br Carotenoids are known to
Carotenoids are known to be representative phytopigments and phytonutrients that have antioxidant and chemopreventive eﬀects (Johnson, 2002; Niranjana et al., 2015; Tanaka, Shnimizu, & Moriwaki, 2012). Dietary GastrinI and β-carotene supplementation are re-ported to have beneficial eﬀects on liver, especially chronic liver dis-eases such as alcoholic and non-alcoholic fatty liver, fibrosis and he-patic cancer because of their antioxidant, anti-inflammatory and anticarcinogenic activities (Latief & Ahmad, 2018; Latief, Husain, &
Ahmad, 2018). Additionally, carotenoids are known to enhance the immune system (Hughes, 1999), and β-carotene inhibits tumor growth by improving the immunity (Cui, Liu, Wang, & Lin, 2012). Therefore, Treg recruitment and polarization by the TL extract might be related to the previous results above. The apoptotic activity of β-carotene may also help to suppress tumor growth (Kavalappa et al., 2019). TL is a new breed developed to increase the content of β-carotene in the cabbage, which is one of the main carotenoids in Chinese cabbage (Tuan et al., 2012). According to our HPLC analysis, β-carotene was a main car-otenoid included in TL extract (27.9 ± 2.1 μg/g). In addition to β-carotene, four minor peaks including lutein, zeaxanthin, β-apo-8′-car-otenal and β-cryptoxanthin were also detected in the TL extract by HPLC analysis (Howe & Tanumihardjo, 2006). However, these car-otenoids were not detectable in NL extracts by HPLC, suggesting that the amount of the carotenoids in NL extracts could be beyond the limits of detection. Therefore, the anticancer eﬀects of TL extracts in this study could be, at least in part, due to β-carotene.
In conclusion, treatment with the TL extract blocked Treg recruit-ment into PC. This phenomenon seems to be the main pathological mechanism for avoiding host immunity, via downregulation of Treg-related genes and expression of cytokines in tumor and spleen cells. Additionally, Tl extract showed cytotoxicity against pancreatic tumor cells. As the result, chemo preventive activity of TL extract could be because of cytotoxicity through the intracellular alternation in a tumor cell as well as changes micro environment near tumor cells. Our finding was corroborated by some phenotypic characteristics such as tumor size. Besides, TL contained β-carotene, which is regarded as a phyto-chemical with anticancer properties. Taken together, our data suggest that TL (developed by breeding to increase the concentration of car-otenoids) could be a natural agent for prevention or alleviation of cancer especially PC at an early stage.
All the experiments and procedures were conducted in accordance with the National Institutes of Health Guide for the care and use of laboratory animals, and the protocol was approved by the Chung-Ang University’s IACUC of the Laboratory Animal Research Center.
Declaration of Competing Interest
The authors declare that they have no conflicts of interest.
This work was supported and funded by Jeil Seed Bio Co., Ltd.
Tuan, P. A., Kim, J. K., Lee, J., Park, W. T., ... Park, S. U. (2012). Analysis of carotenoid accumulation and expression of carotenoid biosynthesis genes in diﬀerent organs of Chinese cabbage (Brassica rapa subsp. pekinensis). Experimental and Clinical Sciences Journal of Functional Foods 58 (2019) 301–310
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International Journal of Biological Macromolecules
Anti-tumor activity and the mechanism of a green tea (Camellia sinensis) polysaccharide on prostate cancer
a Department of Urology, Hunan Provincial People's Hospital, the First Affiliated Hospital of Hunan Normal University, Changsha 410005, P.R. China
b Department of Surgery, Hunan Provincial People's Hospital, the First Affiliated Hospital of Hunan Normal University, Changsha 410005, P.R. China
Green tea polysaccharide
In this study, a homogeneous polysaccharide (GTP), with a molecular weight of 7.0 × 104 Da, was isolated from Green tea, which was only composed of glucose. The antitumor effects of GTP on prostate cancer (PC) cell line along with the possible mechanism was examined. First, we investigate the potential role of microRNA-93 (miR-93) in PC progression. Our results showed that miR-93 was significantly upregulated in human PC tissues and several PC cell lines, and its overexpression was correlated with poor survival in PC patients. Furthermore, functional analysis showed that miR-93 overexpression promoted the migration, invasion and proliferation of PC-3 cells transfected with miR-93 mimics, while its knockdown displayed an opposite result in DU145 cells fol-lowing miR-93 inhibitor transfection. Additionally, in vivo tumorigenic studies on nude mice confirmed that miR-93 mimic treatment accelerated the growth of PC-3 xenograft tumors. As expected, GTP (25, 50 and 100 μg/ml) inhibited growth of PC-3 cells via inducing apoptosis, which was achieved by elevation of bax/bcl-2 ratio and caspae-3 protein expression, as well as a decrease of miR-93. Thus, miR-93 may be a potential therapeutic target by GTP for PC therapy.