The Dioscorea Genus (Yam)-An Appraisal of Nutritional and Therapeutic Potentials

Comprehensive evaluation on nutritional characteristics and anti-hyperglycemic active ingredients of different varieties of Yam

Yam is a versatile economic crop that serves both medicinal and dietary purposes. Dehua County, located in Fujian Province, China, is renowned as one of the major yam production areas, with a cultivation history spanning over 600 years. It has successfully cultivated Qingfeng yam and Ziyu yam, both of which have been recognized with China's "Geographical Indications for Agricultural Products." However, no comprehensive studies have been conducted to evaluate their quality. This study meticulously utilized the authentic medicinal material "Iron yam" as a benchmark, employing advanced techniques such as high-performance liquid chromatography (HPLC), ultraviolet spectrophotometry, and flame atomic absorption spectrometry to systematically analyze the nutritional and hypoglycemic active components of three distinct yam varieties. In order to interpret the data, descriptive statistics, correlation analysis, principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), cluster analysis and multiple linear regression analysis were systematically applied. The results revealed significant variations in the concentrations of various indicators across the three yam types. Correlation analysis identified 65 pairs of indicators with exceptionally strong correlations and 39 pairs with statistically significant associations. Additionally, the principal component analysis demonstrated that Iron yam exhibited the most favorable overall quality. Notably, Ziyu yam, characterized by its high concentration of hypoglycemic active compounds, emerged as a promising raw material for the production of hypoglycemic products, showcasing significant potential in this field.

An Updated Review of Molecular Mechanisms Implicated with the Anticancer Potential of Diosgenin and Its Nanoformulations

Dietary components have gained broader recognition in preventing and managing numerous human carcinomas. Plant-derived natural compounds offer several benefits, including their limited toxicity and multi-targeted agents in modulating deregulated oncogenic pathways, including PI3K/AKT, NF-κB/STAT3, and HIF-1α, and hence, they emerged as better chemotherapeutic alternatives. Diosgenin (phytosteroidal saponin) and its nanoformulations have been extensively reported to impact cancer progression and metastasis. Research has indicated that diosgenin and its nanoformulations possess significant anticancer potential with improved bioavailability. However, novelty of this review relies on compiling the updated anticancer role of diosgenin and its nanoformulations in modulating numerous oncogenic targets associated with carcinogenesis and metastasis. Diosgenin has also been utilized with traditional therapies to enhance the sensitivity of cancerous cells towards normal chemotherapeutic processes. More focus should be given to gain detailed insights about the mechanisms associated with the anticancer potential of diosgenin and its nanoformulations, which can further potentiate its candidature in developing efficient cancer therapies. However, more preclinical studies are warranted to exploit the anticancer efficacy of this plant-based compound in an efficient manner.

Exploring the molecular mechanism of Dioscorea alata L. for the treatment of menstrual disorders using network pharmacology and molecular docking

Menstrual disorders (MDs), including premenstrual syndrome, amenorrhea, and dysmenorrhea, affect women globally. Dioscorea alata L., a traditional yam species, has been used medicinally, but its potential in treating MDs remains understudied. This study employs a network pharmacology approach to examine the effects of D. alata's secondary metabolites on MDs via multi-target mechanisms. Compounds were identified from literature and PubChem, while disease-related targets were gathered from GeneCards, DisGeNET, and CTD databases. Swiss target prediction was used to link compounds to targets. A protein-protein interaction (PPI) network was constructed using STRING, and Gene Ontology (GO) and KEGG enrichment analyses were conducted to predict functional pathways. Eighteen bioactive compounds and 120 therapeutic targets specific to MDs were identified. KEGG analysis revealed 20 significant pathways related to menstrual disturbances. Among the 120 targets, TNF α, PPARG, ESR1, and AKT1 were highlighted as key therapeutic targets. Molecular docking showed strong interactions between Daidzein and ESR1, Diosgenin and TNF α, Alatanin and AKT1, and PPARG. The findings suggest that D. alata's bioactive compounds, such as Diosgenin, Daidzein, Genistin, Cycloartane, and Alatanin, could modulate pathways involved in ovarian follicle formation, hormone regulation, estrogen receptor signaling, and the stress-activated MAP kinase pathway. This study provides new insights into the multi-target potential of D. alata for treating menstrual disorders, supporting further investigation and therapeutic development.

Genetic parameter estimates and selection gain for multiple traits in white Guinea yam (Dioscorea rotundata) in Ghana

Quantifying selection gains enables a more targeted assessment of breeding program effectiveness, highlighting opportunities for strategic improvement and optimized genetic advancement in white Guinea Yam. This study assessed genetic parameters and gain for key traits in a white Guinea yam (D. rotundata) breeding population. A total of 81 genotypes were evaluated for two seasons using a 9 × 9 lattice design with three replicates. Data was collected on yam mosaic virus disease severity, tuber yield and tuber dry content for genetic analysis. Broad sense heritability was generally high (> 60) for most of the traits. At the same time, the corresponding genetic advance as a percentage of the mean was exceptionally high (30.28-93.96%) for tuber yield, tuber flesh oxidation, average tuber weight and number of tubers per plant, suggesting additive genetic effects. A multi-trait selection index of the 5% highest performing genotypes revealed positive genetic gain for plant vigour, tuber length, and width, tuber weight per plant, average tuber weight and fresh tuber yield. The genetic gain was, however, negative for tuber dry matter content compared to the check varieties, necessitating a modification of the current breeding scheme such that post-harvest food quality is not sacrificed for tuber yield. Ranking of the breeding lines based on the multi-trait selection index identified four lines (TDr1700004_014, TDr1700004_113, TDr1700001_112 and TDr1700002_090) with high genetic merits for all the economic traits. These lines can be used as potential trait progenitors and evaluated further for possible release as new varieties. Our results decipher the genetic control and provide an overview of the performance of the breeding program for key traits in white Guinea yam.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10681-025-03467-x.

Haplotype-resolved genome and population genomics provide insights into dioscin biosynthesis and evolutionary history of the medicinal species Dioscorea nipponica

Dioscorea nipponica, a perennial herb widely distributed in the Sino-Japanese Floristic Region, is renowned for its medicinal properties, particularly its ability to produce dioscin. Here, we present a haplotype-resolved genome assembly of the diploid D. nipponica, comprising 511.41 Mb for Haplotype A and 498.29 Mb for Haplotype B, each organized into 10 chromosomes. The two haplotypes exhibited high similarity, with only 2.75% of the allelic genes exhibiting specific expression. Key genes in the dioscin biosynthesis pathway were identified, and expression analysis revealed that the majority (16/21) of genes involved in the first two stages were highly expressed in rhizomes. Notably, significant expansion of the CYP90, CYP94, and UGT73 gene families was observed in dioscin-producing species, highlighting their critical roles in dioscin biosynthesis. Additionally, genome size estimation and population genomic analyses of diverse D. nipponica accessions identified four principal clades in D. nipponica, corresponding to diploid, di-tetra-octoploid, tetraploid, and hexaploid accessions from various geographic regions, with clade A (diploids) further divided into five subclades. Demographic analysis of the diploid D. nipponica revealed a prolonged decline in effective population size from the Pleistocene to the Last Glacial Maximum, with population splits occurring during the mid-to-late Pleistocene. Selective sweep analysis identified key genes, including HD-Zip I, ADH1, SMT1, and CYPs that may contribute to adaptation to high-latitude environments and the geographical variations in dioscin content. Overall, this study enhances our understanding of the genomic architecture, biosynthetic pathways, and evolutionary dynamics of D. nipponica, providing valuable insights into its medicinal potential and evolution.

