Characterization of Potential Virulence, Resistance to Antibiotics and Heavy Metals, and Biofilm-Forming Capabilities of Soil Lignocellulolytic Bacteria.

Soil bacteria participate in self-immobilization processes for survival, persistence, and production of virulence factors in some niches or hosts through their capacities for autoaggregation, cell surface hydrophobicity, biofilm formation, and antibiotic and heavy metal resistance. This study investigated potential virulence, antibiotic and heavy metal resistance, solvent adhesion, and biofilm-forming capabilities of six cellulolytic bacteria isolated from soil samples: Paenarthrobacter sp. MKAL1, Hymenobacter sp. MKAL2, Mycobacterium sp. MKAL3, Stenotrophomonas sp. MKAL4, Chryseobacterium sp. MKAL5, and Bacillus sp. MKAL6. Strains were subjected to phenotypic methods, including heavy metal and antibiotic susceptibility and virulence factors (protease, lipase, capsule production, autoaggregation, hydrophobicity, and biofilm formation). The effect of ciprofloxacin was also investigated on bacterial susceptibility over time, cell membrane, and biofilm formation. Strains MKAL2, MKAL5, and MKAL6 exhibited protease and lipase activities, while only MKAL6 produced capsules. All strains were capable of aggregating, forming biofilm, and adhering to solvents. Strains tolerated high amounts of chromium, lead, zinc, nickel, and manganese and were resistant to lincomycin. Ciprofloxacin exhibited bactericidal activity against these strains. Although the phenotypic evaluation of virulence factors of bacteria can indicate their pathogenic nature, an in-depth genetic study of virulence, antibiotic and heavy metal resistance genes is required.

Pharmacological evidence of Vitex thyrsiflora, Entandrophragma cylindricum, and Anonidium mannii used for the management of inflammation in Cameroon.

Background Inflammation is the most common health problem faced in life relating to a vast number of diseases. The present study evaluated the pharmacological effect of three plants (Vitex thyrsiflora, Entandrophragma cylindricum, and Anonidium mannii) commonly used in the Cameroon pharmacopeia for the management of inflammatory response. Methods The pharmacological effect was characterized by the antioxidant capacity, anti-inflammatory, analgesic, and antipyretic properties of the ethanol extracts of the three plants. Antioxidant capacity was determined using total phenolic content, total flavonoid content, hydrogen peroxide, ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical scavenging assays. Anti-inflammatory activity was evaluated in vitro by protein denaturation and hypotonic-induced hemolysis methods and in vivo by carrageenan paw edema method. Analgesic and antipyretic activities were studied in vivo using acetic acid-induced writhing and brewer's yeast-induced hyperpyrexia models. Results All selected extracts showed high phenolic (15.93-64.45 mgCAE/g) and flavonoid (336.03-1053.48 mgCAE/g) contents and high ferric reducing power (288.75-364.91 mgCAE/g). These extracts exhibited good DPPH (IC50 = 0.30-1.65 µg/mL), ABTS (IC50 = 0.52-1.90 µg/mL), and H2O2 (IC50 = 1.40-3.55 µg/mL) radical scavenging activities. All extracts inhibited protein denaturation (6.79-82.27%) and protected the erythrocyte membrane from lysis induced by hypotonic solution (18.90-88.00%). The extracts significantly reduced dose-dependent paw edema (p < 0.05), fever, and abdominal writhing (p < 0.001) especially at 400 mg/kg. Conclusions All extracts exhibited interesting antioxidant properties, as well as significant anti-inflammatory, analgesic, and antipyretic effects.

Hydroethanolic plant extracts from Cameroon positively modulate enzymes relevant to carbohydrate/lipid digestion and cardio-metabolic diseases.

Cardiovascular diseases are the greatest cause of death globally and are frequently associated with type 2 diabetes mellitus and metabolic syndrome, a condition including visceral obesity, hypertension, elevated triglycerides and low HDL cholesterol and hyperglycaemia. Several medicinal plants, including spices, are used in Cameroon as herbal medicines and are traditionally employed for the treatment of several ailments such as diabetes and related diseases. In this study, we chemically characterized eleven Cameroonian spice extracts and evaluated their effects on some enzyme activities relevant to carbohydrate and lipid digestion and cardio-metabolic diseases. Hydroethanolic spice extracts were characterized by GC-MS analysis and screened for their ability to modulate the activity of α-glucosidase, α-amylase, pancreatic lipase, 3-hydroxy-3-methylglutaryl-coenzyme A reductase and angiotensin-converting enzyme (ACE). Among the spice extracts tested, those from Xylopia parviflora showed the widest inhibitory spectrum, with a relevant effect on all enzyme activities. Dichrostachys glomerata and Aframomum citratum extracts were more selective. The selected and strong activity of some plants, such as that of Aframomum citratum on pancreatic lipase and that of Xylopia aethiopica on ACE, suggests their specific use in obesity and hypertension, respectively. Chemical analysis indicated that for some spice extracts such as Xylopia parviflora and Aframomum citratum their secondary metabolites (chlorogenic acid, pimaric acid, and catechin and its derivatives) could potentially justify the biological properties observed. Our findings clearly show significant inhibition of cardio-metabolic enzymes by hydroethanolic Cameroonian spice extracts, suggesting the potential usefulness of nutraceuticals derived from these plants to develop novel management strategies for obesity and diabetes complications.