Evaluation of in-vitro interactions of streptomyces antibiotic substances and standard antibiotics against sensitive and resistant bacteria by activity index profile

Evaluation of the combined in-vitro antibacterial activities of Streptomyces antibiotic substances (UY1 – UY9) produced by Streptomyces species isolated from soil and standard antibiotics: ampicillin (AMP), tetracycline (TET) and chloramphenicol (CHL) against bacterial isolates: Staphylococcus aureus (SA), coagulase-negative Staphylococcus aureus (CONSA), methicillin–resistant Staphylococcus aureus (MRSA), Bacillus subtilis (BS), Streptococcus pnueumoniae (SP), Escherichia coli (EC), Pseudomonas aeruginosa (PA), Salmonella typhimurium (ST), Shigella dysentariae (SD) and Vibrio cholerae (VC) was carried out at 1 x MIC by the modified agar – well diffusion technique. The inhibitory zones of the interactions were assessed by the activity index profile (AIP), to evaluate the nature of the interactions. The combination of the agents at 1 x MIC against the test organisms showed qualitative inhibitory activity within the range (10.0 – 25.0 mm). The comparative assessment of the inhibitory activities by AIP, indicated synergism, additivity, indifferent and antagonism interactions. The standard definitions of synergy, additivity, indifference and antagonism were utilized in the assay. All the antimicrobial combinations demonstrated some degrees of synergism against the test organisms mostly the Gram-positives for ampicillin, and both Gram-positives and Gram–negatives for chloramphenicol; and lessly, tetracycline with infrequent antagonism. Conversely, antagonism was predominantly demonstrated in the combinations with tetracycline, while synergism was infrequent.Keywords: In-vitro interactions, Streptomyces Antibiotic Substances, Sensitive and Resistant Bacteria, Activity Index Profil

Molecularly pegylated lipid microparticles as a novel sustained-release vaginal delivery system for miconazole nitrate

The purpose of this study was to investigate intravaginal drug delivery system based on biocompatible phytolipids [Softisan® 154 (SF) (hydrogenated palm oil) and super-refined sunseed oil (SO)] and polyethylene glycol (PEG)-4000 for sustained delivery of miconazole nitrate (MN). Lipid matrices (LMs) consisting of optimized 1:9 blend of SO and SF with increasing amounts of PEG-4000 (0, 10, 20, 40 % w/w) were prepared by fusion, characterized by differential scanning calorimetry and employed to formulate MN-loaded solid lipid microparticles (SLMs) by melt-homogenization. In vitro drug permeation of the SLMs was evaluated in simulated vaginal fluid (SVF, pH 4.2). Results of thermal analysis confirmed the amorphous nature of the LMs and also indicated that PEG-4000 was molecularly integrated in non-PEGylated LM yielding more amorphous PEGylated LMs. Drug-loaded PEGylated SLMs based on SO:SF (1:9) and PEG-4000 (40 %w/w) (batch DM) exhibited significantly (p < 0.05) higher in vitro permeation coefficient (1.8022 × 10-4 cm/min) than commercial topical formulation of MN (Fungusol® lotion) (1.3765 x 10-4 cm/min) and pure MN sample (1.1892 x 10-4 cm/min). The developed formulations could be exploited as alternative sustained release intravaginal delivery platform for miconazole nitrate.Keywords: Miconazole nitrate, Softisan® 154, Intravaginal drug delivery, PEGylated solid lipid microparticles, Sustained release, Sunseed oi

Phytochemical constituents and wound healing properties of ointment formulations of Ocimum gratissimum crude aqueous leaf extracts

There is need for safe, acceptable and cost-effective wound healing remedies. In this work, the phytochemical constituents of the aqueous leaf extract of Ocimum gratissimum and its wound healing properties were evaluated using the excision wound healing model. The leaves were air-dried and extracted with Soxhlet extractor. Phytochemical constituents of the crude extract were evaluated. The extract was used to formulate simple ointments containing 1 and 2 % w/w of the extract. Male albino rats weighing 65 – 180 g were divided into 4 groups, shaved, inflicted with circular wounds of 2 mm diameter and treated with the ointment formulations. Animals in Group I were treated with the formulation containing 1% of extract, animals in Group 2 with ointments containing 2 % of extract, animals in Groups 3 with a bland ointment and animals in Group 4 with Cicatrin powder (a standard wound healing agent. Groups 3 and 4 animals served as controls. Wound healing degree was determined by the size of the wound over a period of 21 days. The extract contain alkaloids, glycosides, tannins, flavonoids and resins but not saponin. Concentration- independent, timedependent wound healings were observed in the animals treated with the ointment formulations containing Ocimum gratissimum aqueous leaf extract, superior to those observed in animals treated with the blank ointment and Cicatrin® powder. The aqueous leaf extract of Ocimum gratissimum can be formulated into ointments for use in wound treatments.Keywords: Ocimum gratissimum, wound healing, aqueous extract, excision wound mode

