In this study, toxicological safety (mutagenicity) and therapeutic potential (antimutagenicity)
of water extract of Centella asiatica Linn., were evaluated using the Allium cepa assay. The
mitotic index (MI) at 6.25% concentration of the extract decreased significantly from 3.13% to
2.05% after 24 h and 48 h, respectively, however, the MI increased significantly by 60% and
400% at 12.5% and 50.0% concentrations, respectively. There was total arrest of cell division
at 100% concentration after 24 h and 48 h of onion’s roots exposure to the water extract.
The chromosomal aberrations (CA) induced by the extract were not significantly different
from the negative control (p ≥ 0.05) at the tested concentrations. The mutagenic activity of
cyclophosphamide was significantly suppressed above 50% at the tested concentrations. These
results suggest non-genotoxic effect, and antimutagenic potency of water extract of C. asiatica
in A. cepa cells, being desirable characteristics of anticancer therapeutics.
Natural plant extracts offer a promising hope in the prevention/treatment of cancer arising from genetic mutations. This study evaluated in vitro and in vivo mutagenic and antimutagenic effects of aqueous fraction of Myristica fragrans (AFMF) leaves on TA100 strain of Salmonella typhimurium and Mus musculus (Male Swiss albino mice), respectively. The antioxidant activity of AFMF against 2,2-diphenyl-1-picrylhydrazyl (DPPH), total phenolic and flavonoid contents were determined, followed by its phytochemical elucidation using the Ultra Performance Liquid Chromatography technique (UPLC). The mutagenicity of AFMF at 4, 20, 50, 100, 200, 500, and 1000 µg/well was <2.0 in S. typhimurium and the induced micronucleated polychromatic and normochromatic erythrocytes at 500, 1000, 2000, and 4000 mg/kg were not significantly different from the negative control (p≥0.05). The mutagenic activity of benzo[a]pyrene and cyclophosphamide was significantly suppressed above 50.0% throughout the tested concentrations. Fifty percent of the free radicals from DPPH were scavenged by AFMF at 0.11 mg/ml. Total phenolic and flavonoid contents of AFMF were 51.0 mg GAE/g and 27 mg QE/g, respectively. Rutin was elucidated by the UPLC technique, and thereby suspected to be the phytochemical responsible for the observed antimutagenic activity. Thus far, AFMF seems to contain a promising chemotherapeutic agent for the prevention of genetic damage that is crucial for cancer development.
Unwanted side effects from a polluted water body may not be limited to the flora and fauna, they may also be transferred to the organisms along the food chain. Four water samples collected immediately and five days after rainfall from two locations inside the polluted Sungai Dua River (SGD) were tested for toxicity using the Allium cepa assay. The samples were analysed for metal content and were both macroscopically and microscopically evaluated. The water samples contained more sodium (Na(+)) and calcium (Ca(2+)) than the control tap water, and they showed root growth and mitotic inhibitions (MI) in A. cepa. However, the inhibitory effects were not dose-dependent. No chromosomal aberration (CA) was induced at 100.00% (undiluted water sample). These results suggest the water samples from SGD had weak mitodepressive and genotoxic effects on the A. cepa cells.
The role of diets in causing cancers necessitates the ongoing search for natural antimutagens of promising anticancer therapeutics. This study determined the potential anticancer efficacy of the leaf extract of Myristica fragrans (Houtt.). Methanol leaf extract of M. fragrans (Houtt.) alone was screened for mutagenicity in the bacterial reverse mutation (Ames) test, using the Salmonella typhimurium TA100 strain, the Allium cepa, and the mouse in vivo bone marrow micronucleus tests. The antimutagenicity of this extract against benzo[a]pyrene- and cyclophosphamide-induced mutations was evaluated. An antioxidant test on the extract was performed with 2,2-diphenyl-1-picrylhydrazyl, using butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as the standards, whereas its phytochemicals were elucidated by following the gas chromatography/mass spectrometry protocol. In S. typhimurium (TA100), the mutagenicity ratio at 200,500 and 1,000 µg/well was >2. Cell division in the A. cepa root tips and mouse bone marrow was significantly (P ≤ 0.05) inhibited at 2,000 and 4,000 mg/kg, whereas the observed chromosomal aberrations and micronucleated polychromatic erythrocytes were non-dose-related and were insignificantly (P ≥ 0.05) different from the negative control. Inhibition of benzo[a]pyrene- and cyclophosphamide-induced mutagenicity by this extract was above 40%. Half-maximal inhibitory concentration of the extract in the antioxidant test was lower than that of BHA and BHT. Phytochemical compounds, possessing antioxidant activity, may be responsible for the observed effects, suggesting a strong antimutagenic activity of the MeOH leaf extract of M. fragrans, a necessary characteristic of a promising anticancer agent.
In this study, freeze-dried water extract from the leaves of Myristica fragrans (Houtt.) was tested for mutagenic and antimutagenic potentials using the Allium cepa assay. Freeze-dried water extract alone and its combination with cyclophosphamide (CP) (50 mg/kg) were separately dissolved in tap water at 500, 1000, 2000, and 4000 mg/kg. Onions (A. cepa) were suspended in the solutions and controls for 48 h in the dark. Root tips were prepared for microscopic evaluation. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radicals' scavenging power of the extract was tested using butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as standards. Water extract of Myristica fragrans scavenged free radicals better than BHA, but worse than BHT. The extract alone, as well as in combination with CP suppressed cell division, and induced chromosomal aberrations that were insignificantly different from the negative control (P ≤ 0.05). However, cytotoxic and mutagenic actions of CP were considerably suppressed. The observed effects on cell division and chromosomes of A. cepa may be principally connected to the antioxidant properties of the extract. The obtained results suggest mitodepressive and antimutagenic potentials of water extract of the leaves of M. fragrans as desirable properties of a promising anticancer agent.