# Increased Anticancer Activity of Organic Kimchi with Starters Demonstrated in HT-29 Cancer Cells
## 4 Discussion
In addition, it was also confirmed that kimchi mixed with mistletoe extract, pear, mustard leaf, mushroom, and sea tangle juice was confirmed to present higher anticancer activity than standardized kimchi on HT-29 cells [4; 37]. In the case of LP and LM, which were used as starter cultures LAB isolated from kimchi, they presented all the basic properties of probiotics, such as acid resistance, bile resistance, intestinal adhesion, and heat stability [38]. LP has antimutagenic effects, phagocytosis, and inhibits the growth of pathogenic bacteria, and LM is mainly used as a starter for kimchi and imparts a refreshing taste with non-carcinogenic properties [39; 40]. When these two were used as starters for kimchi, [PERSON] et al. [8] confirmed that they had an anti-obesity effect, and [PERSON] et al. [9] found that starter-added kimchi had highly effective anticancer effects on HT-29 and HCT-116 cells. nF1 is a heat-treated LP biogenic consisting of non-viable _Laciplantiobacillus plantarum_ cells. In a recent study by [PERSON] et al. [41], it was shown to have an immune-enhancing effect on immunosuppressed animal models, and in the study by [PERSON] et al. [42], it was confirmed that nF1-added kimchi improved the symptoms of irritable bowel syndrome (IBS). As seen in Figure 3, AK and OAK display a higher HT-29 cancer cell death rate than SK, which appears to be due to the addition of sub-materials, starter strains, and nF1 included in AK and OAK, as mentioned above. In addition, OAK was manufactured with the same organic ingredients as CK; however, there were differences in the contents of ingredients and sub-ingredients. Specifically, mushroom and sea tangle juice, mistletoe extract, starters, and nF1 are believed to have increased the death rate of HT-29 cells in OAK. Uncontrolled cell proliferation and abnormal gene function and expression are the hallmarks of cancer, and tumor cells usually result from damage to genes that regulate cell cycle arrest [43]. To inhibit the growth of these cancer cells, cell cycle arrest and apoptosis are achieved by regulating the expression of transcription factors and suppressing growth signaling pathways [44]. The tumor suppressor gene p53 is involved in cell cycle arrest and apoptosis and is activated by signals, such as DNA damage, oncogene activation, and stress [45]. When p53 is activated, it plays an important role in determining the duration and outcome of cell cycle arrest at the G2 checkpoint, an important cell cycle checkpoint, and it can activate pro-apoptosis genes, such as Bax, or down-regulate anti-apoptosis genes, such as Bcl-2 [46]. p21, a downstream mediator of p53, induces G1 arrest in the cell cycle by binding to cyclin E/cyclin-dependent kinases (Cdk)2 and cyclin D/Cdk4 complexes. It also inhibits DNA replication by promoting the transcriptional silencing of transcription factor E2F1 targets important for DNA replication and cell cycle progression [47]. The p53 and p21 genes are involved in cell division throughout the G1, S, and G2/M phases of the cell cycle, and by measuring the expression of these genes, it is possible to determine how much a substance, such as an anticancer drug, inhibits cancer cell division [48]. Therefore, we investigated the effect of kimchi samples on the expression levels of p21 and p53. Both AK and OAK significantly increased the mRNA expression levels of p21 and p53 in HT-29 cells (Figure 4), and also increased the protein expression level of p53 (Figure 6). Between them, OAK was observed to increase the mRNA and protein expression levels the most. Previous studies have reported that kimchi inhibits the growth of cancer cells by up-regulating the expression of cell cycle arrest-related genes [49]. Similarly, in this study, the expression levels of p21 and p53 were increased the most by OAK, suggesting that functional recipes, starters, and organic ingredients induce the up-regulation of cell cycle arrest-related factors in HT-29 cells. Apoptosis is a type of programmed cell death observed in multicellular organisms.