Anti-tumoral effects of a trypsin inhibitor derived from buckwheat in vitro and in vivo

Abstract

Native buckwheat, a common component of food products and medicine, has been observed to inhibit cancer cell proliferation in vitro. The aim of the present study was to evaluate the in vitro and in vivo anti-tumoral effects of recombinant buckwheat trypsin inhibitor (rBTI) on hepatic cancer cells and the mechanism of apoptosis involved. Apoptosis in the H22 cell line induced by rBTI was identified using MTT assays, DNA electrophoresis, flow cytometry, morphological observation of the nuclei, measurement of cytochrome C and assessment of caspase activation. It was identified that rBTI decreases cell viability by inducing apoptosis, as evidenced by the formation of apoptotic bodies and DNA fragmentation. rBTI-induced apoptosis occurred in association with mitochondrial dysfunction, leading to the release of cytochrome C from the mitochondria to the cytosol, as well as the activation of caspase-3, -8 and -9. In conclusion, the results of the present study suggested that rBTI specifically inhibited the growth of the H22 hepatic carcinoma cell line in vitro and in vivo in a concentration-dependent and time-dependent manner, while there were minimal effects on the 7702 normal liver cell line. In addition, rBTI-induced apoptosis in H22 cells was, at least in part, mediated by a mitochondrial pathway via caspase-9.

Protein-Rich Flours from Quinoa and Buckwheat Favourably Affect the Growth Parameters, Intestinal Microbial Activity and Plasma Lipid Profile of Rats

“…Recent studies on mouse and macrophage cells have shown that the immune response(s) induced by the administration of ATIs may differ and depend(s) on the type of cereal [10,11]. In addition to ATIs, trypsin inhibitors (rBTIs), which can also modulate immunometabolic mechanisms in hepatocytes, were also found in the protein fractions of buckwheat seeds [12]. Notably, recent reports have demonstrated the implication of innate immune effectors as determinants shaping gut microbiota and lipid homeostasis [13].…”

Cysteine Proteases from V. cundinamarcensis (C. candamarcensis) Inhibit Melanoma Metastasis and Modulate Expression of Proteins Related to Proliferation, Migration and Differentiation

“…These notable biological activities attributed to cysteine proteases from V. cundinamarcensis were also observed in other proteolytic enzymes, such as bromelain, papain, and the serine proteases trypsin and chymotrypsin [ 10 , 11 ]. In the case of trypsin and chymotrypsin, their role is controversial as some evidence support the antitumoral effect, while others attribute to them a tumorigenic effect [ 12 , 13 ]. Preclinical and clinical studies showed that plant proteolytic enzymes act as antitumor and chemopreventive agents due to a variety of biological activities, encompassing pro-apoptotic [ 14 , 15 , 16 , 17 ] and anti-inflammatory effects [ 18 ].…”

Molecular Cloning and Structure–Function Analysis of a Trypsin Inhibitor from Tartary Buckwheat and Its Application in Combating Phytopathogenic Fungi

“…Plant protease inhibitors have been isolated and characterized from Leguminosae, Solanaceae, Gramineae, and Cruciferae [6][7][8]. In their defense against natural enemies, plants have formed a variety of protease inhibitors, the best-characterized being members of four different families: the Kunitz-type (18)(19)(20)(21)(22), the Bowman-Birk (8-10 kDa), the Kazal (6-8 kDa), and potato protease inhibitor I (10-14 kDa) [9]. In these four families, the reactive P1 residue is always an arginine or lysine [9,10].…”

“…Tartary buckwheat is widely cultivated in the southwestern mountains of China and grows mainly on the Yunnan-Guizhou Plateau (altitude range: 2100-3400 m above sea level). Common buckwheat protease inhibitors have remarkable functions and anti-inflammatory, anti-leukemia, anticancer, anti-bollworm, and anti-plant fungal disease effects [18][19][20][21][22][23]. However, there are relatively few studies on tartary buckwheat protease inhibitors.…”