The application of 1,8-cineole, a terpenoid oxide present in medicinal plants, inhibits castor oil-induced diarrhea in rats

Abstract

Context: 1,8-Cineole, a terpene, characterized as a major constituent occurring in the essential oils of several aromatic plants. It is widely used in pharmaceutical industry, as a food additive and for culinary purposes.

Objective: This study investigates the inhibitory effect of 1,8-cineole on transit time and diarrhea in animal models.

Materials and methods: Acute toxicity and lethality of 1-8-cineole was determined by Lork’s guidelines. The antidiarrheal effect of 1,8-cineole was investigated by determining the intestinal transit and enterpooling in rats. In all experiments, different doses of 1,8-cineole (20–120 mg/kg), atropine, and loperamide were administered orally.

Results: The LD₅₀ of 1,8-cineole for oral administration was estimated to be 1280 mg/kg. 1,8-Cineole (20–120 mg/kg) did not show a significant decrease in small intestine transit (p > 0.05); however, the highest dose displayed a significant decrease in comparison with atropine (p < 0.05). This substance decreased the peristaltic index value to 68 ± 0.36% at a dose of 120 mg/kg compared with the control group (85.22 ± 4.31%) in the castor oil transit test. 1,8-Cineole significantly delayed the onset of diarrhea to −142.33 ± 6.08 min at 120 mg/kg, while the time was 103.66 ± 20.73 min for the control and >240 min for the loperamide. Moreover, 1,8-cineole significantly decreased intestinal fluid accumulation (p < 0.05).

Conclusions: This study demonstrated antispasmodic and antisecretory activities of 1,8-cineole and rationalized the traditional use of the plant containing various levels of this terpene in the treatment of gastrointestinal complains such as diarrhea.

• Antispasmodic
• essential oil
• intestinal transit
• in vivo
• terpenes

Acknowledgements

The authors wish to thank Milad Moloudizargari and Shahin Aghajanshakeri for revising the manuscript. We also thank Laya Hatefi-Afshar, Alireza Yusefi, and Mehdi Abdollahi for their technical assistance.

Declaration of interest

The authors declare no conflicts of interest associated the present work. Financial support for this work was provided by the Research Council of the Urmia University, Iran.