Utility Assessment of Isolated Starch and Extract from Thai Yam (Dioscorea hispida Dennst.) for Cosmetic via In Vitro and In Vivo Studies

In Thailand, wild yam, or Dioscorea hispida Dennst., is a starchy crop that is usually underutilized in industry. The purpose of this study was to isolate the starch and extract the phytochemical from D. hispida and use them in cosmetics. Starch was used instead of talcum, which can cause pulmonary talcosis in dusting powder formulas (DP 1-5). GC-MS was used to identify the bioactive components present in the ethanolic extract of D. hispida. The main compounds were identified as 9,12-octadecadienoic acid (Z,Z)- (6.51%), stigmasta-5,22-dien-3-ol, (3.beta.,22E)- (6.41%), linoleic acid ethyl ester (5.72%), (Z,Z)-9,12-octadeca-dienoic acid, 2,3-dihydroxy-propyl (3.89%), and campesterol (3.40%). Then, the extract was used as an ingredient in facial sleeping mask gel formulas (SM 1-SM 5). Stability tests, physical characteristics, enzyme inhibitions, and sensitization dermal toxicity tests were used to evaluate the DP and SM formulations. The results showed that the fresh tubers of D. hispida showed a 12.5% w/w starch content. The findings demonstrated that starch powder had a restricted size distribution, ranging from 2 to 4 μm, and a smooth surface that was polygonal. Following stability testing, the color, odor, size, and flowability of all DP formulations did not significantly differ. The SEM investigation revealed that DP particles were homogenous. For the sensitization dermal toxicity test, DP denoted no erythema or skin irritation in the guinea pigs. After stability testing, the colors of the SM formulas were deeper, and their viscosity slightly increased. The pH did not significantly change. After the stability test, SM formulas that contained Glycyrrhiza glabra and D. hispida extracts exhibited stable tyrosinase and elastase inhibitory activities, respectively. In the sensitization dermal toxicity test, guinea pigs showed skin irritation at level 2 (not severe) from SM, indicating that redness developed. All of these findings indicate that D. hispida is a plant that has potential for use in the cosmetics industry. Furthermore, D. hispida starch can be made into a beauty dusting powder, and more research should be conducted to develop an effective remedy for patients or those with skin problems.

Anti-Inflammatory and Prebiotic Potential of Ethanol Extracts and Mucilage Polysaccharides from Korean Yams (Dioscorea polystachya and Dioscorea bulbifera)

Korean yams are abundant in bioactive compounds with significant health-promoting properties. This study evaluated the anti-inflammatory potential of ethanol and water extracts from Dioscorea polystachya and Dioscorea bulbifera in RAW 264.7 macrophage cells. Among the extracts, the 95% ethanol extract exhibited the most potent inhibition of reactive oxygen species (ROS) and nitric oxide (NO) production, warranting further exploration of its mechanisms of action. Further analysis revealed that the ethanol extract modulated key inflammatory signaling pathways, including MAPK and NF-κB, contributing to its anti-inflammatory activity. Additionally, mucilage polysaccharides, a key bioactive component of Korean yams, were extracted and characterized for their structural and functional properties. These polysaccharides demonstrated immune-enhancing effects by reducing ROS and NO production while increasing phagocytic activity in the RAW 264.7 cells. Their prebiotic potential was also assessed through microbial growth assays, which showed an enhanced proliferation of beneficial bacteria such as Lactobacillus and Bifidobacterium. Furthermore, the adhesion assays using Caco-2 intestinal epithelial cells revealed that these polysaccharides promoted probiotic adhesion while inhibiting the adhesion of pathogenic bacteria. These findings highlight the bioactive potential of ethanol extracts and mucilage polysaccharides from Korean yams, emphasizing their promising applications as anti-inflammatory, immune-modulating, and prebiotic agents for functional food and nutraceutical development.

Plant-Based Functional Foods from Borneo

Borneo, the third-largest island in the world, is shared between Malaysia (Sabah and Sarawak), Indonesia (Kalimantan) and Brunei. As a biodiversity hotspot, it is home to about 15,000 flowering plants and 3000 tree species, of which many are endemic to the region. Locally derived plant-based foods are gaining popularity due to their lower environmental impact, contribution to food sustainability and health benefits. The local fruits and vegetables of Borneo have been used traditionally by the indigenous community for medicinal purposes. This community knowledge can provide a valuable guide to their potential for use as functional foods. This review explores the contemporary foods from Borneo, including fruit, vegetables, seaweeds and plant-derived food products that are locally consumed. The findings show that the unique tropical food groups have a wide diversity of phytochemical compositions that possess a wide array of biological activities including anti-inflammatory, antioxidant, anti-microbial, anti-proliferative, anti-fungal, wound healing and expectorant properties. The wide range of plant-based foods in Borneo deserves further development for wider applications as functional foods.

Ethnobotany, Phytochemistry, and Pharmacological Activity of Dioscorea bulbifera: A Comprehensive Review

Dioscorea bulbifera (Family: Dioscoreaceae) also referred to as 'Air potato,' carries significant importance in the traditional medicine of China, West Africa and India. It is a common ingredient in numerous herbals and Ayurvedic formulations used to treat a variety of ailments. The literature review extensively examined the historical usage, phytoconstituents, characterisation of phytoconstituents, and medicinal uses of tubers, leaves, rhizomes and bulbils, with a particular focus on comparing research findings. Among the bioactive constituents, aglycone forms of steroidal saponins such as dioscorine, dioscin, diosbulbins, and diosgenin exhibit significant biological activities. Extracts from different parts of the plant exhibited pharmacological activities like anti-viral, anti-malarial, analgesic, antidiabetic, and anticancer. It is necessary to conduct an in-depth investigation to bridge between traditional knowledge and scientific evidence. This comprehensive review aims to provide a detailed understanding of the ethnobotany, phytoconstituent, chemical characterization and pharmacological potential of D. bulbifera, highlighting its prospects and challenges for future research and medicinal application.

Evaluation of selected minerals and health risk and proximate analysis of wasawasa (a street food)

This study was carried out to determine the proximate composition and the potential heavy metal health risk that may be associated with the consumption of wasawasa, a dish made from locally milled yam peels, by examining the presence of six metals (iron, nickel, chromium, sodium, and magnesium and potassium) in samples procured. Sixteen (16) samples of ready-to-eat wasawasa were collected from Aboabo, Manhyia, Sawaba, Asawase, Adenyase, and Ayigya in Kumasi, since these are the communities where wasawasa is mainly produced, sold, and consumed. The samples were digested with a nitric, perchloric, and sulfuric acid mixture and analyzed using a microwave plasma atomic emission spectrometer (Agilent 4210 MP-AES). The average concentrations of metals were Na (8506.88 mg/kg), Mg (222.63 mg/kg), Fe (84.45 mg/kg), Cr (2.31 mg/kg), K (1702.08 mg/kg, and Ni (1.12 mg/kg). Proximate analysis was used to determine Protein, fat, ash, moisture, and fiber content of the local wasawasa, which were found to be 15.667 %, 0.45 %, 1.00 %, 27.54 %, and 0.41 %, respectively. The hazard index of the heavy metals (Fe, Ni and Cr) for both adults and children were each greater than one, indicating the population is likely to experience non-carcinogenic effects from the consumption of wasawasa.

Underutilized crops for diverse, resilient and healthy agri-food systems: a systematic review of sub-Saharan Africa

Sub-Saharan Africa (SSA) faces increasing water scarcity, food and nutrition insecurity, poverty and inequality under climate change. Under these circumstances, promoting locally adapted and nutrient-dense crops is touted as a plausible climate adaptation strategy. We reviewed the utility of neglected and underutilized crop species (NUS) as a climate change adaptation strategy to diversify local food systems and diets and improve nutritional health and environmental outcomes in SSA. We conducted a systematic literature review using Web of Science and Scopus research databases. Of the 1,545 studies retrieved, 75 were included following a multi-level screening process on Covidence guided by the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The review consolidates fragmented knowledge on the application of NUS in different contexts. Despite growing interest, NUS remain gendered and stigmatized crops, marginalized and fragmented in research, development, and marketing efforts and lack explicit support from policy and decision-makers. Despite rhetoric purporting to support them, there is a worrying rise in policies and regulations that inadvertently hinder the development of these crops and reinforce dependence on a narrow basket of crops for food and nutrition security, undermining food sovereignty. Some NUS have received increasing recognition for their potential in the past decade. However, this is neither universal nor systematic, which makes scaling up necessary but challenging. Consequently, progress in mainstreaming NUS in local food systems continues to lag. Despite these challenges, NUS remain sub-Saharan Africa's better-bet option for diversifying food systems and transitioning them to be equitable, inclusive, resilient and healthy; hence, NUS provide positive outcomes for people and the planet under climate change.

