Enhancement of postoperative recovery by preoperative oral co-administration of the amino acids, cystine and theanine, in a mouse surgical model

Ameliorating effects of cystine and theanine in a cancer cachexia mouse model

Cachexia is a common cancer complication and is associated with weight loss and anorexia. In this study, we investigated the ameliorating effects of cystine and theanine on cancer cachexia using a mouse model. In mice carrying the colon cancer cell line C-26, there was a suppression of body weight increase and reduction in both internal fat and lower limb muscles. Repeated cystine and theanine administration significantly prevented weight loss, internal fat loss, lower limb muscle loss, and serum IL-6 increase in the cachexia model. These results suggested that cystine and theanine may be effective in ameliorating cancer cachexia.

The effects of cystine and theanine mixture on the chronic survival rate and tumor incidence of rats after total body X-ray irradiation†

Cystine and theanine (CT), an amino acid mixture, provides the substrates cysteine and glutamic acid that promote glutathione synthesis. We previously reported that CT pre-treatment significantly improved the acute survival rate and reduced acute radiation injury of the small intestine and bone marrow of rats after 5 Gy of total body X-ray irradiation. To examine the long-term effects of CT administration after irradiation, we investigated the effects of CT pre-treatment and pre- and post-treatment on the chronic survival rate and solid tumor (spleen, skin and subcutis, and thyroid) incidence after irradiation using 7-week-old male Wistar rats. CT pre-treatment of 280 mg/kg was administered orally for 5 days before 5 Gy irradiation, and CT pre- and post-treatment was administered 5 days before and 5 days after irradiation. A 0.5% carboxymethyl cellulose solution was administered as a control. The chronic survival rate of the pre-treated rats was higher than that of the control rats at 441 days after irradiation (40 vs 8.1%, P = 0.011). However, the survival rate did not significantly differ between the pre- and post-treatment and control rats at 467 days after irradiation (33.8 vs 30.2%, P = 0.792). In addition, more solid tumors, especially subcutis sarcomas, were observed in the pre-treatment rats (26.1%, 6/23) than in the control rats (4.5%, 1/22) after irradiation. Therefore, pre-administration of CT improves the chronic survival rate after irradiation; however, the occurrence of solid tumors was not suppressed.

L-Theanine and Immunity: A Review

L-theanine (N-ethyl-γ-glutamine) is the main amino acid in tea leaves. It not only contributes to tea flavor but also possesses several health benefits. Compared with its sedative and calming activities, the immunomodulatory effects of L-theanine have received less attention. Clinical and epidemiological studies have shown that L-theanine reduces immunosuppression caused by strenuous exercise and prevents colds and influenza by improving immunity. Numerous cell and animal studies have proven that theanine plays an immunoregulatory role in inflammation, nerve damage, the intestinal tract, and tumors by regulating γδT lymphocyte function, glutathione (GSH) synthesis, and the secretion of cytokines and neurotransmitters. In addition, theanine can be used as an immunomodulator in animal production. This article reviews the research progress of L-theanine on immunoregulation and related mechanisms, as well as its application in poultry and animal husbandry. It is hoped that this work will be beneficial to future related research.

The Impact of General Anesthesia on Redox Stability and Epigenetic Inflammation Pathways: Crosstalk on Perioperative Antioxidant Therapy

Worldwide, the prevalence of surgery under general anesthesia has significantly increased, both because of modern anesthetic and pain-control techniques and because of better diagnosis and the increased complexity of surgical techniques. Apart from developing new concepts in the surgical field, researchers and clinicians are now working on minimizing the impact of surgical trauma and offering minimal invasive procedures due to the recent discoveries in the field of cellular and molecular mechanisms that have revealed a systemic inflammatory and pro-oxidative impact not only in the perioperative period but also in the long term, contributing to more difficult recovery, increased morbidity and mortality, and a negative financial impact. Detailed molecular and cellular analysis has shown an overproduction of inflammatory and pro-oxidative species, responsible for augmenting the systemic inflammatory status and making postoperative recovery more difficult. Moreover, there are a series of changes in certain epigenetic structures, the most important being the microRNAs. This review describes the most important molecular and cellular mechanisms that impact the surgical patient undergoing general anesthesia, and it presents a series of antioxidant therapies that can reduce systemic inflammation.

