Isolation of the hemeoxygenase-1 inducer from rice-derived peptide.

Bioactive peptides with various health benefits have been reported from rice protein hydrolysates. We previously showed that rice-derived peptides (RP) increased intracellular glutathione levels and induced the expression of γ-glutamylcysteine synthetase, which is regulated by nuclear transcription factor-erythroid 2-related factor 2 (Nrf2). Heme oxygenase-1 (HO-1) is an important Nrf2 downstream antioxidant enzyme that protects against oxidative stress. This study aimed to investigate the protective effects of RP on hydrogen peroxide (H2O2)-induced oxidative stress in human hepatoblastoma cell line HepG2 and identified HO-1 induced peptides from RP. Pretreatment of cells with RP reduced the cytotoxicity caused by H2O2 in a dose-dependent manner. Moreover, RP induced HO-1 expression in a concentration- and time-dependent manner. Next, we attempted to isolate the HO-1 inducer from RP by bioactivity-guided fractionation. Purification of the active peptides using a Sep-Pak C18 cartridge and reversed-phase HPLC, followed by sequence analysis by mass spectrometry, led to the identification of the three peptides. These peptides effectively reduced H2O2-induced oxidative stress. Among them, only P3 (peptide sequence: RSAVLLSH) increased HO-1 protein expression. Additionally, the knockdown of Nrf2 suppressed the induction of HO-1 expression by P3. Our results indicated that P3 identified from RP induced HO-1 by activating the Nrf2 signaling pathway.

Hepatoprotective Activity of Yellow Chinese Chive against Acetaminophen-Induced Acute Liver Injury via Nrf2 Signaling Pathway.

Glutathione, the most abundant intracellular antioxidant, protects cells against reactive oxygen species induced oxidative stress and regulates intracellular redox status. We previously demonstrated that yellow Chinese chive (ki-nira) increased the intracellular glutathione levels. Acetaminophen (APAP) is a commonly used analgesic. However, an overdose of APAP causes severe hepatotoxicity via depletion of the hepatic glutathione. In this study, we investigated the hepatoprotective effects of yellow Chinese chive extract (YCE) against APAP-induced hepatotoxicity in mice. YCE (25 or 100 mg/kg) was administered once daily for 7 d, and then APAP (700 mg/kg) was injected at 6 h before the mice were sacrificed. APAP treatment markedly increased the serum biological markers of liver injury such as alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and alkaline phosphatase. Pretreatment with YCE significantly prevented the increases in the serum levels of these enzymes. Histopathological evaluation of the livers also revealed that YCE prevented APAP-induced centrilobular necrosis. Pretreatment with YCE dose-dependently elevated glutathione levels, but the difference was not significant. Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a critical role in APAP-induced hepatotoxicity by regulating the antioxidant defense system. Therefore, we investigated the expression of Nrf2 and its target antioxidant enzyme. YCE led to an increased expression of Nrf2 and its target antioxidant enzymes, NAD(P)H quinone oxidoreductase 1 (NQO1), glutathione peroxidase (GPx), cystine uptake transporter (xCT), especially hemeoxygenase-1 (HO-1) in mice livers. These results suggest that YCE could induce HO-1 expression via activation of the Nrf2 antioxidant pathway, and protect against APAP-induced hepatotoxicity in mice.

Sake lees hydrolysate protects against acetaminophen-induced hepatotoxicity via activation of the Nrf2 antioxidant pathway.

Acetaminophen is a commonly used analgesic. However, an overdose of acetaminophen causes severe hepatotoxicity via depletion of hepatic glutathione. Here, we investigated the protective effects of sake lees hydrolysate against acetaminophen-induced hepatotoxicity in mice. Sake lees hydrolysate was administered orally to ICR mice for seven days. Six hours after acetaminophen treatment, the mice were sacrificed, and blood and liver samples were collected for analysis. Treatment with acetaminophen markedly increased the levels of serum alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and alkaline phosphatase. Pretreatment with sake lees hydrolysate significantly prevented the increases in the serum levels of these enzymes and inhibited acetaminophen-mediated glutathione depletion. In addition, histopathological evaluation of the livers also revealed that sake lees hydrolysate prevented acetaminophen-induced centrilobular necrosis. The expression of γ-glutamylcysteine synthetase (γ-GCS), hemeoxygenase-1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf2) in the liver were decreased after acetaminophen treatment, whereas pretreatment with sake lees hydrolysate led to an increased expression of all three proteins. Furthermore, sake lees hydrolysate induced the expression of these proteins in HepG2. These results suggested that sake lees hydrolysate could induces HO-1 and γ-GCS expression via activation of the Nrf2 antioxidant pathway, and protects against acetaminophen-induced hepatotoxicity in mice.

