Search Results (357)

Roselle beverage residue (RBR), a by-product of Hibiscus sabdariffa L. processing, retains bioactive compounds, including soluble and insoluble dietary fiber and polyphenols. Its antihyperglycemic effect in type 2 diabetes mellitus (T2DM) has been previously demonstrated; however, its role in lipid metabolism remains unknown. This study assessed the preventive and therapeutic potential of RBR on dyslipidemia and hepatic steatosis in a rodent model of late-stage T2DM characterized by hyperglycemia and hypoinsulinemia. Male Wistar rats with T2DM induced by a high-fat and high-fructose diet combined with streptozotocin received 6% RBR supplementation as either a preventive intervention (starting at week 1 in healthy rats or week 9 in insulin-resistant rats) or a therapeutic intervention (starting at week 14 in diabetic rats). After 17 weeks, RBR supplementation significantly reduced serum triglycerides and total cholesterol, attenuating hepatic lipid accumulation regardless of the timing of intervention. Hepatic Acadm expression, involved in fatty acid β-oxidation, was significantly upregulated in rats treated with RBR from week 1 and 9, whereas no significant modulation was observed for genes related to fatty acid synthesis or uptake. These findings suggest that RBR supplementation may contribute to improving lipid metabolism and hepatic steatosis in a rat model of late-stage T2DM. Full article

In traditional medicine, laboratory tests are essential tools used to evaluate practices in healthcare that use natural products, particularly when there are few established treatments such as in the case of chronic diseases like sickle cell disease (SCD). SCD is a genetic hemoglobin disorder associated with hemolysis, oxidative stress, inflammation, and vaso-occlusive complications. This study aims to document medicinal plants used in the management of SCD and the traditional practices associated with their use, in order to assess their added value in relation to biological activities relevant to SCD. First, this study carried out an ethnobotanical survey at Kisangani, with 384 participants. A total of 201 respondents, 58% of whom were women, identified 45 medicinal plant species from 30 families. They reported the use of sugar, caramel, ash, and lemon juice as additives in traditional remedies. Based on several criteria, Alchornea cordifolia Müll. Arg. and Hibiscus tiliaceus L. were selected for laboratory evaluation. Their leaves were collected from arid and marshy soils and prepared according to the respondents’ descriptions for antioxidant and anti-inflammatory assessments. A. cordifolia showed significantly higher activities than H. tiliaceus regarding antioxidant (p = 0.001) and anti-inflammatory (p = 0.01) properties. Soil type was observed to influence the bioactivity of H. tiliaceus, with better performance in marshy soil samples. Sugar and caramel were found to reduce antioxidant activity, whereas ash and lemon juice preserved it without markedly altering anti-inflammatory effects. These findings are promising for supporting local knowledge about these two plant species. Full article

Alternative substrates to traditional Camellia sinensis tea are increasingly investigated to diversify kombucha and enhance its functional properties. This review synthesizes evidence (2020–2025) on how non-tea substrates influence microbial ecology, metabolite composition, and bioactivity of kombucha. A semi-systematic search of PubMed, Scopus, Web of Science, and publisher platforms identified studies on fruit, vegetable, herbal, algal, cereal, dairy, and food-industry by-product substrates reporting compositional or functional outcomes. Extracted data included substrate characteristics, fermentation conditions, SCOBY features, analytical methods, and reported antioxidant, anti-inflammatory, metabolic, probiotic, and dermatological effects. Fermentation often leads to an increase in total phenolic content and antioxidant capacity. These effects are highly dependent on fermentation conditions, particularly duration and substrate composition. In some cases, prolonged fermentation may result in phenolic degradation or transformation, leading to reduced levels of certain compounds. Fruit- and hibiscus-based systems enhanced anthocyanin-driven antioxidant and anti-inflammatory activity. Vegetable and cereal substrates supplied phenolic acids and β-glucans associated with metabolic regulation and gut health, whereas by-products and algal fermentations supported waste valorization and enrichment in chlorogenic acids, pigments, fibers, and peptides. Despite promising functionality, substantial inter-study variability and limited in vivo validation and the lack of standardized fermentation protocols constrain translational application. In addition, the inherent variability in SCOBY microbial composition represents a major source of inconsistency, as differences in microbial communities can significantly influence fermentation dynamics, metabolite profiles, and functional outcomes. Full article