Trends in Plants Phytochemistry and Bioactivity Analysis

Biologically active compounds, derived from various natural sources, have garnered significant attention due to their potential therapeutic applications [...].

A Review of Medicinal Plants Used in the Management of Microbial Infections in Angola

The use of medicinal plants in the management of microbial infections is significant to the health of the indigenous people in many Angolan communities. The present study provides a comprehensive overview of medicinal plants used for the management of microbial infections in Angola. Relevant information was extracted from research articles published and associated with the use of medicinal plants in the management of microbial infections in Angola (from January 1976 to November 2023). Data or information were gathered from the literature sourced from Wiley Online, SciFinder, Google Scholar, Web of Science, Scopus, ScienceDirect, BMC, Elsevier, SpringerLink, PubMed, books, journals and published M.Sc. and Ph.D. thesis. A total of 27 plant species, representing 19 families, were recorded in this study. Hypericaceae (11%), Lamiaceae (11%), Malvaceae (11%), Phyllanthaceae (11%), Fabaceae (16%) and Rubiaceae (16%) were the most predominant families. The leaves are the most used parts (96%), followed by bark (74%) and root (70%). The data revealed that medicinal plants continue to play significant roles in the management of microbial infections in Angola. In order to explore the benefits of the therapeutic potential of indigenous medicinal plants for diseases related to infections; further scientific research studies are important to produce data on their effectiveness using appropriate test models. This approach might assist with the continuing drive regarding the integration of Angolan traditional medicine within mainstream healthcare systems.

Yam Carbon Dots Promote Bone Defect Repair by Modulating Histone Demethylase 4B

Introduction

Chronic apical periodontitis is a typical inflammatory disease of the oral cavity, the pathology is characterized by an inflammatory reaction with bone defects in the periapical area. Chinese medicine is our traditional medicine, Carbon Dots (CDs) are a new type of nanomaterials. The purpose of this study was to prepare Yam Carbon Dots (YAM-CDs) to investigate the mechanism of action of YAM-CDs on bone differentiation in vivo and in vitro.

Methods

We characterized YAM-CDs using transmission electron microscopy (TEM), Fourier Transform Infrared Spectrometer (FTIR), X-Ray Diffraction (XRD) and photoluminescence (PL). CCK-8 assay, Real-time qPCR, and Western Blot were conducted using bone marrow mesenchymal stem cells (BMSCs) to verify that YAM-CDs promote osteoblast differentiation. In addition, we investigated the role of YAM-CDs in promoting bone formation in an inflammatory setting in an in vivo mouse model of cranial defects.

Results

The results of TEM and PL showed that the YAM-CDs mostly consisted of the components C1s, O1s, and N1s. Additionally the average sizes of YAM-CDs were 2-6 nm. The quantum yield was 4.44%, with good fluorescence stability and biosafety. Real-time qPCR and Western blot analysis showed that YAM-CDs promoted osteoblast differentiation under an inflammatory environment by regulating expression of histone demethylase 4B (KDM4B). In vivo, results showed that YAM-CDs effectively repaired cranial bone defects in a mouse model and reduced the expression of inflammatory factors under the action of lipopolysaccharides (LPS).

Conclusion

YAM-CDs promoted the proliferation and differentiation of osteoblasts by regulating the expression of KDM4B to repair cranial bone defects in mice under an LPS-induced inflammatory milieu, which will provide a new idea for the treatment of clinical periapical inflammation and other bone defect diseases.

Aqueous extracts from Dioscorea sansibarensis Pax show cytotoxic and radiosensitizing potential in 3D growing HPV-negative and HPV-positive human head and neck squamous cell carcinoma models

Numerous natural substances have anti-cancer properties. Especially indigenous people use aqueous plant extracts for tea or ointments including Dioscorea sansibarensis Pax to treat various diseases. The aim of this study was to evaluate the cytotoxic and radiosensitizing potential of aqueous extracts from Dioscorea sansibarensis Pax collected from Kenya in a panel of HPV-negative and -positive head and neck squamous cell carcinoma (HNSCC) cells grown in three-dimensional laminin-rich extracellular matrix (3D lrECM). The results show cytotoxicity, radiosensitization and increased levels of residual double strand breaks (DBS) by Dioscorea sansibarensis Pax extracts in HPV-negative and -positive HNSCC models in a concentration- and cell model-dependent manner. Application of ROS scavengers indicated an association between ROS-induced DSB and radiosensitization through Dioscorea sansibarensis Pax pretreatment. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) based characterization of Dioscorea sansibarensis Pax identified the main components of the extract including camptothecin. Overall, Dioscorea sansibarensis Pax aqueous extracts alone and in combination with X-ray irradiation showed effective anticancer properties, which are worthy of further mechanistic investigation.

Investigating the impact of ultrasound on the structural, physicochemical, and emulsifying characteristics of Dioscorin: Insights from experimental data and molecular dynamics simulation

This study investigated the impact of ultrasound treatment on dioscorin, the primary storage protein found in yam tubers. Three key factors, namely ultrasound power, duration, and frequency, were focused on. The research revealed that ultrasound-induced cavitation effects disrupted non-covalent bonds, resulting in a reduction in α-helix and β-sheet contents, decreased thermal stability, and a decrease in the apparent hydrodynamic diameter (Dh) of dioscorin. Additionally, previously hidden amino acid groups within the molecule became exposed on its surface, resulting in increased surface hydrophobicity (Ho) and zeta-potential. Under specific ultrasound conditions (200 W, 25 kHz, 30 min), Dh decreased while Ho increased, facilitating the adsorption of dioscorin molecules onto the oil-water interface. Molecular dynamics (MD) simulations showed that at lower frequencies and pressures, the structural flexibility of dioscorin's main chain atoms increased, leading to more significant fluctuations between amino acid residues. This transformation improved dioscorin's emulsifying properties and its oil-water interface affinity.

Phytoecdysteroids from Dioscorea dumetorum (Kunth) Pax. and their antioxidant and antidiabetic activities

Diabetes is a significant global health challenge, affecting circa 540 million adults worldwide. Dioscorea dumetorum, a Nigerian folkloric antidiabetic plant is severely understudied in terms of its bioactive phytochemical constituents. Antidiabetic guided isolation of the tubers and peels of D. dumetorum afforded three phytoecdysteroids bearing a cis-fused A/B ring junction including two new ones: 24-hydroxymuristerone A (1) and 24-hydroxykaladasterone (2), alongside the known muristerone A (3). Additionally, 2,2',7,7'-tetramethoxy-[1,1'-biphenanthrene]-4,4',6,6'-tetraol (4), batatasin I (5), and dihydroresveratrol (6) were isolated. Structural elucidation relied on spectroscopic, spectrometric methods, and comparison with existing literature. The ethyl acetate extracts of both the tubers and peels of D. dumetorum exhibited the highest phenolic content, correlating with potent antioxidant activity. Compounds 4 (IC50 = 0.10 mg/mL) and 6 (IC50 = 0.22 mg/mL) demonstrated superior inhibitory effects against α-glucosidase compared to acarbose (IC50 = 0.63 mg/mL). In contrast, compounds 3, 4, and 5 showed reduced α-amylase inhibition, with IC50 values of 2.58, 3.78, and 1.12 mg/mL, respectively, compared to acarbose (IC50 = 0.42 mg/mL). These observed bioactivities validate the traditional use of D. dumetorum and contribute valuable phytochemical data to the scientific literature of the species.

