Lonicera caerulea (Haskap berries): a review of development traceability, functional value, product development status, future opportunities, and challenges

Carbon quantum dots from fallen leaves of Lonicera caerulea L.: An innovative plant growth promoter and fruit quality enhancer

With increasing environmental pollution and resource wastage, utilizing waste for high-value applications has become crucial. This study explores the preparation of carbon dots (CDs) from blue honeysuckle leaves and their potential in enhancing plant photosynthesis. CDs derived from these leaves have a particle size of ∼2.6 nm and emit blue fluorescence under 365 nm UV light, making them suitable for foliar spraying. When applied, CDs enter leaf cells and impact chloroplasts, significantly improving photosystem II (PSII) performance and Rubisco enzyme activity. At an optimal concentration of 1000 mg/L, PSII electron transfer efficiency and Rubisco activity increased by 29.84% and 208.12%, respectively, boosting net photosynthetic rate by 60.4%. This treatment also enhanced blue honeysuckle yield and fruit quality, with higher levels of soluble solids, ascorbic acid, flavonoids, anthocyanins, and total phenolics. These improvements were linked to increased sucrose synthesis (up 25.99%) and leaf assimilative capacity (up 25%). Additionally, CDs enhanced post-harvest soil enzyme activity and microbial abundance, promoting nutrient cycling and soil utilization. This study demonstrates that preparing CDs from waste blue honeysuckle leaves not only mitigates environmental pollution but also offers a sustainable, high value use for plant resources. The findings highlight the potential of nanomaterials in improving agricultural productivity and provide a novel pathway for waste reuse.

Composition and micromorphological determination of blue honeysuckle fruit (Lonicera caerulea L.) cuticular wax and its effects on fruit post-harvest quality

The chemical composition and structure of the cuticular wax in blue honeysuckle fruit were investigated using gas chromatography-mass spectrometry (GC-MS) and scanning electron microscopy (SEM). The results revealed that the cuticular wax was dense and uniform, taking on a tubular form. A total of 158 wax components were identified, including alkanes, terpenes, ketones, alcohols, fatty acids, and esters. The wax was found to be particularly rich in alkanes. After storage, the wax content decreased, whereas an increase in 1-undecanol. The destruction or reduction of cuticular wax resulted in a more rapid decline in storage quality, loss of nutrients, and a decrease in antioxidant phytochemicals. Meanwhile, wax metabolizing enzyme activity and gene expression increased. This study presents a deeper understanding of blue honeysuckle fruit cuticular wax composition and aids to developing effective measures to delay its postharvest fruit quality deterioration.

Taming the wild: domesticating untapped northern fruit tree and shrub resources in the era of high-throughput technologies

New crop`s need to emerge to provide sustainable solutions to climate change and increasing abiotic and biotic constraints on agriculture. A large breadth of northern fruit trees and shrubs exhibit a high potential for domestication; however, obstacles to implementing traditional breeding methods have hampered or dissuaded efforts for improvement. This review article proposes a unique roadmap for de novo domestication of northern fruit crops, with a focus on biotechnological (e.g. genome editing, rapid cycle breeding, and in planta transformation) approaches that can boast rapid evolutionary gains. In addition, numerous biotechnological (e.g. virus-induced flowering and grafting-mediated flowering) and breeding strategies (e.g. adaptation of speed breeding to fruit trees) that can hasten the transition from juvenility to sexual maturity are described. A description of an accelerated genetic breeding strategy with insights for 16 underutilized species (e.g. shagbark hickory, running serviceberry, horse chestnut, and black walnut) is provided to support their enhancement. Deemed unrealistic only a decade ago, progress in the realm of bioengineering heralds a future for northern orphan crops through the implementation of fast-tracked crop improvement programs. As such, the roadmap presented in this article paves the way to integrating these novel biotechnological discoveries and propel the development of these forgotten crops in a sustainable and timely manner.

Combination transcriptomic and metabolomic reveal deterioration of the blue honeysuckle (Lonicera caerulea L.) fruit and candidate genes regulating metabolism in the post-harvest stage

Blue honeysuckle, a new berry with high nutritional value, possesses typical berry postharvest properties, including extreme perishability, rapid quality loss, and high sensitivity to microbial infections. At present, the underlying mechanisms of postharvest quality deterioration, senescence, and low-temperature regulation remain largely unknown. This study aimed to elucidate the metabolic shifts and genetic regulation underlying the preservation or deterioration of blue honeysuckle during storage at room temperature (25 °C) and low temperature (4 °C). Storage at 4 °C inhibited fruit decay and preserved better visual quality, weight, firmness, and total soluble solid and acid contents. We identified 24 key differentially accumulated metabolites that specifically changed during the qualitative shift at room temperature and were effectively regulated by 4 °C. Commonly associated metabolites, sorbitol, succinic acid, malic acid, naringenin, pinobanksin, and taxifolin, characterize the deterioration of blue honeysuckle. These metabolites were integrated with transcriptomic data for weighted correlation network analysis (WGCNA). Regulatory networks were used for the identification of key genes and transcription factors (TFs) influencing sugar, organic acid, flavonoid, and phenolic acid metabolism during storage. The findings provide insight into metabolic regulation and the improvement of flavor in postharvest blue honeysuckle fruit.

