Phytochemical Profiling by UHPLC-Q-TOF/MS and Chemopreventive Effect of Aqueous Extract of Moringa oleifera Leaves and Benzyl Isothiocyanate on Murine Mammary Carcinogenesis.

Moringa oleifera Lam, commonly known as moringa, is a plant widely used both as a human food and for medicinal purposes around the world. This research aimed to evaluate the efficacy of the aqueous extract of Moringa oleifera leaves (MoAE) and benzyl isothiocyanate (BIT) in rats with induced breast cancer. Cancer was induced with 7,12-dimethylbenz[a]anthracene (DMBA) at a dose of 60 mg/kg by orogastric gavage once only. Forty-eight rats were randomly assigned to eight groups, each consisting of six individuals. The control group (healthy) was called Group I. Group II received DMBA plus saline. In addition to DMBA, Groups III, IV, and V received MoAE at 100, 250, and 500 mg/kg/day, respectively, while Groups VI, VII, and VIII received BIT at 5, 10, and 20 mg/kg/day, respectively. Treatment was carried out for 13 weeks. Secondary metabolite analysis results identified predominantly quercetin, caffeoylquinic acid, neochlorogenic acid, vitexin, and kaempferol, as well as tropone, betaine, loliolide, and vitexin. The administration of MoAE at a dose of 500 mg/kg and BIT at 20 mg/kg exhibited a notable decrease in both the total tumor count and the cumulative tumor weight, along with a delay in their onset. Furthermore, they improved the histological grade. A significant decrease in serum levels of VEGF and IL-1ß levels was observed (p < 0.001) with a better effect demonstrated with MoAE at 500 mg/kg and BIT at 20 mg/kg. In conclusion, this study suggests that both the aqueous extract of Moringa oleifera leaves and the benzyl isothiocyanate possess antitumor properties against mammary carcinogenesis, and this effect could be due, at least in part, to the flavonoids and isothiocyanates present in the extract.

Ribonucleoside labeling with Os(VI): a methodological approach to evaluation of RNA methylation by HPLC-ICP-MS.

Covalent modifications of nucleobases are thought to play an important role in regulating the functions of DNA and various cellular RNA types. Perhaps the best characterized is DNA methylation on cytosine (methyl tag attached to carbon 5 position) and such modification has also been detected in stable and long-lived RNA molecules. In this work, we propose a novel procedure enabling very sensitive quantification of methylcytidine and other ribonucleosides, based on reversed phase liquid chromatography with inductively coupled plasma mass spectrometry (ICP-MS) detection. The procedure relies on labeling ribose residues with osmium, by formation of a ternary complex between cis-diol ribose groups, hexavalent osmium (K(2)OsO(2)(OH)(4)) and tetramethylethylenediamine (TEMED). The derivatization reaction was carried out with 50 : 1 molar excess of Os to ribonucleoside, pH 4, for 2 h at room temperature. The structures of Os-labeled cytidine and methylcytidine were confirmed by electrospray ionization mass spectrometry. The separation of Os-labeled cytidine (C), uridine (U), 5-methylcytidine (5mC) and guanosine (G) was achieved on C18 column (Gemini, 150 × 3 mm, 5 µm) with isocratic elution (0.05% triethylamine + 6 mmol L(-1) ammonium acetate, pH 4.4: methanol (85 : 15)) and a total flow rate 0.6 mL min(-1). The column effluent was on-line introduced to ICP-MS (a model 7500 ce, Agilent Technologies) for specific detection at (189)Os. Calibration was performed within the concentration range 0-200 nmol L(-1) of each ribonucleoside and the analytical figures of merit were evaluated. For 100 µL injection, the detection limits for C, U, 5mC, G were 24, 38, 21 and 28 pmol L(-1), respectively. While introducing Os(vi)-TEMED to the column, it eluted in the dead volume and the detection limit for osmium was 20 pmol L(-1). The results obtained in this work might be helpful in the analysis of RNA digests, providing quantitative data on the ribonucleoside composition and RNA methylation (measured as the percentage of methylated cytidines with respect to total RNA cytidines).