Search

Introduction: Microbial infections cause high morbidity and mortality in humans globally. Antimicrobial resistance, emergence of new strains, high costs of antibiotics, inaccessibility-especially in remote areas, and adverse effects, impede successful eradications of pathogens, hence the need for novel strategies. Bridellia micrantha is used in traditional medicine to treat microbial infections; however, it has not been empirically validated. Methods: Antimicrobial activity of the aqueous and methanolic stem bark extracts of Bridellia micrantha was investigated using the disk diffusion and broth microdilution techniques, described by the Clinical Laboratory Standards Institute (CLSI) guidelines. The brine shrimp lethality assay technique was used to investigate the cytotoxic effects of the studied plant extracts in exposed nauplii. Acute oral toxicity effects of the studied plant extracts in Winstar rats were investigated following the up-and-down procedure described by the Organisation for Economic Development and Co-operation (OECD). Qualitative phytochemical screening was performed following standard procedures. Results: The aqueous and methanolic extract of B. micrantha indicated varied antimicrobial activities against E. coli, S. typhimurium, S. aureus, and C. albicans, with inhibition zones ranging from 6.00mm to 19.00mm. Furthermore, the studied plant extracts exhibited low MIC values (=100 µg/ml) on selected microbes. Since the MIC values were much lower than 1000µg/ml (the cutoff for antimicrobial efficacy appraisal), it is anticipated that, the studied plant extracts can be strong antibiotics. The aqueous and methanolic stem bark extracts of B. micrantha were cytotoxic to brine shrimp nauplii, with LC50 values of 486.67±3.15 µg/ml and 458.33±2.87 µg/ml, respectively; however, these extracts did not elicit any observable signs of toxicity in rat models. Pharmacologically active phytochemicals, including flavonoids, alkaloids, saponins, tannins, phenols, and anthraquinones were detected in the two studied extracts. Conclusions: The aqueous and methanolic stem bark extracts of B. micrantha have appreciable antimicrobial activity against E. coli, S. typhimurium, S. aureus and C. albicans. Besides, the studied plant extracts are cytotoxic to brine shrimp nauplii; but they do not cause acute oral toxicity effects in rat models. Additionally, the studied plant extracts contain bioactive phytochemicals, with antimicrobial activity. [ABSTRACT FROM AUTHOR]

Over 50 million persons are living with cognitive deficits worldwide, with over 80% of these individuals living in the developing world. The number of affected persons is projected to go over 152 million by the year 2050. Current drugs used for cognitive impairment are debatably ineffective, costly, inaccessible, and associated with undesirable events that call for the search for alternative and complementary approaches. Plants are arguably affordable, accessible, and efficacious. However, despite the reported healing claims, scientific data validating these claims are lacking. L. eriocalyx is traditionally used for the management of various conditions, including cognitive impairment but has not been scientifically explored. In this study, the Morris Water Maze (MWM) method was used to evaluate in vivo cognitive-enhancing effects of studied extracts of L. eriocalyx. Furthermore, following MWM experiments, brains were dissected and processed, and malondialdehyde profiles were determined. Qualitative phytochemical profiles of the studied plant extracts were also determined. The results showed that mice that were treated with the studied plant extracts took significantly shorter transfer latencies, navigation distances, and significantly longer latencies in the target quadrant (NW) (p < 0.05) compared with the negative control mice, indicating cognitive-enhancing activities. Furthermore, cognitively impaired mice that received the studied plant extracts had significantly lower MDA profiles compared with the MDA profile of the negative control group mice (p < 0.05). The cognitive-enhancing and MDA profile lowering effects were attributed to the presence of antioxidant phytoconstituents that ought to have modulated the redox state, thereby attenuating brain damage. These extracts can be, therefore, used for the management of cognitive deficits. Further studies leading to isolation and characterization of active molecules for cognitive impairment are recommended. Furthermore, the precise mechanism(s) through which these extracts exert their pharmacologic activity should be established. [ABSTRACT FROM AUTHOR]