Cancer Chemopreventive Effect of Spirogyra Neglecta (Hassall) Kützing on Diethylnitrosamine-Induced Hepatocarcinogenesis in Rats

Abstract

Spirogyra neglecta, a freshwater green alga, is a local food in the northern and northeastern parts of Thailand. This investigation explored the anticarcinogenicity of S neglecta and its possible cancer chemopreventive mechanisms in rats divided into 14 groups. Groups 1 and 10 served as positive and negative control groups, respectively. Groups 1-9 were intraperitoneally injected with diethylnitrosamine (DEN) once a week for 3 weeks. Groups 10-14 received normal saline instead. One week after the last DEN injection, groups 2-5 were administered for 9 consecutive weeks various doses of S neglecta extract (SNE) and dried S neglecta (SND), mixed with basal diet. Groups 6-9 and 11-14 similarly were administered various doses of SNE and SND starting from the first week of the experiment. Administration of SNE and SND was not associated with formation of glutathione-Stransferase placental form (GST-P) positive foci in rat liver. SNE and SND during initiation phase significantly reduced the number of GST-P positive foci in rats injected with DEN. The number of GST-P also diminished in groups treated with SNE and SND after injection with DEN, except for the low dose extract group. SNE showed stronger anticarcinogenic potency than SND. Furthermore, SNE also decreased the number of Ki-67 positive cells. However, the numbers of TUNEL-positive cells in the liver of the SNE-treated groups were not statistically different from the controls. The GST activity in 50 mg/kg bw of SNE and 1% of SND groups was significantly increased as compared to the positive control. In conclusion, Spirogyra neglecta (Hassall) Kützing showed cancer chemopreventive properties at the early stages of diethylnitrosamine-induced hepatocarcinogenesis in rats. Possible inhibitory mechanisms include enhancement of the activities of some detoxifying enzymes and/or suppression of precancerous cells.

Protective Role of Vanillic Acid against Diethylnitrosamine- and 1,2-Dimethylhydrazine-Induced Hepatocarcinogenesis in Rats

“…The avidin–biotin complex method was used to stain the hepatic GST-P positive foci ( Figure 6 A), according to the method of Thumvijit et al [ 29 ]. The number and the areas of the GST-P positive foci that were greater than 0.2 mm in diameter were determined using the LAS Interactive Measurement program.…”

Protective Effects of Defatted Sticky Rice Bran Extracts on the Early Stages of Hepatocarcinogenesis in Rats

“…The glutathione S -transferase placental form (GST-P) positive foci were stained by the avidin–biotin complex method according to Thumvijit et al [41]. The liver tissues were deparaffinized and rehydrated with xylene and ethanol, respectively, at optimal concentration.…”

Preventive Effects of Spirogyra neglecta and a Polysaccharide Extract against Dextran Sodium Sulfate Induced Colitis in Mice

“…Histologically, DSS-induced colitis is characterized by erosion, ulceration, submucosal infiltration of inflammatory cells and crypt loss (Wirtz et al, 2007). It is commonly believed that DSS causes direct toxicity to gut epithelial cells and abrogates the integrity of the mucosal barrier, allowing lumen bacteria into the rat liver (Thumvijit et al, 2014). Furthermore, not only different alga but also derivatives have been reported as bioactive agents (Wijesekara et al, 2011;Ngo and Kim, 2013).…”

“…As it has been found that Spirogyra neglecta mainly contains sulfated polysaccharides and chlorophyll (Thumvijit et al, 2014), we hypothesized that it could have preventive effects on DSS-induced colitis. To investigate modifying effects of SNE, polysaccharide (PE) and nonpolysaccharide (CF) fractions on DSS-induced colitis in ICR mice and to elucidate mechanisms, we performed the present histopathological analysis, evaluating alteration in cellular proliferation and apoptosis, as well as identifying differentially expressed proteins and affected upstream regulators in the colon mucosa of mice after short-term administration of DSS and test agents.…”