The two-spot cotton leafhopper (TSCL), Amrasca biguttula (Hemiptera: Cicadellidae), is an emerging invasive pest in the southeastern United States. Although TSCL has historically been associated with cotton and vegetable crops, recent detections on ornamental hibiscus have raised regulatory concern, including “Stop Sale and Hold” orders and an emergency quarantine in Texas. Despite increasing pressure on hibiscus, no insecticide efficacy data exist for ornamental systems. We evaluated the acute (0–24 h) and residual (24–96 h) toxicity of bifenthrin, flupyradifurone, and tolfenpyrad against adult and immature TSCL using a sequential-cohort leaf-disc bioassay. New insects were introduced at 24 h and 72 h to isolate residue-based mortality from prolonged exposure effects. Bifenthrin caused the highest acute mortality at 24 h, whereas flupyradifurone and tolfenpyrad exhibited slower initial activity but strong residual performance. Immatures were more susceptible than adults across all doses. By 72 h, all three insecticides produced near-complete mortality, with significant treatment and dose effects confirmed by ANOVA and binomial GLM analyses. Dose–response curves showed steep concentration-dependent mortality for bifenthrin and tolfenpyrad and a time-dependent response for flupyradifurone. These results provide the first insecticide efficacy data for TSCL on ornamental hibiscus and offer immediate guidance for nursery producers and regulatory agencies. The findings establish a foundation for whole-plant and greenhouse evaluations to support integrated management and interstate plant-movement compliance. Full article

This paper investigates the AWJ machinability of Hibiscus Rosa-Sinensis/carbon nanotube (CNT) fiber/epoxy-based hybrid composites by analyzing key machinability metrics such as kerf width (KW), material removal rate (MRR), and surface roughness (Ra). Various process parameters including CNT weight percentage, CNT diameter, stand-off distance, and traverse speed have been varied to optimize the machining performance. Experimental analysis suggested that increasing the CNT weight percentage significantly enhanced material hardness, thereby reducing both the MRR and surface roughness. Moreover, adjusting the stand-off distance and traverse speed further improved the machinability of the composite. ANOVA results highlighted that CNT weight percentage was a significant factor, accounting for 94.17% of the variation in MRR and 93.72% of the variation in surface finish, while the stand-off distance influenced 87.03% of the variation in kerf width. Additionally, response surface methodology (RSM) was utilized to develop predictive models that estimated KW, MRR, and Ra with error rates of 2.95%, 2.23%, and 5.65%, respectively. These insights offer a valuable framework for tailoring the AWJ process to achieve optimal machining outcomes in HRS/CNT/epoxy composite materials Full article

The intensive use of chemical fertilizers in medicinal plant production raises significant environmental and quality concerns, particularly under arid and high-temperature conditions. This study investigated the effectiveness of indigenous endophytic bacteria consortium as a sustainable approach to reduce mineral fertilizer inputs while improving the growth, yield, and phytochemical quality of roselle (Hibiscus sabdariffa L.) under Upper Egypt conditions. A field experiment was conducted during the summer of 2024 in Aswan, Egypt, using a factorial randomized complete block design. Treatments included a ten-strain endophytic consortium applied alone or combined with 25%, 50%, and 75% of the recommended NPK dose, alongside an unfertilized control and 100% NPK alone. Results highlighted clear percentage-based improvements with integrated treatments. The combination of 75% NPK with endophytic inoculation increased dry calyx yield by 16% relative to the conventional 100% NPK treatment. Significant increases were also observed in vegetative growth, fruit number, biomass accumulation, and photosynthetic pigments relative to full chemical fertilization. Moreover, antioxidant activity and concentrations of anthocyanins, phenolics, and flavonoids were maintained or enhanced under reduced fertilizer regimes, indicating qualitative gains without yield penalties. In contrast, complete fertilizer omission caused marked reduction in growth and yield parameters. Overall, substituting 25% of mineral fertilizers with indigenous endophytic inoculation not only sustained productivity but generated measurable yield gains, improved nutrient use efficiency, and strengthened crop resilience, demonstrating a practical and environmentally sound strategy for sustainable roselle cultivation in arid regions. Full article

