Ibrahim Darah

Genotoxicity of Euphorbia hirta: An Allium cepa Assay

The potential genotoxic effects of methanolic extracts of Euphorbia hirta which is commonly used in traditional medicine to treat a variety of diseased conditions including asthma, coughs, diarrhea and dysentery was investigated using Allium cepa assay. The extracts of 125, 250, 500 and 1,000 µg/mL were tested on root meristems of A. cepa. Ethylmethanesulfonate was used as positive control and distilled water was used as negative control. The result showed that mitotic index decreased as the concentrations of E. hirta extract increased. A dose-dependent increase of chromosome aberrations was also observed. Abnormalities scored were stickiness, c-mitosis, bridges and vagrant chromosomes. Micronucleated cells were also observed at interphase. Result of this study confirmed that the methanol extracts of E. hirta exerted significant genotoxic and mitodepressive effects at 1,000 µg/mL.

In Vivo. and In Vitro. Toxicity Study of Gracilaria changii.

Abstract The methanol extract of Gracilaria changii. B.M. Xia & I.A. Abbott (Gracilariaciae), which exhibited antimicrobial activity, was tested for in vivo. brine shrimp lethality and in vitro.anticancer cell line activity. Both toxicity tests [brine shrimp test with LC50 value 4.28 mg/mL (12 h), 3.13 mg/mL (24 h) and anticancer cell line activity with IC50 value 44.10 μ g/mL] exhibited no significant toxicity result. These alga extracts, with high LC50 and IC50 values, are potential sources for novel antimicrobial compounds.

Acute and Subchronic Toxicity Study of Euphorbia hirta L. Methanol Extract in Rats

Despite Euphorbia hirta L. ethnomedicinal benefits, very few studies have described the potential toxicity. The aim of the present study was to evaluate the in vivo toxicity of methanolic extracts of E. hirta. The acute and subchronic oral toxicity of E. hirta was evaluated in Sprague Dawley rats. The extract at a single dose of 5000 mg/kg did not produce treatment related signs of toxicity or mortality in any of the animals tested during the 14-day observation period. Therefore, the LD 50 of this plant was estimated to be more than 5000 mg/kg. In the repeated dose 90-day oral toxicity study, the administration of 50 mg/kg, 250 mg/kg, and 1000 mg/kg/day of E. hirta extract per body weight revealed no significant difference (P > 0.05) in food and water consumptions, body weight change, haematological and biochemical parameters, relative organ weights, and gross findings compared to the control group. Macropathology and histopathology examinations of all organs including the liver did not reveal morphological alteration. Analyses of these results with the information of signs, behaviour, and health monitoring could lead to the conclusion that the long-term oral administration of E. hirta extract for 90 days does not cause sub-chronic toxicity.

In vitro antimicrobial activity against Pseudomonas aeruginosa and acute oral toxicity of marine algae Gracilaria changii

Methanol extract of the Gracilaria changii has been screened for antimicrobial activity against Pseudomonas aeruginosa. Antimicrobial activities were carried out using disc diffusion assay and broth dilution method against P. aeruginosa. The methanol extract of G. changii showed a good antimicrobial activity against P. aeruginosa with MIC (Minimum Inhibitory Concentration) value of 6.25mg/ml. Exposure of P. aeruginosa cells to 6.25mg/ml of methanol extract of G. changii resulted in complete inhibition of the bacterial cells. The main abnormalities noted via SEM and TEM studies were the alterations in morphology and cytology of the bacterial cells. The main reason for this deterioration was discussed. The effect of the methanol extract on the growth profile for the bacteria was also done and confirmed the bactericidal effect of the G. changii methanol extract on P. aeruginosa by changing the normal growth profile of P. aeruginosa. In an acute toxicity study using mice, the median lethal dose (LD(50)) of the extract was greater than 2000 mg/kg, and we found no pathological changes in macroscopic examination by necropsy of mice treated with extract. We conclude that G. changii might be safely used as an antimicrobial agent.

Toxicity study of Vernonia cinerea.

The methanol extract of Vernonia cinerea Less (Asteraceae), which exhibited antimicrobial activity, was tested for toxicity. In an acute toxicity study using mice, the median lethal dose (LD50) of the extract was greater than 2000 mg/kg, and we found no pathological changes in macroscopic examination by necropsy of mice treated with extract. As well as the oral acute toxicity study, the brine shrimp lethality test was also done. Brine shrimp test LC50 values were 3.87 mg/mL (6 h) and 2.72 mg/mL (24 h), exhibiting no significant toxicity result. In conclusion, the methanol extract of V. cinerea did not produce toxic effects in mice and brine shrimp.

