Apoptotic effect of Bulbine Natalensis and Chlorophytum Comosum in myelogenous Leukemia K562 cell line / Efeito apoptótico da natalensia bulbina e do clorofito comoso na linhagem celular mielogênea da leucemia K562

Abstract Bulbine natalensis and Chorophytum comosum are potential medicinal source for the treatment of cancers. Chronic myeloid leukaemia is a hematopoietic stem cells disorder treated by tyrosine kinase inhibitors but often cause recurrence of the leukaemia after cessation of therapy, hence require alternative treatment. This study determines the anti-cancer effect of leaf, root and bulb methanolic and aqueous extracts of B. natalensis and C. comosum in chronic human myelogenous leukaemia (K562) cell line by MTT, Hoechst bis-benzimide nuclear and annexin V stain assays. The root methanolic extract of B. natalensis and C. comosum showed a high cytotoxicity of 8.6% and 16.7% respectively on the K562 cell line at 1,000 μg/ml concentration. Morphological loss of cell membrane integrity causing degradation of the cell and fragmentation were observed in the root methanolic extract of both plants. A high apoptosis (p < 0.0001) was induced in the K562 cells by both leaf and root extracts of the C. comosum compared to the B. natalensis. This study shows both plants possess apoptotic effect against in vitro myelogenous leukaemia which contributes to the overall anti-cancer properties of B. natalensis and C. comosum to justify future therapeutic applications against chronic myelogenous leukaemia blood cancer.

Resumo Bulbine natalensis Baker e Chorophytum comosum (Thunb.) Jacques são potenciais fontes medicinais para o tratamento de cânceres. A Leucemia Mieloide Crônica (LMC) é um distúrbio das células-tronco hematopoiéticas que é tratado com inibidores da tirosina quinase, mas frequentemente, causa recorrência da leucemia após a interrupção da terapia, portanto, requer um tratamento alternativo. Este estudo determinou o efeito anticancerígeno de extratos metanólicos e aquosos de folha, raiz e bulbo de B. natalensis e C. comosum na linhagem celular de leucemia mieloide humana crônica (K562) por ensaios de MTT, Hoechst bis-benzimida nuclear e anexina V. O extrato metanólico da raiz de B. natalensis e C. comosum apresentou alta citotoxidade de 8,6% e 16,7% respectivamente, na linhagem celular K562 com a concentração de 1,000 μg / ml. Perda morfológica da integridade da membrana celular causando degradação dos núcleos, citoplasma e encolhimento celular foi observada no extrato metanólico da raiz de ambas as plantas. Uma alta apoptose (p <0,0001) foi induzida nas células K562 por extratos de folhas e raízes de C. comosum em comparação com B. natalensis. Este estudo mostrou que ambas as plantas possuem efeito apoptótico contra leucemia mieloide in vitro que contribui para as propriedades anticâncer gerais de B. natalensis e C. comosum para justificar futuras aplicações terapêuticas contra câncer de sangue de LMC.

Apoptotic effect of Bulbine Natalensis and Chlorophytum Comosum in myelogenous Leukemia K562 cell line

Abstract Bulbine natalensis and Chorophytum comosum are potential medicinal source for the treatment of cancers. Chronic myeloid leukaemia is a hematopoietic stem cells disorder treated by tyrosine kinase inhibitors but often cause recurrence of the leukaemia after cessation of therapy, hence require alternative treatment. This study determines the anti-cancer effect of leaf, root and bulb methanolic and aqueous extracts of B. natalensis and C. comosum in chronic human myelogenous leukaemia (K562) cell line by MTT, Hoechst bis-benzimide nuclear and annexin V stain assays. The root methanolic extract of B. natalensis and C. comosum showed a high cytotoxicity of 8.6% and 16.7% respectively on the K562 cell line at 1,000 g/ml concentration. Morphological loss of cell membrane integrity causing degradation of the cell and fragmentation were observed in the root methanolic extract of both plants. A high apoptosis (p 0.0001) was induced in the K562 cells by both leaf and root extracts of the C. comosum compared to the B. natalensis. This study shows both plants possess apoptotic effect against in vitro myelogenous leukaemia which contributes to the overall anti-cancer properties of B. natalensis and C. comosum to justify future therapeutic applications against chronic myelogenous leukaemia blood cancer.