Background: Abelmoschus esculentus L. (okra) has shown potential efficacy in animal models of metabolic disorders; however, evidence from clinical studies emanates from trials with a small sample size, and the findings remain contradictory. This study aims to evaluate the impact of okra on glycemia and insulin resistance in individuals with type 2 diabetes (T2D) and prediabetes. Method: A literature search was conducted on PubMed, Scopus, ScienceDirect, and Web of Science, including manual screening of references. Abelmoschus esculentus, okra, Hibiscus esculentus, lady’s finger, and diabetes were used as potential keywords and adjusted for each database. A meta-analysis web tool was used to analyze the data, with results reported as the mean difference (MD) or standardized mean difference (SMD), along with 95% confidence intervals (CI). Results: Nineteen clinical studies conducted in patients with T2D and prediabetes were analyzed. The evidence revealed that, compared to the control group, okra significantly reduced fasting blood glucose (SMD = −0.70 (95% CI, −1.03 to −0.36), p < 0.0001) and glycated hemoglobin (MD = −0.77%, 95%CI (−1.36 to −0.18), p = 0.0102. Furthermore, it reduced the homeostatic model assessment of insulin resistance (HOMA-IR) levels, MD = −0.61, 95% CI (−1.07, −0.15), p < 0.0097. However, no significant effect was observed on insulin (p = 0.5823). Conclusions: The evidence gathered in this study suggests that okra may have the potential to regulate glycemia in individuals with T2D and prediabetes. However, the effect on insulin resistance remains controversial, as only HOMA-IR was improved. Full article

The two-spot cotton leafhopper, Amrasca biguttula (Ishida) (Hemiptera: Cicadellidae), was recently detected in Florida and other southeastern states, USA. This is a quarantine pest of regulatory significance, since it can infest staple crops, such as okra, cotton, eggplant, and tropical hibiscus. While collecting infested okra plants in Homestead, Florida, five female Anagrus (Hymenoptera: Mymaridae) parasitoids emerged from eggs of Am. biguttula. The specimens were identified morphologically and molecularly by sequencing the cytochrome c oxidase subunit I (COI) gene and internal transcribed spacer 2 (ITS2) region of nuclear ribosomal RNA. Two Anagrus species were identified: Anagrus vulneratus and Anagrus sp. near vulneratus. These parasitoids are not known to occur in the Old World, the origin of Am. biguttula. Rather, they are native to North America. The available evidence suggests that the collected specimens switched from unknown local hosts in southern Florida to parasitize eggs of the invasive Am. biguttula. Future research to ascertain the identity of A. sp. near vulneratus and evaluate the efficiency of both parasitoids as natural enemies of Am. biguttula is warranted. Full article

Background: Antimicrobial resistance is one of the major challenges in healthcare, leading to more severe infections, higher mortality, and increased healthcare costs. Therefore, exploring new alternatives, such as plant extracts with antimicrobial properties helps to reduce bacterial resistance. Artemisia annua L., Hibiscus sabdariffa L., and Paronychia argentea Lam. are traditionally used for their biological properties, including antimicrobial activity. However, scientific evidence regarding their antibacterial effects against clinically important bacteria remains limited. Methods: Extracts were obtained from the mentioned plants and phytochemically characterized by GC/MS. Phytochemical analysis revealed the presence of fatty acids, phenolic compounds, aliphatic compounds, and terpenoids. Antibacterial activity was evaluated using the diffusion method with a modified Kirby-Bauer technique and the microdilution method employing the massive plate sealing drop approach. Results: All extracts exhibited bacterial inhibition, with H. sabdariffa L. showing the strongest activity against E. coli (256 mg/mL), K. pneumoniae (256 mg/mL), P. aeruginosa (128 mg/mL), Salmonella sp. (128 mg/mL), and S. aureus (64 mg/mL). Conclusions: Hydroethanolic extracts of A. annua L., H. sabdariffa L., and P. argentea Lam. exhibit antibacterial activity against clinically relevant bacteria and represent promising candidates for future preclinical studies. Full article

