Table 2.
Clinical studies evaluating antispasmodic potential of essential oils.
| Area of Interest | Authors | Type of Clinical Study | Number of Patients | Treatment | Results |
|---|---|---|---|---|---|
| Functional dyspepsia | Papathanasopoulos et al., 2013 [56] | Randomized, crossover study | 13 healthy volunteers | Peppermint oil 182 mg p.o., single dose | Decreased intragastric pressure and gastric motility |
| Functional dyspepsia | Inamori et al., 2007 [57] | Randomized control study | 10 healthy volunteers | Peppermint oil 0.64 mL p.o., single dose | Enhancement of gastric emptying without altering gastric emptying coefficient |
| Functional dyspepsia | May et al., 2000 [58] | Randomized control study | 96 patients with functional dyspepsia | Peppermint oil and caraway oil combination 90 mg + 50 mg p.o., 4 weeks | Reduction of symptoms (pain, fulness, heaviness) |
| Functional dyspepsia | Madisch et al., 1999 [59] | Randomized control study | 118 patients with functional dyspepsia | Peppermint oil and caraway oil combination 90 mg + 50 mg p.o., 4 weeks | Reduction of dyspeptic symptoms |
| Irritable bowel syndrome (IBS) | Cash et al., 2016 [60] | Randomized control study | 72 patients with IBS | Peppermint oil 180 mg p.o., 4 weeks | Reduction of symptoms |
| IBS | Khanna et al., 2014 [61] | Meta-analysis | 9 studies with 726 patients with IBS | Peppermint oil 200 mg | Global improvement of IBS symptoms (RR 2.23, 95% CI 1.78–2.81) |
| IBS | Merat et al., 2010 [62] | Randomized control study | 90 patients with IBS | Peppermint oil 187 mg p.o., 8 weeks | Reduction of abdominal pain and discomfort |
| IBS | Cappello et al., 2007 [63] | Randomized control study | 57 patients with IBS | Peppermint oil 225 mg p.o., 4 weeks |
Reduction of total IBS symptoms |
| IBS | Pittler and Ernst 1998 [64] | Meta-analysis | 8 randomized control studies | Peppermint oil | Reduction of IBS symptoms not established beyond reasonable doubt |
| IBS | Liu et al., 1997 [65] | Randomized control study | 110 patients with IBS | Peppermint oil 187 mg p.o., 4 weeks | Improvement of pain and other IBS symptoms |
| Endoscopic procedures | Inoue et al., 2014 [66] | Randomized control study | 226 patients with colonoscopy | L-menthol applied on the mucosa | Reduction of discomfort |
| Endoscopic procedures | Hiki et al., 2012 [67] | Randomized control study | 131 patients with gastric endoscopy | L-menthol applied on the mucosa | Reduction of peristalsis |
| Endoscopic procedures | Yamamoto et al., 2006 [68] | Randomized, control study | 40 patients with endoscopic cholangiopancreatography | Peppermint oil applied to papilla | Non-significant reduction of duodenal contractions |
| Infantile colic | Bezerra Alves et al., 2012 [69] | Randomized crossover study | 30 infants | Mentha piperita liquid drops, 1 drop/kg | Decreased frequency and duration of infantile colic |
| Primary dysmenorrhea | Ghodsi and Asltoghiri, 2014 [70] | Randomized control study | 80 female students | Fennel capsules 180 mg/day, 3 months | Reduction of dysmenorrhea symptoms |