Exploring the Larvicidal and Repellent Potential of Taurus Cedar (Cedrus libani) Tar against the Brown Dog Tick (Rhipicephalus sanguineus sensu lato).

This study investigated the potential acaricidal and repellent effects of tar obtained from the Lebanon cedar (Cedrus libani A. Rich.) against the brown dog tick species Rhipicephalus sanguineus sensu lato Latreille (Acari: Ixodidae). The goal was to find an alternative, safe, and effective way to eliminate ticks. Tar is traditionally extracted from cedar trees in the Antalya region of Türkiye. The composition of the tar is primarily characterized by a diverse mixture of terpenes, with ß-himachalene (29.16%), α-atlantone (28.7%), ar-turmerone (8.82%), longifolene-(V4) (6.66%), α-himachalene (5.28%), and ß-turmerone (5.12%) emerging as the predominant constituents. The toxic effects of tar on tick larvae were studied through larval immersion tests (LIT), and its repellent activity was evaluated using a new larval repellent activity test (LRAT). The results revealed significant acaricidal effects, with mortality rates of 77.7% and 82.2% for the Konyaalti and Kepez strains of the brown dog tick, respectively, in response to a 1% concentration of tar. LC50 and LC90 values were determined as 0.47% and 1.52% for the Kepez strain and 0.58% and 1.63% for the Konyaalti strain, respectively. When comparing the repellent effect of tar to the widely used synthetic repellent DEET, repellency rates of up to 100% were observed. As a result, this study establishes, for the first time, the larvicidal and repellent effects of C. libani tar on ticks.

Nutrient pools and loss due to the removal of harvesting residue in cedar plantations (a case study from Türkiye).

Determining the nutrient stocks and revealing the extent to which these stocks will be affected by the interventions in forest ecosystems are crucial for sustainable forest management. This study aimed to determine the nutrient stock of cedar (Cedrus libani A. Rich.) plantations at different stands with various diameter classes and estimate the nutrient stock to be removed from the forest due to harvesting. Soil and plant samples were collected from 40 plots in Eskisehir and Afyonkarahisar provinces in Turkey. The variation in the nutrient concentrations and stocks of different components of the ecosystem were evaluated by analysis of variance and the decrease via harvesting by regression analysis. The results showed that the concentrations of N, P, K, Mg, S, Fe, Zn, and Mn were highest in the needles, Ca in the bark, Cu in the needles, dead branches, and root. In the large-diameter forest (LDF), dbh=20.0-35.9 cm, the highest P stock was found in the trees, Fe stock in the forest floor, and S stock in the soil and trees. As a result, the forest floor should be protected as it is the crucial component of both the nutrient cycle and the Fe stock in the ecosystem. In LDF, 28.4-37.3% of the nutrient stored in the trees would be removed from the ecosystem in the case of moderate thinning with whole-tree harvesting, while only 5.9-14.1% of the nutrient stock in the case of stem-only harvesting. For these reasons, leaving logging residues after harvesting in the forest would minimize nutrient loss. The study results showed that improved nutrient management in a forest ecosystem will make a significant contribution to the sustainability of forests.

Investigating the anti-inflammatory and analgesic properties of leaves ethanolic extracts of Cedrus libani and Pinus brutia.

This investigation aimed to assess the anti-inflammatory and analgesic effects of Cedrus libani and Pinus brutia leaves. The anti-inflammatory property was evaluated by Human Red Blood Cells (HRBC) membrane stabilization assay and Albumin denaturation assay using Sodium diclofenac as a positive control. To evaluate the analgesic property, formalin and tail flick tests were carried out using ethanolic extracts at a dose of 30 mg/kg and gel containing 2% (w/v) of ethanolic extract of each plant. Diclofenac sodium, diclofenac gel 1% and lidocaine gel 2 % were used as positive controls. Results: The effect of inhibiting hemolysis was observed at concentrations (2.5-12.5) µg/ml for P. brutia, and (2.5-25) µg/ml for C. libani. Moreover, albumin denaturation test showed protection effect for both plant extracts with IC50 of 47.74 and 81.50 µg/ml for C. libani and P. brutia extract, consecutively. In Formalin test, both extracts could significantly reduce paw licking time, and in tail flick test, each plant extract gel showed greater efficacy than diclofenac gel by calculating the maximum possible effect (MPE %) for both extracts and Diclofenac. Conclusion: We concluded that both extracts showed in vitro anti-inflammatory activity at different concentrations when compared to standard drug of diclofenac as well as analgesic activity in formalin and tail flick tests.

Himachalol induces apoptosis in B16-F10 murine melanoma cells and protects against skin carcinogenesis.