Perioperative Administration of Cystine and Theanine Suppresses Inflammation and Facilitates Early Rehabilitation and Recovery after Esophagectomy: A Randomized, Double-Blind, Controlled Clinical Trial

Oral administration of cystine and theanine (CT) increases glutathione levels to modulate the inflammatory response, which has yet to be sufficiently explored for patients’ recovery and early rehabilitation. We planned a randomized, double-blind, placebo-controlled trial to determine whether perioperative oral administration of CT promotes recovery after esophagectomy. Patients were randomized into either CT or placebo groups, who received preoperative and postoperative treatments for 4 and 13 days, respectively. The main outcome measures were triaxial accelerometer readings, inflammation indicators, a 6 min walk test (6MWT), and a quality of life questionnaire (QoR-40). The study involved 32 patients. Although the CT group (n = 16) showed better patient activity across the investigated period, there was no significant difference between the two groups. However, white blood cell count on postoperative days (POD) 2 and 10, neutrophil count (POD 2, 7, and 10), and C-reactive protein level (POD 13) in the CT group were significantly lower than in the placebo group. Furthermore, 6MWT on POD 7 and QoR-40 on POD 13 were significantly higher in the CT group than those in the placebo group. This study suggests that perioperative administration of CT may contribute to early recovery and rehabilitation after esophagectomy via suppression of inflammatory response.

Cystine and Theanine as Stress-Reducing Amino Acids-Perioperative Use for Early Recovery after Surgical Stress

Perioperative nutritional therapy requires the consideration of metabolic changes, and it is desirable to reduce stress aiming at early metabolic normalization. Glutathione (GSH) is a tripeptide composed of glutamic acid, cysteine, and glycine. It is one of the strongest antioxidants in the body and important for adjusting immune function. Cystine and theanine (γ-glutamylethylamide) provide substrates of GSH, cysteine and glutamic acid, promoting the synthesis of GSH. It has been reported that the ingestion of cystine (700 mg) and theanine (280 mg) exhibits inhibitory effects against excess inflammation after strong exercise loads in athletes, based on which its application for invasive surgery has been tried. In patients undergoing gastrectomy, ingestion of cystine (700 mg) and theanine (280 mg) for 10 days from 5 days before surgery inhibited a postoperative increase in resting energy expenditure, promoted recovery from changes in interleukin-6, C-reactive protein, lymphocyte ratio, and granulocyte ratio and inhibited an increase in body temperature. In a mouse small intestine manipulation model, preoperative 5-day administration of cystine/theanine inhibited a postoperative decrease in GSH in the small intestine and promoted recovery from a decrease in behavior quantity. Based on the above, cystine/theanine reduces surgical stress, being useful for perioperative management as stress-reducing amino acids.

Oral administration of cystine and theanine attenuates 5-fluorouracil-induced intestinal mucositis and diarrhea by suppressing both glutathione level decrease and ROS production in the small intestine of mucositis mouse model

BACKGROUND

Chemotherapy is frequently used in cancer treatment; however, it may cause adverse events, which must be managed. Reactive oxygen species (ROS) have been reported to be involved in the induction of intestinal mucositis and diarrhea, which are common side effects of treatment with fluoropyrimidine 5-fluorouracil (5-FU). Our previous studies have shown that oral administration of cystine and theanine (CT) increases glutathione (GSH) production in vivo. In the present study, we hypothesized that CT might inhibit oxidative stress, including the overproduction of ROS, and attenuate 5-FU-induced mucositis and diarrhea.

METHODS

We investigated the inhibitory effect of CT administration on mucositis and diarrhea, as well as its mechanism, using a mouse model of 5-FU-induced intestinal mucositis.

