Chemical characterization, antioxidant, enzyme inhibitory and cytotoxic properties of two geophytes: Crocus pallasii and Cyclamen cilicium

The Cryopreservation of Medicinal and Ornamental Geophytes: Application and Challenges

Nowadays, plant genetic resources are often at risk of loss and destruction. Geophytes are herbaceous or perennial species that are annually renewed by bulbs, rhizomes, tuberous roots, or tubers. They are often subject to overexploitation, which, combined with other biotic and abiotic stresses, can make these plants more vulnerable to a decline in their diffusion. As a result, multiple endeavors have been undertaken to establish better conservation strategies. Plant cryopreservation at ultra-low temperatures in liquid nitrogen (-196 °C) has proven to be an effective, long-term, low-cost, and suitable conservation method for many plant species. Over the last two decades, major advances in cryobiology studies have enabled successful explants of multiple genera and types, including pollen, shoot tips, dormant buds, and zygotic and somatic embryos. This review provides an update on recent advances and developments in cryopreservation and its application to medicinal and ornamental geophytes. In addition, the review includes a brief summary of factors limiting the success of bulbous germplasm conservation. The critical analysis underpinning this review will benefit biologists and cryobiologists in their further studies on the optimization of geophyte cryopreservation protocols and will support a more complete and wider application of knowledge in this area.

The Influence of Different Extraction Techniques on the Chemical Profile and Biological Properties of Oroxylum indicum: Multifunctional Aspects for Potential Pharmaceutical Applications

Oroxylum indicum (L.) Kurz (Bignoniaceae), a traditional Chinese herbal medicine, possesses various biological activities including antioxidant, anti-inflammatory, antibacterial, and anticancer. In order to guide the practical application of O. indicum in the pharmaceutical, food, and cosmetic industries, we evaluated the effects of five different extraction techniques (maceration extraction (ME), oxhlet extraction (SOXE), ultrasound-assisted extraction (UAE), tissue-smashing extraction (TSE), and accelerated-solvent extraction (ASE)) with 70% ethanol as the solvent on the phytochemical properties and biological potential. The UHPLC-DAD Orbitrap Elite MS technique was applied to characterize the main flavonoids in the extracts. Simultaneously, the antioxidant and enzyme inhibitory activities of the tested extracts were analyzed. SOXE extract showed the highest total phenolic content (TPC, 50.99 ± 1.78 mg GAE/g extract), while ASE extract displayed the highest total flavonoid content (TFC, 34.92 ± 0.38 mg RE/g extract), which displayed significant correlation with antioxidant activity. The extract obtained using UAE was the most potent inhibitor of tyrosinase (IC50: 16.57 ± 0.53 mg·mL−1), while SOXE extract showed the highest activity against α-glucosidase (IC50: 1.23 ± 0.09 mg·mL−1), succeeded by UAE, ME, ASE, and TSE extract. In addition, multivariate analysis suggested that different extraction techniques could significantly affect the phytochemical properties and biological activities of O. indicum. To sum up, O. indicum displayed expected biological potential and the data collected in this study could provide an experimental basis for further investigation in practical applications.

Exogenously Applied GA3 Enhances Morphological Parameters of Tolerant and Sensitive Cyclamen persicum Genotypes under Ambient Temperature and Heat Stress Conditions

Cyclamen genus is part of the Primulaceae family consisting of 24 species widely cultivated as ornamental and medicinal plants. They also possess high plasticity in terms of adaptability to alternating environmental conditions. In this regard, the present study investigates the germination and morphological parameters of heat-tolerant and heat-sensitive Cyclamen persicum accessions in the presence of different GA3 solutions (0, 30, 70 and 90 mg/L) under ambient temperature and heat stress conditions. Heat-tolerant genotypes, mainly C3-Smartiz Victoria (6.42%), C15-Merengue magenta (6.47%) and C16-Metis silverleaf (5.12%) had the highest germination rate with 90 mg/L GA3 treatment compared with control. Regarding heat-sensitive genotypes, C11-Verano (5.11%) and C13-Metis Origami (4.28%) had the lowest values in mean germination time, along with the Petticoat genotypes C1 (73.3%) and C2 (80.0%) with a high germination percentage. Heat-tolerant genotypes positively responded to GA3 (70 and 90 mg/L) even under heat stress conditions, by their higher values in plant height, an ascending trend also seen in heat-sensitive genotypes under GA3 treatment (70 and 90 mg/L). According to the hierarchical clustering, several heat-tolerant genotypes showed peculiar behavior under heat stress conditions, namely C3 (Smartiz Victoria), C7 (Halios falbala) and C8 (Latinia pipoca) which proved to be susceptible to heat stress even under GA3 application, compared with the other genotypes which showed tolerance to higher temperatures. In the case of heat-sensitive genotypes, C4 (Smartiz violet fonce), C6 (Metis blank pur), C11 (Verano) and C13 (Metis origami) possessed higher positive or negative values compared with the other heat-sensitive genotypes with increased doses of GA3. These genotypes were shown to be less affected by heat stress, suggesting their positive response to hormone treatment. In conclusion, the above-mentioned genotypes, particularly heat-tolerant C15 and heat-sensitive C2 with the highest germination capacity and development can be selected as heat-resistant genotypes to be deposited in gene banks and used in further amelioration programs under biotic and/or abiotic stresses to develop resistant genotypes.