Hepatoprotective effects of rice-derived peptides against acetaminophen-induced damage in mice.

Glutathione, the most abundant intracellular antioxidant, protects cells against reactive oxygen species induced oxidative stress and regulates intracellular redox status. We found that rice peptides increased intracellular glutathione levels in human hepatoblastoma HepG2 cells. Acetaminophen is a commonly used analgesic. However, an overdose of acetaminophen causes severe hepatotoxicity via depletion of hepatic glutathione. Here, we investigated the protective effects of rice peptides on acetaminophen-induced hepatotoxicity in mice. ICR mice were orally administered rice peptides (0, 100 or 500 mg/kg) for seven days, followed by the induction of hepatotoxicity via intraperitoneal injection of acetaminophen (700 mg/kg). Pretreatment with rice peptides significantly prevented increases in serum alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase levels and protected against hepatic glutathione depletion. The expression of γ-glutamylcysteine synthetase, a key regulatory enzyme in the synthesis of glutathione, was decreased by treatment with acetaminophen, albeit rice peptides treatment recovered its expression compared to that achieved treatment with acetaminophen. In addition, histopathological evaluation of the livers also revealed that rice peptides prevented acetaminophen-induced centrilobular necrosis. These results suggest that rice peptides increased intracellular glutathione levels and could protect against acetaminophen-induced hepatotoxicity in mice.

Anti-oxidative Activity of Hydrolysate from Rice Bran Protein in HepG2 Cells.

Glutathione (GSH) is an ubiquitous thiol-containing tripeptide, which plays important roles in cellular protection from oxidative stress. In our search for a dietary source that can increase GSH levels, we discovered that a 24 h treatment of HepG2 cells with rice bran protein hydrolysate (RBPH), prepared by Umamizyme G-catalyzed hydrolysis, increased the GSH content in a dose-dependent manner. RBPH elevated the expression levels of γ-glutamylcysteine synthetase (γ-GCS), which constitutes the rate-limiting enzyme of GSH synthesis, and of another two enzymes, hemeoxygenase-1 (HO-1) and reduced nicotinamide adenine dinucleotide (phosphate): quinone oxidoreductase 1 (NQO1). This induction was preceded by the accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2) inside the nucleus, which is a key transcription factor for the expression of the γ-GCS, HO-1, and NQO1. Pre-treatment of cells with RBPH produced a significant protective effect against cytotoxicity caused by H2O2 or ethanol. These results indicate that RBPH exerts a protective effect against oxidative stress by modulating GSH levels and anti-oxidative enzyme expression via the Nrf2 pathway.

[A case of thoracolithiasis].

Many kinds of tumor shadows have been reported on chest X rays in recent years, some of which are difficult to diagnose. A 72-year-old man was admitted to our hospital for further tests, because of an abnormal shadow recorded on a chest X ray on a routine health examination. Chest CT scan demonstrated a round mass lesion, about 2cm in diameter, at the pleural surface of the S6 segment of the right lung. Our attempt at CT guided percutaneous lung needle biopsy failed because the needle was unable to penetrate the tumor, resulting in right pneumothorax. Later, a tumor was located in the basal part of the right lung, which was confirmed by CT scan. Video-assisted thoracic surgery (VATS) was performed, and a white 2-cm nodule in the right pleural cavity and two grayish-white 2-3-mm nodules on the right pleural surface were removed. The cut surfaces of these nodules showed a small black core surrounded by white concentric structures. Histologically, a small quantity of coal dust and many histiocyte-like cells were found in the core, surrounded by acidophilic fibrous connective tissue. These findings were consistent with thoracolithiasis, which is a rare disorder but one that requires diagnostic differentiation from peripherally located lung tumors.

