Absorption and Bioavailability of Major Monoterpenes in Mastiha Oil; a Kinetic Study in Humans.
Condition: Absorption
Study type: Interventional

Summary: 
      Plant derived foods contain large quantities of non-nutrient phytochemicals that have been
      extensively studied for their beneficial health effects on the prevention of chronic
      diseases. Although research on their health effects is abundant, our knowledge on absorption
      and bioavailability is yet narrow and in some cases zero. The concept of bioavailability
      involves the identification of the fraction of administered compounds that can reach plasma
      and body tissues in an unchanged form. The bioactivity of components in foods that are part
      of our nutrition, either as parent foods or as food supplements, is directly related to
      bioavailability, the latter being a necessary step to prove efficacy.

      Mastiha Oil (MO) is extracted from the resin of Pistacia Lentiscus var. Chia (of the
      Anacardiaceae family), a concentrated source of monoterpenes (e.g., α-pinene, β-pinene,
      β-myrcene) and triterpenes (e.g., mastihadienonic acid, isomastihadienonic acid), and to a
      lesser extent of plant sterols, simple phenols and approximately 10% MO (Assimopoulou, &
      Papageorgiou, 2005, Paraschos et al, 2007, Kaliora, Mylona, Chiou, Petsios, & Andrikopoulos,
      2004). MO is a 100% natural product used as a food additive and flavoring and it is
      manufactured according to the legal standards that make it suitable for human consumption.
      Its nutritional analysis is presented in Supplementary Table 1. A total of 90 components have
      been detected in MO (50% monoterpene hydrocarbons, 20% oxygenated monoterpenes, 25%
      sesquiterpenes). Monoterpenes seem to exhibit beneficial health effects contributing to
      mechanisms of inflammation and oxidative stress (Subramaniyan, 2017; Madhuri, & Naik, 2017).

      Research upon the bioavailability of monoterpenes in humans is limited. Herein, we aimed at
      investigating the bioavailability of the main monoterpenes of MO in humans for the first
      time. To this end, a novel GC-MS-MS method was employed, since the tandem MS technique can
      help overcome matrix difficulties. Additionally, based on the existing data regarding the
      antioxidant activity of monoterpenes, the effect on human antioxidant capacity was evaluated
      applying the serum oxidisabilty assay.

      .
    

Detailed description: 
      After enrolment, the volunteers will undergo a medical and dietary assessment and their
      health status will be evaluated through a complete blood count. On the day of the experiment
      and after overnight fasting, the volunteers will consume g of mastiha oil (1ml) and blood
      samples will be obtained on timepoints 0.5h, 1h, 2h, 4h, 6h and 24h after intake. Until
      timepoint 6h, they will be allowed to consume only water. After collection, the monoterpenes
      will be identified in plasma samples applying a GC-MS-MS technique. Additionally, oxidative
      stress will be evaluated through the CuSO4 technique in serum samples.
    

Intervention name(s): Mastiha oil
Intervention type(s): Other
Intervention description(s): After overnight fasting, the authorized study staff inserted a plastic cannula in an arm vein of the volunteers in order to minimize discomfort during consecutive blood sampling. A blood sample was collected on time point 0h and then the volunteers consumed 1mL of MO. The dose selection was based on the study of Papada et al. (2017) who administered healthy volunteers with 10g of Mastiha (containing ~10% MO). Afterwards blood samples were collected on time points 0.5h, 1h, 2h, 4h, 6h and 24h after MO intake, and were centrifuged at 3000rpm for 10 minutes at 4◦C for plasma and serum isolation. All samples were stored at -80◦C until further analysis.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: mastiha oil, bioavailability