RESULTS

CT administration suppressed 5-FU-induced diarrhea and weight loss in the studied mice. After 5-FU administration, the GSH level and the GSH/GSSG ratio in the small intestine mucosal tissue decreased compared to normal control group; but CT administration improved the GSH/GSSG ratio to normal control levels. 5-FU induced ROS production in the basal region of the crypt of the small intestine mucosal tissue, which was inhibited by CT. CT did not affect the antitumor effect of 5-FU.

CONCLUSIONS

CT administration suppressed intestinal mucositis and diarrhea in a mouse model. This finding might be associated with the antioxidant characteristics of CT, including the improved rate of GSH redox and the reduced rate of ROS production in the small intestine mucosal tissue. CT might be a suitable candidate for the treatment of gastrointestinal mucositis associated with chemotherapy.

Protective effects of a cystine and theanine mixture against acute radiation injury in rats

This study aims to examine the effects of cystine and theanine (CT), which increases glutathione biosynthesis, on the survival rate and acute radiation injury of the small intestine and bone marrow using a rat model. CT pre-treatment (280 mg/kg for 5 days) significantly improved weight loss and survival rate of rats as compared with the control group after 5 Gy. CT pre-treatment significantly increased the rate of mucosa and crypt length, and decreased the number of apoptotic cells, TUNEL and cleaved caspase-3 positive cells, while increasing the number of mitotic cells and Ki-67 positive cells in jejunal crypts and villi compared to control rats post-irradiation. CT also suppressed bone marrow cell loss and reduced the number of apoptotic cells in bone marrow. These results suggest a protective effect of CT pre-treatment for acute injury after irradiation through apoptosis inhibition and increased proliferative activity in jejunal crypt cells and bone marrow cells.

Oral administration of Cystine and Theanine ameliorates oxaliplatin-induced chronic peripheral neuropathy in rodents

Oxaliplatin frequently causes severe peripheral neuropathy as a dose-limiting toxicity. However, this toxicity lacks a strategy for prevention. Cystine/Theanine is a supplement, which includes precursors for the biosynthesis of glutathione. In this study, we investigated the effects of Cystine/Theanine on oxaliplatin-induced peripheral neuropathy using an in vivo model. Repeated injection of oxaliplatin (4 mg/kg intraperitoneally twice a week for 2 weeks) caused mechanical allodynia, cold hyperalgesia and axonal degeneration of the sciatic nerve in rats. Mechanical allodynia and axonal degeneration, but not cold hyperalgesia, were ameliorated by daily co-administration of Cystine [200 mg/kg orally (p.o.)] and Theanine (80 mg/kg p.o.). Moreover, co-administration of Cystine and Theanine to rats significantly increased the glutathione level in the sciatic nerve compared with the oxaliplatin group. Furthermore, Cystine and Theanine did not attenuate the tumour cytotoxicity of oxaliplatin in C-26 tumour cell-bearing mice. These findings suggest that Cystine and Theanine may be beneficial for preventing oxaliplatin-induced peripheral neuropathy.

Topical delivery of l-theanine ameliorates TPA-induced acute skin inflammation via downregulating endothelial PECAM-1 and neutrophil infiltration and activation

l-theanine, the most abundant free amino acid in tea, has been documented to possess many different bioactive properties through oral or intragastrical delivery. However, little is known about the effect of topical delivery of l-theanine on acute inflammation. In the present study, by using 12-O-tetradecanoylphorbol-13-acetate (TPA, 2.5 μg/ear)-induced ear edema model in mice, we first found that single-dose local pretreatment of l-theanine 30 min before TPA time- and dose-dependently suppressed the increases in both skin thickness and weight. Subsequently l-theanine ameliorated TPA-induced erythema, vascular permeability increase, epidermal and dermal hyperplasia, neutrophil infiltration and activation via downregulating the expression of PECAM-1 (a platelet endothelial adhesion molecule-1) in blood vessels and the production of pro-inflammatory cytokines IL-1β, TNF-α, and mediator cyclooxygenase-2 (COX-2), which is mainly expressed in neutrophils. It highlighted the potential of l-theanine as a locally administrable therapeutic agent for acute cutaneous inflammation.