Anthocyanins and Carotenoids Characterization in Flowers and Leaves of Cyclamen Genotypes Linked with Bioactivities Using Multivariate Analysis Techniques

The present study was carried out to evaluate and compare in vitro antioxidant (2,2-diphenyl-1-picrylhydrazyl (DPPH), Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP)), antimicrobial, anticancer activities, and the individual carotenoids and anthocyanins content of methanol extracts of the Cyclamen genotypes: Persian cyclamen accessions (Cyclamen persicum Mill.), sowbread (C. mirabile Hildebr.), and ivy-leaved cyclamen (C. hederifolium Mill.) aerial parts. The HPLC-PDA analysis revealed the presence of five individual carotenoids (i.e., neoxanthin, violaxanthin, lutein, β-carotene, and cis-β-carotene) as the main compounds in Cyclamen leaves, and the presence of seven individual anthocycanins (i.e., cyanidin 3,5-di-O-glucoside, peonidin-rutinoside, peonidin 3,5-di-O-glucoside, peonidin 3-O-glucoside, malvidin 3-O-glucoside, malvidin 3,5-di-O-glucoside, and malvidin-rutinoside) in Cyclamen flowers reported, hereby, for the first time. The highest phenolic content was found in the leaves of LC6, C. mirabile (46.32 ± 0.14 mg/g gallic acid equivalents [GAE]), and in the flowers of C. persicum Merengue Magenta (FC15) (58.63 ± 0.17 mg/g GAE), whereas the highest flavonoid content was reported in C. persicum Halios Falbala leaves, namely LC9 (54.90 ± 0.27 mg/g quercetin equivalents [QE]) and in flowers of C. persicum Victora (FC2) (77.87 ± 0.25 mg/g QE). The highest antioxidant activity in DPPH and FRAP assays was reported in C. persicum Dark Violet (LC1) and Victoria (LC2), whereas C. mirabile (LC6) had the highest activity in the TEAC assay. In flowers, high antioxidant activities in DPPH and TEAC were noticed in C. persicum Superserie Red (FC7) and Dark Violet (FC1), respectively, and Halios Falbala (FC9) exhibited the highest activity in the TEAC assay. Additionally, FC9 exhibited the highest antibacterial activity in almost all tested bacteria compared with the leaves extracts. Furthermore, the highest in vitro citotoxicity in MDA-MB-231 cells was noticed in C. hederifolium LC18 (56.71-69.35%) and FC18 (40.07-41.43%), with a lower effect against BJ cells demonstrating selective toxicity. The above findings, highlight the potential use of the Cyclamen flower and leaf extracts as significant anticancer agents along with their antioxidant and antimicrobial properties.

A robust workflow for indirect somatic embryogenesis and cormlet production in saffron (Crocus sativus L.) and its wild allies; C. caspius and C. speciosus

Saffron (Crocus sativus L.) and its wild relatives, Crocus caspius and Crocus speciosus are of considerable significance in the pharmaceutical, nutraceutical, and ornamental bulbs industry. Towards the ultimate goal of the conservation of wild Crocus species and establishment of an efficient workflow for in vitro production of Crocuses, efficient protocols were developed for disinfection and in vitro production of cormlets in C. sativus and its wild allies C. caspius and C. speciosus. Moreover, the differential expression of the Somatic Embryogenesis Receptor-like Kinase (SERK) gene was evaluated as a potential molecular marker during embryogenesis between embryogenic and non-embryogenic calli. A highly efficient disinfection recipe and a low-cost TDZ-free protocol have been successfully developed for in vitro cormlet production in three Crocus species. MS medium containing 10.18 μM 2, 4-D + 4.44 μM BAP was most efficiently induced callus and somatic embryo formation. The highest conversion frequency and maximum cormlet weight were achieved in MS containing 5.37 μM NAA + 8.88 μM BAP. The SERK expression was significantly much higher in embryogenic calli than non-embryogenic in all Crocus species. The current low-cost and easy-to-use recipe suggests a promising in vitro propagation workflow for mass production of uniform pathogen-free cormlets of Crocus species, as well as a platform to better conservation of wild Crocus species and effective gene and genome editing using CRISPR-Cas9 in future studies.

Antioxidant and antidiabetic activities of vanadium-binding protein and trifuhalol A

The antioxidant and antidiabetic activities of vanadium-binding protein (VBP) and trifuhalol A, alone or combined, were investigated. Both VBP and trifuhalol A showed potent radical scavenging activity (RSA) on 2,2'-azinobis (3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), hydrogen peroxide, and ferric-reducing antioxidant power. Their combination at a concentration of 100 μg/ml VBP and 40 μg/ml trifuhalol A exhibited more than 99% RSA against ABTS. Additionally, VBP and trifuhalol A, alone or combined, displayed potential antidiabetic activities against Saccharomyces cerevisiae α-glucosidase. The highest inhibition of 70.26% against S. cerevisiae α-glucosidase was observed in the case of the combination of 250 μg/ml VBP and 1.75 μg/ml trifuhalol A. Kinetics study revealed that VBP and trifuhalol A were noncompetitive inhibition type against S. cerevisiae α-glucosidase, while VBP and trifuhalol A combined treatment was a mixed inhibition type against S. cerevisiae α-glucosidase. These results indicated that VBP and trifuhalol A, alone or combined, had high free radical scavenging activity and inhibitory activity against S. cerevisiae a-glucosidase, suggesting that VBP and trifuhalol A could be used as candidates for the development of natural antidiabetic drugs or functional food. PRACTICAL APPLICATIONS: The present study showed that VBP and trifuhalol A, alone or combined, had potential antioxidant and antidiabetic activities, suggesting that VBP and trifuhalol A could be developed to a novel nutraceutical or natural antidiabetic drugs in the management of obesity or diabetes. This finding will be beneficial for all peoples who are directly or indirectly associated with obesity or diabetes.