Acute and sub-acute toxicity study of the root extracts of Fagaropsis hildebrandtii in mice and evaluation of their antimicrobial effects

Abstract

Background: Among the Kamba community of Kenya, roots of Fagaropsis hildebrandtii (FH) are boiled and used in managing cough, fertility problems, and microbial infections. The safety of this plant in oral administration and the validity of the ethnomedical claims are unverified. This study evaluated the toxicity of the aqueous and hexane root extracts of FH in mice and antimicrobial effects against Staphylococcus aureus, Salmonella typhimurium and Candida albicans. Methods: Doses (300 and 2000 mg/kg) of the extracts were administered orally to mice for 14 days. The weight, feed, and water consumption, organ weight of mice and gross macroscopy of the liver were used in evaluating acute toxicity. Mice were additionally treated with 250, 500, and 1000 mg/kg body-weight doses of the extracts for 28 days and haematological, biochemical, and histological parameters noted. The minimum inhibitory and minimum bactericidal/fungicidal concentrations (MIC; MBC/MFC) of the extracts against the aforementioned pathogens were determined by broth dilution. Results: Acute oral toxicity of the extracts was >2000 mg/kg, there were dose dependent changes in haematological and biochemical parameters, all female mice died when treated with doses of 1000mg/kg and doses ≥500 mg/kg caused tubular degeneration and haemorrhage of the kidney, cloudy swelling of hepatocytes, and multifocal necrosis and pyknosis in the liver. The MBC/MIC ratio of each of the extracts against Staph. aureus and S. typhimurium was 2, while C. albicans was not sensitive to any of the extracts. Conclusions: Long term use of FH root extracts was associated with dose-dependent changes in the mice kidney, liver and in biochemical and haematological parameters. Root extracts of FH are bactericidal against Staph. aureus and S. typhimurium but have no effect on C. albicans. Future work should aim at identifying the metabolites responsible for the observed toxic and bactericidal effects of the FH root extracts.

Evaluation of the antimalarial activity and toxicity of Mahanil-Tang-Thong formulation and its plant ingredients

“…In our study, the liver function parameters showed that the ethanolic wood extract of M. fragrans significantly altered the AST and ALP values. These findings may indicate that an extract can induce some degree of liver changes, which may result from the detoxification of compounds in this organ [ 41 ]. However, the ALT level was normal, and this value is a marker for monitoring acute drug-induced liver injury in early clinical trials [ 42 ].…”

Evaluation of Antimicrobial Activity, Cytotoxicity, and Phytochemical Composition of Ocimum americanum L. (Lamiaceae)

“…Minimum bactericidal/ fungicidal concentration (MBC/MFC) of the crude extracts and fractions of Ocimum americanum L. was sensitive to all microbes except the crude extract and fractions while hydroethanolic crude extracts and fractions were not sensitive to the fungus C. albicans (Table 4). Compounds/extracts that demonstrate antimicrobial properties are categorized as bactericidal when MBC/MIC ratio ≤4 and bacteriostatic when the ratio of MBC/MIC >4 [41,42]. Using this as a standard, we propose that acetone (MBC/ MIC � 4.01) crude extract is bacteriostatic in nature while its fractions are bactericidal against B. cereus, S. aureus, and C. albicans microbes.…”

“…Similarly, we noted that hydroethanolic crude extract and fractions are bactericidal against Gram-positive bacteria but not fungus. Nevertheless, discretion ought to be exercised in interpretation of the data, since the higher the MIC values, the more probable that the analyzed data lose clinical significance [41]. Additionally, various studies have stated much lower MIC values against Gram-positive bacteria.…”

Cytotoxicity, acute and sub-chronic toxicities of the fruit extract of Tetrapleura tetraptera (Schumm. & Thonn.) Taub. (Fabaceae)

“…Although plants are traditionally used in the management of several diseases, their toxicity is not excluded. Many previous works related to the study of the toxicity of plant extracts demonstrated their aggressiveness towards many organs altering their physiological functions [ 47 , 48 ]. It has also been reported that repeated and prolonged administration of methanol extract of some spices such as Piper capense and Imperata cylindrica at doses higher than 500 mg/kg BW provoked adverse effects on liver and kidney function [ 49 , 50 ].…”