Antibacterial, antioxidant, and cytotoxic activities of Syzygium aromaticum (L.) Merr. & Perry essential oil with identification of its chemical constituents

Aromatic plants embrace volatile compounds with efficiency in treating different diseases. In Jordan, Syzygium aromaticum flower buds (clove) are extensively used as folk medicine without awareness of its bio-safe dosage. Herein, clove buds were hydrodistilled using the Clevenger apparatus, and the resulting essential oil (CEO) was analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). The antibacterial activity was evaluated against tested bacterial strains by agar diffusion test and micro-broth dilution assay. The antioxidant capacity was assessed using DPPH radical scavenging assay, while the cytotoxic potency was unraveled by determination of its anti-proliferative activity against MDA-MB-231 breast adenocarcinoma and normal Vero cell lines. CEO yield was 5.7 ± 1.3% (w/w); encompassed 24 volatile ingredients with eugenol as the principal compound (73.41%). The CEO inhibited the growth of both Gram-positive and Gram-negative bacterial test strains, causing the formation of 13.7 ± 1.5-17.3 ± 0.6 mm and 11.7 ± 1.5-20.7 ± 1.2 mm inhibition zones, respectively with MIC 1.25-5 μL/mL. Moreover, it showed antioxidant activity with IC₅₀ 0.0016 ± 0.0001 μL/mL (1.6 ± 0.1 μg/mL, 2.98 ± 0.4 µg Trolox^®/µg CEO). Intriguingly, the CEO was cytotoxic against both cancerous and noncancerous cell lines at IC₅₀ of 0.25 ± 0.02 μL/mL and 0.18 ± 0.01 μL/mL, respectively. Herein results unveil the potential application of CEO as a pharmaceutical remedy with considering its bio-safe dosage.

Essential oils from Elettaria cardamomum (L.) Maton grains and Cinnamomum verum J. Presl barks: Chemical examination and bioactivity studies

Context: Elettaria cardamomum (L.) Maton grains and Cinnamomum verum J. Presl barks are immensely consumed by Jordanian population as food flavoring and remedies in treating different disorders without awareness of their effect or dose toxicity. Aims: To evaluate the antibacterial, antioxidant and cytotoxic effects of essential oils (EOs) hydro-distilled from E. cardamomum grains and C. verum barks. Methods: Hydro-distillation was carried out using Clevenger apparatus; the EOs were analyzed using GC/MS, and their constituents were quantified using GC/FID. The antibacterial activity was determined by agar diffusion test and micro-broth dilution assay, while the antioxidant activity was evaluated by DPPH and ABTS scavenging assays. The cytotoxic activity was evaluated against the MDA-MB-231 breast cancer cell line. Results: E. cardamomum EO was most effective against Bacillus subtilis with MIC 3.75 µL/mL and exhibited antioxidant activity in DPPH assay with IC50 0.057 ±0.013 µL/mL (0.076 ±0.017 µL EO/µg Trolox®) but was ineffective in the ABTS test up to 5 µL/mL; 86.22% of its EO constituent are oxygenated monoterpenes with α-terpinyl acetate as the major component. Whilst C. verum EO was active against both tested Gram-positive and negative bacterial strains with MIC 1.25-5.00 µL/mL but was devoid of significant antioxidant activity up to 5 µL/mL; phenylpropanoids constituted 69.48% of its EO with E-cinnamaldehyde as the major component. Both EOs showed cytotoxic activity against the breast cancer cell line withIC50 0.14-0.46 µL/mL. Conclusions: The current results unveil the potential application of C. verum and E. cardamomum in complementary and alternative medicine as biosafe remedies besides their usage as flavoring and seasoning sources.