**4. Application to oral diseases**

Oral cares are important to maintain the normal oral functions and prevent oral diseases. Recent report suggests an association between oral health and the risk of lacunar infarction [12]. Tooth‐blushing and myofunctional therapy stimulate the secretion of saliva [13, 14]. Mouthrinsing with aqueous biocompatible 2‐methacryloyloxyethyl phosphorylcholine (MPC)‐polymer inhibited the increase in oral bacterial numbers, especially of *S. mutans* [15]. The inhibition of bacterial adherence and biofilm development may prevent the aspiration pneumonia and the periodontitis [16].

However, if the extent of oral diseases exceeds the capacity of oral care, we have to rely on medicines. Various Kampo medicines are used to treat oral diseases such as stomatitis, xero‐ stomia, taste disturbance, halitosis, glossodynia, temporomandibular joint and muscle disor‐ ders (TMJ), tooth extraction and periodontal disease (**Table 2**).


**Table 2.** Application of Kampo medicines to oral diseases.

Hochuekkito and Juzentaihoto. However, licorice present therein may induce hypokalemia (hypertension, edema, feeling of weakness, convulsions paralysis of the extremities, arrhyth‐ mia) [10]. Shosaikoto, which also contains licorice, is known to induce interstitial pneumonia (fever, dry cough, exertional dyspnea) [11]. The use of herbal medicines is increasing all over the world and when a patient with such risk factors is prescribed an herbal medicine containing licorice, careful follow‐up is required. The patient's symptoms should be carefully monitored and if no improvement in symptoms is observed, continuous treatment should be avoided.

Oral cares are important to maintain the normal oral functions and prevent oral diseases. Recent report suggests an association between oral health and the risk of lacunar infarction [12]. Tooth‐blushing and myofunctional therapy stimulate the secretion of saliva [13, 14]. Mouthrinsing with aqueous biocompatible 2‐methacryloyloxyethyl phosphorylcholine (MPC)‐polymer inhibited the increase in oral bacterial numbers, especially of *S. mutans* [15]. The inhibition of bacterial adherence and biofilm development may prevent the aspiration

However, if the extent of oral diseases exceeds the capacity of oral care, we have to rely on medicines. Various Kampo medicines are used to treat oral diseases such as stomatitis, xero‐ stomia, taste disturbance, halitosis, glossodynia, temporomandibular joint and muscle disor‐

**4. Application to oral diseases**

6 Biological Activities and Action Mechanisms of Licorice Ingredients

pneumonia and the periodontitis [16].

Hachimijiogan ●

Jiinkokato ●

Inchinkoto ●

Jumihaidokuto ●

ders (TMJ), tooth extraction and periodontal disease (**Table 2**).

**Stomatitis**

**Bakumondoto** ● ● ● Byakkokaninjinto ● ● ● ●

**Xerostomia**

Daisaikoto ●

Hochuekkito ● ● ● ●

Goreisan ● ● ● ●

Hangekobokuto ● ● ● ● ●

**Hangeshoshinto** ● ● ● ●

**Taste disturbance**

**Halitosis** **Glossodynia**

**TMJ**

**Tooth extraction**

**Periodontal disease**

**Presence of Licorice**

Hangeshashashashinto showed anti‐inflammatory [17], oral ulcer‐induced pain‐releasing [18], antimicrobial [19], antimucositis [20] and antioxidative activities [21]. Orento prevented the inflammatory responses in lipopolysaccharide‐treated human gingival fibroblasts [22]. Rikkosan also induced anti‐inflammatory activity [17]. Shosaikoto showed anti‐inflammatory [23] and anti‐hyperlipidemic and anti‐atherosclerotic activities [24]. It should be noted that all these four Kampo medicines contain licorice **(Table 2).**

Kampo medicines are also effective to alleviate the glossodynia [25] and cancer thermother‐ apy‐induced side effects [26–28].
