Chemical Composition, Antioxidant, Cytotoxic and Anti-Inflammatory Activities of Coleus ambionicus Lour. Essential Oil against Antibiotic-Resistant Helicobacter pylori

The purpose of this study was to evaluate the efficacy of the C. ambionicus Lour. essential oil in the treatment of gastric ulcers and the eradication of drug-resistant H. pylori strains being the cause of gastric ulcers, which delay healing and increase the chance of gastric cancer. The essential oil was extracted from the fresh leaves of C. amboinicus Lour. yielded 0.05 ± 0.0032%. The main compounds of essential oil were thymol (52.79%) and caryophyllene (9.47%) as they exhibited inhibitory activity against amoxicillin -resistant H. pylori ATCC 43579 and metronidazole-resistant H. pylori ATCC 43504 with inhibition zones of 29.5 ± 0.71 and 25.5 ± 0.71 mm, respectively. The MIC values of essential oil for H. pylori ATCC 43579 and H. pylori ATCC 43504 were of 25 and 50 µg/mL, respectively. The antioxidant activity exhibited an IC50 of 4,126 ± 0.03 μg/mL in the DPPH radical scavenging assay which yielded a value of 142.93 ± 2.86 mg TE/g of essential oil extract in the FRAP assay. The essential oil concentrations of 5, 10 and 25 μg/mL exhibit anti-inflammatory effects by inhibiting NO production at values of 15.62 ± 7.29%, 19.67 ± 6.34% and 22.17 ± 5.03%, respectively. The anti-inflammatory effect significantly inhibited NO production in Lipopolysaccharides (LPS)-stimulated RAW 264.7 cells at no lower concentration than 5 µg/mL. The essential oil extract at concentrations were not higher than 250 µg/mL exhibited no cytotoxic effects on RAW 264.7 macrophage cell line. The findings suggest that the potential of essential oil from C. amboinicus Lour. shows antibiotic-resistant activity against H. pylori strains, exhibits antioxidant and anti-inflammatory properties, and is non-toxicity to cells. Consequently, it potentially serves as an alternative for developing drugs for the treatment of gastric ulcers and preventing recurrence, as it can be used alone or in combination with present drugs. HIGHLIGHTS Your The essential oil of C. amboinicus Lour. is abundant in thymol and exhibits potential antioxidant and anti-inflammatory properties, which is non-toxic to cells. This research reveals the first study to show the susceptibility of C. amboinicus Lour. essential oil to antibiotic-resistant Helicobacter pylori. Consequently, it shows potential of drug development for the treatment of gastric ulcers caused by the antibiotic-resistant Helicobacter pylori, thereby preventing the onset of gastric cancer in patients.