Chemoprotective effect of theanine in 1,2‐dimethylhydrazine‐induced colorectal cancer in rats via suppression of inflammatory parameters

Abstract

Colorectal cancer is considered as a major cancer among all types of cancers, especially in developed countries. The colorectal cancer has few to no symptoms and mostly the tumor is often diagnosed in the later stage of cancer. Oxidative stress and inflammatory reaction play an important role in the expansion and the progression of colorectal cancer. Theanine exhibits antioxidant and anti-inflammatory potential against various diseases. As a result of its antioxidant and anti-inflammatory nature, in this study, we estimated the protective effect of theanine against 1,2-dimethylhydrazine (DMH)induced colorectal cancer and explored the possible mechanism. Subcutaneous injection (35 mg/kg) of DMH was used to induce colorectal cancer in rats. Rats were divided into different groups and were orally administrated with theanine (5, 10, and 20 mg/kg) for 16 weeks. Body weight, tumor size, and average tumor weight were determined at the end of the experimental study. Biochemical tests, antioxidant properties, phase I and phase II enzymes, and inflammatory mediators were estimated.The mRNA expression of p38 mitogen-activated protein kinase (p38MAPK), p53, and apoptosis was also estimated at the end of the experimental study. Theanine significantly (p < .001) increases the body weight and suppressed the average tumor size in DMH-induced colorectal cancer. Similarly, it significantly (p < .001) reduces the level of prostaglandin (PGE 2 ), cyclooxygenase-2 (COX-2), and myeloperoxidase (MPO). It also decreases the oxidative stress by suppressing the level of malonaldehyde (MDA) and enhancing the level of SOD, GPx, CAT, and GR. Theanine considerably reduced tumor markers, such as lactate dehydrogenase (LDH) and carcinoembryonic antigen (CEA) and phase I and phase II enzymes in a dose-dependent manner. It also significantly (p < .001) suppressed the expression of p38-MAPK, p-53, caspase-3, caspase-8, and caspase-9 in a dose-dependent manner. Collectively, we can say that theanine exhibited the chemoprotective effect against the colorectal cancer by inhibiting the oxidative stress and inflammatory reaction.

L-Theanine and Immunity: A Review

“…The biological activity of L-theanine in vivo is much higher than that of D-theanine [8]. As one of the major active ingredients in tea and a new food additive, L-theanine has been found to possess many health benefits, such as anti-oxidation [9], anti-inflammation [10], neuroprotection [11], anti-anxiety [12], anticancer [13], anti-obesity [14], metabolic regulation [15], cardiovascular protection [16], liver and kidney protection [17], and immune regulation [18]. Compared with other biological activities, the immunomodulatory function of L-theanine has received less attention [19].…”

Association between tea consumption and quality of life in men with esophageal squamous carcinoma based on TTD model

“…Tea polyphenols can play an anti-cancer role by scavenging free radicals, blocking lipid peroxidation, and increasing the activity of enzymes in the body (Chen et al 2022b). Tea leaf extracts, such as epigallocatechin and theanine, have been shown to inhibit the development and progression of gastrointestinal tumors such as colorectal cancer (Ma et al 2022), esophageal cancer (Nechuta et al 2012), and gastric cancer (Yuan et al 2020) by regulating various signaling pathways (Alam et al 2022), initiating apoptosis, inhibiting in ammatory pathways, and suppressing oxidative stress, among other mechanisms. In addition, a report found that tea consumption after gastric cancer surgery could promote the recovery of postoperative gastrointestinal function and improve the quality of life of patients (Liu et al 2021).…”

Improvement of postoperative quality of life in patients with esophageal squamous cell carcinoma: does tea consumption have a role?

“…Tea polyphenols can play an anti-cancer role by scavenging free radicals, blocking lipid peroxidation, and increasing the activity of enzymes in the body [8]. Tea leaf extracts, such as epigallocatechin and theanine, have been shown to inhibit the development and progression of gastrointestinal tumors such as colorectal cancer [9], esophageal cancer [10], and gastric cancer [11] by regulating various signaling pathways [12], initiating apoptosis, inhibiting inflammatory pathways, and suppressing oxidative stress, among other mechanisms. In addition, a report found that tea consumption after gastric cancer surgery could promote the recovery of postoperative gastrointestinal function and improve the quality of life of patients [13].…”