Comparison of the nutritional and phytochemical composition and antioxidant activities of Aralia elata (Miq.) Seem fruits in Northeast China

Functional identification of AeHMGR gene involved in regulation of saponin biosynthesis in Aralia elata

Aralia elata (Miq.) Seem, a significant tree species in the Araliaceae family, has medicinal and edible properties. Saponins are the primary active components of A. elata. The 3-hydroxy-3-methylglutaryl- CoA reductase (HMGR) is the initial rate-limiting enzyme of the major metabolic pathway of saponins in A. elata. In this study, the AeHMGR gene was identified through screening of transcriptome data. Through the qRT-PCR analysis, it was determined that the expression level of AeHMGR gene is highest in the somatic embryo and stem of A. elata. Heterologous transformation in tobacco revealed that ectopic expression of the AeHMGR gene leads to a significant reduction in the expression levels of the NtSS, NtFPS, and NtSE genes in transgenic tobacco lines, with a minimum expression level of 0.24 times that of the wild type. In the overexpressed callus lines of A. elata, the expression levels of the AeFPS, AeSE, AeSS, and Aeβ-AS genes were also significantly lower compared to the wild type, with a minimum expression level of approximately 0.3 times that of the wild type. Interestingly, the overexpression of the AeHMGR gene in A. elata somatic embryos led to a substantial decrease in the expression levels of AeFPS and AeSS, while the expression levels of AeSE and Aeβ-AS increased. Among the transgenic somatic embryo strain lines, line 7 exhibited the highest expression levels of AeSE and Aeβ-AS, with fold increases of 11.51 and 9.38, respectively, compared with that of the wild-type. Additionally, a high-performance liquid chromatography method was established to detect five individual saponins in transgenic A. elata. The total saponin content in line 7 somatic embryos was 1.14 times higher than that of wild-type materials, but only 0.30 times that of wild-type cultivated leaves. Moreover, the content of oleanolic acid saponin in line 7 was 1.35 times higher than that of wild-type cultivated leaves. These indicate that HMGR can affect triterpene biosynthesis.

Identification and Quantitation of the Bioactive Components in Wasted Aralia elata Leaves Extract with Endothelial Protective Activity

Aralia elata, a renowned medicinal plant with a rich history in traditional medicine, has gained attention for its potential therapeutic applications. However, the leaves of this plant have been largely overlooked and discarded due to limited knowledge of their biological activity and chemical composition. To bridge this gap, a comprehensive study was conducted to explore the therapeutic potential of the 70% ethanol extract derived from Aralia elata leaves (LAE) for the treatment of cardiovascular disease (CVD). Initially, the cytotoxic effects of LAE on human umbilical vein endothelial cells (HUVECs) were assessed, revealing no toxicity within concentrations up to 5 μg/mL. This suggests that LAE could serve as a safe raw material for the development of health supplements and drugs aimed at promoting cardiovascular well-being. Furthermore, the study found that LAE extract demonstrated anti-inflammatory properties in HUVECs by modulating the PI3K/Akt and MAPK signaling pathways. These findings are particularly significant as inflammation plays a crucial role in the progression of CVD. Moreover, LAE extract exhibited the ability to suppress the expression of adhesion molecules VCAM-1 and ICAM-1, which are pivotal in leukocyte migration to inflamed blood vessels observed in various pathological conditions. In conjunction with the investigation on therapeutic potential, the study also established an optimal HPLC-PDA-ESI-MS/MS method to identify and confirm the chemical constituents present in 24 samples collected from distinct regions in South Korea. Tentative identification revealed the presence of 14 saponins and nine phenolic compounds, while further analysis using PCA and PLS-DA allowed for the differentiation of samples based on their geographical origins. Notably, specific compounds such as chlorogenic acid, isochlorogenic acid A, and quercitrin emerged as marker compounds responsible for distinguishing samples from different regions. Overall, by unraveling its endothelial protective activity and identifying key chemical constituents, this research not only offers valuable insights for the development of novel treatments but also underscores the importance of utilizing and preserving natural resources efficiently.

Natural Deep Eutectic Solvents for the Extraction of Triterpene Saponins from Aralia elata var. mandshurica (Rupr. & Maxim.) J. Wen

The roots of the medicinal plant Aralia elata are rich in biologically active natural products, with triterpene saponins constituting one of their major groups. These metabolites can be efficiently extracted by methanol and ethanol. Due to their low toxicity, natural deep eutectic solvents (NADES) were recently proposed as promising alternative extractants for the isolation of natural products from medicinal plants. However, although NADES-based extraction protocols are becoming common in routine phytochemical work, their application in the isolation of triterpene saponins has not yet been addressed. Therefore, here, we address the potential of NADES in the extraction of triterpene saponins from the roots of A. elata. For this purpose, the previously reported recoveries of Araliacea triterpene saponins in extraction experiments with seven different acid-based NADES were addressed by a targeted LC-MS-based quantitative approach for, to the best of our knowledge, the first time. Thereby, 20 triterpene saponins were annotated by their exact mass and characteristic fragmentation patterns in the total root material, root bark and root core of A. elata by RP-UHPLC-ESI-QqTOF-MS, with 9 of them being identified in the roots of this plant for the first time. Triterpene saponins were successfully extracted from all tested NADES, with the highest efficiency (both in terms of the numbers and recoveries of individual analytes) achieved using a 1:1 mixture of choline chloride and malic acid, as well as a 1:3 mixture of choline chloride and lactic acid. Thereby, for 13 metabolites, NADES were more efficient extractants in comparison with water and ethanol. Our results indicate that new, efficient NADES-based extraction protocols, giving access to high recoveries of triterpene saponins, might be efficiently employed in laboratory practice. Thus, our data open the prospect of replacing alcohols with NADES in the extraction of A. elata roots.

Aralia cordata Thunb. as a Source of Bioactive Compounds: Phytochemical Composition and Antioxidant Activity

Plant primary and secondary metabolites are a significant source for many applications, including extractions of functional components, green synthesis development, and producing higher-added value products. However, in the variety of botanicals, Aralia cordata Thunb. plant is getting attention for its similarity to ginseng. This study comprehensively examines the biochemical and phytochemical profiles of different A. cordata morphological parts: root, stem, leaf, inflorescence, berry, and seed. Additionally, the establishment of total phenolic content and quantitative analysis of powerful antioxidants such as chlorophyll, carotenoids (zeaxanthin, lutein, and β-carotene), proanthocyanidins, and anthocyanins content were evaluated. The results indicated that A. cordata stem and berries are an excellent source of anthocyanins in the range from 18.27 to 78.54 mg/100 g DW. Meanwhile, the antioxidant activity was evaluated using three different methods based on the capacity to scavenge: DPPH^• scavenging capacity, ABTS^•+ radical cation assay, and ferric reducing antioxidant power (FRAP) and ranged from 27 to 168 µmol TE/g DW, 8 to 117 µmol TE/g DW, and 18 to 157 µmol TE/g DW, respectively. This study proposes a novel competitive plant for many health-promoting applications in the nutraceutical, pharmaceutical, material, and food industries.