New Approaches on Japanese Knotweed (Fallopia japonica) Bioactive Compounds and Their Potential of Pharmacological and Beekeeping Activities: Challenges and Future Directions

Known especially for its negative ecological impact, Fallopia japonica (Japanese knotweed) is now considered one of the most invasive species. Nevertheless, its chemical composition has shown, beyond doubt, some high biological active compounds that can be a source of valuable pharmacological potential for the enhancement of human health. In this direction, resveratrol, emodin or polydatin, to name a few, have been extensively studied to demonstrate the beneficial effects on animals and humans. Thus, by taking into consideration the recent advances in the study of Japanese knotweed and its phytochemical constituents, the aim of this article is to provide an overview on the high therapeutic potential, underlining its antioxidant, antimicrobial, anti-inflammatory and anticancer effects, among the most important ones. Moreover, we describe some future directions for reducing the negative impact of Fallopia japonica by using the plant for its beekeeping properties in providing a distinct honey type that incorporates most of its bioactive compounds, with the same health-promoting properties.

Effects of invasive japanese knotweed on diversity and structure of soil nematode communities

In this study we investigated the communities of soil nematodes in the forest habitats invaded and uninvaded by Fallopia japonica (Houtt.) Ronse Decr., in Tatra National Park, Slovakia. We found that invasion by F. japonica altered nematode communities and their structures. Total nematode abundance, species number and nematode biomass were significantly lower in invaded than uninvaded plots, but species diversity remained unaffected throughout the study. The overall abundance of all nematode trophic groups well represented the negative impact of F. japonica invasion on soil food webs, supported by low values of all maturity indices, a structural index and the Jaccard index of faunal similarity. A weighted faunal analysis similarly characterized the food webs of invaded plots as poorly developed or highly disturbed, with bacterial decomposition and a low C/N ratio. Our findings thus suggest that dense plots of knotweed simplify the structural complexity of the soil environment by reducing the richness of plant species, which may have contributed to the negative changes in the structures of the nematode communities.

Comparison of the Carbon and Water Fluxes of Some Aggressive Invasive Species in Baltic Grassland and Shrub Habitats

Biological systems are shaped by environmental pressures. These processes are implemented through the organisms exploiting their adaptation abilities and, thus, improving their spreading. Photosynthesis, transpiration, and water use efficiency are major physiological parameters that vary among organisms and respond to abiotic conditions. Invasive species exhibited special physiological performance in the invaded habitat. Photosynthesis and transpiration intensity of Fallopia japonica, Heracleum sosnowskyi, and Rumex confertus of northern and trans-Asian origin were performed in temperate extensive seminatural grassland or natural forest ecotones. The observed photosynthetically active radiation (PAR) ranged from 36.0 to 1083.7 μmol m−2 s−1 throughout the growing season depending on the meteorological conditions and habitat type. F. japonica and H. sosnowskyi settled in naturally formed shadowy shrub habitats characterized by the lowest mean PAR rates of 58.3 and 124.7 μmol m−2 s−1, respectively. R. confertus located in open seminatural grassland habitats where the mean PAR was 529.35 μmol m−2 s−1. Correlating with the available sunlight radiation (r = 0.9), the highest average photo assimilation rate was observed for R. confertus (p = 0.000). The lowest average intensity of photosynthesis rates was exhibited of F. japonica and H. sosnowskyi in shadowy shrub habitats. Transpiration and water use effectivity at the leaf level depended on many environmental factors. Positive quantitative responses of photosynthesis and transpiration to soil and meteorological conditions confirmed positive tolerance strategies of the invasive species succeeded by environmental adaptation to new habitats during their growing period sustained across a range of environments.

Invasive Plants in Support of Urban Farming: Fermentation-Based Organic Fertilizer from Japanese Knotweed

In this study, fermentation-based organic fertilizer (OF) was produced from the aboveground parts of Fallopia japonica (Houtt.) Ronse Decr. The quantity of N in OF (17.2 kg t−1 fresh lactic-fermented OF) was higher than average in cattle farmyard manure, but on a comparable level to solid poultry and rabbit manure. The OF was applied on a field to evaluate its effect on Chinese cabbage. The applied nutrients with OF N159 were 159, 44 and 121 kg ha−1 for N, P, and K, respectively. The applied nutrients with OF N317 were 317, 38, and 200 kg ha−1 for N, P, and K, respectively. The average mass of marketable Chinese cabbage (Brassica pekinensis Rupr.) single heads ranged from 253 g with N0 treatment to 602 g with N317 treatment. The nutrient recovery efficiency REN,P,K was 37, 20, and 50% for N317 and 55, 48, and 77% for N159. The OF was found to be a suitable alternative to farmyard manure. Additionally, OF produced from F. japonica could complement existing approaches to limit the spread of invasive species in cities. Further research should focus on perennial crop rotations and cropping patterns, different soil types, and a greater variety of crops and consider the possible retention of urban farmers using fertilizer from invasive plants.

