Radical Scavenging Activity of the Essential Oil of Silver Fir (Abies alba)

Abstract

Summary The essential oil of silver fir (Abies alba) is known to help respiratory system and have easing and soothing effect for muscle. In the present study, we investigated the chemical composition, cytotoxicity and its biological activities of silver fir (Abies alba) essential oil. The composition of the oil was analyzed by GC-MS and bornyl acetate (30.31%), camphene (19.81%), 3-carene (13.85%), tricyclene (12.90%), dl-limonene (7.50%), α-pinene (2.87%), caryophyllene (2.18%), β-phellandrene (2.13%), borneol (1.74%), bicyclo[2.2.1]hept-2-ene,2,3-dimethyl (1.64%) and α-terpinene (1.24%) were the major components in the oil. The results tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay indicated that the oil showed no cytotoxic effect, at concentrations of 1 and 5%, for as long as 24 and 3 h, respectively. The antiradical capacity was evaluated by measuring the scavenging activity of the essential oil on the 2,20-diphenylpicrylhydrazyl (DPPH) and 2,2'-azino-bis 3-ethyl benzothiazoline-6-sulfonic acid (ABTS) radicals. The oil was able to reduce the both radicals dose-dependently, and the concentration required for 50% reduction (RC50) against DPPH radicals (2.7 ± 0.63%) was lower than ABTS radicals (8.5 ± 0.27%). The antibacterial activity of the oil was also evaluated using disc diffusion method against Staphylococcus aureus, Streptococcus mutans, Listeria monocytogenes, Acinetobacter baumannii, Escherichia coli, and Vibrio parahaemolyticcus. The oil exhibited no antibacterial activity against all the bacterial strains tested except S. aureus of mild activity.

Screening of Polish Fir Honeydew Honey Using GC/MS, HPLC‐DAD, and Physical‐Chemical Parameters: Benzene Derivatives and Terpenes as Chemical Markers

“…However, to the best of our knowledge, there was no report on occurrence of those compounds in any honey variety type including honeydew honeys. Moreover, regarding the source traceability, the presence of borneol and α ‐terpineol in the headspace as well as limonene in dichloromethane extract can be relevant, since those compounds or their precursors were found also in the essential oil of fir . Nevertheless, the investigated honey samples did not contain other typical compounds of the essential oil.…”

“…The latter, in contrast to the other honeys, contained also a relevant amount of p ‐menth‐1‐en‐9‐al isomers (up to 18.5%) . Other identified compounds such as α ‐terpineol and borneol are more relevant regarding the source traceability, since those compounds are present in fir essential oil and could also be generated by transformation from related, more abundant components such as pinene, limonene, or bornyl acetate present in fir . Until now, borneol has been found along with other bicyclic terpenes such as pinocarvone, myrtenal, verbenone, in the headspace of Polish willow nectar honey .…”

“…Nevertheless, the investigated honey samples did not contain other typical compounds of the essential oil. One of the main compounds of fir essential oil is bornyl, acetate that could be hydrolyzed to borneol, e.g ., in elevated pH during passage through aphid digestive system or during the honeydew maturation. Similarly, limonene could undergo biotransformation to α ‐terpineol during honeydew formation or maturation.…”

“…[27] Other identified compounds such as a-terpineol and borneol are more relevant regarding the source traceability, since those compounds are present in fir essential oil and could also be generated by transformation from related, more abundant components such as pinene, limonene, or bornyl acetate present in fir. [28] [29] Until now, borneol has been found along with other bicyclic terpenes such as pinocarvone, myrtenal, verbenone, in the headspace of Polish willow nectar honey. [26] However, in FHH, the latter compounds were not detected, therefore, the presence of borneol could be helpful for fir honeydew identification.…”

“…Moreover, regarding the source traceability, the presence of borneol and a-terpineol in the headspace as well as limonene in dichloromethane extract can be relevant, since those compounds or their precursors were found also in the essential oil of fir. [28] Nevertheless, the investigated honey samples did not contain other typical compounds of the essential oil. One of the main compounds of fir essential oil is bornyl, acetate [28] that could be hydrolyzed to borneol, e.g., in elevated pH during passage through aphid digestive system or during the honeydew maturation.…”