Hydrogen sulfide (H₂S) is essential for renal function; however, it is toxic at high concentrations. H₂S is increased during reductive stress (RS). Increased antioxidant capacity and reduced/oxidized glutathione (GSH/GSSG) characterize a rat model of RS associated with chronic consumption of 6% Hibiscus sabdariffa Linnaeus (HSL). Here, we evaluate if chronic consumption of an infusion of HSL causes kidney damage associated with an increase in H₂S. Twenty-one Wistar rats were divided into three groups. Group 1: rats received plain tap water ad libitum (G1); Group 2: rats received an ad libitum infusion of 6% HSL for one month (G2); and Group 3: rats consumed a 6% HSL infusion for one month and were then given natural water for another month (G3). We evaluated renal vasodilatation, cystathionine–β–synthase (CBS), cystathionine–γ–lyase (CSE), 3–mercaptopyruvate-sulfur-transferase (3–MST), γ-glutamylcysteine synthetase (GCLC), Nrf2, total OXPHOS, H₂S concentration, GSH/GSSG and oxidized/reduced thiols in the kidney. Renal vasodilatation and total OXPHOS in complex IV and I and oxidized/reduced thiols were decreased (p ≤ 0.01) but H₂S, CBS, SCE, GCLC, and NrF2 expression and GSH/GSSG were increased (p ≤ 0.04). The HSL infusion provided cysteine that was metabolized by CBS and CSE, elevating chronic H₂S and favoring renal damage. Full article

Kenaf (Hibiscus cannabinus) core, an abundant renewable byproduct rich in cellulose and hemicellulose, has emerged as a candidate to replace or supplement peat and coco coir in soilless culture. This review synthesizes the physical, chemical, and biological performance of ground kenaf core and benchmarks it against conventional substrates. Kenaf core exhibits low bulk density (0.06 to 0.15 g cm⁻³), high total porosity (approximately 90%), and substantial plant available water (approximately 42%), supporting root aeration and water supply. Its pH (6.0–7.2) is near optimal for most crops, whereas electrical conductivity (EC) (3.2–4.7 dS m⁻¹) can exceed recommended ranges for salt-sensitive species, which necessitates pre-leaching or blending. Growth studies show comparable shoot and root performance in blends containing 20 to 70% kenaf, with composted kenaf often outperforming raw core. Pure kenaf generally requires more frequent irrigation and may shrink at high proportions. We outline processing variables such as core purity, particle size, composting, and leaching that govern stability and plant response, identify critical data gaps (including standardized EC and pH methods, and long-term shrinkage), and frame a sustainability agenda. Practically, studies to date indicate that pre-leached kenaf core, incorporated at up to about 70% by volume into peat or coir-based blends with structurally stable components such as perlite, can maintain growth and quality for several ornamental and bedding crops under greenhouse and nursery conditions. At the same time, reports of poor performance in some conifers and early suppression in direct-sown vegetables underscore that the suitability of kenaf-based substrates remains crop specific and dependent on material processing and management. Full article

The clean-label trend demands stable natural colorants. H. sabdariffa L. calyces is a sustainable anthocyanin source; however, the effects of dehydration and food-grade extraction on pigment recovery and performance remain unclear. Fresh and dehydrated calyces were physicochemically characterized, and dehydrated material with aqueous and hydroalcoholic food-grade solvents was used for extraction. Extraction efficiency was evaluated through total phenolic compound (TPC) content and anthocyanin characterization by HPLC-DAD-ESI-MS/MS. The aqueous extract with the highest anthocyanin concentration was selected for the syrup formulation containing 5–35% sucrose. The physicochemical stability of the formulations was monitored during refrigerated storage (4 °C/30 days) and subsequently tested in food matrices with different pH values. Dehydration calyces reduced moisture content (11.61%) and water activity (a_w = 0.56), indicating improved storage stability. The anthocyanin concentration was highest in the 5% sucrose syrup (495.12 ± 40.66 mg mv-3,5-glc·100 g⁻¹), with a 12.71% loss over 30 days. Application in food matrices demonstrated a pH-dependent color response, with correlations between hue angle (h°, r = 0.86) and color saturation (C*, r = −0.77).These results demonstrate that hibiscus calyx syrups are promising natural colorants and bioactive ingredients, particularly for acidic food systems, offering stability. Full article

