The Japan Kampo Medicines Manufacturers Association (JKMA) established "self-imposed limits of residual pesticides for Kampo products, conventional crude drug products, and crude drugs" in 1996 to ensure their safe use. The self-imposed limits were modified twice, and presently, organochlorine, organophosphorus, and pyrethroid classes of pesticides are being regulated. As reported previously, we have been regularly surveying the on-site implementation of self-imposed limits in member companies since 2005. This report presents the findings of our fourth survey for a one-year target period from April 2016 to March 2017. Consequently, the implementation rate of these limits in at least 13,927 samples was 80.0%. Furthermore, all the detected residual pesticides were within the limits. However, the detection values of chlorpyrifos, diphenylamine, linuron, and pentoxazone from crude drugs were beyond the self-imposed limits, and exceeded the maximum residue limit of the positive list under the Food Sanitation Law. However, considering the difference in water contents between fresh foods and crude drugs, the values, except for pentoxazone, were within the maximum residue limit of fresh foods. Moreover, the detection value of pentoxazone was higher than the maximum residue limit, while isofenphos-methyl had no reference value. Therefore, we estimated their safety based on their acceptable daily intake and daily dosages. Subsequently, these values were not problematic for crude drug users. Nevertheless, we will continue to regularly monitor these pesticides to prevent their contamination of crude drugs.

The Glechoma hederacea subsp. Grandis is traditionally used for the treatment of asthma, colds and bronchitis, and is reportedly effective in promoting bile secretion and diuretic action and preventing diabetes. In this study, we investigated the effect of hot water extract of Glechoma on 3T3-L1 adipocyte differentiation. Oil Red O staining showed more neutral lipid droplets in 3T3-L1 adipocytes treated with the hot water extract of Glechoma. In addition to morphological change, the expression of CCAAT/enhancer-binding protein α, peroxisome proliferator activator γ2 (PPARγ2), adipogenic regulators at the intermediate stage of adipocyte differentiation and adipocyte protein 2, an adipocyte differentiation marker gene, was increased in cells treated with extract of Glechoma. PPARγ2, a ligand-activated transcription factor of a nuclear receptor, is known to normalize adipocyte functions and improve insulin sensitivity by promoting the differentiation of preadipocytes into small-sized adipocytes. Treatment with the hot water extract of Glechoma increased transcriptional activity of PPARγ, suggesting that Glechoma contains an active ingredient at least PPAR agonist. Our results demonstrate that the hot water extract of Glechoma could promote adipocyte differentiation in part through the activation of PPARγ. Taken together, Glechoma has the potential to improve insulin resistance and prevent the onset of type 2 diabetes.

In order to explore new aldose reductase (AR) inhibitory substances, the H₂O, EtOH, and EtOAc extracts of 92 crude drugs were evaluated for the AR inhibitory activities. As a result, the H₂O, EtOH, and EtOAc extracts of clove showed relatively potent AR inhibitory activities. Phytochemical investigation of the H₂O extract of clove identified 10 flavonol derivatives 　(1－10), a chromone derivative (11), a sesquiterpene derivative (12), and an acetophenone derivative (13). Among the isolated compounds, 3 (rhamnocitrin) significantly inhibited AR activity with an IC₅₀ value of 0.57 μM, which is comparable to epalrestat used as the positive control.