Labdanum resin from Cistus ladanifer L. (Cistaceae) is an abundant natural resource in the Iberian Peninsula worth being explored in a sustainable manner. It is already used in the cosmetic industry; mainly by the fragrances/perfumery sector. However, given the highest market share and traditional uses, labdanum resin also has the potential to be used and valued as a cosmetic ingredient for skincare. Aiming to evaluate this potential, labdanum methanolic absolute and fractions purified by column chromatography were characterized by UPLC-DAD-ESI-MS and then evaluated for UV-protection, antioxidant, anti-elastase, anti-inflammatory, and antimicrobial activities. Labdanum absolute represented ~70% of the resin; diterpenoid and flavonoid fractions represented ~75% and 15% of the absolute, respectively. Labdane-type diterpenoids and methylated flavonoids were the main compounds in labdanum absolute and in diterpenoid and flavonoid fractions, respectively. Labdanum absolute showed a spectrophotometric sun protection factor (SPF) near 5, which is mainly due to flavonoids, as the flavonoids’ SPF was 13. Low antioxidant activity was observed, with ABTS radical scavenging being the most significant (0.142 ± 0.017, 0.379 ± 0.039 and 0.010 ± 0.003 mgTE/mgExt, for the absolute and flavonoid and terpene fractions, respectively). Anti-aging and anti-inflammatory activity are reported here for the first time, by the inhibition of elastase activity (22% and 13%, by absolute and flavonoid extract at 1 mg/mL), and by the inhibition of nitric oxide production in LPS-induced RAW 264.7 cells (84% to 98%, at 15 µg/mL extracts, flavonoid fraction the most active), respectively. Antimicrobial activity, against relevant skin and cosmetic product microorganisms, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Escherichia coli, revealed that only S. aureus was susceptible to labdanum absolute (MIC: 1.2 mg/mL) and its fractions (MIC: <0.3 mg/mL). In conclusion, labdanum resin showed potential to be used in sunscreen cosmetics, anti-inflammatory skincare cosmeceuticals or medicines but has low potential as a cosmetic product preservative given the low antioxidant and low-spectrum antimicrobial activities.

Distilled spirits are usually made from fermented sugar-based materials, such as wines or fermented fruits, but other products can be used, namely berries or honey. In this work, an evaluation of honey spirits is done based on its physicochemical and sensory characteristics. Fourteen honey spirit samples of different brands of honey spirit were purchased at the market and from artisan Portuguese producers. Several analytical determinations, namely alcoholic strength, dry matter, density, total acidity, chromatic characteristics, methanol, acetaldehyde, ethyl acetate and higher alcohols were done to characterize all samples. The results pointed out several differences in physicochemical composition of samples. In general, these drinks are characterized by an alcohol strength between 37.4% and 53.0% and a low methanol content, quite null for most samples. Samples with higher ethanol content corresponded to the artisanal samples. Significant differences (p < 0.05) were also observed in the volatile composition and chromatic characteristics suggesting different production technologies. A first list of sensory attributes was obtained for this beverage. Therefore, further research must be done in order to characterize this spirit drink, which has gained market value.

Labdanum resin or “gum” can be obtained from Cistus ladanifer L. by two different extraction methods: the Zamorean and the Andalusian processes. Although its main use is in the fragrance and perfumery sectors, ethnobotanical reports describe its use for medicinal purposes in managing hyperglycemia and mental illnesses. However, data concerning the bioactivities and pharmacological applications are scarce. In this work, it was found that the yield of labdanum resin extracted by the Andalusian process was 25-fold higher than the Zamorean one. Both resins were purified as absolutes, and the Andalusian absolute was purified into diterpenoid and flavonoid fractions. GC-EI-MS analysis confirmed the presence of phenylpropanoids, labdane-type diterpenoids, and methylated flavonoids, which are already described in the literature, but revealed other compounds, and showed that the different extracts presented distinct chemical profile. The potential antidiabetic activity, by inhibition of α-amylase and α-glucosidase, and the potential neuroprotective activity, by inhibition of acetylcholinesterase, were investigated. Diterpenoid fraction produced the higher α-amylase inhibitory effect (~30% and ~40% at 0.5 and 1 mg/mL, respectively). Zamorean absolute showed the highest α-glucosidase inhibitory effect (~14% and ~24%, at 0.5 and 1 mg/mL, respectively). Andalusian absolute showed the highest acetylcholinesterase inhibitory effect (~70% and ~75%, at 0.5 and 1 mg/mL, respectively). Using Caco-2 and HepG2 cell lines, Andalusian absolute and its purified fractions showed moderate cytotoxic/anti-proliferative activity at 24 h exposure (IC₅₀ = 45–70 µg/mL, for Caco-2; IC₅₀ = 60–80 µg/mL, for HepG2), whereas Zamorean absolute did not produce cytotoxicity (IC₅₀ ≥ 200.00 µg/mL). Here we show, for the first time, that labdanum resin obtained by the Andalusian process, and its fractions, are composed of phytochemicals with anti-diabetic, neuroprotective and anti-proliferative potential, which are worth investigating for the pharmaceutical industry. However, toxic side-effects must also be addressed when using these products by ingestion, as done traditionally.

