RESUMO
Background: In Ghana, Cymbopogon citratus leaves together with guava, pawpaw, and lime are processed into a decoction to treat fever. To encourage its usage, preclinical validation of the safety profile of the plant is required. The acute and subchronic toxicities of the conventional Soxhlet ethanolic Cymbopogon citratus leaves extract in Sprague-Dawley rats were investigated. Methods: Pulverized Cymbopogon citratus leaves were extracted with 98% ethanol using the conventional Soxhlet extraction (CSE) method and dried. In the acute toxicity study, a single dose of 5000 mg/kg body weight was administered to six female Sprague-Dawley rats and 1 ml/100 g body weight normal saline to control (6) once, and signs of toxicity were observed every hour for the first 12 hr, 24 hr, and 48 hr through to 14 days. In the subchronic study, the treatment groups were administered 200 mg/kg, 600 mg/kg, and 1200 mg/kg, respectively, of the CSE C. citratus leaves extract for six weeks. Analyses were conducted on the blood, urine, and serum samples of the rats. Histopathological examination of the liver, heart, kidney, spleen, and lungs was carried out at termination. Analysis of variance (ANOVA) was performed to determine statistically significant differences between the test and control rats at P < 0.05. Results: The results revealed that there were no statistically significant differences (p > 0.05) in the urinalysis and haematological analysis between control and test rats over the treatment period. Similarly, CSE C. citratus leaves extract did not induce any significant biochemical changes in the treatment group; however, there was a weight loss effect on the treated rats. There were no noticeable morphological changes in the heart, liver, spleen, lung, and kidney of the test rats compared to the control. Conclusion: CSE ethanolic C. citratus leaves extract has a weight loss effect, and long-term administration of the extract may not cause any organ-specific toxicity to the consumers.
RESUMO
BACKGROUND: Medicinal plants represent a valuable source for new effective and safe antimicrobial drugs making them an alternative therapy. Existing antimicrobial agents are costly and mostly associated with possible side effects. The aim of the present study therefore, was to assess the antimicrobial property and phytochemical composition of hydroethanolic extract of Tapinanthus bangwensis leaves and its fractions. METHOD: T. bangwensis leaves (harvested from its host plant, Persea americana) was extracted by cold maceration with 70% ethanol and further fractionated with different organic solvents using the solvent partitioning method to obtain the crude extract, petroleum ether, chloroform, ethyl acetate and the resulting aqueous fractions. The phytochemical constituents of the extracts were screened and quantified. Also, the TLC of the extracts were analyzed to serve as a fingerprint. Using the agar diffusion and broth dilution methods, the antimicrobial properties of the extracts were assessed. RESULTS: The study showed that the hydroethanolic (70%) crude extract of T. bangwensis leaves and its fractions contain phenolic compounds, flavonoids, saponins, phytosterols and reducing sugars. The phytoconstituents were well extracted into the ethyl acetate fraction than the other fractions evidenced in the high levels (p < 0.0001) of saponins (66.47 ± 1.72% w/w), phenolic compounds (77.75 ± 1.06 mg/100 mg GAE) and flavonoids (44.34 ± 0.06 mg/100 mg QE) contents. From the antimicrobial studies, all the microorganisms tested exhibited varying degrees of susceptibility to the extracts with MIC values between 0.78 to 12.5 mg/mL. The crude extract of T. bangwensis leaves, its ethyl acetate and chloroform fractions also exhibited lethal antimicrobial activity with MLC between 6.25 to 50 mg/mL. CONCLUSION: The crude extract of T. bangwensis leaves and its fractions demonstrated antimicrobial properties against Escherichia coli, Staphylococcus aureus, Staphylococcus saprophyticus and Candida albicans, thereby representing a potential source of natural antimicrobial agent. Further study is required to identify and isolate antimicrobial compounds from the plant for the development of the natural bioactive antimicrobial agents.