Mixed elicitation with salicylic acid and hydrogen peroxide modulates the phenolic and iridoid pathways in Castilleja tenuiflora plants.

MAIN CONCLUSION: SA and H2O2, in single and mixed elicitation stimulate specialized metabolism and activate oxidative stress in C. tenuiflora plants. Single elicitation with salicylic acid (SA at 75 µM) and, hydrogen peroxide (at 150 µM), and mixed elicitation (75 µM SA + 150 µM H2O2) were evaluated on specialized metabolism in Castilleja tenuiflora Benth. plants. Total phenolic content (TPC), phenylalanine ammonia-lyase (PAL) activity, antioxidant enzymes and specialized metabolite profiles, as well as the expression levels of eight genes involved in phenolic (Cte-TyrDC, Cte-GOT2, Cte-ADD, Cte-AO3, Cte-PAL1, Cte-CHS1) and terpene pathways (Cte-DXS1 and Cte-G10H) and their correlation with major metabolite (verbascoside and aucubin) concentrations were investigated. TPC content (three-fold) and PAL activity (11.5-fold) increased with mixed elicitation, as well as catalase and peroxidase activity (11.3-fold and 10.8-fold, respectively), compared to single elicitation. Phenylethanoid accumulation was greatest under mixed elicitation, followed by SA and H2O2. Lignan accumulation was differential, depending on the plant part and the elicitor. Flavonoids only appeared after mixed elicitation. The high concentration of verbascoside under mixed elicitation was related to a high gene expression. Single elicitation induced iridoid accumulation in specific parts (H2O2 in aerial parts and SA in roots), whereas under mixed elicitation, it accumulated in both parts. A high concentration of aucubin in the aerial part was related to a high expression level of genes of the terpene pathway Cte-DXS1 and Cte-G10H, and in the root with Cte-G10H, while Cte-DXS1 was downregulated in this tissue in all treatments. Mixed elicitation with SA and H2O2 represents an interesting tool to increase the production of specialized metabolites in plants.

Assessing the Larvicidal Properties of Endemic Campeche, Mexico Plant Piper cordoncillo var. apazoteanum (Piperaceae) against Aedes aegypti (Diptera: Culicidae) Mosquitoes.

The research aims to investigate the mortality effect of essential oil from Piper cordoncillo var. apazoteanum, an endemic plant from Campeche, Mexico, on early second-instar Aedes aegypti larvae; it also aims to identify the volatile compounds present in the fresh leaves of the plant. To test the effectiveness of the essential oil, we followed World Health Organization Standard Procedures. Larvae were observed for 17 consecutive days after treatment to determine the mortality and growth-inhibitory effect exerted by the essential oil. The results showed that the essential oil was effective in controlling mosquito populations. At a concentration of 800 ppm, the oil achieved an effectiveness rate of 70.00 ± 8.16% after 24 h, increasing to 100.00 ± 0.01% mortality after 72 h. With a concentration of 400 ppm, the effectiveness was 98.33 ± 0.17% by the end of the experiment. Furthermore, the obtained results demonstrated that the LC50 value was 61.84 ± 6.79 ppm, while the LC90 value was 167.20 ± 11.49 ppm. Essential oil concentrations inhibited the growth of immature insect stages, with concentrations between 800-100 ppm demonstrating very high inhibitory activity, and the lowest concentration of 50 ppm showing high inhibitory activity. The study also identified 24 chemical compounds representing 86.71% of the volatile compound composition of the fresh leaves of P. cordoncillo; the most abundant compounds were Safrole, Caryophyllene oxide, E-Nerolidol, and Calarene epoxide. The method used to extract the volatile compounds, solvent-free microwave extraction (SFME), is a promising alternative to traditional methods that avoids the use of potentially harmful solvents, making it more ecologically friendly and potentially safer for professionals handling the extracted compounds. Overall, the study demonstrates the potential of P. cordoncillo essential oil as an effective means of controlling mosquito populations, and provides valuable information on the chemical composition of the plant.Moreover, our study is the first to report on the biological activity and chemical composition of P. cordoncillo worldwide.

Inhibition of Phytopathogenic and Beneficial Fungi Applying Silver Nanoparticles In Vitro.

In the current research, our work measured the effect of silver nanoparticles (AgNP) synthesized from Larrea tridentata (Sessé and Moc. ex DC.) on the mycelial growth and morphological changes in mycelia from different phytopathogenic and beneficial fungi. The assessment was conducted in Petri dishes, with Potato-Dextrose-Agar (PDA) as the culture medium; the AgNP concentrations used were 0, 60, 90, and 120 ppm. Alternaria solani and Botrytis cinerea showed the maximum growth inhibition at 60 ppm (70.76% and 51.75%). Likewise, Macrophomina spp. required 120 ppm of AgNP to achieve 65.43%, while Fusarium oxisporum was less susceptible, reaching an inhibition of 39.04% at the same concentration. The effect of silver nanoparticles was inconspicuous in Pestalotia spp., Colletotrichum gloesporoides, Phytophthora cinnamomi, Beauveria bassiana, Metarhizium anisopliae, and Trichoderma viridae fungi. The changes observed in the morphology of the fungi treated with nanoparticles were loss of definition, turgidity, and constriction sites that cause aggregations of mycelium, dispersion of spores, and reduced mycelium growth. AgNP could be a sustainable alternative to managing diseases caused by Alternaria solani and Macrophomina spp.

