Clara Shui Fern Bah

Slaughterhouse Blood: An Emerging Source of Bioactive Compounds

Slaughterhouse blood is an inevitable part of the meat production food chain and represents a rich source of protein. The physicochemical characteristics and utilization of animal blood in various food and industrial applications has been well explored. However, in recent years much attention has been paid to the generation of peptides with biological activities from food by-products including blood. This review examines the angiotensin-converting enzyme inhibitory, antioxidant, antimicrobial, and other bioactive peptides derived from various slaughterhouse animal blood sources. Furthermore, the effect of enzyme choice, degree of hydrolysis, and peptide sequence or size on the potency of these bioactivity is discussed.

Bauhinia variegata var. variegata trypsin inhibitor: From isolation to potential medicinal applications

Here we report for the first time of a new Kunitz-type trypsin inhibitor (termed BvvTI) from seeds of the Camels foot tree, Bauhinia variegata var. variegata. BvvTI shares the same reactive site residues (Arg, Ser) and exhibits a homology of N-terminal amino acid sequence to other Bauhinia protease inhibitors. The trypsin inhibitory activity (K(i), 0.1 x 10(-9)M) of BvvTI ranks the highest among them. Besides anti-HIV-1 reverse transcriptase activity, BvvTI could significantly inhibit the proliferation of nasopharyngeal cancer CNE-1 cells in a selective way. This may partially be contributed by its induction of cytokines and apoptotic bodies. These results unveil potential medicinal applications of BvvTI.

Purification and Modes of Antifungal Action by Vicia faba cv. Egypt Trypsin Inhibitor

A new 15 kDa Bowman-Birk type trypsin inhibitor (termed VFTI-E1) from fava beans (Vicia faba cv. Egypt 1) was isolated using liquid chromatography. Though it exhibited substantial homology in N-terminal amino acid sequence to other protease inhibitors, VFTI-E1 showed antiproteolytic activity against trypsin (K(i) 11.9 × 10(-9) M) but hardly any activity against chymotrypsin. It demonstrated antifungal activity toward the filamentous fungus Valsa mali with an IC(50) of 20 μM. The mechanism of its antifungal action toward V. mali included (1) induction of alteration of hyphal morphology, (2) growth inhibition by chitin deposition at hyphal tips, and (3) permeabilization of fungal membrane. The antifungal activity of VFTI-E1 was dependent on the ambient ionic strength as increasing concentrations of NaCl, CaCl(2), and MgCl(2) diminished the activity. The membranolytic action of VFTI-E1 was confined to fungus, but not exerted on human and rabbit erythrocytes. This study sheds light on the mode of hyphal growth inhibitory activity of protease inhibitors with antifungal activity. The antifungal activity of VFTI-E1 amplifies the scope of its potential applications.

A potential human hepatocellular carcinoma inhibitor from Bauhinia purpurea L. seeds: from purification to mechanism exploration

A 20-kDa Kunitz-type trypsin-chymotrypsin inhibitor, Bauhinia purpurea trypsin inhibitor (BPLTI), has been isolated from the seeds of B. purpurea L. by using liquid chromatography procedures that involved ion exchange chromatography on Sp-Sepharose and Mono S and gel filtration on Superdex 75. BPLTI demonstrated protease inhibitory activities of 7226 BAEE units/mg and 65 BTEE units/mg toward trypsin and α-chymotrypsin, respectively. BPLTI was relatively thermal (0–60°C) and pH (3–10) stable and its activity could be decreased by dithiothreitol treatment. BPLTI exhibited a wide spectrum of anti-proliferative and pro-apoptotic activities especially on human hepatocellular carcinoma Hep G2 cells. However, it was devoid of a significant antiproliferative effect on immortal human hepatic WRL 68 cells. We show here that BPLTI stimulates apoptosis in Hep G2 cells, including (1) evoking DNA damage including the production of chromatin condensation and apoptotic bodies; (2) induction of cell apoptosis/necrosis; (3) mitochondrial membrane depolarization; and (4) increasing the production of cytokines. Taken together, our findings show for the first time that purified protease inhibitor from B. purpurea L. seeds is a promising candidate for the treatment of human hepatocellular carcinoma.

Purification and characterization of a rhamnose-binding chinook salmon roe lectin with antiproliferative activity toward tumor cells and nitric oxide-inducing activity toward murine macrophages.

In this study, a rhamnose-binding lectin from the roe of chinook salmon (Oncorhynchus tshawytscha) was purified and characterized, and its biological activities were examined in several model systems. Chinook salmon roe lectin had a molecular mass of 30 kDa and agglutinated rabbit and bovine erythrocytes. The hemagglutination activity of the lectin was not affected by metal ions. The lectin was stable up to 70 °C and between pH 4 and pH 11. Chinook salmon roe lectin did not exert antifungal activity toward the fungal species tested and did not exhibit mitogenic response toward mouse splenocytes up to a concentration of 5 mg/mL. The lectin had selective antiproliferative activity toward human breast cancer MCF-7 cells and hepatoma Hep G2 cells. It also induced the production of nitric oxide from mouse peritoneal macrophages. This is the first report that demonstrates these biological activities from chinook salmon roe lectin.

Production of bioactive peptide hydrolysates from deer, sheep, pig and cattle red blood cell fractions using plant and fungal protease preparations.

