Comfortable and dermatological effects of hot spring bathing provide demonstrative insight into improvement in the rough skin of Capybaras

Abstract

The purpose of this study was to clarify dermatologically the favorable effects of hot spring bathing on the rough skin in Capybaras. Non-volcanic hot springs used in this study showed alkaline quality of water (pH 9.3), containing sodium and chloride ions. The normal skin in Capybaras was characterized by the presence of relatively thick epidermis with mild alkaline state (pH 8.26). The dorsal skin had melanin granules in the basal layer. Their rough skin affected in the Japanese cold winter was improved by daily bathing in an alkaline hot spring. The skin properties returned to the normal skin conditions (moisture, melanin and erythema values) observed in the summer. The facial expression mainly changes in the eyes was scored to evaluate comfortable status. The comfortable status during hot spring bathing significantly increased as compared with that observed before bathing (p < 0.01). The thermography revealed a heat retention effect of body temperature after hot spring bathing for 30 min. In conclusion, this study demonstrates that hot spring had significantly comfortable and dermatological effects on the basis of evaluation for the skin and body conditions in Capybaras.

Hot spring bathing accelerates wound healing and enhances heat retention effect in guinea pigs

“…In the thermograph test, the transition of the body surface temperature after bathing was clearly different between the two groups. A similar heat retention effect has been confirmed in the outdoor Yuda hot spring bathing test for large rodents [26]. In this study, it was revealed that the heat retention effect of hot springs is superior to that of tap water under controlled air conditioning.…”

“…Therefore, it is believed to accelerate wound healing, and many people visit for this effect. Previously, we conducted a hot spring bathing test using Capybaras [ 26 ] and confirmed the improvement in skin properties such as an increase in skin moisture content and the heat retention effect by bathing in Yuda hot spring. However, the test was not under controlled conditions.…”

“…Bathing in a hot spring with high reducibility lowers the ORP value of the skin and suppresses oxidation and aging, resulting in improved skin elasticity [ 56 , 60 , 62 , 64 , 65 ]. We previously reported that bathing in Yuda hot spring improves skin properties, such as skin moisture [ 26 ]. It was suggested that the high reducibility of the Yuda hot spring, as revealed in this test, is related to its beneficial effect on the skin, in addition to the properties of an alkaline hot spring that are low in skin stimulation.…”

“…The reason was considered to be stress and loss of appetite due to pain, but the results of the blood tests in the hot spring group were within the reference values. Hot springs have stress-reducing and pain-reducing effects [ 2 , 10 , 26 , 53 , 54 , 89 , 90 ], and the results of hematological examination suggested a relationship with these effects.…”

“…Alkaline hot springs are supposed to stimulate the skin less than acid hot springs and help smooth the skin; however, this has not been clearly elucidated. The Yuda hot spring, which we use for research, is also a simple alkaline hot spring [ 26 ], and the skin-smoothing effect has been handed down empirically for a long time. Therefore, it is believed to accelerate wound healing, and many people visit for this effect.…”