Purshia plicata Triggers and Regulates Proteins Related to Apoptosis in HeLa Cancer Cells.

Cervical cancer represents a public health problem, develops resistance to traditional therapies and cost-of-treatment is high. These disadvantages have led to the search for alternative bioactive-compound-based therapies. Said bioactive compounds include phenolic compounds, flavonoids, and tannins. The present study aimed to evaluate the therapeutic effect of a P. plicata extract on the HeLa cell line. Viability and apoptosis assays were run on the two cell lines treated with the extract. The peptides, up- and down-expressed in both cell lines, were identified by PDQuest analysis software and high-performance liquid chromatography/mass spectrometry/mass spectrometry (HPLC/MS/MS). Our results show that a 500 mg/L treatment deregulated cell viability, with different apoptotic morphologies observed which are associated with the presence of bio-compounds, which up- and down-regulated the peptides. In conclusion, P. plicata regulates proteins associated with apoptosis in HeLa cancer cells.

Punicalin and ellagic acid from pomegranate peel extract facilitate apoptotic behaviour in the Hela cell line.

Polyphenols may be an effective therapy for both the prevention and treatment of cancer. Previous studies have found that these compounds may inactive Hela cells, which may even be converted into a normal cells post-treatment. The present study extracted phenolic compounds from pomegranate peel, with the polyphenols then purified using different solvents and identified by means of high-performance liquid chromatography-tandem mass spectrometry (HPLC/MS). Once the phenolic compounds had been purified, we evaluated their cytotoxic effects on both the Hela and NIH-3T3 cell lines, on which an apoptosis assay was also carried out. Additionally, apoptosis assay was carried out on Hela and NIH-3T3. Lastly, the proteome profile was analysed via two-dimensional gel electrophoresis (2-DE) and liquid chromatography-tandem mass spectrometry (LC/MS/MS). We isolated and then purified punicalagin and ellagic acid (EA) from pomegranate peel, with both compounds likely to have a cytotoxic effect on Hela and NIH-3T3. However, this effect depends on both concentration and exposure time. Results obtained using a Cayman commercial assay kit suggests that punicalin and EA regulate the apoptosis on the Hela and NIH-3T3 cell lines. Finally, we observed that polyphenols compounds regulate the expression of proteins related to apoptosis. In conclusion, punicalin and EA have a cytotoxic effect on Hela and, furthermore, reactive the apoptotic pathway in this cell.

Strictosidine-related enzymes involved in the alkaloid biosynthesis of Uncaria tomentosa root cultures grown under oxidative stress.

The activity and gene expression of strictosidine-related enzymes in Uncaria tomentosa root cultures exposed to oxidative stress were studied. Elicitation with 0.2 mM hydrogen peroxide (H2 O2 ) or a combination of 0.8 mM buthionine sulfoximine and 0.2 mM jasmonic acid (BSO-JA) increased peroxidase activities by twofold at Day 8 and glutathione reductase by 1.4-fold at Day 5 in H2 O2 elicited cultures respect to the control. Production of monoterpenoid oxindole alkaloids (MOA), 3α-dihydrocadambine, and dolichantoside was stimulated after H2 O2 elicitation, reaching levels of 886.4 ± 23.6, 847.7 ± 25.4, and 87.5 ± 7.2 µg/g DW, at Day 8 which were 1.7-, 2.1-, and 2.3-fold higher relative to control. BSO-JA elicited cultures produced about twice alkaloids than H2 O2 -treated cultures, following a biphasic pattern with maxima at 0.5 and 8 days. Alkaloid production was preceded by increase in strictosidine synthase (STR) and strictosidine glucosidase (SGD) activities. After elicitation with H2 O2 or BSO-JA, the STR activity (pKat/mg protein) increased by 1.9-fold (93.8 ± 17.8 at 24 h) or 2.5-fold (102.4 ± 2.2 at 6 h) and the SGD activity (pKat/mg protein) by 2.8-fold (245.2 ± 14.4 at 6 h) or 4.2-fold (421.2 ± 1.8 at 18 h) relative to control. STR and SGD transcripts were upregulated after elicitation. H2 O2 -treated roots showed higher levels of STR at 48-192 h and SGD at 24-48 h, while BSO-JA treatments showed STR increased at 12 h and SGD at 24 h. Also, LC/ESI-MS confirmed the biosynthesis of dolichantoside from N-ω-methyltryptamine and secologanin by U. tomentosa protein extracts.