ETHNOPHARMACOLOGICAL RELEVANCE: Cedrus libani A. Rich (C. libani) is majestic evergreen Mediterranean conifer growing in the mountains of Lebanon. The ethnobotanical and traditional uses of cedar wood oil traces back to ancient times for the treatment of various ailments including cancer. Previous work in our laboratories revealed that himachalol (7-HC), a major sesquiterpene isolated from C. libani, possesses potent cytotoxic activity against various human cancer cell lines as well as promising anti-inflammatory effect in isolated rat monocytes. AIM OF THE STUDY: The present study aims to elucidate the mechanism of action behind the cytotoxic activity of 7-HC against murine melanoma cells (B16F-10) and evaluates its chemopreventive effect against chemically-induced skin carcinogenesis in mice. MATERIALS AND METHODS: 7-HC was extracted and purified from Cedrus libani wood. Cell viability was evaluated using WST-1 kit. Cell cycle analysis and apoptosis were assessed by Flow cytometry using propidium iodide (PI) and fluorescein Isothiocyanate (FITC)-conjugated Annexin V/PI staining respectively. Apoptosis related protein were quantified using western blot. The chemopreventive activity of 7-HC was evaluated for 20 weeks using a DMBA/TPA induced skin carcinogenesis model in Balb/c mice. RESULTS: 7-HC displayed a potent anti-proliferative activity against the melanoma cells with an IC50 of 8.8 µg/ml and 7.3 µg/ml at 24 and 48 h, respectively. Co-treatment with Cisplatin did not show any synergistic or additive effect on cell viability. Flow cytometry analysis using PI revealed that 7-HC treatment (5 and 10 µg/ml) induces the accumulation of cells in the sub-G1 phase and causes a decline in cell populations in the S and G2/M phases. Annexin/PI staining also reveals that 7-HC treatment significantly increases the percentage of cells undergoing early and late apoptosis. Western blot analysis shows that 7-HC treatment decreases the level of the anti-apoptotic protein Bcl-2 and increases the level of the pro-apoptotic protein Bax. A reduction in the level of phosphorylated Erk and Akt was also observed. 7-HC via topical (2.5%), intraperitoneal (10, 25 and 50 mg/kg) or gavage (50 mg/kg) treatment revealed a significant decrease in papilloma volume with no adverse effect on liver and kidney function. CONCLUSIONS: The present study demonstrates that 7-HC treatment protects against chemically-induced skin carcinogenesis, promotes cell cycle arrest and induces apoptosis partially through an inhibition of both the MAPK/Erk and PI3K/Akt pathways.

Effect of geographical origin on yield and composition of cone essential oils of Cedrus libani A. Rich. growing in Lebanese protected areas and variability assessment in comparison with literature survey.

Gas chromatography-mass spectrometry analysis together with principal component analysis revealed that geographical origin influenced the yield and composition of the essential oils (EOs) extracted by hydrodistillation performed for 3 h using a Clevenger-type apparatus, from the cones of Cedrus libani A. Rich., growing wild at four Lebanese natural reserves and protected areas: Bsharri, Chouf, Ehden, and Tannourine, and from a cultivated cedar growing in Qartaba. Essential oil chemical variability established between the different studied provenances suggested the involvement of abiotic factors such as geographical conditions, cultivation conditions, soil composition, and environmental factors in the chemical polymorphism of C. libani cones EOs. α-Pinene/ß-pinene characterized Ehden (ß-pinene 35.6%/α-pinene 27.7%), Chouf (α-pinene 37.3%/ß-pinene 26.1%), Bsharri (α-pinene 27.7%/ß-pinene 21.4%), and Tannourine (α-pinene 25.1%/ß-pinene 16.0%) samples, whereas Qartaba EO was distinguished by the dominance of myrcene (30.6%), α-pinene(26%), and limonene (14.1%). Comparison with the existing literature reinforced the chemical variability of C. libani EOs. This current study helped the estimation of a best harvest location for a good EO quality production, resource optimization, and pharmacological properties evaluation, according to the market demand.

Scale-dependent intraspecific competition of Taurus cedar (Cedrus libani A. Rich.) saplings in the Southern Turkey.

Better understanding of the competitive interaction at the early development stages of the stand is crucial to help schedule silvicultural treatments for young stands and for the better management of the future stands. We used scale-dependent analysis to improve our understanding of sapling dynamics in the pure Taurus cedar (Cedrus libani A. Rich.) stands in Southern Turkey. Using data from nine plots established at the western Taurus Mountains, diameter, height, and crown radii of saplings were compared, and spatial point pattern analyses were performed. We found significant differences for the mean diameter and height, and crown radii of saplings among the plots. Univariate pair correlation function showed that sapling pattern was regular only at small scales (r < 0.4 m) but was predominantly random. Bivariate pair correlation function revealed no evidence of spatial interaction between tall saplings and short saplings. Univariate mark correlation function revealed that strong intraspecific competition was detected at small scales (up to 0.55 m). This distance is reasonable for the juvenile age tending of Taurus cedar saplings and should be under consideration during silvicultural treatments to use the site productivity more efficiently.

Phytochemical and pharmacological properties of essential oils from Cedrus species.