The evaluation of the wide variety of allelochemicals present in allelopathic plants allows the detection of safer bioherbicides with new mechanisms of action. This study tested two phenolic compounds of Cistus ladanifer essential oil (2-Methoxyphenol and 2,6-Di-tert-butyl-4-methylphenol), which are commercially available. At 0.01 mM, these compounds, both separately and in combination (1/1), inhibited up to over 50% of germination, cotyledon emergence and seedling growth of Lactuca sativa for the tests conducted on paper. Against Allium cepa, cotyledon emergence and seedling growth were inhibited at 0.5 mM. When the tests were carried out in the soil, the mixture of the two study compounds significantly inhibited the germination of L. sativa and A. cepa when applied at 0.5 and 1 mM, respectively, and seedling growth inhibition was greater for the latter in the paper tests. The greatest inhibitions were observed, with the highest concentrations analysed. Although there was no statistically significant difference among treatments, 2-Methoxyphenol seemed to affect germination and cotyledon emergence to a greater extent, whereas 2,6-Di-tert-butyl-4-methylphenol had a greater impact on seedling size. The effect of the mixture was greater than that of both compounds separately.

Cistus ladanifer L. (Cistaceae) occupies extensive areas as a dominant species (shrublands) or is associated to other major forest typologies in the Iberian Peninsula. Cistus ladanifer shrublands are mostly present in oligotrophic lands with little valorisation and management and as they develop over the years (up to 20-years-old) they promote the ignition and perpetuation of fire. To contribute to the proper management and valorisation of such systems, a 5-year-old dense shrubland was evaluated for its labdanum resin, seeds, and biomass productivity using different non-destructive harvest periodicities (annual and biennial) and seasons (early, mid-, and late summer), in a two-year case-study. Annual harvest modality maximized labdanum resin productivity (reaching 230 ± 50 kg∙ha⁻¹∙2 years⁻¹ at late summer) and photosynthetic biomass productivity. In contrast, a biennial harvest yielded significant amounts of more diversified products. It maximized seeds productivity (reaching 75 ± 41 kg∙ha⁻¹∙2 years⁻¹ independently of the summer season) and lignified biomass. However, it also reached a labdanum resin productivity of 134 ± 20 kg∙ha⁻¹∙2 yearrs⁻¹ at late summer and a photosynthetic biomass productivity around two times lower than the annual harvest. In this study, we propose two modalities of periodic harvest to be considered as proper long cycle management practices of rockrose lands. It intends to minimize fire risks, break the vegetation auto-succession mechanism, and increase profit from non-productive lands based on three direct outputs with a myriad of applications and valorisation pathways.

The evaluation of the broad variety of allelochemicals present in allelopathic plants allows detecting safer bioherbicides with new mechanisms of action. This study tested two phenolic compounds of Cistus ladanifer essential oil (2-Methoxyphenol and 2,6-Di-tert-butyl-4-methylphenol), which are commercially available. At 0.01mM, these compounds, both separately and in combination, inhibited up to over 50% of germination, cotyledon emergence and seedling growth of Lactuca sativa for the tests conducted on paper. Against Allium cepa, cotyledon emergence and seedling growth was inhibited at 0.5mM. When the tests were carried out in soil, the mixture of the two study compounds significantly inhibited the germination of L. sativa and A. cepa when applied at 0.5 and 1mM, respectively, and seedling growth inhibition was greater for the latter in the paper tests. The greatest inhibitions were observed with the highest concentrations analysed. Although there was no statistically significant difference among treatments, 2-Methoxyphenol seemed to affect germination and cotyledon emergence to a greater extent, whereas 2,6-Di-tert-butyl-4-methylphenol had a greater impact on seedling size. The effect of the mixture was greater than that of both compounds separately.