Effects of different cultivation conditions on the production of β-cyclocitral and β-ionone in Microcystis aeruginosa

New insights into odor release from sediments in Lake Chaohu and the potential role of sediment microbial communities

Odor events often occur along with algal blooms, posing potential threats to water quality and human health. However, studies on the role of sediments and microbial communities in the production and release of odor compounds remain limited. Seasonal monitoring of Lake Chaohu revealed that pore-terpenoids significantly contributed to terpenoid concentrations in water, explaining 37.1 % of their variability. Environmental factors like temperature primarily influenced terpenoid concentrations by regulating the diffusion of pore-terpenoids. Conversely, pore-nor-carotenoids explained only 11.2 % of nor-carotenoid variability, with phytoplankton communities explaining 59.4 %. Abiotic factors like nutrients influenced nor-carotenoid levels by impacting phytoplankton growth. Microbial communities with a greater proportion of cyanobacteria exhibited more fragile microbial networks, increased competition, and enhanced metabolic activity. We hypothesized that microbial community composition may influence odor production. Laboratory experiments further supported this: sediments with added cyanobacteria showed a 48.1 % reduction in 2-methylisoborneol contents after 30-day incubation, whereas the control group exhibited a 66.38 % increase. Conversely, the experimental group showed significant increases in β-cyclocitral (99.19 %) and β-ionone (48.55 %), while the control group experienced reductions of 54.01 % and 43.53 %, respectively. These findings underscore the importance of considering microbial interactions and sediment dynamics in future odor research, offering insights for water quality management in eutrophic lakes.

Wild grown Portulaca oleracea as a novel magnetite based carrier with in vitro antioxidant and cytotoxicity potential

The latest research on nanotechnology through the new tailored scaffolds encompassed the therapeutic effects of natural compounds, and the unique properties of metallic nanoparticles offer new possibilities in emerging biomedical fields. Various strategies have been developed to address the limitations of existing therapeutic agents concerning specificity, vectorization, bioavailability, drug resistance, and adverse effects. In this study, the medicinal plant Portulaca oleracea L. and magnetite nanoparticles were used to develop an innovative target carrier system, designed to enhance the cytotoxic effect and overcome the main drawbacks (permeability and localization) of the phytoconstituents. The low-metabolite profile of Romanian wild-grown Portulaca oleracea L. exhibits a diverse range of hundred fifty-five compounds across various chemical categories (amino acids, peptides, fatty acids, flavonoids, alkaloids, terpenoids, phenolic acids, organic acids, esters, sterols, coumarins, nucleosides, lignans, and miscellaneous compounds). Morpho-structural and magnetic properties of the new phytocarrier were investigated using a variety of methods, including XRD, FTIR, Raman, SEM, DLS), and magnetic determinations. The MTT assay was conducted to evaluate in vitro the potential cytotoxicity on normal human dermal fibroblasts (NHDF), as well as on two tumoral cell lines: human osteosarcoma (HOS) and cervical cancer (HeLa). Results indicated that significant inhibition of both cancer cell lines' viability was exerted by the new phytocarrier compared to herbal extract. Furthermore, the results obtained for the total phenolic content and the antioxidant potential screening performed using the FRAP and DPPH assays were superior for the new carrier system. These findings suggest the potential biomedical applications of the developed carrier system and its promising implications for future research and development in the field.

Phytochemical and Pharmacological Insights into Mentha asiatica Boriss.: A Promising Antimicrobial Plant

Mentha asiatica Boriss., a species native to Central Asia, has garnered significant attention for its diverse phytochemical profile and antimicrobial potential. This review synthesizes current knowledge on the antimicrobial activities of M. asiatica, focusing on its essential oils and other bioactive constituents. The study contextualizes the importance of natural antimicrobials in the era of rising antibiotic resistance and highlights the plant's traditional use in ethnomedicine. The main methodologies explored include gas chromatography-mass spectrometry (GC-MS) for phytochemical characterization and various in vitro assays to assess antimicrobial efficacy against bacterial and fungal pathogens. The essential oils of M. asiatica demonstrate a broad spectrum of activity, attributed to compounds such as menthol, menthone, and carvone. Other phytochemicals, including sesquiterpenes and terpenoids, also contribute to its bioactivity. The review underscores the potential of M. asiatica as a source of novel antimicrobial agents and calls for further research into its mechanisms of action, bioavailability, and safety profiles. The findings position M. asiatica as a promising candidate for developing plant-based antimicrobial formulations, addressing critical needs in healthcare and food preservation.

β-ionone inhibits the grazing of Daphnia sinensis by reducing the activity of acetylcholinesterase

β-ionone is a volatile metabolite of Microcystis aeruginosa that is toxic to aquatic organisms. Using Daphnia sinensis as model, our present study found that β-ionone could significantly reduce heart rate and feeding rate, and induce intestinal emptying. Transcriptomic analysis showed that β-ionone could significantly inhibit the expression of acetylcholinesterase (AchE) mRNA, while metabolomics further revealed that β-ionone could significantly increase the level of acetylcholine (Ach) in D. sinensis. These results indicated that β-ionone might act as an AchE inhibitor, resulting in an increase in Ach levels. To test this hypothesis, both in vivo and in vitro experiments demonstrated that β-ionone could significantly reduce AchE activity. Furthermore, the inhibitory effects of β-ionone on heart rate and feeding rate could be blocked by the M-type Ach receptor (mAchR) blocker. These findings confirm that β-ionone is a novel AchE inhibitor. β-ionone could inhibit the activity of AchE, which in turn resulted in an increase of Ach in D. sinensis. Consequently, elevated levels of Ach could suppress the heart rate and feeding rate of D. sinensis by activating the mAchR, while concurrently accelerating the rate of intestinal emptying by stimulating intestinal peristalsis, thereby obstructing the digestion of algae within the intestinal tract.

β-Cyclocitral: Emerging Bioactive Compound in Plants

β-cyclocitral (βCC), a main apocarotenoid of β-carotene, increases plants’ resistance against stresses. It has recently appeared as a novel bioactive composite in a variety of organisms from plants to animals. In plants, βCC marked as stress signals that accrue under adverse ecological conditions. βCC regulates nuclear gene expression through several signaling pathways, leading to stress tolerance. In this review, an attempt has been made to summarize the recent findings of the potential role of βCC. We emphasize the βCC biosynthesis, signaling, and involvement in the regulation of abiotic stresses. From this review, it is clear that discussing compound has great potential against abiotic stress tolerance and be used as photosynthetic rate enhancer. In conclusion, this review establishes a significant reference base for future research.