Modelling convectional oven drying characteristics and energy consumption of dehydrated yam (Dioscorea rotundata) chips

The influence of pre-treatments and different dehydrating temperatures on the drying dynamics, energy consumption, and quality attribute of yam chips was studied. Dehydration was executed employing a convectional oven dryer under four temperatures (50, 60, 70, and 80 °C) and 2.0 m/s air velocity. Yam chips were subjected to pre-treatment conditions of blanching (for 1, 2, 3, 4, and 5 min), citric acid (1 and 5 %), and ascorbic acid (1 and 5 %) solutions whereas, untreated yam chips samples served as the control. Dehydrated yam chips were further assessed for textural and colour properties. The drying rate was found to be faster at a higher temperature of 80 °C compared to lower temperatures of 50, 60, and 70 °C. The asymptotic model was established to be the suitable descriptive model for predicting moisture profile in the pre-treated yam chips based on highest R2 values (0.995-0.999), lowest χ2 values (4.422-18.498), and the root mean square error (RMSE) values (2.103-4.30). Pre-treatment and drying temperature had a significant (p < 0.05) impact on the hardness and colour of dehydrated yam chips. Blanching at 4 min yielded yam chips with most preferred texture (hardness: 81.3 N) and lightness (L*) in colour values (71.07 %) after drying compared to other pre-treated samples. The effective moisture diffusivity values of the pre-treated samples were in the range of 5.17294 × 10-9m2/s to 1.10143 × 10-8m2/s for 5 % citric acid samples at 50 °C and all pre-treated samples at 80 °C respectively. The general findings of the study indicated a least energy usage of 43.68 kWh as a cost-effective method of drying. Also, 4 min blanching, 5 % citric acid, and 1 % ascorbic acid at 80 °C were found to be the optimum conditions for pre-treating yam chips based on lower energy level consumption rates and improved sensory properties thus attributing to the quality of the dried yam chips.

The Pros and Cons of Estrogens in Prostate Cancer: An Update with a Focus on Phytoestrogens

The role of estrogens in prostate cancer (PCa) is shrouded in mystery, with its actions going from angelic to devilish. The findings by Huggins and Hodges establishing PCa as a hormone-sensitive cancer have provided the basis for using estrogens in therapy. However, despite the clinical efficacy in suppressing tumor growth and the panoply of experimental evidence describing its anticarcinogenic effects, estrogens were abolished from PCa treatment because of the adverse secondary effects. Notwithstanding, research work over the years has continued investigating the effects of estrogens, reporting their pros and cons in prostate carcinogenesis. In contrast with the beneficial therapeutic effects, many reports have implicated estrogens in the disruption of prostate cell fate and tissue homeostasis. On the other hand, epidemiological data demonstrating the lower incidence of PCa in Eastern countries associated with a higher consumption of phytoestrogens support the beneficial role of estrogens in counteracting cancer development. Many studies have investigated the effects of phytoestrogens and the underlying mechanisms of action, which may contribute to developing safe estrogen-based anti-PCa therapies. This review compiles the existing data on the anti- and protumorigenic actions of estrogens and summarizes the anticancer effects of several phytoestrogens, highlighting their promising features in PCa treatment.

Prospects of yam (Dioscorea) polysaccharides: Structural features, bioactivities and applications

Yam (Dioscorea) is a tuber crop cultivated for food security, revenue, and medicinal purposes. It has been used to treat diabetes, asthma, diarrhea, and other diseases. The main active ingredients in yam, polysaccharides, are regarded to be the important reason for its widespread applications. Now, a comprehensive review of research developments of yam polysaccharides (YPs) was presented to explore their prospects. We outlined the structural characteristics, biological activities, structure-activity relationships, and potential applications. Around 13 neutral components and 17 acidic components were separated. They exhibited various bioactivities, including immunomodulatory, hypoglycemic, hypolipidemic, antioxidant, gastrointestinal protective, anti-fatigue, and senile disease treatment activities, as well as prebiotic effect. Structure-activity relationships illustrated that unique structural properties, chemical modifications, and carried biopolymers could influence the bioactivities of YPs. The potential applications in medicine, food, and other fields have also been summarized.

Unambiguous Characterization of Commercial Natural (Dihydro)phenanthrene Compounds Is Vital in the Discovery of AMPK Activators

These days, easy access to commercially available (poly)phenolic compounds has expanded the scope of potential research beyond the field of chemistry, particularly in the area of their bioactivity. However, the quality of these compounds is often overlooked or not even considered. This issue is illustrated in this study through the example of (dihydro)phenanthrenes, a group of natural products present in yams, as AMP-activated protein kinase (AMPK) activators. A study conducted in our group on a series of compounds, fully characterized using a combination of chemical synthesis, NMR and MS techniques, provided evidence that the conclusions of a previous study were erroneous, likely due to the use of a misidentified commercial compound by its supplier. Furthermore, we demonstrated that additional representatives of the (dihydro)phenanthrene phytochemical classes were able to directly activate AMPK, avoiding the risk of misinterpretation of results based on analysis of a single compound alone.

Resistant starch from yam: Preparation, nutrition, properties and applications in the food sector

Yam is a significant staple food and starch source, particularly in tropical and subtropical regions, holding the fourth position among the world's top ten tuber crops. Yam tubers are rich in essential nutrients and a diverse range of beneficial plant compounds, which contribute to their multifaceted beneficial functions. Furthermore, the abundant starch and resistant starch (RS) content in yam can fulfil the market demand for RS. The inherent and modified properties of yam starch and RS make them versatile ingredients for a wide range of food products, with the potential to become one of the most cost-effective raw materials in the food industry. In recent years, research on yam RS has experienced progressive expansion. This article provides a comprehensive summary of the latest research findings on yam starch and its RS, elucidating the feasibility of commercial RS production and the technology's impact on the physical and chemical properties of starch. Yam has emerged as a promising reservoir of tuber starch for sustainable RS production, with thermal, chemical, enzymatic and combination treatments proving to be effective manufacturing procedures for RS. The adaptability of yam RS allows for a wide range of food applications.

Genome-wide association analysis and transgenic characterization for amylose content regulating gene in tuber of Dioscorea zingiberensis

BACKGROUND

Amylose, a prebiotic found in yams is known to be beneficial for the gut microflora and is particularly advantageous for diabetic patients' diet. However, the genetic machinery underlying amylose production remains elusive. A comprehensive characterization of the genetic basis of amylose content in yam tubers is a prerequisite for accelerating the genetic engineering of yams with respect to amylose content variation.

RESULTS

To uncover the genetic variants underlying variation in amylose content, we evaluated amylose content in freshly harvested tubers from 150 accessions of Dioscorea zingibensis. With 30,000 high-quality single nucleotide polymorphisms (SNP), we performed a genome-wide association analysis (GWAS). The population structure analysis classified the D. zingiberensis accessions into three groups. A total of 115 significant loci were detected on four chromosomes. Of these, 112 significant SNPs (log10(p) = 5, q-value < 0.004) were clustered in a narrow window on the chromosome 6 (chr6). The peak SNP at the position 75,609,202 on chr6 could explain 63.15% of amylose variation in the population and fell into the first exon of the ADP-glucose pyrophosphorylase (AGPase) small subunit gene, causing a non-synonymous modification of the resulting protein sequence. Allele segregation analysis showed that accessions with the rare G allele had a higher amylose content than those harboring the common A allele. However, AGPase, a key enzyme precursor of amylose biosynthesis, was not expressed differentially between accessions with A and G alleles. Overexpression of the two variants of AGPase in Arabidopsis thaliana resulted in a significantly higher amylose content in lines transformed with the AGPase-G allele.

CONCLUSIONS

Overall, this study showed that a major genetic variant in AGPase probably enhances the enzyme activity leading to high amylose content in D. zingiberensis tuber. The results provide valuable insights for the development of amylose-enriched genotypes.

