Effects of Essential Oils of Elettaria cardamomum Grown in India and Guatemala on Gram-Negative Bacteria and Gastrointestinal Disorders

Abstract

The present study examined the chemical composition and antimicrobial and gastrointestinal activity of the essential oils of Elettaria cardamomum (L.) Maton harvested in India (EC-I) and Guatemala (EC-G). Monoterpenes were present in higher concentration in EC-I (83.24%) than in EC-G (73.03%), whereas sesquiterpenes were present in a higher concentration in EC-G (18.35%) than in EC-I (9.27%). Minimum inhibitory concentrations (MICs) of 0.5 and 0.25 mg/mL were demonstrated against Pseudomonas aeruginosa in EC-G and EC-I, respectively, whereas MICs of 1 and 0.5 mg/mL were demonstrated against Escherichia coli in EC-G and EC-I, respectively. The treatment with control had the highest kill-time potential, whereas the treatment with oils had shorter kill-time. EC-I was observed to be more potent in the castor oil-induced diarrhea model than EC-G. At 100 and 200 mg/kg, P.O., EC-I exhibited 40% and 80% protection, respectively, and EC-G exhibited 20% and 60% protection, respectively, in mice, whereas loperamide (10 mg/kg, i.p., positive control) exhibited 100% protection. In the in vitro experiments, EC-I inhibited both carbachol (CCh, 1 µM) and high K⁺ (80 mM)-induced contractions at significantly lower concentrations than EC-G. Thus, EC-I significantly inhibited P. aeruginosa and E. coli and exhibited more potent antidiarrheal and antispasmodic effects than EC-G.

Keywords: Elettaria cardamomum; GC-MS; antibacterial; antidiarrheal; antispasmodic; essential oil.

Figure 1

GC-MS chromatograms of Elettaria cardamomum of (A) (Indian, EC-I) and (B) Guatemala, EC-G) essential oils.

Figure 2

Time-kill analysis of (A) P. aeruginosa and (B) E. coli.

Figure 3

Concentration-response curves showing comparison of the extracted essential oil of Elettaria cardamomum of Indian (EC-I) and Guatemala (EC-G) for the inhibitory effect against (A) carbachol (CCh, 1 µM) and (B) high K⁺-induced contractions in isolated rat ileum preparations. Values shown are mean ± SEM, n = 4.