Chemical characterization and biological activity of mastic gum essential oils from Pistacia lentiscus var. chia from Turkey

Authors: Tabanca, Nurhayat; NALBANSTOY, AYSE - Ege University; Kendra, Paul; DEMIRCI, FATIH - Anadolu Universtiy; DEMIRCI, BETUL - Anadolu Universtiy

Submitted to: Molecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2020
Publication Date: 5/2/2020
Citation: Tabanca, N., Nalbanstoy, A., Kendra, P.E., Demirci, F., Demirci, B. 2020. Chemical characterization and biological activity of mastic gum essential oils from Pistacia lentiscus var. chia from Turkey. Molecules. 25(9): 2136. https://doi.org/10.3390/molecules25092136.
DOI: https://doi.org/10.3390/molecules25092136

Interpretive Summary: Mastic gum is a natural resin obtained from the tree Pistacia lentiscus var. chia (Anacardiaceae), which is naturally distributed in the Aegean and Mediterranean regions. Mastic gum essential oil (MGEO) has recently gained remarkable interest due to its therapeutic properties, which are now widely used in foods, perfumes, and cosmetics. Despite the natural occurrence of mastic trees Cesme-Urla-Karaburun Peninsula in the Aegean region of Turkey, no studies on the volatile composition of mastic gum collected from that areas were reported. One of the objectives of this study was to compare the chemical composition of MGEOs obtained from wild and cultivated trees of P. lentiscus from the Aegean region, Turkey. Another objective was performed to evaluate wide range of biological activities such as cytotoxicity against multiple cancer cells, antimicrobial activity against human and food-borne pathogens and kairomone activity on Ceratitis capitata (Mediterranean fruit fly, medfly). To accomplish these objectives, scientists from the USDA-ARS (Miami, FL) collaborated with researchers from Anadolu and Ege University in Turkey. Results indicated that certain compounds differentiated between wild and cultivated MGEOs, especially ratios between (-)/(+)-a-pinene and (-)-a-pinene/myrcene, which are desirable for mastic gum quality. In biological assays, MGEOs did not exhibit any significant activity against bacteria and yeast and did not show strong attractants of male medflies; however, oils demonstrated better cytotoxicity against human cancer cells. This research will be important to pharmaceutical, food and cosmetic industries interested in products containing MGEOs and local communities who supply raw materials to consumers.

Technical Abstract: The essential oils (EOs) were isolated by hydrodistillation from wild and cultivated Pistacia lentiscus L. var. chia – mastic gum tree (Anacardiaceae) from two natural habitats namely from Cesme-Uzunkoy (1) and Mordogan (2), and one cultivated source, Cesme-Germiyan (3), in Izmir, Turkey. This comparative study evaluated the chemical composition and biological activity of mastic gum essential oils (MGEOs). For this purpose, MGEOs 1-3 were analyzed by GC-FID, GC-MS, and chiral GC for a-pinene. Laboratory assays were conducted to assess for potential in vitro cytotoxicity (multiple in vitro cancer cell lines), antimicrobial properties (five bacterial species and yeast), anti-inflammatory activity (inhibition of inducible nitric oxide synthase, iNOS), and attraction of Ceratitis capitata (Mediterranean fruit fly, medfly), respectively. Chemical analysis indicated that MGEOs 1 and 2 were rich in a-pinene (56.2 and 51.9%), myrcene (20.1 and 18.6%), and b-pinene (2.7 and 3.1%), respectively; whereas MGEO-3 was characterized by a high level of a-pinene (70.8%), followed by b-pinene (5.7%) and myrcene (2.5%). Chiral GC analyses showed that concentration ratios between (-)/(+)-a-pinene and (-)-a-pinene/myrcene allowed for differentiation between wild and cultivated MGEO sources. In biological assays, MGEOs 1-3 did not exhibit significant antimicrobial effects against the pathogens evaluated and were not strong attractants of male medflies; however, all three MGEOs displayed dose-dependent inhibition of iNOS, and MGEOs 1 and 2 exhibited selective in vitro cytotoxicity against human cancer cells. These results suggest that wild-type mastic gum oils from Cesme and Mordogan (MGEOs 1 and 2) are potential sources of beneficial products and warrant further investigation.