[A case of primary mediastinal choriocarcinoma].

A 30-year-old man presented with cough and bloody sputum. He brought a chest radiogram showing abnormal findings. His chest computed tomography revealed a large mediastinal mass and multiple nodular shadows in both lungs. The serum beta-HCG level was remarkably elevated, and physical examination revealed bilateral gynecomastia and right supraclavicular lymph node swelling. His lymph node was biopsied and choriocarcinoma was diagnosed. After 3 cycles of BEP therapy (cisplatin, etoposide, bleomycin), the tumors regressed and the serum beta-HCG level decreased. Although there were residual tumors and serum beta-HCG was mildly elevated, he refused additional therapy. The choriocarcinoma progessed rapidly again and he died seven months after his first visit. Primary mediastinal germ cell tumors are rare, and in particular the pure type of choriocarcinoma arising in the mediastinum is even rarer. Patients with mediastinal choriocarcinoma are mostly young men. The prognosis of primary mediastinal choriocarcinoma is still very poor despite the introduction of combination chemotheraphy including cisplatin. We report a case of primary mediastinum pure choriocarcinoma. Chemotherapy was effective for the patient, but he died because of recurrence after refusal of future treatment. Establishment of more effective treatment is necessary.

[A case of primary pulmonary leiomyosarcoma with history of pneumonia 5 years before].

A 35-year-old woman with past history of pneumonia in the right lung field 5 years before was admitted to our hospital because of fever and cough. Chest radiographs showed a pulmonary tumor with atelectasis of the right lower lung. Chest CT also revealed a round clear-edged tumor at the right S6 with atelectasis of the right lower lung lobe. Bronchoscopic findings showed a yellowish endobronchial tumor in the right truncus intermedius, which proved to be leiomyosarcoma. We could not find any other malignant lesion, and therefore, on a diagnosis of primary pulmonary leiomyosarcoma, right middle and lower lobectomy was performed with lymph node excision. Retrospective examination of the chest radiographs revealed not only that the original region of the leiomyosarcoma seemed to be near the site of the earlier pneumonia, but also that the atelectasis-like findings 2 years before were similar to the findings on this admission. It was reported that, if an operation could not be performed at an early stage, the prognosis might be poor. In the follow-up of the abnormal chest radiographic findings, the clinic physician should observe the symptoms from the same viewpoint as hospital doctors. It is important to keep an active relationship between clinic and hospital. We might have reached our final diagnosis earlier if we had been more active in seeking an examination for abnormal chest radiographic findings, without attaching too much importance to the patient's age.

Cigarette smoking-induced acute eosinophilic pneumonia showing tolerance in broncho-alveolar lavage findings.

A 19-year-old man was admitted due to acute respiratory failure. He had started cigarette smoking (CS) about three weeks prior to onset. Multiple nodular shadows and patchy infiltrations were found on chest computed tomography. His respiratory state improved promptly by intravenous methylprednisolone. He resumed CS soon after discharge without any symptoms. We suspected CS-induced acute eosinophilic pneumonia and performed broncho-alveolar lavage (BAL) about one month after onset. The proportion of eosinophils in BAL fluid was 72%. A second BAL was performed about 18 months after onset and BAL fluid included no eosinophils, despite the fact that he had continued CS.

[A case of severe pneumoconiosis with synchronous triple lung cancer].

A 70-year-old man who had worked in a stonepit for about fifty years was admitted to our hospital for detailed examination of the signs of pneumoconiosis (3/3, q) and a nodular shadow in the right upper lung field. Under a clinical diagnosis of lung cancer complicated with pneumoconiosis, right upper lobectomy with a right S6 resection was performed. Pathological examination revealed moderately differentiated adenocarcinoma of the right S2, well-differentiated adenocarcinoma of the right S6, and a squamous cell carcinoma of the right S1 which was not detected by chest CT. In addition to the difficulty of diagnosing lung cancer in a patient with severe pneumoconiosis, treatment for lung cancer may be limited by the poor pulmonary function that results from pneumoconiosis. Although the labor administration's decision that lung cancer patients with concomitant pneumoconiosis deserve compensation can be evaluated as a good one, the study of the relationship between pneumoconiosis and lung cancer needs further study through follow-up examination of pneumoconiosis cases.