Wound healing properties of ointment formulations of Ocimum gratissimum crude n-hexane bark extracts using the excision wound model

present work evaluated the phyto-constituents and wound healing  properties of ointments formulated with the n-hexane crude bark extract of a plant used folklorically in wound healing, Ocimum gratissimum. The excision wound model was employed in the wound healing studies. The air-dried, size-reduced barks were subjected to Soxhlet extraction using n-hexane. The resulting n-hexane extract was subjected to phytochemical screening to identify the phytochemical constituents present.  Subsequently, the extract was employed at two concentrations (1 % w/w and 2 % w/w) in the formulation of simple ointments which were applied to excision wounds inflicted on male albino rats. The wound healings were evaluated in the animals over a period of 21 days. Results obtained showed that the ointments formulated with n-hexane bark extract of Ocimum gratissimum showed superior wound healing properties  compared to those exhibited by Cicatrin®, a standard wound healing agent, thus predisposing the extract as a potential wound healing agent when formulated as ointments.Keywords: wound healing, ointment, Ocimum gratissimum, bark, methanol extract, Cicatrin

Evaluating the ethyl-acetate fraction of crude methanol leaf extract of Ocimum gratissimum formulated as ointments for wound healing properties using the excision wound model

Ointment formulations of the ethyl acetate fraction of the crude methanol leaf extract of <i>Ocimum gratissimum</i> was in this study evaluated for wound healing activities in rat using the excision wound model. The air-dried and pulversied leaves were extracted with methanol in a Soxhlet extraction apparatus to obtain the crude methanol extract. This was  subsequently shaken with ethyl acetate and to obtain the ethyl acetate fraction, which was later dried and used in two different concentrations ( 1% w/w and 2 % w/w to formulate simple ointments. The ointments were evaluated for wound healing properties using male albino rats (65 – 180 g) aged 3 – 4 months. Prior to this, the crude methanol extract and ethyl acetate fraction were subjected to phytochemical studies to ascertain their phyto-constituents .The phytochemical studies showed the presence of alkaloids, tannins, flavonoids and resins and absence of glycosides and saponins. The ointment formulations had wound healing activities which were time-dependent, but concentration independent. The ointment formulations containing the extracts showed more effective wound healing than the positive control, Cicatrin® a standard wound healing agent, with the ointment containing 1 % w/w extract having superior effects than the batch containing 2 % w/w, implying that the extract, at 1 % w/w concentration, can be exploited in ointment form, as a potential wound healing remedy.Keywords: wound healing, ointment, ethyl acetate fraction, methanol extract, Ocimum gratissimum, Cicatrin

Plants as sources of antiviral agents

Antivirals are substances other than a virus or virus containing vaccine or specific antibody which can produce either a protective or therapeutic effect to the clear detectable advantage of the virus infected host. The search for antiviral agents began in earnest in the 1950s but this was directed mainly by chance, with little or no scientific basis. It had a turning point in 1964 with a number of narrow spectrum agents whose values have been more difficult to establish. A lot of success has been achieved in the screening of plants for antibacterial, antifungal and antiviral actions. The use of plants or plant products, traditionally, as antiviral agents is relatively wider than their use in modern medicine. Some antiviral substances have so far been isolated from higher plants, algae and lichens. Suitable methods for evaluating antiviral properties of plants and their extracts include use of animal models, animal protection studies, egg inoculation studies and cell culture methods

Phytochemical constituents and wound healing properties of ointment formulations of Ocimum gratissimum crude aqueous leaf extracts

There is need for safe, acceptable and cost-effective wound healing remedies. In this work, the phytochemical constituents of the aqueous leaf extract of Ocimum gratissimum and its wound healing properties wereevaluated using the excision wound healing model. The leaves were air-dried and extracted with Soxhlet extractor. Phytochemical constituents of the crude extract were evaluated. The extract was used to formulate simple ointments containing 1 and 2 % w/w of the extract. Male albino rats weighing 65 – 180 g were divided into 4 groups, shaved, inflicted with circular wounds of 2 mm diameter and treated with the ointment formulations. Animals in Group I were treated with the formulation containing 1% of extract, animals in Group 2 with ointments containing 2 % of extract, animals in Groups 3 with a bland ointment and animals in Group 4 with Cicatrin powder (a standard wound healing agent. Groups 3 and 4 animals served as controls. Wound healing degree was determined by the size of the wound over a period of 21 days. The extract contain alkaloids, glycosides, tannins, flavonoids and resins but not saponin. Concentration- independent, timedependent wound healings were observed in the animals treated with the ointment formulations containing Ocimum gratissimum aqueous leaf extract, superior to those observed in animals treated with the blank ointment and Cicatrin® powder. The aqueous leaf extract of Ocimum gratissimum can be formulated into ointments for use in wound treatments.Keywords: Ocimum gratissimum, wound healing, aqueous extract, excision wound modelJournal of Pharmaceutical and Allied Sciences Vol. 16 No.4 (2019

Physicochemical and safety characteristics of novel microstructured lipid-based drug delivery system encapsulating miconazole nitrate

