Anticariogenic activity of Nelumbo nucifera leaf extract in oral healthcare.

BACKGROUND: We aimed to evaluate the antimicrobial effect of the Nelumbo nucifera leaf extract. There have been no studies related to dental caries inducing bacteria up to now. OBJECTIVE: This study reviewed the inhibitory effect of glucose transferase (GTase) activation and acid production to confirm the anticariogenic activity of Nelumbo nucifera leaf extract. METHODS: This study used 100 g Nelumbo nucifera leaves cultivated in Yeongcheon-si, Gyeongbuk, after adding 70% methanol tenfold. The leaves were then concentrated (Gotary vacuum evaporator; N-Nseries, EYELA Co., Japan) and were placed under an aspirator (A-3S, EYELA Co., Japan) and a freeze dryer (Ilshin Lab Co., Korea). The anticariogenic effect of Nelumbo nucifera leaves extract was investigated using the growth inhibitory effect, as well as GTase activation. RESULTS: Among the nine kinds of oral-disease-causing bacteria, the Nelumbo nucifera leaf extract most effectively inhibited the growth of Streptococcus anginosus (S. anginosus), but it was difficult to inhibit the growth of Streptococcus oralis (S. oralis). For the anticariogenic effect of Nelumbo nucifera leaf extract, GTase activation was inhibited by at least 50% in all the nine types of bacteria, including Streptococcus mutans (S. mutans). It was shown that Nelumbo nucifera leaf extract had the strongest GTase activation inhibitory effect (85%) in S. anginosus. In addition, Nelumbo nucifera leaf extract showed an acid production inhibitory effect in the nine types of strains by maintaining almost pH 6.2 even after being cultured for 24 hours in the Nelumbo-nucifera-leaf-extract-added culture, while the control culture without Nelumbo nucifera leaf extract showed only about pH 5.0 after 4 hours. CONCLUSIONS: In conclusion, Nelumbo nucifera leaf extract showed the strongest GTase activation inhibitory effect in S. anginosus. Based on this, it was confirmed that Nelumbo nucifera leaf extract showed anticariogenic activity against oral cavity disease microorganisms.

An engagement factor for caregiver radiation dose assessment with radioiodine treatment.

This study aims to suggest ways to better manage thyroid cancer patients treated with high- and low-activity radioiodine ((131)I) by assessing external radiation doses to family members and caregivers and the level of radiation in the surrounding environment. The radiation doses to caregivers of 33 inpatients (who were quarantined in the hospital for 2-3 d after treatment) and 31 outpatients who received radioiodine treatment after thyroidectomy were measured using passive thermoluminescence dosemeters. In this study, 33 inpatients were administered high-activity (100-200 mCi) (131)I, and 31 outpatients were administered low-activity (30 mCi) (131)I. The average doses to caregivers were measured at 0.61 mSv for outpatients and 0.16 mSv for inpatients. The total integrated dose of the recovery (recuperation) rooms where the patients stayed after release from hospital was measured to be 0.83 mSv for outpatients and 0.23 mSv for inpatients. To reflect the degree of engagement between the caregiver and the patient, considering the duration and distance between two during exposure, the authors used the engagement factor introduced by Jeong et al. (Estimation of external radiation dose to caregivers of patients treated with radioiodine after thyroidectomy. Health Phys 2014; 106: :466-474.). This study presents a new engagement factor (K-value) of 0.82 obtained from the radiation doses to caregivers of both in- and out-patients treated with high- and low-activity radioiodine, and based on this new value, this study presented a new predicted dose for caregivers. A patient treated with high-activity radioiodine can be released after 24 h of isolation, whereas outpatients treated with low-activity radioiodine should be isolated for at least 12 h.