Chlorella vulgaris triggers apoptosis in hepatocarcinogenesis-induced rats

Abstract

Chlorella vulgaris (CV) has been reported to have antioxidant and anticancer properties. We evaluated the effect of CV on apoptotic regulator protein expression in liver cancer-induced rats. Male Wistar rats (200~250 g) were divided into eight groups: control group (normal diet), CDE group (choline deficient diet supplemented with ethionine in drinking water to induce hepatocarcinogenesis), CV groups with three different doses of CV (50, 150, and 300 mg/kg body weight), and CDE groups treated with different doses of CV (50, 150, and 300 mg/kg body weight). Rats were sacrificed at various weeks and liver tissues were embedded in paraffin blocks for immunohistochemistry studies. CV, at increasing doses, decreased the expression of anti-apoptotic protein, Bcl-2, but increased the expression of pro-apoptotic protein, caspase 8, in CDE rats, which was correlated with decreased hepatoctyes proliferation and increased apoptosis as determined by bromodeoxy-uridine (BrdU) labeling and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, respectively. Our study shows that CV has definite chemopreventive effect by inducing apoptosis via decreasing the expression of Bcl-2 and increasing the expression of caspase 8 in hepatocarcinogenesis-induced rats.

Cytotoxic Effect of Clerosterol Isolated from Codium fragile on A2058 Human Melanoma Cells

“…The mechanisms underlying Chlorella vulgaris -induced apoptosis were investigated in another study, which examined the expression and activity of the tumor suppressor protein, p53 and a host of pro- and anti-apoptotic proteins, such as Bcl-2, Bax and caspases 3 and 8 [29]. In animal studies, Chlorella vulgaris had anti-atherogenic, anti-cholesterolemic, anti-inflammatory and antitumor effects [30,31,32]. Also, an aqueous extract from the sea staghorn ( Codium fragile ) suppressed the growth of colon carcinoma cells by promoting apoptosis and downregulating the expression of the anti-apoptotic protein, Bcl-xL, leading to the activation of caspases 3 and 7 [33].…”

Microalgae as sources of high added‐value compounds—a brief review of recent work

“…For example, campesterol, a sterol found in Tetraselmis suecica ,77 has been reported to be antiangiogenic 78. Extracts of Chlorella vulgaris have also been found to be active against liver cancer in vitro and in vivo, where the inhibition of proliferation and increased apoptosis were reported 79. Additional examples of antitumoral compounds synthesized by microalgae are provided in Table 5.…”

Immunostimulatory and Immunomodulatory Effects of Nitzschia navis-varingica, Heterocapsa pygmaea and Chrysochromulina alifera Whole Cell Extracts on Mammalian Macrophage Cells

“…Oral administration of 500 mg/Kg of Chlorella vulgaris provided 55% survival rate of Listeria monocytogene infected mice (Dantas et al, 1999). Oral administration of Chlorella vulgaris extracts had definite chemopreventive effect by inducing apoptosis in hepatocarcinogenesis-induced rats (Azamai et al, 2009).…”