Safety Evaluation of Tsubaki (Camellia japonica) Leaves Extract

Kuba, Megumi; Tsuha, Kazuyo; Hirose-Yasumoto, Mina; Tsuha, Keiko; Yasumoto, Takeshi

doi:10.3136/nskkk.55.379

Cited by 3 publications

(3 citation statements)

References 8 publications

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“…rats that oral intake of CJE at 500 and 2000 mg/kg has no adverse effects on body weight and produces no undesirable changes in clinical parameters, as determined by repetitive oral toxicity tests for 28 days. 12) Further effort is being made to elucidate the mechanism of action of OCS with increased amounts of OCS and with sophisticated methods such as microarray analysis.…”

Section: Effects Of Ocs In Cedar Pollinosis Model With Micementioning

confidence: 99%

In Vivo Analysis of the Anti-allergic Activities of Camellia japonica Extract and Okicamelliaside, a Degranulation Inhibitor

Kuba

Tsuha

et al. 2008

JOURNAL OF HEALTH SCIENCE

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Based on the previous finding of okicamelliaside (OCS), a highly potent anti-degranulation ellagic acid glucoside, in the leaves of Camellia japonica (C. japonica), we evaluated an extract of these leaves and OCS itself for their potential to suppress allergic reactions in vivo. Two conventional animal allergy models were used. In the allergic conjunctivitis model, male S.D. rats were stimulated with anti-ovalbumin (OVA) serum and challenged with OVA/Evans blue mixture. Oral administration of extracts from C. japonica at 1000 mg/kg for 10 days significantly reduced the vascular permeability of conjunctivas. In the second model, male BALB/c mice were stimulated with a Japanese cedar pollen extract and challenged by nasal instillation of the antigen. The sneezing frequency during the 10 min immediately after the challenge tended to decrease by intraperitoneal administration of 0.2 mg/kg of OCS for 24 days. These results suggest that C. japonica extracts (CJE) and OCS prepared from them could be useful to alleviate the symptoms of an immediate-type allergy.

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Section: Effects Of Ocs In Cedar Pollinosis Model With Micementioning

confidence: 99%

In Vivo Analysis of the Anti-allergic Activities of Camellia japonica Extract and Okicamelliaside, a Degranulation Inhibitor

Kuba

Tsuha

et al. 2008

JOURNAL OF HEALTH SCIENCE

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Section: Introductionmentioning

confidence: 55%

“…In contrast, the leaves of C. japonica are commonly used for drinks in Okinawa and in Korea. The safety of the oral administration of an extract from the leaves of C. japonica has been confirmed previously . Bioactive components in C. japonica leaves have been reported to be as follows: (−)‐epicathechin and (+)‐cathechin ; anti‐inflammatory and anti‐allergic active substances, okicamelliaside (3,4‐dioxoloellagic acid 4′‐ O ‐ β ‐D‐glucopyranoside) , quercetin‐3‐ β ‐D‐glucoside and eugenol ; and the diphenylpicrylhydrazyl (DPPH) radical scavenging active compounds camellianoside (quercetin‐3‐ O ‐ β ‐D‐xylopylanosyl‐(1→3)‐ O ‐ α ‐L‐rhamnopylanosyl‐(1→6)‐ O ‐ β ‐D‐glucopylanoside), rutin, hyperoside and isoquercitrin .…”

Section: Introductionmentioning

confidence: 60%

Anti‐photoaging capability of antioxidant extract from Camellia japonica leaf

Mizutani

Hashimoto

2014

Experimental Dermatology

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It is well known that the Camellia japonica leaf exhibits antioxidant activity because of its high content of polyphenolic compounds. Thus, the extract prepared from mature leaves of C. japonica (CJML) has been widely used as an anti-ageing material in foods and cosmetics. Concerning the process of growing C. japonica, it is expected that the extract from green leaves (CJGL) has superior effects compared with that from mature leaves. However, there are few reports that discuss the difference between green and mature leaves. In this study, both CJML and CJGL were extracted with 50% 1,3-butylene glycol (1,3-BG) and used for investigations. In a chemical examination, we compared both extracts in terms of scavenging activities against hydrogen peroxide (H2 O2 ) and hydroxyl radicals. CJGL exhibited higher scavenging activities against both types of ROSs compared with CJML. In addition, CJGL reduced the carbonylation of tape-stripped stratum corneum (SC) after UVB irradiation. In a biological study, the intra-cellular ROS level of HaCaT keratinocytes precultured with CJGL for 24 h was significantly lower than that of the control cells. Furthermore, cell damage induced by H2 O2 exposure was attenuated by 24 h precultivation with CJGL but not by 2 h precultivation. The results of examinations indicate that CJGL possess properties that reduce oxidative stress. In addition, the result of 2 h precultivation with CJGL suggests that CJGL might affect the status of intra-cellular antioxidants.

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