In situ dynamic rheological analysis of raw yam tubers: a potential phenotyping tool for quality evaluation

BACKGROUND

Most rheological analyses in yam have been done on starch gels, which requires starch extraction from the tubers. In situ rheology bypasses the need of starch extraction and relies on the original cell structure and complex matrix organization under stress or strain. Dynamic rheological properties of tuber from 16 accessions belonging to four yam species (Dioscorea rotundata, D. alata. D. bulbifera and D. dumetorum) were investigated for potential use as a medium throughput phenotyping screening tool that can indicate the quality of yam food products or their industrial potentials.

RESULTS

Rheographs of the tubers illustrated differences in the structure of D. bulbifera compared to other yam species. High initial storage modulus (G') of yam parenchyma indicated tubers with strong and rigid structure which do not lose their structural integrity easily on heating. Dioscorea rotundata and D. alata varieties exhibited a lower temperature at which gelatinization took place (Tgel) equivalent to the irreversible transition during starch gelatinization (75.3 and 79.8 °C) and took shorter time (867 and 958 s, respectively) to reach the G' maximum, compared to other species. The stress relaxation test showed that the higher the dry matter of the tubers, the higher the work to rupture the structure.

CONCLUSION

Rheological characteristics G', loss modulus (G″), swelling capacity and Tgel showed potential as suitable quality indicators for yam products. In situ rheological characterization of yam tubers could be used as an instrumental screening tool to phenotype for quality in yam products. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

An overview on pharmacological significance, phytochemical potential, traditional importance and conservation strategies of Dioscorea deltoidea: A high valued endangered medicinal plant

Dioscorea deltoidea Wall. ex Griseb. is an endangered species of the Dioscoreaceae family. It is the most commonly consumed wild species as a vegetable due to its high protein, vital amino acid, vitamin, and mineral content. There are approximately 613 species in the genus Dioscorea Plum. ex L., which is found in temperate and tropical climates. Dioscorea deltoidea, a plant species widespread across tropical and sub-tropical regions, called by different names in different languages. In English, it is commonly referred to as "Wild yam" or "Elephant foot". The Sanskrit name for this plant is "Varahikand," while in Hindi, it is known as "Gun" or "Singly-mingly." The Urdu language refers to it as "Qanis," and in Nepali, it is called "Tarul," "Bhyakur," or "Ghunar." Dioscorea deltoidea has been used to cure a wide range of human ailments for centuries. This plant has nutritional and therapeutic uses and also contains high amounts of steroidal saponins, allantoin, polyphenols, and most notably, polysaccharides and diosgenin. These bioactive chemicals have shown potential in providing protection against a wide spectrum of inflammatory conditions, including enteritis (inflammation of the intestines), arthritis (joint inflammation), dermatitis (skin inflammation), acute pancreatitis (inflammation of the pancreas), and neuro inflammation (inflammation in the nervous system). Furthermore, the valuable bioactive chemicals found in D. deltoidea have been associated with a range of beneficial biological activities, such as antibacterial, antioxidant, anti-inflammatory, immunomodulatory, hepatoprotective, and cytotoxic properties. Sapogenin steroidal chemicals are highly valued in the fields of medicine, manufacturing, and commerce. It has both expectorant and sedative properties. It is employed in the treatment of cardiovascular diseases, encompassing various ailments related to the heart and blood vessels, skin disease, cancer, immune deficiencies, and autoimmune diseases. Additionally, it finds application in managing disorders of the central nervous system and dysfunctional changes in the female reproductive system. Furthermore, it is valued for its role in treating bone and joint diseases. Metabolic disorders are also among the ailments for which D. deltoidea is employed. It has traditionally been used as a vermifuge, fish poison, and to kill lice. Diosgenin, a steroidal compound found in D. deltoidea, plays a crucial role as a precursor in the chemical synthesis of various hormones. Due to the presence of valuable bioactive molecule, like corticosterone and sigmasterol, D. deltoidea is cultivated specifically for the extraction of these beneficial phytochemicals. The current study aims to assess D. deltoidea's medicinal properties, ethnobotanical usage, phytochemicals, pharmacological properties, threats, and conservation techniques.

Chemical, structural, and techno-functional characterization of yam (Dioscorea) flour from South West Ethiopia

Yam (Dioscorea spp.) is a versatile tuber crop that holds nutritional, cultural, and economic values. Yam is a major source of carbohydrates for tropical Countries and provides various nutrients and health benefits. This study aims to characterize the chemical, structural, and thermal properties of yam flour using various analytical techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermal analysis. Additionally, the pasting and rheological properties of yam flour were evaluated, as they are crucial for product development and enhancing the value of this unconventional vegetable. D. cayenensis complex had the highest total starch (64.63 ± 1.61 %) and soluble sugar (4.95 ± 0.46 %) content, which was significantly higher than other yam species. The amylose content of yam flours showed significant (p < 0.05) differences among the yam species. D. cayenensis flour exhibited significantly the highest peak (2923.66 cP) and steak back viscosity (2097.66 cP) among the yam species associated with their greater amylose content. There were notable variations in pasting and gelatinization parameters among the species. The peak temperatures of D. bulbifera and D. cayenensis complex were significantly (p < 0.05) higher than D. cayenensis and D. rotundata flours. The rheological measurements of yam flours demonstrated solid-like behavior with varying intensities. Furthermore, the morphology of tuber yam flour particles was oval to ellipsoidal shaped, with some appearing ovoid, and the smaller granules appearing spherical. The X-ray diffraction showed that all yam flours exhibit a B-type pattern. This study provide a better understanding of this unconventional vegetable's potential applications in the food industry and contribute to its value addition.

Development and Application of an Atomic Absorption Spectrometry-Based Method to Quantify Magnesium in Leaves of Dioscorea polystachya

The Chinese yam (Dioscorea polystachya, DP) is known for the nutritional value of its tuber. Nevertheless, DP also has promising pharmacological properties. Compared with the tuber, the leaves of DP are still very little studied. However, it may be possible to draw conclusions about the plant quality based on the coloration of the leaves. Magnesium, as a component of chlorophyll, seems to play a role. Therefore, the aim of this research work was to develop an atomic absorption spectrometry-based method for the analysis of magnesium (285.2125 nm) in leaf extracts of DP following the graphite furnace sub-technique. The optimization of the pyrolysis and atomization temperatures resulted in 1500 °C and 1800 °C, respectively. The general presence of flavonoids in the extracts was detected and could explain the high pyrolysis temperature due to the potential complexation of magnesium. The elaborated method had linearity in a range of 1-10 µg L-1 (R2 = 0.9975). The limits of detection and quantification amounted to 0.23 µg L-1 and 2.00 µg L-1, respectively. The characteristic mass was 0.027 pg, and the recovery was 96.7-102.0%. Finally, the method was applied to extracts prepared from differently colored leaves of DP. Similar magnesium contents were obtained for extracts made of dried and fresh leaves. It is often assumed that the yellowing of the leaves is associated with reduced magnesium content. However, the results indicated that yellow leaves are not due to lower magnesium levels. This stimulates the future analysis of DP leaves considering other essential minerals such as molybdenum or manganese.

Discrimination of Dioscorea species (Chinese yam) using FT-IR integrated with chemometric approach

Dioscorea oppositifolia is an important crop and functional food. D. oppositifolia tuber is often adulterated with D. persimilis, D. alata, and D. fordii tuber in the commercial market. This study proposed an integrated Fourier transform infrared spectroscopy (FT-IR) with chemometric approach to differentiate these four Dioscorea species. A total of 107 Dioscorea spp. tuber samples were collected from different locations in China. Principal Component Analysis (PCA), PCA-Class, and Orthogonal Partial Least Square Discriminant Analysis (OPLS-DA) were utilised to classify the FT-IR spectra. In this PCA is unable to differentiate the Dioscorea spp. tuber effectively. However, PCA-Class and OPLS-DA can distinguish spp. these 4 species Dioscorea tuber with high accuracy, sensitivity, and specificity. Additionally, the RMSEE, RMSEP and RMSECV values for OPLS-DA model were low, showing that it is a good model. The combination of FT-IR with the PCA-Class and OPLS-DA is practical in discriminating Dioscorea spp. tubers.

