prepared from several solvent polarities including: hexane (Hex), chloroform (CHCl3), ethyl acetate (EtOAc), ethanol (EtOH), methanol (MeOH) and water (H2O). The anti-HIV properties were assessed on HIV-1 subtype C integrase while the cytotoxicity was tested against Hela cells. The antibacterial activity was studied on a panel of pathogens including gastrointestinal, skin, respiratory and urinary-tract infection causing Gram positive bacteria viz.; Bacillus cereus (ATCC 11778), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 25923) and Staphylococcus saprophyticus (ATCC 15305)] and Gram-negative bacteria, i.e., Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13883), Moraxella catarrhalis (ATCC 23246). All the tested samples were determined to be non-toxic due to the low inhibitions observed. The most potent anti-HIV activity was observed for the methanolic extract of A. laxiflora root (ALR4) with an IC50 value of 0.21 ng/ml, which was more active than chicoric acid used as reference drug (6.82 nM). Roots, stem and leaves of A. laxiflora extracts exhibited antibacterial activities against most of the Gram-positive bacteria with the minimum inhibitory concentrations (MIC) ranging between 50 and 63 μg/ml. Compounds 1–5 displayed antibacterial activities against S. saprophyticus with MIC values as low as 4 μg/ml. The results inferred from this study demonstrate the potential of A. laxiflora root as a source for new anti-HIV drugs and scientifically validate the traditional use of A. laxiflora in the treatment of gastrointestinal, skin, respiratory and urinary tract related infections. These results reaffirm the ethnopharmacological significance of African traditional medicines

Anti-HIV-1 integrase potency of methylgallate from Alchornea cordifolia using in vitro and in silico approaches:

According to the 2018 report of the United Nations Programme on HIV/AIDS (UNAIDS), acquired immune deficiency syndrome (AIDS), a disease caused by the human immunodeficiency virus (HIV), remains a significant public health problem. The non-existence of a cure or effective vaccine for the disease and the associated emergence of resistant viral strains imply an urgent need for the discovery of novel anti-HIV drug candidates. The current study aimed to identify potential anti-retroviral compounds from Alchornea cordifolia

Learning Pelvic Examination with Professional Patients

Performing pelvic examination is a vital skill to learn during gynecological and obstetrical training. It's a difficult maneuver to master as there is very little to see and more to feel and interpret. In addition, learning PE in usual clinical set-up has been found to induce lot of stress and anxiety among both the patients and the students. Students fear of hurting the patients and being judged inept, whereas patients feel embarrassed having to expose their most intimate body parts for learning purpose. This hampers effective learning. Learning PE on sedated women before surgery or on mannequins has been practiced as alternative learning models. But, they have been found to miss out on teaching the communication skills, which are as important as the palpation skills. However, there exists another model of learning PE--the professional patients, who are specially trained to act as patients and also guide the students on how to make a proper PE. They provide stress-free environment for the students to learn PE and at the same time, provide immediate feedback on each of their maneuvers. They form a complete learning model and help students to see patients as partner and not just a person seeking help. Keywords: learning model, pelvic examination, stress, students

Current Advances in Specialised Niosomal Drug Delivery: Manufacture, Characterization and Drug Delivery Applications

Development of nanomaterials for drug delivery has received considerable attention due to their potential for achieving on-target delivery to the diseased area while the surrounding healthy tissue is spared. Safe and efficiently delivered payloads have always been a challenge in pharmaceutics. Niosomes are self-assembled vesicular nanocarriers formed by hydration of a non-ionic surfactant, cholesterol or other molecules that combine to form a versatile drug delivery system with a variety of applications ranging from topical delivery to targeted delivery. Niosomes have advantages similar to those of liposomes with regards to their ability to incorporate both hydrophilic and hydrophobic payloads. Moreover, niosomes have simple manufacturing methods, low production cost and exhibit extended stability, consequently overcoming the major drawbacks associated with liposomes. This review provides a comprehensive summary of niosomal research to date, including the types of niosomes and critical material attributes (CMA) and critical process parameters (CPP) of niosomes and their effects on the critical quality attributes (CQA) of the technology. Furthermore, physical characterisation techniques of niosomes are provided. The review then highlights recent applications of specialised niosomes in drug delivery. Finally, limitations and prospects for this technology are discussed