Antibacterial and cytotoxicity evaluation of Arum hygrophilum Bioss

OBJECTIVE

Arum hygrophilum Bioss is a plant native to Asia, Europe, and Northern Africa. It is consumed as beverages, spices, or cooked leaves to cure gastrointestinal infections and cancer. This study aims to determine the antibacterial and anticancer effectivenesss of A. hygrophilum Bioss.

MATERIALS AND METHODS

Using the well-diffusion method, the antimicrobial activity of the plant's aqueous extract and five other organic extracts were evaluated against bacteria often associated with food poisoning. The assessment of the antiproliferative activity by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was done on five cancerous cell lines and on fibroblasts as a reference cell line.

RESULTS

The growth of L. monocytogenes was significantly inhibited by the aqueous and ethanolic extracts. Both extracts had a minimum inhibitory concentration (MIC) of 62.5 mg/mL. The inhibition caused by the methanolic extract had a MIC of 500 mg/mL. The growth of S. aureus and MRSA were inhibited by the aqueous extract with a MIC of 500 mg/mL, while the inhibition caused by the ethanolic extract had a MIC of 250 mg/mL on MRSA and 500 mg/mL on S.aureus. Both strains of S.aureus were also inhibited by the 3-pentanon extract, while the butanol extract only exhibited a moderate growth inhibition against MRSA. The MTT assay showed that the aqueous extract had not affected the proliferation of cancer cell lines. The cytotoxicity of the ethanolic and methanolic extracts had no concentration-inhibition relationship and the IC50 values were above 800 μg/mL for all extracts.

CONCLUSIONS

L. monocytogenes, S. aureus, and methicillin-resistant Staphylococcus aureus (MRSA) were inhibited by different Arum extracts. The antibacterial activity of Arum hygrophilum Bioss against foodborne pathogens makes it safe to use as a natural food preservative, and as a source for sanitizers and antimicrobials. Further investigation is recommended to determine the cytotoxicity of the plant against additional cancer cell lines.

Stability of batanopride hydrochloride in aqueous solutions

The degradation of batanopride hydrochloride, an investigational antiemetic drug, was studied in aqueous buffer solutions (pH 2-10; ionic strength, 0.5; 56 degrees C) in an attempt to improve drug stability for parenteral administration. Degradation occurs by two different mechanisms depending on the pH of the solution. In acidic media (pH 2-6), the predominant reaction was intramolecular cyclization followed by dehydration to form a 2,3-dimethylbenzofuran. There was no kinetic or analytical (high-performance liquid chromatography) evidence for the formation of an intermediate; therefore, the rate of dehydration must have been very rapid compared with the rate of cyclization. In alkaline media (pH 8-10), the primary route of degradation was cleavage of the C-O alkyl ether bond. In the intermediate pH range (pH 6-8), both reactions contributed to the overall degradation. Both degradation reactions followed apparent first-order kinetics. The pH-rate profile suggests that batanopride hydrochloride attains its optimal stability at pH 4.5-5.5. Citrate buffer was catalytic at pH 3 and 5, and phosphate buffer was catalytic at pH 8. No catalytic effect was observed for the borate buffer at pH 9-10.

Effects of structural variations on the rates of enzymatic and nonenzymatic hydrolysis of carbonate and carbamate esters

The effect of structural variations on the rates of elastase-catalyzed hydrolysis of model carbonate and carbamate esters was studied using HPLC. It is shown that branching in the immediate vicinity of the carbonate or carbamate functionally results in decreased hydrolysis rates. Whereas aryl carbonates act as substrates for elastase, p-nitrophenyl butyl carbamate inhibits the enzyme. A novel method was developed for the entrapment and quantitation of 14CO2 produced upon hydrolysis of carbonyl-14C-labeled carbonate esters. This technique could be useful in studying the mechanism of enzymatic hydrolysis of this type of compound and has the potential of being adapted as a convenient method in the assessment of estrolytic activity of tissue homogenates.