Amplifying Bioactivity of blue honeysuckle (Lonicera caerulea L.) fruit puree through Ultrasonication: Antioxidant and antiproliferative activity

Blue honeysuckle (Lonicera caerulea L.) serves as a significant reservoir of polyphenol compounds. This impact of ultrasonication processing on the bioaccessibility of blue honeysuckle fruit puree during in vitro digestion was evaluated. The polyphenol compounds, antioxidant capacity and antiproliferative activity were measured, with a particular focus on determining the total proanthocyanidin content of the puree during digestion. The results revealed that the U300 W treatment significantly increased antioxidant content and enhanced the stability of antioxidant capacity, leading to stronger antiproliferative activity. A total of 33 compounds, including 14 phenolic acids, 5 flavanols, 1 flavanol-3-ol, 1 flavanone alcohol, 3 flavanones, 1 flavanone, and 8 non- polyphenols were found in both untreated and ultrasonicated puree during in vitro digestion. The untreated puree contained 22 compounds, while the ultrasonicated puree contained 33. Compared to untreated samples, ultrasonicated samples contained significantly higher levels of loganic acid, dihydrokaempferol, kaempferol derivatives, and plantagoside. Except for vanillic acid, citric acid, protocatechuic acid, and luteolin-4'-O-glucoside, the polyphenols showed a decreasing trend during oral-gastric-small intestinal-colon digestion. The U500 W ultrasonicated fruit puree exhibited the strongest antiproliferative activity. Overall, the results demonstrated that ultrasonication has the potential to enhance the bioaccessibility of antioxidant compounds and the antiproliferative activity of blue honeysuckle fruit puree.

Effects of Growth Stages on Leaf Nutrients, Metabolites, and Polyphenols of Three Varieties of Haskap

Haskap (Lonicera caerulea L.) has gained much research interest, given the diverse biologically active compounds found in different parts of the plant. It is, therefore, important to study the concentration of some of these biologically active compounds at different developmental stages. The present study investigated the effect of growth stages on nutrients, metabolites, and polyphenol concentrations in the leaves of three haskap varieties (Indigo Gem, Wojtek, and Jolanta). A targeted quantitative metabolomics approach was used to analyze the haskap leaves using a combination of direct injection mass spectrometry with a reverse LC-MS/MS custom assay. The results showed that the concentrations of soluble sugar, organic acids, polyphenols, and amino acids in the leaves of different varieties of haskap were decreased at the fruiting stage. The leafing stage may be the best period to harvest haskap leaves with the highest nutrients and polyphenol concentrations. Studies on polyphenols and nutrient characterization of haskap leaf at the leafing stage could be further investigated.

Comprehensive structural analysis of anthocyanins in blue honeysuckle (Lonicera caerulea L.), bilberry (Vaccinium uliginosum L.), cranberry (Vaccinium macrocarpon Ait.), and antioxidant capacity comparison

The objectives of this research were to analyze anthocyanins in blue honeysuckle (Lonicera caerulea L.), bilberry (Vaccinium vitis-idaea L), and cranberry (Vaccinium macrocarpon Ait.), using HPLC-ESI-QTOF-MS2, Fourteen, fifteen, and eight anthocyanins were identified in blue honeysuckle, bilberry, and cranberry, respectively. Cyanidin-3-glucoside (C3G) and peonidin-3-glucoside were detected in all three types of berries, with blue honeysuckle showing the highest C3G content at 5686.28 mg/100 g DW. Total phenolic content (TPC) and total flavonoid content (TFC), along with ABTS, DPPH, and FRAP assays, were measured. Blue honeysuckle exhibited the highest levels of TPC and TFC. The SOD, POD, and CAT activities in blue honeysuckle were 1761.17 U/g, 45,525.65 U/g, and 1043.24 U/g, respectively, which were significantly superior to those in bilberry and cranberry. The antioxidant mechanisms of these enzymes were investigated by molecular docking, C3G showed a higher affinity for POD, confirming the effectiveness of C3G as an antioxidant.

