ABSTRACT
BACKGROUND: Colon cancer is a major health problem worldwide. Available treatments such as surgery, chemotherapy, radiation and anticancer drugs are limited due to stage of cancer, side effects and altered biodistribution. The use of peptides extracted from natural products has appeared as a potential therapy. Gloriosa superba is known to contain colchicine and other alkaloids with anticancer activity. However, these peptides contained within the extracts have not been studied. This study, therefore, focuses on an investigation of anti-colon cancer activity from a partially purified protein hydrolysate of G superba rhizome. METHODS: Dried G superba rhizome was extracted using 0.5% sodium dodecyl sulfate and digested with pepsin. The protein hydrolysates with molecular weight lesser than 3kDa were collected and subjected for cell viability assay. Then, the partial purification of the protein hydrolysate was performed using reverse-phase high-performance liquid chromatography. Fractions containing anticancer peptides were investigated, and their effects on apoptosis and protein expression using apoptosis test and Western blot, respectively. RESULTS: Partially purified peptides of G superba rhizome demonstrated anticolon activity in SW620 cells by inducing apoptosis through upregulation of p53 and downregulation of nuclear factor kappa B (NF-κB). CONCLUSIONS: Consequently, G superba peptides showed high potential for further purification and development of anticolon therapeutics.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Colchicaceae/chemistry , Colonic Neoplasms/drug therapy , Gene Expression Regulation, Neoplastic/drug effects , Peptides/pharmacology , Plant Proteins/pharmacology , Rhizome/chemistry , Tumor Suppressor Protein p53/biosynthesis , Up-Regulation/drug effects , Animals , Antineoplastic Agents, Phytogenic/chemistry , Apoptosis/drug effects , Cell Line, Tumor , Chlorocebus aethiops , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Humans , Peptides/chemistry , Plant Proteins/chemistry , Vero CellsABSTRACT
Angiotensin-I-converting enzyme (ACE) plays an important role in blood pressure regulation. In this study, an ACE-hexapeptide inhibitor (Asp-Glu-Asn-Ser-Lys-Phe) designated as chebulin was produced from the fruit protein of Terminalia chebula Retz. by pepsin digestion, ultrafiltrated through a 3 KDa cut-off membrane, a reverse-phase high-performance liquid chromatography, and nano-liquid chromatography tandem mass spectrometry analysis. Chebulin was found to inhibit ACE in a noncompetitive manner, as supported by the structural model. It bounds to ACE by the hydrogen bond, hydrophobic and ionic interactions via the interactions of C-terminal Phe (Phe-6), and N-terminal residues (Asp-1 and Glu-2) with the amino acid residues on noncatalytic sites of the ACE. The results showed that chebulin derived from fruits of T. chebula Retz. is a potential ACE-peptide inhibitor that could be used as a functional food additive for the prevention of hypertension and as an alternative to ACE inhibitor drug.
Subject(s)
Angiotensin-Converting Enzyme Inhibitors/pharmacology , Fruit/chemistry , Oligopeptides/pharmacology , Peptidyl-Dipeptidase A/metabolism , Terminalia/chemistry , Amino Acid Sequence , Angiotensin-Converting Enzyme Inhibitors/chemistry , Angiotensin-Converting Enzyme Inhibitors/isolation & purification , Angiotensin-Converting Enzyme Inhibitors/metabolism , Humans , Kinetics , Models, Molecular , Oligopeptides/chemistry , Oligopeptides/isolation & purification , Oligopeptides/metabolism , Plant Proteins/metabolism , Protein ConformationABSTRACT
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.
Subject(s)
Jatropha/chemistry , Ribosome Inactivating Proteins, Type 1/metabolism , Seeds/chemistry , Amino Acid Sequence , Animals , Chlorocebus aethiops , Electrophoresis, Polyacrylamide Gel , Jatropha/embryology , Mass Spectrometry , Molecular Sequence Data , Ribosome Inactivating Proteins, Type 1/chemistry , Vero CellsABSTRACT
α-Amylase is a common enzyme for hydrolyzing starch. In the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), α-amylase is found in both digestive fluid and hemolymph. Here, the complete genomic sequence of the Amy gene encoding α-amylase from a local Thai silkworm, the Nanglai strain, was obtained. This gene was 7981 bp long with 9 exons. The full length Amy cDNA sequence was 1749 bp containing a 1503 bp open reading frame. The ORF encoded 500 amino acid residues. The deduced protein showed 81-54% identity to other insect α-amylases and more than 50% identity to mammalian enzymes. Southern blot analysis revealed that in the Nanglai strain Amy is a single-copy gene. RT- PCR showed that Amy was transcribed only in the foregut. Transgenic B. mori also showed that the Amy promoter activates expression of the transgene only in the foregut.