Effect of Combined Treatment With Fallopia Japonica and Prunella Vulgaris Extract on Myopia Progress

BackgroundThe increased global incidence of myopia requires the establishment of therapeutic approaches. Previous studies have suggested that inflammation plays an important role in the development and progression of myopia. This study aimed to investigate the effect of Fallopia Japonica (FJ) and Prunella Vulgaris (PV) extract on myopia caused by monocular form deprivation (MFD) and elucidate the underlying mechanisms. MethodsWe used human retinal pigment epithelial cell to study the molecular mechanisms on how FJE and PVE lowering the inflammation of the eye. The effect of FJE and PVE in MFD induced hamster model and explore the role of inflammation cytokines in myopia.ResultsMyopia progression was enhanced upon tumor necrosis factor (TNF)-α or interleukin (IL)-6 administration. Expression levels of IL-6, IL-8, and TNF-α were upregulated in retinal pigment epithelium (RPE) cells treated with IL-6 and TNF-α. FJ extract (FJE) + PV extract (PVE) reduced IL-6, IL-8, and TNF-α expression in RPE cells. Furthermore, FJE and PVE inhibited inflammation by attenuating the phosphorylation of protein kinase B (AKT), and nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) pathway. In addition, we report two resveratrol + ursolic acid compounds from FJ and PV and their inhibitory activities against IL-6, IL-8, and TNF-α expression levels in RPE cells treated with IL-6 and TNF-α. FJE, PVE, and FJE + PVE were applied to MFD hamsters and their axial length was measured after 21 days. The axial length showed statistically significant differences between phosphate-buffered saline- and FJE-, PVE-, and FJE + PVE-treated MFD eyes. FJE + PVE suppressed expressions of IL-6, IL-8, and TNF-α. They also inhibited myopia-related transforming growth factor-beta (TGF)-β1, matrix metalloproteinase (MMP)-2, and NF-κB expression while increasing type Ⅰ collagen expression. ConclusionOverall, these results suggest that FJE + PVE may have a therapeutic effect on myopia and be used as a potential treatment option.

Fallopia japonica (Japanese knotweed).

F. japonica is an extremely invasive weed despite its lack of extensive sexual reproduction in most of its introduced range. It is included on various lists of invasive weeds and is one of the 100 worst invasive species as identified by the IUCN. It is a potential contaminant of soil, and its ability to tolerate a remarkable range of soil types and climates means that it has the potential to spread much further than it has to date. It has gained a fearsome reputation for breaking through hard structures in the built environment and being almost impossible to eradicate once it has taken hold and is often recognized as one of the most pernicious weeds in any recipient country.

Flavan-3-ols and Proanthocyanidins in Japanese, Bohemian and Giant Knotweed

Flavan-3-ols and proanthocyanidins of invasive alien plants Japanese knotweed (Fallopia japonica Houtt.), giant knotweed (Fallopia sachalinensis F. Schmidt) and Bohemian knotweed (Fallopia × bohemica (Chrtek & Chrtkova) J.P. Bailey) were investigated using high performance thin-layer chromatography (HPTLC) coupled to densitometry, image analysis and mass spectrometry (HPTLC–MS/MS). (+)-Catechin, (−)-epicatechin, (−)-epicatechin gallate and procyanidin B2 were found in rhizomes of these three species, and for the first time in Bohemian knotweed. (−)-Epicatechin gallate, procyanidin B1, procyanidin B2 and procyanidin C1 were found in giant knotweed rhizomes for the first time. Rhizomes of Bohemian and giant knotweed have the same chemical profiles of proanthocyanidins with respect to the degree of polymerization and with respect to gallates. Japanese and Bohemian knotweed have equal chromatographic fingerprint profiles with the additional peak not present in giant knotweed. Within the individual species giant knotweed rhizomes and leaves have the most similar fingerprints, while the fingerprints of Japanese and Bohemian knotweed rhizomes have additional peaks not found in leaves. Rhizomes of all three species proved to be a rich source of proanthocyanidins, with the highest content in Japanese and the lowest in Bohemian knotweed (based on the total peak areas). The contents of monomers in Japanese, Bohemian and giant knotweed rhizomes were 2.99 kg/t of dry mass (DM), 1.52 kg/t DM, 2.36 kg/t DM, respectively, while the contents of dimers were 2.81 kg/t DM, 1.09 kg/t DM, 2.17 kg/t DM, respectively. All B-type proanthocyanidins from monomers to decamers (monomers—flavan-3-ols, dimers, trimers, tetramers, pentamers, hexamers, heptamers, octamers, nonamers and decamers) and some of their gallates (monomer gallates, dimer gallates, dimer digallates, trimer gallates, tetramer gallates, pentamer gallates and hexamer gallates) were identified in rhizomes of Bohemian knotweed and giant knotweed. Pentamer gallates, hexamers, hexamer gallates, nonamers and decamers were identified for the first time in this study in Bohemian and giant knotweed rhizomes.