Comparison in Antioxidant Potential and Concentrations of Selected Bioactive Ingredients in Fruits of Lesser-Known Species

Fruits with a high content of biologically active compounds are essential in preventing many diseases. Therefore, the interest in searching for and testing new plant sources for bioactive constituents remains strong. Although many publications on individual species exist, their results are difficult to compare directly due to varying methods and conditions of analysis. Only a few studies have investigated many different species in a single analysis. Therefore, we examined and compared 21 different genotypes, using various measurement methods for total phenolic content (TPC) (Folin-Ciocalteu, FBBB), total antioxidant capacity (ABTS, FRAP, DPPH), and the HPLC technique for the total ascorbate concentration in freshly harvested fruits. One-way ANOVA, Principal Component Analysis, and Pearson Correlation were used to analyse and compare the results. The tested samples showed significant differences in TPC, ascorbate content, and antioxidant capacity. The correlation between the content of bioactive compounds and antioxidant capacity depended on the analytical methods, with results obtained using the FRAP test being the most strongly correlated. Due to higher levels of polyphenols, ascorbate, and antioxidant potential, the most promising species for further evaluation appear to be Chaenomeles × californica, Actinidia kolomikta, Mespilus germanica, and ×Sorboaronia fallax.

Isolation and characterization of a hepatoprotective polysaccharide from Lonicera caerulea L. var. edulis Turcz. ex Herd. fruit against APAP-induced acute liver injury mice

The structure and bioactivities of a novel polysaccharide from Lonicera caerulea L. var. edulis Turcz. ex Herd. fruit (THP-3) were investigated. The crude polysaccharides of Turcz. ex Herd. (THP) were extracted by hot water extraction. After purification, the chemical structure of polysaccharides was identified. Then, a mouse model of acute drug-induced liver injury was constructed using 4-acetamidophenol (APAP) and pretreated with THP. The number-average molecular weight of THP-3 was 48.89 kDa and the mass average molar mass was 97.87 kDa. THP-3 was mainly composed of arabinose (42.54 %), glucose (27.62 %), galacturonic acid and galactose (29.84 %). The main linkage types of THP-3 were 1-linked Araf, 1,4-linked Glcp, and 1,3,6-linked Galp. In addition, after THP treatment, serum Alanine aminotransferase (ALT), Aspartate aminotransferase (AST) and γ-glutamyl transpeptidase (γGT) in AILI mice were successfully down-regulated. The results showed that THP could prevent the characteristic morphological changes of hepatic lobular injury and lipid depletion caused by APAP, reduced the level of oxidative damage in mice, increased the expression of APAP-induced hypolipidemia and related inflammatory indicators, and improved the detoxification function of liver. In general, the newly extracted THP polysaccharide has a good liver protection effect and is an ideal natural medicine for the treatment of liver diseases.

A Systematic Review of Cardio-Metabolic Properties of Lonicera caerulea L

In the light of growing concerns faced by Western societies due to aging, natality decline, and epidemic of cardio-metabolic diseases, both preventable and treatable, new and effective strategical interventions are urgently needed in order to decrease their socio-economical encumbrance. The recent focus of research has been redirected towards investigating the potential of haskap (Lonicera caerulea L.) as a novel functional food or superfruit. Therefore, our present review aims to highlight the latest scientific proofs regarding the potential of Lonicera caerulea L. (LC), a perennial fruit-bearing plant rich in polyphenols, in reversing cardio-metabolic dysfunctions. In this regard, a systematic search on two databases (PubMed and Google Scholar) from 1 January 2016 to 1 December 2023 was performed, the keyword combination being Lonicera caerulea L. AND the searched pharmacological action, with the inclusion criteria consisting of in extenso original articles, written in English. The health-enhancing characteristics of haskap berries have been examined through in vitro and in vivo studies from the 35 included original papers. Positive effects regarding cardiovascular diseases and metabolic syndrome have been assigned to the antioxidant activity, hypolipidemic and hypoglycemic effects, as well as to the hepatoprotective and vasoprotective potential. Latest advances regarding LCF mechanisms of action are detailed within this review as well. All these cutting-edge data suggest that this vegetal product would be a good candidate for further clinical studies.