Natural products frequently exert pharmacological activities. The present review gives an overview of the ethnobotany, phytochemistry and pharmacology of the Cedrus genus, e.g. cytotoxic, spasmolytic immunomodulatory, antiallergic, anti-inflammatory and analgesic activities. Cancer patients frequently seek remedies from traditional medicinal plants that are believed to exert less side effects than conventional therapy with synthetic drugs. A long-lasting goal of anti-cancer and anti-microbial therapy research is to find compounds with reduced side effects compared to currently approved drugs. In this respect, Cedrus species might be of interest. The essential oil isolated from Cedrus libani leaves may bear potential for drug development due to its high concentrations of germacrene D and ß-caryophyllene. The essential oils from Cedrus species also show bioactivity against bacteria and viruses. More preclinical analyses (e.g. in vivo experiments) as well as clinical trials are required to evaluate the potential of essential oils from Cedrus species for drug development.

The antileishmanial effects of Lowsonia inermis and Cedrus libani on Leishmania major promastigotes: an in vitro study.

Leishmaniasis is a parasitic disease caused by different species of protozoan parasites belonging to the genus Leishmania. In this study, Leishmania major (MRHO/IR/75/ER) promastigotes were cultured at 23-25 °C in brain heart infusion (BHI) medium supplemented with 10 % heat-inactivated fetal bovine serum (FBS) and penicillin and streptomycin. Antileishmanial effects of Lowsonia inermis and Cedrus libani methanolic extracts (0.07, 0.15, 0.31, 0.62, 1.25, 2.5, 5, 10 mg/mL) on Leishmania major promastigotes were evaluated using the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. All experiments were repeated at least three times. Cedrus libani methanolic extract did not show any activity while Lowsonia inermis methanolic extract inhibited the growth of promastigote forms of L. major in vitro after 72 h of incubation and had a 50 % inhibitory concentration (IC50) of 1.25 mg/mL. The methanolic extract of Lawsonia inermis (henna) can be a promising antileishmanial agent in the future. Further experiments are needed for isolation of active fractions and identification of the active components of methanolic extract.

Cambial activity and xylogenesis in stems of Cedrus libani A. Rich at different altitudes.

BACKGROUND: The dynamics of cambial activity and xylogenesis provide information on how and to what extent wood formation respond to climatic variability. The Lebanon Cedar (Cedrus libani A.Rich) is a montane tree species which is distributed along a wide altitudinal range in the northeastern Mediterranean region, currently considered as a potential forest species for Central Europe with respect to climate change. This study provides first data on intra-annual growth dynamics at cellular level using the microcore technique for a montane Mediterranean tree species at different altitudes within and outside its natural range. RESULTS: Microcores were collected fortnightly in the growing season of 2013 in order to study temporal dynamics of cambial activity and xylogenesis in stems of C. libani at different altitudes in the Taurus Mountains (1000 - 2000 m a.s.l.) and at a plantation at Bayreuth (330 m a.s.l.; Germany). The dormant cambium consisted of about 5 cells at the Turkish sites and 7 cells at Bayreuth. Cambial activity set in, when daily minimum temperatures exceeded 0 °C and daily means of air and stem temperature exceeded 5 °C. Xylogenesis started between April and May, ended approximately the end of September to the beginning of October and lasted 134 (at tree line) to 174 days (at the lowest Turkish site). Mean ring widths varied from 0.55 to 3.35 mm, with highest values observed at Bayreuth very likely resulting from a steady water supply during growing season. Means of daily cell production rates varied from 0.73 to 0.12. Samples containing traumatic resin ducts occurred only rarely and where not used for analysis. CONCLUSIONS: In C. libani, onset and dynamics of cambial activity and xylogenesis are triggered by daily means of stem and air temperatures whereas water availability has a higher influence on growth rates and cessation of wood formation. Within sites, duration of xylogenesis does not significantly differ with respect to age and tree size. C. libani grows well outside its natural range and thus may be a promising species for forestation in Central Europe with respect to climate change. We suggest further studies on if/how traumatic resin ducts influence tree ring width.

Effects of endogenous ABA levels and temperature on cedar (Cedrus libani Loudon) bud dormancy in vitro.

Axillary and apical buds of in-vitro-propagated cuttings of Cedrus libani are unable to burst at 24 °C, but this inhibition was overcome at 30 °C. Here we have used cedar microcuttings to investigate whether the levels of endogenous hormones vary with bud dormancy and temperature. We analysed the levels of abscisic acid, indole-3-acetic acid, zeatin, isopentenyladenine and their major metabolites using HPLC purification and fractionation of the samples coupled to an ELISA method for hormonal quantitation involving several antibodies elicited against each hormonal family. Abscisic acid levels in microcuttings with dormant buds were higher than those in microcuttings with growing buds. At 24 °C, needles accumulated more abscisic acid than at 30 °C. In addition, when needles were removed, but growth release was achieved at 24 °C. Abscisic acid supplied at 30 °C induced the formation of dormant buds. These results suggest that abscisic acid accumulation in the needles can explain the bud dormancy of cedar microcuttings at 24 °C.