Document Type : Research Paper

Authors

• Mohammad Ali Zarei ¹
• Narges Nourbakhsh ²

¹ Department of Biological sciences. Faculty of Science. University of Kurdistan. Sanandaj. Iran

² Dept. of biological sciences- Faculty of Science- Univ. of Kurdistan- Sanandaj- IRAN

Abstract

Background and Objectives: Antioxidants are a group of chemical compounds naturally present in many foods. These compounds help protect the body’s cells and tissues from oxidative damage by neutralizing free radicals. The most important natural antioxidants are found in grains, vegetables, fruits, and spices. Frankincense (Boswellia thurifera) is a medicinal plant traditionally used in Arabic medicine to enhance memory. Mastic gum, derived from the shrub Pistacia lentiscus, possesses numerous medicinal properties and is considered a medicinal plant. The chemical compounds extracted from frankincense and mastic gums using various solvents may exhibit different antioxidant properties. Consequently, this research aimed to investigate the reducing power, as well as the phenolic and flavonoid contents, of frankincense and mastic extracts prepared using different solvents.
Methodology: Acetone, ethyl acetate, hexane, ethanol, methanol, and ether were selected as solvents for extracting frankincense and mastic gums using a rotary evaporator. The resulting extracts were analyzed to evaluate their reducing power, antioxidant activity, and free radical scavenging ability using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Additionally, the total phenolic content was determined using the Folin–Ciocalteu method, and the total flavonoid content was measured using the aluminum chloride colorimetric method.
Results: In the experiments performed with extracts obtained using various solvents (acetone, hexane, ethyl acetate, methanol, ether, and ethanol), the lowest EC₅₀ value was observed in the hexane extract of frankincense (2.24 mg/mL), and the acetone extract of mastic (3.10 mg/mL), indicating the highest reducing power. Conversely, the highest EC₅₀ values—indicative of the lowest reducing power—were found in the hexane extracts of frankincense (64.75 mg/mL) and mastic (12.59 mg/mL). Regarding total phenolic content, the ethanolic extract of frankincense had the highest value (0.2675 mg/mL), while the hexane extract had the lowest (0.0825 mg/mL). For mastic extracts, the acetone extract exhibited the highest phenolic content (0.261 mg/mL), and the methanolic extract showed the lowest (0.086 mg/mL). As for total flavonoid content, the highest amounts were recorded in the ether extracts of mastic (0.133 mg/mL) and frankincense (0.161 mg/mL). The lowest flavonoid content was found in the methanolic extract of mastic (0.0185 mg/mL) and the ethanolic extract of frankincense (0.0435 mg/mL).
Conclusion: The findings of this study indicate that extracts of mastic and frankincense obtained using acetone, ethanol, methanol, ethyl acetate, hexane, and ether exhibited significant antioxidant activity. Among the frankincense extracts, the methanolic extract, with the highest EC₅₀ value, demonstrated the lowest antioxidant activity, while the hexane extract, with the lowest EC₅₀, had the highest antioxidant activity. Similarly, for mastic, the hexane extract showed the lowest antioxidant activity (highest EC50), while the acetone extract exhibited the highest antioxidant activity (lowest EC₅₀). Another objective of the study was to assess the phenolic and flavonoid content of mastic and frankincense extracts in different solvents. The highest phenolic content was found in the ethanolic extract of frankincense and the acetone extract of mastic, while the lowest was observed in the hexane extract of frankincense and the methanolic extract of mastic. For flavonoids, the ether extracts of both mastic and frankincense gums contained the highest levels, whereas the methanolic extract of mastic and the ethanolic extract of frankincense contained the lowest. Given the strong correlation between phenolic and flavonoid content and antioxidant activity in frankincense and mastic, these plants can serve as valuable natural sources of antioxidants for human health and have potential applications as effective medicinal agents.

Keywords

• Frankincense gum
• Mastic gum
• Phenol
• Flavonoid
• Antioxidant

Main Subjects

• Phytochemistry (extraction, identification and measurement of active components)