Evaluation of cytotoxic and antioxidant potential of Dittrichia viscosa (L.) Greuter used in traditional medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: Dittrichia viscosa (L.) Greuter ("Sari ot, Yapiskan andiz otu" in Turkish) is a medicinal plant that has been traditionally used in the Mediterranean area. This plant is used by the local population for the treatment of cancer. Investigation of their biological activities is therefore very important to be supported by scientific basis for traditional use. AIMS OF THE STUDY: In this study, it is aimed to assess the phytochemical composition, in vitro antioxidant, cytotoxic, and antiproliferative activities of the aqueous and ethanolic extracts obtained from the aerial parts (stems, leaves, flowers) of D. viscosa, collected from two sites in Turkey (Istanbul and Marmaris) against breast and prostate tumor cell lines. MATERIALS AND METHODS: Validated methods were used to evaluate the in vitro antioxidant capacity (DPPH, ABTS, CUPRAC), cytotoxicity (Cell Viability Assay), antiproliferative (Apoptosis assay), and phytochemical compositions. The nepetin (N), 3-O-methylquercetin (Q), and hispidulin (H) in the extracts of D. viscosa were quantified by HPLC and LC-HRMS. Furthermore, in order to control the standards of benefiting from the plant in a healthy way, the contents of some heavy metals were also assessed by ICP-OES in the plant and soil samples as well as the species soil's physical and chemical characteristics. RESULTS: We have found that heavy metal accumulation in the soil does not exceed the allowable limit value except for the nickel. The results showed that ethanol extraction is an efficient strategy to get NQH molecules with a higher content compared with other extraction techniques. However, using the same extraction method revealed that the amount of NQH molecules in the samples of two different regions were variable. The results suggested that all extracts had a high amount of total phenolic content (12.354-22.184 µg GAE/mg) and total flavonoid content (4.442-17.263 µg QE/g). In the antioxidant assay according to the DPPH method, the aqueous ethanol extracts (IC50; 21.00 µg/mL) showed stronger antioxidant activity than BHT. A significant reduction in cell viability was particularly observed in MDA-MB-231 cells, which were sensitive to ethanolic extracts in Istanbul (12-22%) and in Marmaris (14-15%), while PC3 cell lines were also more sensitive to extracts of the aqueous in Istanbul (16%) and the decoction in Marmaris (12%) after 72 h. Especially, it was observed that Marmaris and Istanbul samples induced the toxicity against PC3 cells. CONCLUSION: The study supports the medicinal use of D. viscosa as a potential anticancer against breast and prostate cancer cells in vitro and underlines the immense therapeutic potential of the plant.

Correction: Differential anti-proliferative and apoptotic effects of lichen species on human prostate carcinoma cells.

[This corrects the article DOI: 10.1371/journal.pone.0238303.].

Differential anti-proliferative and apoptotic effects of lichen species on human prostate carcinoma cells.

Lichens are stable symbiotic associations between fungus and algae and/or cyanobacteria that have different biological activities. Around 60% of anti-cancer drugs are derived from natural resources including plants, fungi, sea creatures, and lichens. This project aims to identify the apoptotic effects and proliferative properties of extracts of Bryoria capillaris (Ach.) Brodo & D.Hawksw, Cladonia fimbriata (L.) Fr., Evernia divaricata (L.) Ach., Hypogymnia tubulosa (Schaer.) Hav., Lobaria pulmonaria (L.) Hoffm., and Usnea florida (L.) Weber ex Wigg. lichen species on prostate cancer cells. Lichen extracts were performed by ethanol, methanol, and acetone separately by using the Soxhlet apparatus and the effects of the extracts on cell viability, proliferation, and apoptosis were measured with the utilization of MTT, LDH assay, Annexin V assay, and Western Blot. Findings of our study revealed a positive correlation between the elevation of cell sensitivity and the increase in the treatment doses of the extract in that higher doses applied reverberate to higher cell sensitivity. A similar correlation was also identified between cell sensitivity elevation and the duration of the treatment. Evidence in our study have shown the existence of an anti-proliferative effect in the extracts of Bryoria capillaris, Evernia divaricata (L.) Ach., Hypogymnia tubulosa (Schaer.) Hav., Lobaria pulmonaria (L.) Hoffm., and Usnea florida (L.) Weber ex Wigg., while a similar effect was not observed in the extracts of Cladonia fimbriata. Evernia divaricata induced anti-proliferative and apoptotic effects in PC-3 cells, which induced apoptotic cell death by both extrinsic and intrinsic pathways. Hypogymnia tubulosa has been shown to have anti-proliferative and apoptotic effects in all extractions methods and our findings identified that both the percentage of the apoptotic cells and apoptotic protein expressions recorded an increase at lower treatment concentrations. Although Lobaria pulmonaria is known to have significant cytotoxic effects, we did not observe a decrease in cell proliferation. Indeed, proliferation marker proliferating cell nuclear antigen (PCNA) protein expression levels have shown an increase in all extracts, while Usnea florida exhibited apoptosis induction and slight proliferation reduction in extract treatments with lower concentrations. We tested 18 extracts of six lichen species during our study. Of these, Evernia divaricata and Hypogymnia tubulosa demonstrated significant apoptotic activity on prostate cancer cells including at low concentrations, which implies that it is worth pursuing the biologically active lead compounds of these extracts on prostate cancer in vitro. Further corroboratory studies are needed to validate the relative potential of these extracts as anti-metastatic and anti-tumorigenic agents.