This study was designed to investigate an intravaginal drug delivery system based on biocompatible phytolipids [Softisan® 154 (SF) (hydrogenated palm oil) and super-refined sunseed oil (SO)] and polyethylene glycol (PEG)-4000 for improved physicochemical performance and safe delivery of miconazole nitrate (MN). Lipid matrices (LMs) consisting of optimized 1:9 blend of SO and SF with increasing amounts of PEG-4000 (0, 10, 20, 40 % w/w) were employed to formulate MN-loaded solid lipid microparticles (SLMs) by melt-homogenization. The SLMs were evaluated in terms of encapsulation efficiency (EE), loading capacity (LC), particle size, morphology, tolerability in female rabbits and stability. Results showed that SLMs based on SO:SF (1:9) and PEG-4000 (40 %w/w) gave highest EE (88.05%) and LC (25.00 g of MN per 100 g of lipid). This optimized formulation (DM) had the least particle size, mostly spherical microparticles. Moreover, the formulation was stable and histopathologically safe. This study has shown that the developed microstructured lipid-based formulation could be employed for improved physicochemical performance and safe intravaginal delivery of miconazole nitrate.Keywords: Miconazole nitrate, Softisan® 154, Intravaginal drug delivery, Physicochemical performance, vaginal tolerance test (VTT), Biocompatible phytolipid

Novel 3-Hydroxy-2-naphthoic hydrazone and Ni(II), Co(II) and Cu(II) Complexes: Synthesis, Spectroscopic Characterization, Antimicrobial, DNA Cleavage and Computational Studies

A novel hydrazone ligand derived from condensation reaction of 3-hydroxy-2-naphthoic hydrazide with dehydroacetic acid, and its Ni(II), Cu(II) and Co(II) complexes were synthesized, characterized by spectroscopic, elemental analyses, magnetic susceptibility and conductivity methods, and screened for antimicrobial, DNA binding and cleavage properties. Spectroscopic analysis and elemental analyses indicated the formula, [MLCl 2 ], for the complexes; square planar geometry for the nickel, and tetrahedral geometry for copper and cobalt complexes. The non-electrolytic natures of the complexes in Dimethyl Sulphoxide (DMSO) were confirmed by their molar conductance values in the range of 6.11–14.01 ? -1 cm 2 mol -1 . The copper complex had the best antibacterial activity against Staphylococcus aureus (ATCC 29213). DNA cleavage activities of the compounds, evaluated on pBR322 DNA, by agarose gel electrophoresis, in the presence and absence of oxidant (H 2 O 2 ) and free radical scavenger (DMSO), indicated no activity for the ligand, and moderate activity for the complexes, with the copper complex cleaving pBR322 DNA more efficiently in the presence of H 2 O 2 . When the complexes were evaluated for antibacterial and A-DNA activity using Molecular docking technique, the copper complex was found to be most effective against Gram-positive (S. aureus) bacteria. [CuLCl 2 ] showed good hydrogen bonding interaction with the major-groove (C 2 . G 13 base pair) of A-DNA. Density functional theory (DFT) calculations of the structural and electronic properties of the complexes revealed that [CuLCl 2 ] had a smaller HOMO-LUMO gap, suggesting a higher tendency to donate electrons to electron-accepting species of biological targets. © 2019 John Wiley & Sons, Ltd

Revalence of Metallo- β- Lactamases (MBLs) in carbapenem non-susceptible Escherichia coli isolated from major meat sources

Metallo-β-lactamases (MBLs) are broad spectrum β-lactam degrading enzymes with the „last resort antibiotics‟, carbapenems, in their hydrolytic spectrum. Their emergence and rapid global spread have become a threat to the antibiotics armamentarium. This study was conducted to determine the prevalence of carbapenem non-susceptible Escherichia. coli isolates harbouring MBL enzymes in major meat sources within Nsukka, Enugu State, Nigeria. A total of 250 randomized non-duplicate rectal swab samples of birds and cattle at different poultry and ranches, as well as meat vendors‟ tables were cultured for E. coli isolates. Susceptibility of the properly characterized E. coli isolates to carbapenems and other commonly administered antibiotics was evaluated using disk diffusion method according to Clinical & Laboratory Standard Institute (CLSI) 2018 guideline. MBL production and Multiple Antibiotics Resistance (MAR) Index of the isolates were determined using standard formula and Combined Disc Test (CDT) technique respectively. A total of 138 E. coli were identified, out of which 57% (n = 78) were resistant to carbapenems, while 60% (n = 47) of the carbapenem-non-susceptible isolates were phenotypically confirmed as MBLs-producers. Their MAR Indices and level of resistance to other antibiotics ranged from 0.2 to 1.0 and 20 to 100% respectively. The work identified high levels of carbapenem resistance mediated by MBL enzymes in meat sources among occupants of Nsukka metropolis, necessitating an urgent need for sensitization of livestock and meat handlers, as well as the institutionalization and implementation of proper infection control measures to contain their spread. Further molecular studies are also needed for the full characterization of other carbapenem resistance mechanisms that could be associated. Keywords: E. coli, Carbapenem, Resistance, MBL, CDT, CLS