Resumo Bulbine natalensis Baker e Chorophytum comosum (Thunb.) Jacques são potenciais fontes medicinais para o tratamento de cânceres. A Leucemia Mieloide Crônica (LMC) é um distúrbio das células-tronco hematopoiéticas que é tratado com inibidores da tirosina quinase, mas frequentemente, causa recorrência da leucemia após a interrupção da terapia, portanto, requer um tratamento alternativo. Este estudo determinou o efeito anticancerígeno de extratos metanólicos e aquosos de folha, raiz e bulbo de B. natalensis e C. comosum na linhagem celular de leucemia mieloide humana crônica (K562) por ensaios de MTT, Hoechst bis-benzimida nuclear e anexina V. O extrato metanólico da raiz de B. natalensis e C. comosum apresentou alta citotoxidade de 8,6% e 16,7% respectivamente, na linhagem celular K562 com a concentração de 1,000 g / ml. Perda morfológica da integridade da membrana celular causando degradação dos núcleos, citoplasma e encolhimento celular foi observada no extrato metanólico da raiz de ambas as plantas. Uma alta apoptose (p 0,0001) foi induzida nas células K562 por extratos de folhas e raízes de C. comosum em comparação com B. natalensis. Este estudo mostrou que ambas as plantas possuem efeito apoptótico contra leucemia mieloide in vitro que contribui para as propriedades anticâncer gerais de B. natalensis e C. comosum para justificar futuras aplicações terapêuticas contra câncer de sangue de LMC.

Modulation of CYP3A4 and CYP2C9 activity by Bulbine natalensis and its constituents: An assessment of HDI risk of B. natalensis containing supplements.

BACKGROUND: Bulbine natalensis is an African-folk medicinal plant used as a dietary supplement for enhancing sexual function and muscle strength in males by presumably boosting testosterone levels, but no scientific information is available about the possible herb-drug interaction (HDI) risk when bulbine-containing supplements are concomitantly taken with prescription drugs. PURPOSE: This study was aimed to investigate the HDI potential of B. natalensis in terms of the pregnane X receptor (PXR)-mediated induction of major drug-metabolizing cytochrome P450 enzyme isoforms (i.e., CYP3A4 and CYP2C9) as well as inhibition of their catalytic activity. RESULTS: We found that a methanolic extract of B. natalensis activated PXR (EC50 6.2 ± 0.6 µg/ml) in HepG2 cells resulting in increased mRNA expression of CYP3A4 (2.40 ± 0.01 fold) and CYP2C9 (3.37 ± 0.3 fold) at 30 µg/ml which was reflected in increased activites of the two enzymes. Among the constituents of B. natalensis, knipholone was the most potent PXR activator (EC50 0.3 ± 0.1 µM) followed by bulbine-knipholone (EC50 2.0 ± 0.5 µM), and 6'-methylknipholone (EC50 4.0 ± 0.5 µM). Knipholone was also the most effective in increasing the expression of CYP3A4 (8.47 ± 2.5 fold) and CYP2C9 (2.64 ± 0.3 fold) at 10 µM. Docking studies further confirmed the unique structural features associated with knipholones for their superior inductive potentials in the activation of PXR compared to other anthraquinones. In a CYP inhibition assay, the methanolic extract as well as the anthraquinones strongly inhibited the catalytic activity of CYP2C9 while, inhibition of CYP3A4 was weak. CONCLUSIONS: These results suggest that consumption of B. natalensis may pose a potential risk for HDI if taken with conventional medications that are substrates of CYP3A4 and CYP2C9 and may contribute to unanticipated adverse reactions or therapeutic failures. Further studies are warranted to validate these findings and establish their clinical relevancy.

Antimicrobial activity of the solvent fractions from Bulbine natalensis Tuber.

Bulbine natalensis Baker has been acclaimed to be used as an antimicrobial agent in the folklore medicine of South Africa without scientific evidence to substantiate or refute this claim. In view of this, the in vitro antimicrobial activity of solvent fractions (ethanol, ethyl acetate, n-butanol and water) from Bulbine natalensis Tuber against 4 Gram positive and 12 Gram negative bacteria as well as 3 fungal species were investigated using agar dilution. The ethanolic extract, n-butanol and ethyl acetate fractions inhibited 75, 87.5 and 100% respectively of the bacterial species in this study. The ethanolic, n-butanol and ethyl acetate fractions produced growth inhibition at MIC range of 1-10, 3-10 as well as 1 and 5 mg/ml respectively whereas the water fraction did not inhibit the growth of any of the bacterial species. Again, it was only the ethyl acetate fraction that inhibited the growth of Shigelli flexneri, Staphyloccus aureus and Escherichia coli. The ethanolic, ethyl acetate and n-butanolic fractions dose dependently inhibited the growth of Aspergillus niger and A. flavus whereas the water fraction produced 100% growth inhibition of the Aspergillus species at all the doses investigated. In contrast, no growth inhibition was produced on Candida albicans. The growth inhibition produced by the solvent fractions of B. natalensis Tuber in this study thus justifies the acclaimed use of the plant as an antimicrobial agent. The ethyl acetate fraction was the most potent.