Purpose: Essential oils (EOs) obtained from spices, herbs, and medicinal plants are well known in traditional medicine and are an area of interest due to their various biological activities. Therefore, the present study investigates the chemical composition, phytochemical properties, as well as the biological activity of EOs, recovered from un-irradiated and irradiated (2.5, 5, and 10 kGy) caraway seeds.
Materials and methods: Carum carvi L. seeds were irradiated with gamma irradiation at dose levels 2.5, 5, and 10 kGy, then EOs were recovered from all the samples. The chemical composition, phenols, and flavonoids content were evaluated. As well, antimicrobial and antitumor activities against the two cell lines [colorectal adenocarcinoma (Caco-2) and liver cancer (HepG-2)] were investigated.
Results: The results indicated the percentage of oil increased by radiation, especially a dose of 10 kGy, which gave the highest percentage (3.50%) compared to the control. Also, the Gas Chromatography/Mass Spectrometry (GC-MS) analysis revealed the presence of 26 compounds in the essential oil extracts. The main constituent of caraway seeds EOs was Carvone followed by Limonene. According to the results, there was an increase in the content of phenols and flavonoids by using gamma rays compared with control, the maximum increase was observed at dose level 10 kGy (13.70 and 7.38 mg/g oil, respectively) followed by 5 kGy (11.20 and 5.86 mg/g oil, respectively). The antioxidant properties of the caraway essential oils were increased by increasing the irradiation dose level (2.5-10 kGy) analyzed by DPPH radical and metal chelating activity. Caraway essential oils have an antimicrobial action against Gram-positive and Gram-negative bacteria as well as fungi. The antimicrobial activity was increased as the irradiation dose was raised and the10 kGy dose was more effective in suppressing the growth of bacteria and fungi. Additionally, the caraway essential oils have anticancer activity against the two cell lines studied; colorectal adenocarcinoma (Caco-2) and liver cancer cell line (HepG-2) as reduced the cell viability and density.
Conclusion: The 10 kGy dose was more effective for oil yield, phenols, flavonoids, and antioxidant activity as well as antibacterial and antifungal activities. Furthermore, the caraway essential oils indicated anticancer activity against the two cell lines studied; colorectal adenocarcinoma (Caco-2) and liver cancer cell line (HepG-2) as reduced the cell viability and density. So caraway could be considered an important herb with multiple therapeutic uses.
Keywords: Caraway; GC-MS analysis; biochemical and biological properties; essential oil.