Hiromichi Sumiyoshi

Bio: Hiromichi Sumiyoshi is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 59 citations.

New pharmacological activities of garlic and its constituents

Abstract: According to the recent pharmacological findings, garlic is a preventive rather than therapeutic. Epidemiological studies in China, Italy and USA showed the inverse relationship between stomach and colon cancer incidences and dietary garlic intake. Anti-carcinogenic activities of garlic and its constituents including sulfides and S-allyl cysteine, have been demonstrated using several animal models. Garlic preparations has been also shown to lower serum cholesterol and triglyceride levels, which are major risk factors of cardiovascular diseases, through inhibition of their bio-synthesis in the liver, and to inhibit oxidation of low density lipoprotein. Furthermore, in vitro and in vivo studies have revealed that aged garlic extract stimulated immune functions, such as proliferation of lymphocyte, cytokine release, NK activity and phagocytosis. More recently, aged garlic extract has been demonstrated to prolong life span of senescence accelerated mice and prevent brain atrophy. Manufacturing processes significantly affect chemical constituents in garlic preparations. Different forms contain different phytochemicals and may have different effects and toxicities. For example, aged garlic extract inhibited t-BuOOH-induced oxidation, whereas raw garlic stimulated the oxidation. Although garlic has been used as a condiment and folklore for a long time, it has been noted to cause adverse reactions, such as stomach ulcer and anemia. Among the garlic preparations, only aged garlic extract has been proven to be safe through toxicological studies. Thus, aged garlic extract could be the most promising garlic preparation for disease prevention.

Effect of Allium sativum on the immunity and survival of Labeo rohita infected with Aeromonas hydrophila

Abstract: Summary The aim of this study was to evaluate dietary dosages of garlic on the immune response and disease resistance against infections due to the opportunistic pathogen Aeromonas hydrophila in Labeo rohita fingerlings. Garlic, Allium sativum, was incorporated into the diets (0%, 0.1%, 0.5% and 1.0%) of rohu, L. rohita fingerlings (10 ± 2 g). Every 20 days, different biochemical (serum total protein, albumin, globulin, albumin : globulin ratio, blood glucose), haematological (WBC, RBC and haemoglobin content) and immunological (superoxide anion production, lysozyme activity and serum bactericidal activity) parameters were evaluated. Superoxide anion production, lysozyme, serum bactericidal, serum protein and albumin were enhanced in garlic treated groups compared with the control group. After 60 days, fish were challenged with A. hydrophila and mortality (%) was recorded up to day 10 post-challenge. Survival decreased in control group (57%) up to day 10 after infection. However, this was increased in the garlic treatment group, i.e. 85% survivability in the 1 g garlic kg−1 (B group) and 5 g garlic kg−1 (C group), and 71% survivability in the 10 g garlic kg−1 (D group), respectively. These results indicate that Allium sativum stimulates the immunity and makes L. rohita more resistant to infection by A. hydrophila.

Aged Garlic Extract Prevents a Decline of NK Cell Number and Activity in Patients with Advanced Cancer

Abstract: Aged garlic extract (AGE) has manifold biological activities including immunomodulative and antioxidative effects. It is used as a major component of nonprescription tonics and cold-prevention medicines or dietary supplements. Advanced-cancer patients decline in immune functions and quality of life (QOL). The study's subjects were patients with inoperable colorectal, liver, or pancreatic cancer. In a randomized double-blind trial, AGE was administered to one group and a placebo was administered to another for 6 mo. The primary endpoint was a QOL questionnaire based on the Functional Assessment of Cancer Therapy (FACT). The subendpoints were changes in the natural-killer (NK) cell activity the salivary cortisol level from before and after administering AGE. Out of 55 patients invited to participate in the trial, 50 (91%) consented to enroll. They consisted of 42 patients with liver cancer (84%), 7 patients with pancreatic cancer (14%), and 1 patient with colon cancer (2%). Drug compliance was relatively good in both the AGE and placebo groups. Although no difference was observed in QOL, both the number of NK cells and the NK cell activity increased significantly in the AGE group. No adverse effect was observed in either group. The study showed that administering AGE to patients with advanced cancer of the digestive system improved NK cell activity, but caused no improvement in QOL.

Aged Garlic Extract May Be Safe for Patients on Warfarin Therapy

Abstract: Garlic has been known to have antiplatelet properties. Because of the lack of major clinical data regarding the safety of concomitant use of garlic supplements and anticoagulants, we decided to evaluate the safety of using garlic extract along with oral anticoagulation therapy. During this project we tested aged garlic extract (AGE), a commercial garlic preparation, with warfarin (Coumadin). Sixty-six (66) patients were screened for a double-blind, randomized, placebo-controlled pilot study. Fifty-two (52) patients were randomized for the project. Forty-eight patients (30 men and 18 women, with a mean age of 56+/-10 years) completed the study. Eighteen patients (14 before randomization, 4 after randomization) were dropped from the study. The study medication (AGE or placebo) was administered at a dose of 5 mL twice a day for 12 wk. Potential bleeding and thromboembolic episodes were monitored. There was no evidence of increased hemorrhage in either the placebo or the AGE group. Adverse events included headache, fatigue, colds, and dizziness. However, no significant difference was found in the incidence of these minor adverse events between the groups. Thus, the adverse events are unlikely to be attributable to AGE. The results suggest that AGE is relatively safe and poses no serious hemorrhagic risk for closely monitored patients on warfarin oral anticoagulation therapy. Although the risk-benefit ratio of AGE use needs to be considered carefully when warfarin therapy is necessary, its positive effects may be beneficial to people with a high-risk background or who are taking cardiovascular medications.

Echinacea purpurea and Allium sativum as immunostimulants in fish culture using Nile tilapia (Oreochromis niloticus).

Abstract: The study was conducted to evaluate the efficiency of echinacea (E) and garlic (G) supplemented diets as immunostimulant for tilapia (Oreochromis niloticus). Seven treatments were designed including a control (C). Fish were fed on 35% protein diet at a rate of 3% body weight per day. Echinacea (1.0 ppt) and garlic (3%) were incorporated in the feed, which was administered for periods of 1, 2 and 3 months (summer season), followed by basal diet for 4 more months (winter season). Neutrophil adherence and haematocrit values increased in both supplemented groups with prolonging period of application. The neutrophils adherence was significantly increased in all treatments except group administered echinacea for 1 month. The lymphocytic counts were significantly (p 85%) in all the supplemented groups. The percentage of protection, after challenge infection using pathogenic Aeromonas hydrophila was the highest in groups supplemented with echinacea and garlic for 3 months after summer and winter seasons. It could be concluded that echinacea and garlic improve the gain in body weight, survival rate and resistance against challenge infection. Both compounds showed extended effects after withdrawal and improved resistance to cold stress during the winter season. However, a full commercial cost benefit analysis is necessary before recommending their application in aquaculture.