Bioactivities of Jc‐SCRIP,a Type 1 Ribosome‐Inactivating Protein from Jatropha curcas Seed Coat

In this study, a type 1 RIP, designated as Jc‐SCRIP, was first isolated from the seed coat of Jatropha curcas Linn. It was purified by ammonium sulfate precipitation and chromatography on DEAE‐Sephacel? and CM‐cellulose columns. Purification fold of Jc‐SCRIP increased 113.8 times, and the yield was 1.13% of the total protein in the final step. It was shown to be a monomeric glycoprotein with a molecular mass of 38 938 Da, as determined by MALDI‐TOF/MS. It exhibited hemagglutination activity and possessed strong N‐glycosidase activity. The antimicrobial activity of Jc‐SCRIP was tested against nine human pathogenic bacteria and one fungus; the most potent inhibitory activity was against Staphylococcus epidermidis ATCC 12228, with minimum inhibitory concentration value of 0.20 μm . Jc‐SCRIP demonstrated in vitro cytotoxicity against human breast adenocarcinoma cell line (MCF‐7), a colon adenocarcinoma (SW620), and a liver carcinoma cell line (HepG2), with IC₅₀ values of 0.15, 0.25, and 0.40 mm , respectively. The results suggested that Jc‐SCRIP may be a potential natural antimicrobial and anticancer agent in medical applications.     

Tumor cell-selective antiproliferative effect of the extract from Morinda citrifolia fruits

The methanol extract from Morinda citrifolia fruits was tested for cytotoxicity activity on the MTT assay. The appearance of cytotoxic changes after exposure to the extract was in a concentration dependent manner. The median lethal concentrations (LC(50)) of the extract in baby hamster kidney (BHK) cells, African green monkey kidney (Vero) cells and human laryngeal carcinoma (Hep2) cells were found to be 2.5, 3 and 5 mg/mL, respectively. A concentration of 0.1 mg/mL of crude extract exhibited cytotoxic activity against breast cancer (MCF7) and neuroblastoma (LAN5) cell lines at 29% and 36%, respectively. The same concentration of extract showed no toxicity to Vero and very little toxicity to BHK (6%) and Hep2 (13%) cells.