Intraspecific phylogeny and genomic resources development for an important medical plant Dioscorea nipponica, based on low-coverage whole genome sequencing data

Dioscorea nipponica Makino, a perennial twining herb with medicinal importance, has a disjunctive distribution in the Sino-Japanese Floristic Region. It has a long history in traditional Chinese medicine, with demonstrated efficacy against various health conditions. However, the limited genomic data and knowledge of genetic variation have hindered its comprehensive exploration, utilization and conservation. In this study, we undertook low-coverage whole genome sequencing of diverse D. nipponica accessions to develop both plastome (including whole plastome sequences, plastome-derived SSRs and plastome-divergent hotspots) and nuclear genomic resources (including polymorphic nuclear SSRs and single-copy nuclear genes), as well as elucidate the intraspecific phylogeny of this species. Our research revealed 639 plastome-derived SSRs and highlighted six key mutational hotspots (namely CDS ycf1, IGS trnL-rpl32, IGS trnE-trnT, IGS rps16-trnQ, Intron 1 of clpP, and Intron trnG) within these accessions. Besides, three IGS regions (i.e., ndhD-cssA, trnL-rpl32, trnD-trnY), and the intron rps16 were identified as potential markers for distinguishing D. nipponica from its closely related species. In parallel, we successfully developed 988 high-quality candidate polymorphic nuclear SSRs and identified 17 single-copy nuclear genes for D. nipponica, all of which empower us to conduct in-depth investigations into phylogenetics and population genetics of this species. Although our phylogenetic analyses, based on plastome sequences and single-copy nuclear genes revealed cytonuclear discordance within D. nipponica, both findings challenged the current subspecies classification. In summary, this study developed a wealth of genomic resources for D. nipponica and enhanced our understanding of the intraspecific phylogeny of this species, offering valuable insights that can be instrumental in the conservation and strategic utilization of this economically significant plant.

Ecogeography of Dioscorea remotiflora Kunth: An Endemic Species from Mexico

Dioscorea remotiflora, a perennial climbing herbaceous plant native to Mexico, produces tubers with great nutritional and ethnobotanical value. However, most ecological aspects of this plant remain unknown, which limits its cultivation and use. This is why the objective of this research was to characterize the ecogeography of D. remotiflora as a source to determine its edaphoclimatic adaptability and current and potential distribution. A comprehensive database encompassing 480 geo-referenced accessions was assembled from different data sources. Using the Agroclimatic Information System for México and Central America (SIAMEXCA), 42 environmental variables were formulated. The MaxEnt model within the Kuenm R package was employed to predict the species distribution. The findings reveal a greater presence of D. remotiflora in harsh environments, characterized by arid to semiarid conditions, poor soils, and hot climates with long dry periods. Niche modeling revealed that seven key variables determine the geographical distribution of D. remotiflora: precipitation of the warmest quarter, precipitation of the driest month, minimum temperature of the coldest month, November-April solar radiation, annual mean relative humidity, annual moisture availability index, and May-October mean temperature. The current potential distribution of D. remotiflora is 428,747.68 km2. Favorable regions for D. remotiflora coincide with its current presence sites, while other suitable areas, such as the Yucatán Peninsula, northeast region, and Gulf of Mexico, offer potential expansion opportunities for the species distribution. The comprehensive characterization of Dioscorea remotiflora, encompassing aspects such as its soil habitats and climate adaptation, becomes essential not only for understanding its ecology but also for maximizing its economic potential. This will enable not only its sustainable use but also the exploration of commercial applications in sectors such as the pharmaceutical and food industries, thus providing a broader approach for its conservation and optimal utilization in the near future.

Agronomic and hormonal approaches for enhancing flowering intensity in white Guinea yam (Dioscorea rotundata Poir.)

Developing novel white Guinea yam (Dioscorea rotundata) varieties is constrained by the sparse, erratic, and irregular flowering behavior of most genotypes. We tested the effectiveness of nine agronomic and hormonal treatments to enhance flowering on D. rotundata under field conditions. Genotypes responded differently to flower-inducing treatments (p<0.001). Of the test treatments, pruning and silver thiosulfate (STS) were effective in increasing the number of spikes per plant and the flowering intensity on both sparse flowering and monoecious cultivars. STS and tuber removal treatments promoted female flowers on the monoecious variety while pruning and most treatments involving pruning favored male flowers. None of the treatments induced flowering on Danacha, a non-flowering yam landrace. Flower-enhancing treatments had no significant effect on flower fertility translated by the fruit set, since most treatments recorded fruit sets above the species' average crossability rate. Flower-enhancing techniques significantly influenced number of tubers per plant (p = 0.024) and tuber dry matter content (DMC, p = 0.0018) but did not significantly affect plant tuber yield. Nevertheless, treatments that could enhance substantially flowering intensity, such as pruning and STS, reduced tuber yield. DMC had negative associations with all flowering-related traits. This study provided insights into white yam flower induction and suggests promising treatments that can be optimized and used routinely to increase flowering in yam crop, without significantly affecting flower fertility and tuber yield.

Cultural Influences on African Migrant Pregnant and Postnatal Women's Dietary Behaviours and Nutrition Support Needs in the UK

Black women in the UK face significantly higher risks of overweight and obesity and adverse pregnancy outcomes compared to women from other ethnic groups. Maternal nutrition plays a pivotal role in influencing the health outcomes of women and their children, especially during preconception and pregnancy. Cultural and environmental factors significantly influence the dietary experiences of African women after migration. This study explored the unique nutrition-related challenges faced by African migrant pregnant and postnatal women in the UK, and their nutrition support needs. Interviews were conducted with 23 African migrant women living in the UK, who were either pregnant or had a pregnancy within the past 3 years. These were analysed thematically, resulting in five overarching themes: food rituals and beliefs, pregnancy cravings, limited access to culturally appropriate food, limited access to culturally appropriate and evidence-based nutritional guidance, and the focus on healthy weight. The study identified challenges that African migrant women face in balancing their cultural heritage with the UK food environment and dietary recommendations, including potential implications on their health and pregnancy outcomes. It emphasised the importance of addressing these challenges through culturally sensitive approaches and tailored interventions, to enable informed decision making and enhance health outcomes for these women.

A new osteogenic protein isolated from Dioscorea opposita Thunb accelerates bone defect healing through the mTOR signaling axis

Delayed bone defect repairs lead to severe health and socioeconomic impacts on patients. Hence, there are increasing demands for medical interventions to promote bone defect healing. Recombinant proteins such as BMP-2 have been recognized as one of the powerful osteogenic substances that promote mesenchymal stem cells (MSCs) to osteoblast differentiation and are widely applied clinically for bone defect repairs. However, recent reports show that BMP-2 treatment has been associated with clinical adverse side effects such as ectopic bone formation, osteolysis and stimulation of inflammation. Here, we have identified one new osteogenic protein, named 'HKUOT-S2' protein, from Dioscorea opposita Thunb. Using the bone defect model, we have shown that the HKUOT-S2 protein can accelerate bone defect repair by activating the mTOR signaling axis of MSCs-derived osteoblasts and increasing osteoblastic biomineralization. The HKUOT-S2 protein can also modulate the transcriptomic changes of macrophages, stem cells, and osteoblasts, thereby enhancing the crosstalk between the polarized macrophages and MSCs-osteoblast differentiation to facilitate osteogenesis. Furthermore, this protein had no toxic effects in vivo. We have also identified HKUOT-S2 peptide sequence TKSSLPGQTK as a functional osteogenic unit that can promote osteoblast differentiation in vitro. The HKUOT-S2 protein with robust osteogenic activity could be a potential alternative osteoanabolic agent for promoting osteogenesis and bone defect repairs. We believe that the HKUOT-S2 protein may potentially be applied clinically as a new class of osteogenic agent for bone defect healing.

