# Biocompounds and Bioactivities of Selected Greek Boraginaceae Seeds
## 4 Discussion  
### Fatty Acids Content  
This study shows that some Boraginaceae Greek species, i.e., both _Symphytum_ species and _L. zalnii_, stand out for their high GLA content. _Lithodora_ comprises three range-restricted species, and this genus has a Mediterranean distribution with its diversity center in the western Mediterranean [32]. This is the first report on the FA composition of _L. zalnii_, which is a vulnerable endemic species of Greece found only in certain rocky places of the south Peloponneese peninsula (see Table 1). Previously, the GLA% of total FAs of _Lithodora fruticosa_ was set at 13.3% [33]; thus, _L. zalnii_ constitutes an advantageous GLA producer within this genus. _Glandora_ is a Lithospermeae genus closely related to _Lithodora_, which is native to the western and central Mediterranean region, that was split from the former in 2008 [34]. Previously, the GLA% of other _Glandora_ species has been reported: _G. nitida_ (19.2%, [35]; _G. marocana_ (20.2%) [33]; and _G. diffusa_, _G. oleifolia_, and _G. rosmariniifolia_ (12.8, 12.5, and 12.4%, respectively) [24]. Therefore, there are two types of members belonging to both genera, that is, high- and medium-GLA-producer species. Given that the GLA% in Boraginaceae seed oil depends on several genes (FA desaturase2 (BaFAD2), FA desaturase3 (BaFAD3), and Delta-6-desaturase (BaD6D-1 and BaD6D-2)) [36], the GLA% of both _Glandora_ and _Lithodora_ species should be considered as a possible taxonomical marker, while the molecular characterization of the microsomal FA desaturase pathway gene of these species could shed light on the phylogenetic relationships between both taxa. So far, all surveyed _Symphytum_ spp. have high GLA% of total FAs in their seed oil, for instance, _S. grandifloraum_ (21.1), _S. ibiricum_ (18.9), and _S. tuberosum_ subsp. _tuberosum_ (27.0%) [24]. In this work, the two checked species showed high GLA percentages. Previously, _S. bulosum_ collected in Reggio Calabria (Italy) showed GLA at 27.6% of total FAs [24],  
Figure 3: MTT assay. \(\mathrm{Gl}_{50}\) for HT-29 cells after treatment with selected seeds extracts, pure phenolics, and doxorubicin for 48 and 72 h. The \(\mathrm{Gl}_{50}\) value is detailed over columns, and the selectivity index (SI) for 72 h-exposed cells to seeds extracts/pure compounds is shown in parentheses. Data represent the mean of three complete independent experiments \(\pm\) SD (error bars). In a bar, means followed by different letters are significantly different at \(p<0.05\). which is in good agreement with the percentages found in this work for the last species. Small variations in GLA% could be related to environmental factors (temperature, light, and humidity), which influence the expression of genes involved in GLA biosynthesis, although the existence of chemotypes within this species cannot be ruled out. Concerning _S. creticum_, the native range of this species is S. Greece to E. Aegean Islands. As for Aegean _Symplyutum_, _S. icaricum_ and _S. naxicola_ are included in the Graeca section, while _S. circinale_, _S. insulare_, and _S. creticum_ belong to the Procopiania section. These sections correspond to clear clades obtained through a phylogenetic analysis using ITS total and trnL-F [37]. Taking into account the habitats in which these species develop, they could become advantageous crops adapted to highly arid conditions, which could produce not only a GLA-rich seed oil, but a large number of useful products that are typically obtained from _Symplyutum_ species [38]; thus, expanding knowledge on the chemical composition, food applications, and phytopharmacology of Aegean _Symplyutum_ taxa constitutes a promising research area. The remaining species showed low GLA percentages, thus lacking interest for the obtainment of GLA oils, although they could be used for the recovery of other compounds contained in the unsaponifiable fraction, as discussed below.