Oral administration of the amino acids cystine and theanine attenuates the adverse events of S-1 adjuvant chemotherapy in gastrointestinal cancer patients

Background

Nutritional therapy is used to reduce the adverse events (AEs) of anticancer drugs. Here, we determined whether the amino acids cystine and theanine, which provide substrates for glutathione, attenuated the AEs of S-1 adjuvant chemotherapy.

Methods

Patients scheduled to receive S-1 adjuvant chemotherapy were randomized to the C/T or the control groups. The C/T group received 700 mg cystine and 280 mg theanine orally 1 week before the administration of S-1, which then continued for 5 weeks. Each group received S-1 for 4 weeks. Blood sampling was performed and AEs were evaluated (CTCAE ver. 4.0) before and after the administration of S-1. S-1 was discontinued when AEs ≥ grade 2 occurred.

Results

The incidences of AEs of any grade and those over grade 2 were lower in the C/T group than in the controls. The incidence of diarrhea (G ≥ 2) was significantly less (p < 0.05) in the C/T group (3.1 %) than in the controls (25.8 %). The duration and completion rate of the S-1 adjuvant chemotherapy were significantly longer (p < 0.01) and higher (p < 0.01), respectively, in the C/T group (complete ratio: 75.0 %, duration: 24.8 ± 5.8 days) than in the controls (complete ratio: 35.5 %, duration: 20.0 ± 7.7 days).

Conclusions

The oral administration of cystine and theanine attenuated the AEs of S-1 adjuvant chemotherapy and increased the S-1 completion rate, suggesting that cystine and theanine is a useful supportive care for chemotherapy.

Cystine and theanine: amino acids as oral immunomodulative nutrients

The decreases in the glutathione (GSH) level in the mouse spleen and liver after immune stimulation are suppressed by the oral administration of cystine and theanine (CT). GSH is considered to be important for the control of immune responses. Antibody production in mice after infection is enhanced by the oral administration of CT. In humans, also, the oral administration of CT has been confirmed to enhance antibody production after vaccination against Flu and also reduce the incidence of cold. However, the GSH level is reduced by intense exercise and surgery. In clinical studies of body-builders and long-distance runners, the intake of CT suppressed excessive inflammatory reactions and a decline in immune functions after intense training. Surgery as well as intense exercise induces excessive inflammatory reactions. In mice, the preoperative administration of CT suppressed excessive inflammatory reactions associated with surgery and promoted the postoperative recovery. Moreover, in clinical studies of gastrectomized patients, CT intake suppressed excessive postoperative inflammatory reactions and induced early recovery. If infection is regarded as invasive stress, CT intake is considered to exhibit an immunomodulatory effect by suppressing the decrease in GSH due to invasive stress. The clarification of their detailed action mechanisms and their application as medical or function foods is anticipated.

Physiological effects of L-theanine on Drosophila melanogaster

Green tea has been consumed as the most popular drink in East Asia for centuries, and is believed to have a wide range of health benefits. l-Theanine, the major component of the free amino acids in green tea, has been reported to display neuronal protection and tumor inhibition in vitro, but its physiological effects on animal development and behavior remain elusive. In this report, we used Drosophila melanogaster, the fruit fly, as a model organism to investigate the physiological effects of l-theanine. Flies were fed with three different concentrations of theanine as a dietary supplement after eclosion, and were examined for a variety of physiological parameters at different time points. We found theanine treatment results in significantly increased locomotion and courtship ability, and decreased resistance against wet and dry starvation in males, but not in females. Furthermore, theanine application diminished UV tolerance in females, but not in males. However, we did not perceive distinguishable effect of theanine on animal development, life span, weight, and tolerance of heat and anoxia. This work represents the first comprehensive physiological investigation of l-theanine at the whole animal level, and shall shed light on the mechanistic study of theanine in the future.