Protease preparations from plant (papain and bromelain) and fungal (FP400 and FPII) sources were used to hydrolyze the red blood cell fractions (RBCFs) separated from deer, sheep, pig, and cattle abattoir-sourced blood. After 1, 2, 4 and 24h of hydrolysis, the antioxidant and antibacterial activities of the peptide hydrolysates obtained were investigated. The increase in trichloroacetic acid-soluble peptides over the hydrolysis period was examined using the o-phthaldialdehyde (OPA) assay and the hydrolysis profiles were illustrated using SDS-PAGE. Papain generated RBCF hydrolysates exhibited higher ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) compared to those generated with bromelain, FP400 and FPII. At certain concentrations, 24h hydrolysates of RBCF using FP400 and FPII were able to inhibit the growth of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The results indicated that the use of proteases from plant or fungal sources can produce animal blood hydrolysates with antioxidant and antimicrobial activities.

Production of bioactive peptide hydrolysates from deer, sheep and pig plasma using plant and fungal protease preparations

Plasma separated from deer, sheep and pig blood, obtained from abattoirs, was hydrolysed using protease preparations from plant (papain and bromelain) and fungal (FP400 and FPII) sources. Antioxidant and antimicrobial activities of the peptide hydrolysates obtained after 1, 2, 4 and 24h of hydrolysis, were investigated. The release of trichloroacetic acid-soluble peptides over the hydrolysis period was monitored using the o-phthaldialdehyde (OPA) assay, while the hydrolysis profiles were visualised using SDS-PAGE. The major plasma proteins in the animal plasmas were identified using MALDI-TOF-TOF MS. Hydrolysates of plasma generated with fungal proteases exhibited higher DPPH radical-scavenging, oxygen radical-scavenging capacity (ORAC) and ferric reducing antioxidant power (FRAP) than those generated with plant proteases for all three animal plasmas. No antimicrobial activity was detected in the hydrolysates. The results indicated that proteolytic hydrolysis of animal blood plasmas, using fungal protease preparations in particular, produces hydrolysates with high antioxidant properties.

Generation of bioactive peptide hydrolysates from cattle plasma using plant and fungal proteases.

Four protease preparations from plant and fungal sources (papain, bromelain, FP400 and FPII) were used to hydrolyse plasma which was separated from slaughterhouse cattle blood. The o-phthaldialdehyde assay was used to follow the release of TCA-soluble peptides over a 24h period. Hydrolysis profiles were displayed using SDS-PAGE. The in vitro antioxidant and antimicrobial activities of the hydrolysates were determined. The results showed that hydrolysates of cattle plasma generated with fungal protease FPII had higher antioxidant activities. Overall than hydrolysates generated with papain, bromelain and FP400. None of the hydrolysates demonstrated antimicrobial activity. The FPII peptide hydrolysate was fractionated using gel permeation chromatography, OFFGEL isoelectric focusing and RP-HPLC. The RP-HPLC fraction with highest antioxidant activity contained 15 novel peptide sequences. The use of protease FPII to hydrolyse cattle plasma resulted in a hydrolysate with high antioxidant properties and unique peptide sequences.

Isolation of a New Trypsin Inhibitor from the Faba Bean (Vicia faba cv. Giza 843) with Potential Medicinal Applications

A new 15-kDa Bowman-Birk type trypsin inhibitor (termed VFTI-G1) was isolated from the seeds of Faba bean (Vicia faba cv. Giza 843) using cation exchange chromatography on an SP-Sepharose column, anion exchange chromatography on Q-Sepharose and Mono Q columns, and finally size exclusion chromatography on a Superdex 75 column. VFTI-G1 manifested significant antiproteolytic activity against trypsin (5761 BAEE units/mg, K(i) 20.4 × 10(-9) M), but only a slight chymotrypsin inhibitory activity (< 10 BTEE units/mg). The suitable environment to sustain its trypsin inhibitory activity was at temperatures below 60 °C and at pH 7. Its trypsin inhibitory activity was inhibited by the reducing agent dithiothreitol in a dose-dependent manner, indicating the significance of intact disulfide bonds to the trypsin inhibitory activity. It inhibited HIV-1 reverse transcriptase (RT) activity with an IC(50) of about 0.76 µM. Furthermore, VFTI-G1 showed specific antiproliferative activity toward HepG2 hepatoma cells by inducing chromatin condensation and cell apoptosis. The HIV-1 RT inhibitory activity of VFTI-G1 and its specific antiproliferative activity toward Hep G2 cells may find medical applications.

Medicinal Applications of Plant Lectins

Plant lectins are a unique group of proteins and glycoproteins with potent biological activity and have received widespread attention for many years. They can be found in wheat, corn, tomatoes, peanuts, kidney beans, bananas, peas, lentils, soybeans, mushrooms, tubers, seeds, mistletoe and potatoes among many others. Due to their ability to bind reversibly with specific carbohydrate structures and their abundant availability, plant lectins have commonly been used as a molecular tool in various disciplines of biology and medicine. Whilst once thought of being a dietary toxin, the focus on plant lectins has since shifted to understanding the useful properties of these lectins and utilizing them in medicinal applications to advance human health. This chapter reviews the current and potential applications of plant lectins in various areas of medically related research.