Kombucha’s growing popularity worldwide has been accompanied by a growing consumer interest in exploring new flavors and adopting healthier diets. In this preliminary consumer-driven study, we investigated the application of white hibiscus (WH) calyces in the development of novel kombucha beverages. Kombuchas were made from 100% black tea (BT), 100% WH, and 50% BT/WH blend infusions, then their pH, total titratable acidity (TTA), ethanol content, sucrose, glucose, and fructose concentrations were measured. Untrained sensory participants (N = 97) rated the kombuchas using a 9-point hedonic scale, described them using a check-all-that-apply list of attributes, and answered a willingness-to-pay (WTP) question. Tea infusion and fermentation time had a significant effect on pH, TTA, ethanol, sucrose, fructose, and glucose content (p < 0.05). High residual sugar levels observed in the WH kombucha indicated sluggish fermentation. Kombuchas differed significantly in overall-liking, color, aroma, flavor, and mouthfeel liking, and WTP (p < 0.05). Overall, BT kombucha was preferred over the WH kombuchas (100% and blend). Sensory attributes “refreshing”, “floral”, “hibiscus”, “fruity”, and “sweet” were positive drivers of acceptability, while “pungent” and “astringent” were negative drivers. Results suggest that blends containing less than 50% WH may provide more appealing sensory attributes to consumers, and that further study is needed. Full article

Kenaf (Hibiscus cannabinus) is a versatile fiber crop known for rapid growth and high biomass productivity that is often cultivated in warm-season regions where root-knot nematodes (RKNs) are prevalent. Here, we compared eight kenaf genotypes with Hibiscus acetosella and Hibiscus sabdariffa to evaluate resistance versus susceptibility to five RKN (Meloidogyne spp.) populations in two replicated greenhouse trials. The nematode panel comprised globally dominant species (M. incognita races 2 and 4, M. javanica) and emerging high-impact threats in warm-season systems (M. floridensis and M. enterolobii), which overlap geographically with current and potential kenaf production. Reproduction and galling were quantified using eggs per system, eggs per gram of root, egg masses, gall index, and reproduction factor, and genotypic differences were assessed by nonparametric rank-based tests at α = 0.05. Across nematode species, H. acetosella and H. sabdariffa showed minimal reproduction and galling, whereas most kenaf genotypes were highly susceptible. Susceptibility was most pronounced to M. enterolobii and M. floridensis, and several kenaf lines (‘Whitten’, ‘G 14’, ‘G 32’, ‘Yue 74-3’) had the highest egg counts and near-maximal egg masses and galling. M. incognita race 2 and race 4 produced strong contrasts, with H. acetosella and H. sabdariffa remaining resistant while multiple kenaf lines exhibited heavy reproduction and severe galling. M. javanica followed a similar pattern, with ‘G 32’, ‘Yue 74-3’, ‘Whitten’, ‘G 14’, and ‘74200 I4’ being highly susceptible. These results identify H. acetosella ‘PI 500707’ and H. sabdariffa ‘X17’ as robust donors of RKN resistance and highlight the susceptibility of cultivated kenaf genotypes, underscoring urgent breeding and integrated management needs for kenaf in warm-season production regions. Full article

This study investigated the optimisation of roselle (Hibiscus sabdariffa L.) leaf tisane formulation using response surface methodology (RSM), targeting total phenolic content (TPC), ferric reducing antioxidant power (FRAP), and DPPH radical scavenging activity as quality indicators. A face-centred central composite design was employed to evaluate dose effects (0.5–2.5 g) and infusion time (5–15 min). Multi-response optimisation using the desirability function identified 1.81 g dose and 5 min infusion as the optimum condition, yielding predicted values of 24.46 mg GAE/100 mL (TPC), 61.07 µmol Fe²⁺/100 mL (FRAP), and 80.47% (DPPH), with a composite desirability score of 0.64. Validation experiments confirmed strong predictive accuracy, with deviations of 0.80% (FRAP) and 3.92% (DPPH), and a modest deviation of 13.2% (TPC), acceptable within complex food matrices. The findings demonstrate that short infusion times are sufficient to extract key bioactives, ensuring consumer convenience and energy efficiency, while valorising roselle leaves as an underutilised by-product into a sustainable functional beverage. Future studies should address sensory acceptance, stability, and bioavailability to support industrial applications further. Full article