Blue honeysuckle seeds and seed oil: Composition, physicochemical properties, fatty acid profile, volatile components, and antioxidant capacity

Blue honeysuckle seeds are often overlooked by the processing industry, but they are a good source of healthy oil. The composition, volatiles, and antioxidant capacity of blue honeysuckle seeds and seed oil were investigated for the first time. The fatty acid profile of the seed oil was analysed using GC-MS. The seed oil was particularly rich in polyunsaturated fatty acid, especially linoleic acid (71.24 ± 1.64 %). HS-SPME-GC-MS analysis temporarily detected 34 and 37 volatiles in the seeds and seed oil, respectively. Notably, aldehydes were identified as the major contributors to the aroma. The phytosterols, tocopherols, and triglycerides were identified in the seed oil. Interestingly, the total phenolic content and antioxidant capacity of the seeds were found to be much higher than the seed oil. This study evaluates the nutritional profile and value of blue honeysuckle seed oil, and suggests that it can be used as new functional oil.

Enhancing Postharvest Quality and Antioxidant Capacity of Blue Honeysuckle cv. 'Lanjingling' with Chitosan and Aloe vera Gel Edible Coatings during Storage

This study investigated the impact of chitosan (CH, 1%) and aloe vera gel (AL, 30%) edible coatings on the preservation of blue honeysuckle quality during a 28-day storage at -1 °C. Coating with CH, AL, and CH+AL led to notable enhancements in several key attributes. These included increased firmness, total soluble solids, acidity, pH, and antioxidant capacity (measured through DPPH, ABTS, and FRAP assays), as well as the preservation of primary (ascorbic acid) and secondary metabolites (TPC, TAC, and TFC). The TAC and TFC levels were approximately increased by 280% and 17%, respectively, in coated blue honeysuckle after 28 d compared to uncoated blue honeysuckle. These coatings also resulted in reduced weight loss, respiration rate, color, abscisic acid, ethylene production, and malondialdehyde content. Notably, the CH+AL treatment excelled in preserving secondary metabolites and elevating FRAP-reducing power, demonstrating a remarkable 1.43-fold increase compared to the control after 28 days. Overall, CH+AL exhibited superior effects compared to CH or AL treatment alone, offering a promising strategy for extending the shelf life and preserving the quality of blue honeysuckle during storage.

Evaluation of the Chemical Composition of Selected Varieties of L. caerulea var. kamtschatica and L. caerulea var. emphyllocalyx

Lonicera caerulea fruits are a rich source of vitamins, organic acids, and phenolic compounds, which are characterised by their health-promoting properties. The content of bioactive compounds in this fruit may vary depending on the cultivar and the harvest date. The fruits of the L. caerulea var. kamtschatica cultivars ‘Duet’ and ‘Aurora’ and the L. caerulea var. emphyllocalyx cultivars ‘Lori’, ‘Colin’ and ‘Willa’ were used in this study. L. emphyllocalyx fruit, especially the cultivar ‘Willa’, was characterised as having a higher acidity by an average of 29.96% compared to L. kamtschatica. The average ascorbic acid content of the L. kamtschatica fruit was 53.5 mg·100 g−1 f.w., while L. emphyllocalyx fruit had an average content that was 14.14% lower. The antioxidant activity (determined by DPPH, FRAP, and ABTS) varied according to the cultivar and the species of fruit analysed. The total polyphenol content differed significantly depending on the cultivar analysed; fruits of the L. emphyllocalyx cultivar ‘Willa’ were characterised by the lowest content of total polyphenols—416.94 mg GAE·100 g−1 f.w.—while the highest content of total polyphenols—747.85 GAE·100 g−1 f.w.—was found in the fruits of the L. emphyllocalyx cultivar ‘Lori’. Lonicera caerulea fruits contained 26 different phenolic compounds in their compositions, of which the highest content was characterised by cyanidin 3-O-glucoside (average: 347.37 mg·100 g−1). On the basis of this study, it appears that both L. kamtschatica fruits and L. emphyllocalyx fruits, especially of the cultivars ‘Lori’ and ‘Willa’, can be used in food processing.

Natural Soybean Milk-Derived Bioactive Coatings for Enhanced Wound Healing

Foodborne biomaterials, derived from diets, comprise selfassembled collections of many micro- or nanoscale units with abundant nutrients and active substances. In this study, soybean milk (SBM) was selected as a tissue engineering product for simple and feasible wound repair. SBM is a common drink prepared from soybeans and is rich in soy protein, soy isoflavones, and other bioactive components. Thus, SBM has substantial potential for antioxidation and tissue remodeling. Here, the multifunctional effect of SBM as a bioactive coating for promoting wound healing was studied. The results showed that SBM has good biocompatibility and biological activity. It efficiently scavenges intracellular reactive oxygen species, significantly enhances epithelial cell migration, and improves angiogenesis, thereby accelerating tissue remodeling. The results of animal experiments further confirmed that the SBM-bioinspired coating has promising applications for cutaneous wound regeneration.