Dietary diosgenin transcriptionally down-regulated intestinal NPC1L1 expression to prevent cholesterol gallstone formation in mice

BACKGROUND

Cholesterol gallstone disease is a common disease. Reducing cholesterol burden is important to prevent/treat gallstone. In this study, we investigated the application of diosgenin (DG) to prevent the formation of gallstone in mice.

METHODS

Adult male C57BL/6J mice were fed with the lithogenic diet (LD) only or LD supplemented with DG or ezetimibe for 8 weeks. Incidences of gallstone formation were documented. Intestine and liver tissues were collected to measure the lipid contents and expression of genes in cholesterol metabolism. Caco2 cells were treated with DG to monitor the regulation on cholesterol absorption and the transcriptional regulation of Npc1l1 gene. Changes of gut microbiota by DG was analyzed. Intraperitoneal injection of LPS on mice was performed to verify its effects on STAT3 activation and Npc1l1 expression in the small intestine.

RESULTS

LD led to 100% formation of gallstones in mice. In comparison, dietary DG or ezetimibe supplementary completely prevents gallstones formation. DG inhibited intestinal cholesterol absorption in mice as well as in Caco2 cells by down-regulation of Npc1l1 expression. DG could directly inhibit phosphorylation of STAT3 and its transcriptional regulation of Npc1l1 expression. Furthermore, DG could modulate gut microbiota profiles and LPS mediated STAT3 activation and Npc1l1 expression.

CONCLUSION

Our results demonstrated that dietary DG could inhibit intestinal cholesterol absorption through decreasing NPC1L1 expression to prevent cholesterol gallstone formation.

Widely Targeted Metabolomics Reveals the Effects of Soil on the Metabolites in Dioscorea opposita Thunb

Chinese yam (Dioscorea opposita Thunb. cv. Tiegun), a type of homologous medicinal plant, mainly grows in sandy soil (SCY) and loessial soil (LCY). However, the effects of the soil on the metabolites in SCY and LCY remain unclear. Herein, this study aims to comprehensively elucidate the metabolites in SCY and LCY. A UPLC-MS/MS-based, widely targeted metabolomics approach was adapted to compare the chemical composition of SCY and LCY. A total of 988 metabolites were detected, including 443 primary metabolites, 510 secondary metabolites, and 35 other compounds. Notably, 177 differential metabolites (classified into 12 categories) were identified between SCY and LCY; among them, 85.9% (152 differential metabolites) were upregulated in LCY. LCY significantly increased the contents of primary metabolites such as 38 lipids and 6 nucleotides and derivatives, as well as some secondary metabolites such as 36 flavonoids, 28 phenolic acids, 13 alkaloids, and 6 tannins. The results indicate that loessial soil can improve the nutritional and medicinal value of D. opposita.

Comparative Metabolomics Profiling Reveals Key Metabolites and Associated Pathways Regulating Tuber Dormancy in White Yam (Dioscorea rotundata Poir.)

Yams are economic and medicinal crops with a long growth cycle, spanning between 9-11 months due to their prolonged tuber dormancy. Tuber dormancy has constituted a major constraint in yam production and genetic improvement. In this study, we performed non-targeted comparative metabolomic profiling of tubers of two white yam genotypes, (Obiaoturugo and TDr1100873), to identify metabolites and associated pathways that regulate yam tuber dormancy using gas chromatography-mass spectrometry (GC-MS). Yam tubers were sampled between 42 days after physiological maturity (DAPM) till tuber sprouting. The sampling points include 42-DAPM, 56-DAPM, 87DAPM, 101-DAPM, 115-DAPM, and 143-DAPM. A total of 949 metabolites were annotated, 559 in TDr1100873 and 390 in Obiaoturugo. A total of 39 differentially accumulated metabolites (DAMs) were identified across the studied tuber dormancy stages in the two genotypes. A total of 27 DAMs were conserved between the two genotypes, whereas 5 DAMs were unique in the tubers of TDr1100873 and 7 DAMs were in the tubers of Obiaoturugo. The differentially accumulated metabolites (DAMs) spread across 14 major functional chemical groups. Amines and biogenic polyamines, amino acids and derivatives, alcohols, flavonoids, alkaloids, phenols, esters, coumarins, and phytohormone positively regulated yam tuber dormancy induction and maintenance, whereas fatty acids, lipids, nucleotides, carboxylic acids, sugars, terpenoids, benzoquinones, and benzene derivatives positively regulated dormancy breaking and sprouting in tubers of both yam genotypes. Metabolite set enrichment analysis (MSEA) revealed that 12 metabolisms were significantly enriched during yam tuber dormancy stages. Metabolic pathway topology analysis further revealed that six metabolic pathways (linoleic acid metabolic pathway, phenylalanine metabolic pathway, galactose metabolic pathway, starch and sucrose metabolic pathway, alanine-aspartate-glutamine metabolic pathways, and purine metabolic pathway) exerted significant impact on yam tuber dormancy regulation. This result provides vital insights into molecular mechanisms regulating yam tuber dormancy.

Antifungal Mechanism of Cinnamon Essential Oil against Chinese Yam-Derived Aspergillus niger

Chinese yam with damaged outer skin can be easily oxidized and infected by spoilage fungi. To find preservatives in the storage of the Chinese yam, Aspergillus niger 103 was isolated, identified, and determined as the dominant spoilage fungus in Chinese yam according to Koch’s postulates. Then, the strain was used as a model to screen antifungal agents and study antifungal mechanisms in this study. We found that cinnamon essential oil was the best antifungal agent, and the minimum concentration against Aspergillus niger 103 was 25 μg/mL. The storage life of Chinese yam could significantly extend by 27.66 days by spraying with cinnamon essential oil (25 μg/mL). To further explore the antifungal mechanism of cinnamon essential oil against Aspergillus niger 103, alkaline phosphatase activity and electrolyte content in the fungal solution were measured. The alkaline phosphatase activity and electrolyte content of the fungal solution with cinnamon essential oil were significantly increased than those without cinnamon essential oil, which showed that the cinnamon essential oil could destroy the integrity of the cell wall and cell membrane of Aspergillus niger 103, and disrupted cellular homeostasis of Aspergillus niger 103.

Dioscorea spp.: Bioactive Compounds and Potential for the Treatment of Inflammatory and Metabolic Diseases

Dioscorea spp. belongs to the Dioscoreaceae family, known as "yams", and contains approximately 600 species with a wide distribution. It is a major food source for millions of people in tropical and subtropical regions. Dioscorea has great medicinal and therapeutic capabilities and is a potential source of bioactive substances for the prevention and treatment of many diseases. In recent years, increasing attention has been paid to the phytochemicals of Dioscorea, such as steroidal saponins, polyphenols, allantoin, and, in particular, polysaccharides and diosgenin. These bioactive compounds possess anti-inflammatory activity and are protective against a variety of inflammatory diseases, such as enteritis, arthritis, dermatitis, acute pancreatitis, and neuroinflammation. In addition, they play an important role in the prevention and treatment of metabolic diseases, including obesity, dyslipidemia, diabetes, and non-alcoholic fatty liver disease. Their mechanisms of action are related to the modulation of a number of key signaling pathways and molecular targets. This review mainly summarizes recent studies on the bioactive compounds of Dioscorea and its treatment of inflammatory and metabolic diseases, and highlights the underlying molecular mechanisms. In conclusion, Dioscorea is a promising source of bioactive components and has the potential to develop novel natural bioactive compounds for the prevention and treatment of inflammatory and metabolic diseases.

Variability and genetic merits of white Guinea yam landraces in Nigeria

INTRODUCTION

Landraces represent a significant gene pool of African cultivated white Guinea yam diversity. They could, therefore, serve as a potential donor of important traits such as resilience to stresses as well as food quality attributes that may be useful in modern yam breeding. This study assessed the pattern of genetic variability, quantitative trait loci (QTLs), alleles, and genetic merits of landraces, which could be exploited in breeding for more sustainable yam production in Africa.