In Vitro Antioxidant Activity Potential of Lantadene A, a Pentacyclic Triterpenoid of Lantana Plants

Lantadenes are pentacyclic triterpenoids present in the leaves of the plant Lantana camara. In the present study, in vitro antioxidant activity and free radical scavenging capacity of lantadene A was evaluated using established in vitro models such as ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH•), hydroxyl radical (OH•), nitric oxide radical (NO•), superoxide anion scavenging activities and ferrous ion chelating assay. Interestingly, lantadene A showed considerable in vitro antioxidant, free radical scavenging capacity activities in a dose dependant manner when compared with the standard antioxidant in nitric oxide scavenging, superoxide anion radical scavenging and ferrous ion chelating assay. These findings show that the lantadene A possesses antioxidant activity with different mechanism of actions towards the different free radicals tested. Since lantadene A is a very popular drug in modern medicine, it is a promising candidate for use as an antioxidant and hepatoprotective agent.

Screening antimicrobial activity of various extracts of Gracilaria changii.

The antimicrobial activities of methanol, methanol–chloroform, diethyl ether, ethyl acetate, and butanol extracts of Gracilaria changii B.M. Xia & I.A. Abbott (Gracilariaciae) were studied. These extracts were tested against 22 bacteria, six yeasts strains, and 11 fungal isolates by the disk diffusion and broth dilution methods. The results indicated that all of the solvent systems used in the study had equal effectiveness against the tested microorganisms. All of the extract preparations of G. changii showed significant activities against seven bacterial and four yeast isolates tested. The minimum inhibitory concentration (MIC) values of Pseudomonas aeruginosa and Bacillus subtilis were 6.25 and 3.125 to mg/mL, respectively, while the MIC for Candida albicans was 3.125 mg/mL. No fungal isolates showed any susceptibility against the different crude preparations of G. changii. The activities were compared to known commercialized antibiotics such as chloramphenicol and miconazole nitrate.

Cytotoxicity and genotoxicity assessment of Euphorbia hirta in MCF-7 cell line model using comet assay

OBJECTIVE To evaluate the cytotoxicity and genotoxicity activity of Euphorbia hirta (E. hirta) in MCF-7 cell line model using comet assay. METHODS The cytotoxicity of E. hirta extract was investigated by employing brine shrimp lethality assay and the genotoxicity of E. hirta was assessed by using Comet assay. RESULTS Both toxicity tests exhibited significant toxicity result. In the comet assay, the E. hirta extract exhibited genotoxicity effects against MCF-7 DNA in a time-dependent manner by increasing mean percentage of DNA damage. The extract of E. hirta showed significant toxicity against brine shrimp with an LC₅₀ value of 620.382 µg/mL (24 h). Comparison with positive control potassium dichromate signifies that cytotoxicity exhibited by the methanol extract might have moderate activity. CONCLUSION The present work confirmed the cytotoxicity and genotoxicity of E. hirta. However, the observed toxicity of E. hirta extracts needs to be confirmed in additional studies.

Identification of small molecule inhibitors of p27(Kip1) ubiquitination by high-throughput screening.

Dysregulation of p27Kip1 due to proteolysis that involves the ubiquitin ligase (SCF) complex with S‐phase kinase‐associated protein 2 (Skp2) as the substrate‐recognition component (SCFSkp2) frequently results in tumorigenesis. In this report, we developed a high‐throughput screening system to identify small‐molecule inhibitors of p27Kip1 degradation. This system was established by tagging Skp2 with fluorescent monomeric Azami Green (mAG) and CDK subunit 1 (Cks1) (mAGSkp2–Cks1) to bind to p27Kip1 phosphopeptides. We identified two compounds that inhibited the interaction between mAGSkp2–Cks1 and p27Kip1: linichlorin A and gentian violet. Further studies have shown that the compounds inhibit the ubiquitination of p27Kip1 in vitro as well as p27Kip1 degradation in HeLa cells. Notably, both compounds exhibited preferential antiproliferative activity against HeLa and tsFT210 cells compared with NIH3T3 cells and delayed the G1 phase progression in tsFT210 cells. Our approach indicates a potential strategy for restoring p27Kip1 levels in human cancers.

Cassia spectabilis (DC) Irwin et Barn: A Promising Traditional Herb in Health Improvement

The genus Cassia, comprising about 600 species widely distributed worldwide is well known for its diverse biological and pharmacological properties. Cassia spectabilis (sin Senna spectabilis) (DC) Irwin et Barn (Fabaceae) is widely grown as an ornamental plant in tropical and subtropical areas. C. spectabilis has been commonly used in traditional medicine for many years. Information in the biomedical literature has indicated the presence of a variety of medicinally-important chemical constituents in C. spectabilis. Pharmacological studies by various groups of investigators have shown that C. spectabilis possesses significant biological activity, such as antibacterial, antibiofilm, antifungal and antioxidant properties. Beside this, toxicity studies of this plant have revealed no toxic effect on mice. In view of the immense medicinal importance of C. spectabilis, this review aimed at compiling all currently available information on C. spectabilis’s botany, phytochemistry, pharmacology, and mechanism of actions, toxicology and its ethnomedicinal uses.