Anticholinesterase, Antioxidant, Antiaflatoxigenic Activities of Ten Edible Wild Plants from Ordu Area, Turkey.

Turkey has highly rich floras of medicinal and aromatic plants because of having various climate conditions in different regions. One of these regions is Middle Black Sea Region, especially Ordu Province. Extracts of 10 edible plants (Arum maculatum L., Hypericum orientale L., Ornithogalum sigmoideum Freyn et Sint., Silene vulgaris Garcke var. macrocarpa, Plantago lanceolata L., Achillea millefolium L. subsp. pannonica, Rumex crispus L., Rumex acetosella L., Capsella bursa-pastoris L., Coronopus squamatus Asch.), grown in Ordu, Turkey, were prepared with different solvents (hexane, ethanol and water, separately) and their anticholinestrase and antiaflatoxigenic activities were evaluated. Additionally, the cupric reducing antioxidant capacities (CUPRAC) and ABTS cation radical scavenging abilities of the extracts were assayed. The ethanol extract of R. acetosella exhibited the highest antioxidant activity (A0.5 value of 25.31 µg/mL, for CUPRAC activity; IC50 value of 23.73 µg/mL, for ABTS activity). The hexane extract of C. bursa-pastoris showed the strongest inhibition against AChE enzyme with IC50 value of 7.24 µg/mL, and the hexane extract of A. millefolium subsp. pannonica had the highest BChE activity with IC50 value of 6.40 µg/mL. The ethanol extract of P. lanceolata exhibited the strongest inhibition against aflatoxin with 88% inhibition.

Studies on the chorology, ecology, morphology and conservation strategies of Orchis anatolica Boiss (Orchidaceae).

Orchis anatolica Boiss. is one of the Mediterranean species, which has wide distribution in Turkey. In this study, plant and soil samples of O. anatolica were taken from 26 natural populations in Turkey. There were one hundred ninety locality records in the Mediterranean region of Turkey, but we recorded two hundred sixteen localities thus adding twenty six new localities to the list. Twenty morphological parameters of O. anatolica were evaluated. The correlation coefficients between generative characters and vegetative characters were lower than the character groups of correlation coefficients between themselves. It is found from sea level upto 1700 m. Most common habitats of O. anatolica are macchie, forest lands and stony soils. The soils are loamy, clayey- loam and sandy-clayey- loam and rich in organic matter. The pH of the soils varies from 5.87 to 7.92. Although O. anatolica has wide distribution in Turkey, different types of land uses are posing a threat for it and restricting its distributional area. Lacking the legal regulations about conservation of the O. anatolica populations is one of the most striking requirement.

Morphological, anatomical and ecological studies on some Orchis (Orchidaceae) taxa of Mediterranean region, Turkey.

In this study, nine species mainly distributed in Mediterranean (+ Aegean region) region of Turkey were investigated in terms of 15 morphological, 16 anatomical and 5 ecological characteristics. Those species are Orchis anatolica Boiss., Orchis italica Poiret, Orchis laxiflora Lam., Orchis morio L. subsp. morio, Orchis provincialis Balbis ex DC., Orchis purpurea Hudson, Orchis sancta L., Orchis simia Lam., Orchis tridentata Scop. In conclusion, we found that O. laxiflora was characterized by the longest plant height and O. purpurea had the biggest tuber; whereas O. italica was identified by the highest number of leafs and O. purpurea had the longest leaf length and widest leaf width. Additionally, the other species which were characterized by different morphological and anatomical parameters are as follow: O. sancta with the longest bract length, O. italica and O. simia with the longest sepal lengths, O. laxiflora with the shortest and widest labellum, O. simia with the longest petal length, O. sancta with longest caudiculum length, O. anatolica with the longest spur length and O. provincialis with the longest ovary length. Particularly, O. laxiflora and O. purpurea species present essential divergence from the aspect of anatomical features of leaf surface in comparison with the other species. Morphological and anatomical traits of the species were attributed to the habitat selections of the species since that character differs along with each species.

Investigation of lichen populations and their similarity analysis in Serif Yuksel Forest, Turkey.

Sorensen similarity indices of lichen species in Serif Yuksal forest ranged between 0.29 and 0.84. A linear relation was found between species number sum of two lichen populations and their similarity indices. The linear equation is Y = 0.0076x + 0.1467 and the R2 of the equation is 0.2476 which is significant at p < 0.001. There has been identified a linear relation between the average similarity index of the sites and fir participation percentage. The obtained equation is Y = 0,0009x + 0,5271 and the R2 of the equation is 0,2853 which is significant at p < 0.002. In the pure fir stands there has been found a linear relation between the altitude difference and similarity index. The obtained equation is Y = -0.0011x + 0.6962 and the R2 of the equation is 0.1755 which as significant at p < 0.001.