METHODS

A total of 86 white Guinea yam landraces representing the popular landraces in Nigeria alongside 16 elite clones were used for this study. The yam landraces were genotyped using 4,819 DArTseq SNP markers and profiled using key productivity and food quality traits.

RESULTS AND DISCUSSION

Genetic population structure through admixture and hierarchical clustering methods revealed the presence of three major genetic groups. Genome-wide association scan identified thirteen SNP markers associated with five key traits, suggesting that landraces constitute a source of valuable genes for productivity and food quality traits. Further dissection of their genetic merits in yam breeding using the Genomic Prediction of Cross Performance (GPCP) allowed identifying several landraces with high crossing merit for multiple traits. Thirteen landraces were identified as potential genitors to develop segregating progenies to improve multiple traits simultaneously for desired gains in yam breeding. Results of this study provide valuable insights into the patterns and the merits of local genetic diversity which can be utilized for identifying desirable genes and alleles of interest in yam breeding for Africa.

The Hypoglycemic and Hypocholesterolemic Activity of Dioscorea deltoidea, Tribulus terrestris and Panax japonicus Cell Culture Biomass in Rats with High-Fat Diet-Induced Obesity

Obesity, and its consequences for human health, is a huge and complicated problem that has no simple solution. The constant search for natural and safe compounds with systemic action that can be used for obesity prophylactics and treatment is hampered by the limited availability and variable quality of biomass of wild medicinal plants. Plant cell biotechnology is an alternative approach for the sustainable production of vegetative biomass or individual phytochemicals with high therapeutic potential. In this study, the suspension cell biomass of the medicinal plants, Dioscorea deltoidea Wall., Tribulus terrestris L., and Panax japonicus (T. Nees) C.A. Mey, produced in 20 L and 630 L bioreactors, were tested for therapeutic effects in rat models with alimentary-induced obesity. Three-month intake of water infusions of dry cell biomass (100 mg/g body weight) against the background of a hypercaloric diet reduced weight gain and the proportion of fat mass in the obese animals. In addition, cell biomass preparation reduced the intracellular dehydration and balanced the amounts of intra- and extracellular fluids in the body as determined by bioimpedance spectroscopy. A significant decrease in the glucose and cholesterol levels in the blood was also observed as a result of cell biomass administration for all species. Hypocholesterolemic activity reduced in the line P. japonicus > D. deltoidea > T. terrestris/liraglutide > intact group > control group. By the sum of parameters tested, the cell culture of D. deltoidea was considered the most effective in mitigating diet-induced obesity, with positive effects sometimes exceeding those of the reference drug liraglutide. A safety assessment of D. deltoidea cell phytopreparation showed no toxic effect on the reproductive function of the animals and their offspring. These results support the potential application of the biotechnologically produced cell biomass of medicinal plant species as safe and effective natural remedies for the treatment of obesity and related complications, particularly for the long-term treatment and during pregnancy and lactation periods when conventional treatment is often contraindicated.

Exploiting Polyphenol-Mediated Redox Reorientation in Cancer Therapy

Polyphenol, one of the major components that exert the therapeutic effect of Chinese herbal medicine (CHM), comprises several categories, including flavonoids, phenolic acids, lignans and stilbenes, and has long been studied in oncology due to its significant efficacy against cancers in vitro and in vivo. Recent evidence has linked this antitumor activity to the role of polyphenols in the modulation of redox homeostasis (e.g., pro/antioxidative effect) in cancer cells. Dysregulation of redox homeostasis could lead to the overproduction of reactive oxygen species (ROS), resulting in oxidative stress, which is essential for many aspects of tumors, such as tumorigenesis, progression, and drug resistance. Thus, investigating the ROS-mediated anticancer properties of polyphenols is beneficial for the discovery and development of novel pharmacologic agents. In this review, we summarized these extensively studied polyphenols and discussed the regulatory mechanisms related to the modulation of redox homeostasis that are involved in their antitumor property. In addition, we discussed novel technologies and strategies that could promote the development of CHM-derived polyphenols to improve their versatile anticancer properties, including the development of novel delivery systems, chemical modification, and combination with other agents.

Simulated In Vitro Digestive Characteristics of Raw Yam Tubers in Japanese Diet: Changes in Protein Profile, Starch Digestibility, Antioxidant Capacity and Microstructure

The consumption of raw yam tuber through grated yam "tororo" is a major and popular diet in Japan. However, few studies have been undertaken to evaluate the digestive characteristics of raw yam tubers. This study aimed to fill this gap by investigating the changes in the protein profile, protein and starch digestibility, antioxidant capacity and microstructure of two typical yam tubers (Nagaimo N-10 and Nebaristar) in the Japanese diet, applying a simulated in vitro digestion method. Results showed that both samples contained a considerable protein content of about 11% (dry basis) and a protein digestibility of 43-49%. The electrophoretic patterns confirmed that dioscorin was the main protein of the yam tuber, and it could be digested into peptides and free amino acids with low molecular weight during in vitro digestion. The starch hydrolysis results suggested that eating raw yam tuber cannot induce a fast glycemic increase for consumers due to a low starch digestibility of 4.4-6.1%. In addition, Nebaristar showed a higher bioaccessibility in some key amino acids and total phenolic content than the Nagaimo N-10. This study provides some essential nutritional information and simulated digestion behaviours of the raw yam tubers, which could be useful for consumers and industries when buying and processing yam tubers from the perspective of changes in the nutritional profile during digestion.

Lasiodiplodia iraniensis, a New Causal Agent of Tuber Rot on Yam (Dioscorea Species) Imported into the United States and Implications for Quarantine Decisions

One negative consequence of international trade of agricultural commodities is the inadvertent global spread of crop diseases. Yam (Dioscorea spp.) is a staple food crop in many countries and is traded globally. Most of the commercially traded yams in the United States are imported. In late 2020, samples of yam tubers from a commercial facility were submitted to the plant diagnostic clinic at the UF/IFAS Tropical Research and Education Center in Homestead, Florida. Samples showed rotten symptoms and were drawn from lots that were marked to be destroyed because the source of the rotting symptoms was unknown. Preliminary isolation showed that a fungus was consistently associated with the symptoms and was confirmed in the subsequent pathogenicity test as the causal agent. The fungus grew profusely on potato dextrose agar (PDA) with highly melanized hyphae. Matured conidia showed longitudinal striations. Based on its growth pattern and morphology, it was suspected that this fungus may be in the genus Lasiodiplodia. DNA-based identification using partial sequences of the internal transcribed spacer (ITS), β-tubulin (TUB2), 28S rDNA (LSU), and elongation factor alpha (EF1-α) genes confirmed the identity of the isolates as Lasiodiplodia iraniensis Abdollahz., Zare & A.J.L. Phillips (synonym: L. iranensis). This is the first report of L. iraniensis affecting yam and has implications for international trade. This finding will provide an important foundation for making quarantine decisions to prevent spread of this disease.

Genome Analysis Revives a Forgotten Hybrid Crop Edo-dokoro in the Genus Dioscorea

A rhizomatous Dioscorea crop 'Edo-dokoro' was described in old records of Japan, but its botanical identity has not been characterized. We found that Edo-dokoro is still produced by four farmers in Tohoku-machi of the Aomori prefecture, Japan. The rhizomes of Edo-dokoro are a delicacy to the local people and are sold in the markets. Morphological characters of Edo-dokoro suggest its hybrid origin between the two species, Dioscorea tokoro and Dioscorea tenuipes. Genome analysis revealed that Edo-dokoro likely originated by hybridization of a male D. tokoro to a female D. tenuipes, followed by a backcross with a male plant of D. tokoro. Edo-dokoro is a typical minor crop possibly maintained for more than 300 years but now almost forgotten by the public. We hypothesize that there are many such uncharacterized genetic heritages passed over generations by small-scale farmers that await serious scientific investigation for future use and improvement by using modern genomics information.