Graphical abstract

Background: The increase in synthetic drug resistance by pathogenic microbes has led to the development of plant-based antimicrobial drugs that are more reliable and non-lethal to human health at increased dosage. Methods: The antibacterial and antifungal potential of Geophila obvallata extracts were tested on clinical isolates (Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, Streptococcus pyogenes, Cryptococcus neoformans, Candida albicans and Aspergillus fumigatus) using standard techniques. Results: The zones of inhibition were shown to increase with increasing concentrations of the extracts. Inhibition was higher in Gram positive bacteria (9.10 to 31.00mm in 40mg/mL concentration) than Gram negative bacteria (3.50 to 27.00mm in 40mg/mL concentration), while the fungal isolates had the least zones of inhibition (2.83 to 25.00mm in 40mg/ml concentration). The minimum inhibitory concentrations (MIC) were lowest in the methanol extract than aqueous extract. Simillarly, MIC for bacteria (Bacillus subtilis) and fungi (Aspergillus fumigatus) were 0.3 and 2.0mg/mL respectively. Methanol extract had higher antibacterial and antifungal effect than aqueous extract. Ciprofloxacin, used as control for bacteria had the highest inhibitory activity (33.67mm) when compared to that of the highest concentration of plant extracts administered. Also, ketoconazole gave the highest zones of inhibition (32.33mm) on the fungi isolates compared to those of the extracts. The performance of the methanol extract of 40mg/mL of Geophila obvallata in the inhibition of Bacillus subtilis was not significantly different from that of Ciprofloxacin. Conclusion: The findings in this study therefore validate the antimicrobial effect of Geophila obvallata leaf extracts as well as its possible application in medicine.

Materials and Methods Collection, Identification and Preparation of plant materialsFresh leaves of Vernonia amygdalina were purchased from a local market in Benin City, Edo state, Nigeria. The leaves were identified by Dr.

The study was aimed at comparing the toxic effects of cassava-borne organic cyanide and equivalent level of inorganic cyanide (KCN) in New Zealand White rabbits. Three groups of 3-month old, male weanling rabbits (4 per group) were used. One group received pure growers mash (control), while another was fed isonitrogenous cassava peel flour, CPF containing 702 ppm organic cyanide. A third group was given mash with 702 ppm KCN (inorganic cyanide). Feed intake, body weight gain, and serum SCN-were recorded. The animals were fed for 10 weeks prior to sacrifice and isolation of tissues for assays of rhodanese, LDH, ALT, AST and serum urea and creatinine. Feed intake and weight gain were significantly lower in CPF group than in KCN group, but LDH activities in serum, liver, and lung were significantly higher in the CPF group (p < 0.05). There were no significant differences in the tissue and serum levels of AST and ALT between both groups. In addition, serum urea and creatinine did not differ significantly between the CPF and KCN groups. However liver and kidney rhodanese activities and urinary thiocyanate were significantly higher in the KCN group (p < 0.05). More pronounced pathological lesions (tubular and glomerular necrosis) were evident in the kidney from the CPF group, while liver lesions (congestion, necrosis and inflammatory reactions) were more severe in the KCN group. These results suggest that although the metabolic effects of cassava-borne organic cyanide and inorganic cyanide resemble, the severity of their tissue toxicities may differ

The increase in synthetic drug resistance by pathogenic microbes has led to the development of plant-based antimicrobial drugs that are more reliable and non-lethal to human health at increased dosage. The antibacterial and antifungal potential of Geophila obvallata extracts were tested on clinical isolates (Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis,Streptococcus pyogenes, Cryptococcus neoformans, Candida albicans and Aspergillus fumigatus) using standard techniques. The zones of inhibition were shown to increase with increasing concentrations of the extracts. Inhibition was higher in Gram positive bacteria (9.10 to 31.00mm in 40mg/mL concentration) than Gram negative bacteria (3.50 to 27.00mm in 40mg/mL concentration), while the fungal isolates had the least zones of inhibition (2.83 to 25.00mm in 40mg/ml concentration). The minimum inhibitory concentrations (MIC) were lowest in the methanol extract than aqueous extract. Simillarly, MIC for bacteria (Bacillus subtilis) and fungi (Aspergillus fumigatus) were 0.3 and 2.0mg/mL respectively. Methanol extract had higher antibacterial and antifungal effect than aqueous extract. Ciprofloxacin, used as control for bacteria had the highest inhibitory activity (33.67mm) when compared to that of the highest concentration of plant extracts administered. Also, ketoconazole gave the highest zones of inhibition (32.33mm) on the fungi isolates compared to those of the extracts. The performance of the methanol extract of 40mg/mL of Geophila obvallata in the inhibition of Bacillus subtilis was not significantly different from that of Ciprofloxacin. The findings in this study therefore validate the antimicrobial effect of Geophila obvallata leaf extracts as well as its possible application in medicine.