Search Results (21)

Background: Inflammation and oxidative stress are key mechanisms in underlying skin conditions like psoriasis and eczema. While many plants, including Australian native plants, are proposed to target these pathways due to their phytochemical content, studies on whole extracts and their synergistic effects remain limited. Objectives: This study aimed to investigate individual and combined effects of whole plant extracts on skin protection and healing, focusing on their anti-inflammatory and antioxidant properties. Methods: The antioxidant potential of the individual and combined plant extracts were investigated on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and reactive oxygen species (ROS) assay followed by luciferase assay in MCF-7 AREc32 cells for nuclear factor erythroid 2-related factor 2 (Nrf2) activation. The anti-inflammatory activities were investigated on lipopolysaccharide (LPS)-induced RAW 264.7 murine macrophages for the inhibition of nitric oxide (NO), tumour necrosis factor (TNF)-α, and interleukin (IL)-6. Synergistic interaction was determined by the combination index model (CI < 1). Combination(s) showing synergistic and optimal activity were further investigated on LPS-induced human dermal fibroblasts (HDF) cells for IL-6 inhibition and wound healing activity. Results: Three of the tested Australian native plant extracts demonstrated prominent antioxidant and anti-inflammatory activities including bitter orange, mountain pepper berry and native river mint. In particular, their three-way combination (1:1:1, w/w) showed prominent synergistic (CI < 1) in reducing NO and IL-6, along with enhanced Nrf2 activation. In LPS-inflamed HDF cells, the combination maintained synergistic inhibition of IL-6 levels and promoted wound healing response. Conclusions: These findings highlight the therapeutic potential of Australian native plant as a whole extract for skin protection and repair attributed to antioxidant and anti-inflammatory activities. The observed synergistic anti-inflammatory and antioxidant effects support their use in the development of new cosmetic formulations for skin. Full article

Numerous studies have focused on dioecious plants and their sex-specific responses to drought stress. However, sexual dimorphism in drought stress responses between male and female Litsea cubeba, a dioecious species significant to the terrestrial ecosystem in China that is frequently exposed to drought conditions, remains insufficiently characterized. In this study, we examined the sex-specific physiological and biochemical responses of L. cubeba to natural drought stress. The results revealed that natural drought induced significant sexual dimorphism in physiological and biochemical traits of L. cubeba. Females exhibited a higher malondialdehyde (MDA) content than males under prolonged drought conditions; females also exhibited significantly higher catalase (CAT) and peroxidase (POD) activities in both leaves and roots compared to males, with the average CAT and POD activities of all varieties increasing by 104.28% and 23.67% in leaves and 51.17% and 174.57% in roots, respectively. Meanwhile, the dehydrogenase (DHA) activity and chlorophyll (chl) and carotenoid levels of females were higher than those of males. The contents of proline (Pro), soluble sugar (SS), abscisic acid (ABA), and jasmonic acid (JA) in females were significantly higher than those in males. Our results demonstrated that females possess a greater tolerance to natural drought stress than males; this is due to their more efficient antioxidant system, better osmotic adjustment, lower chlorophyll degradation rate, and higher concentrations of ABA and JA, which aid in stomatal closure and facilitate the reactive oxygen species (ROS)-scavenging abilities of females in response to drought stress. Our findings provide evidence that dioecious L. cubeba may adopt distinct survival strategies during natural drought events and enhance our understanding of sexually dimorphic responses to drought stress in L. cubeba. Full article

Crop rotation is widely recognized as a key strategy to mitigate the adverse effects associated with continuous cropping. Recent studies have demonstrated that biochar has a significant potential for preventing and controlling these challenges. However, the ameliorative effects of green manure rotation and biochar application on continuous pepper cultivation in the karst mountainous regions of Southwest China remain largely unexplored. To address this gap, a field experiment was conducted from 2020 to 2023 to investigate the effects of green manure rotation and biochar application on the continuous cropping of peppers. The experiment consisted of five treatments: CK (no green manure and no biochar), WP (winter fallow and conventional pepper production with chemical fertilization), GP (green manure and pepper rotation, the amount of fresh green manure returned to the field was about 15 t·ha⁻¹), WP + B (winter fallow and pepper rotation with 1500 kg·ha⁻¹ of biochar applied during the pepper season), and GP + B (green manure and pepper rotation with 1500 kg·ha⁻¹ of biochar applied during the pepper season, the amount of fresh green manure returned to the field was about 15 t·ha⁻¹). The results showed that all the improved measures (GP, WP + B, GP + B) increased the yield of fresh pepper and dry pepper by 26.97–72.98% and 20.96–65.70%, respectively, and the yield of dry pod pepper increased by 14.69–40.63% and 21.44–73.29% in 2021 to 2023, respectively, and significantly improved the yield stability and sustainability of continuous cropping of peppers compared with WP treatments. In addition, green manure rotation or biochar application alone or in combination enhanced the nutritional quality of pepper fruits by increasing the content of free amino acids (8.62–19.42%), reducing sugars (15.30–34.62%) and vitamin C (26.19–43.52), and decreasing the nitrate content (26.93–40.17%). Furthermore, the application of green manure rotation or biochar alone or in combination significantly improved the absorption of nitrogen (23.73–60.23%), phosphorus (18.12–61.71%), and potassium (20.57–61.48%) nutrients in the continuous cropping of peppers, which contributed to the improvement of fertilizer use efficiency. Notably, GP + B treatment not only improved the yield and quality of continuous cropping peppers but also resulted in higher production value and net income compared to the GP and WP + B treatments. In conclusion, the combination of green manure rotation and biochar application represents an effective strategy for mitigating the challenges of continuous cropping in pepper cultivation within the karst mountainous regions of Southwest China. Full article

This study explores the correlation between soil nutrient elements and pepper fruit quality in Guizhou Province, highlighting regional variations in nutrient influence. Guizhou, with its unique mountainous and karst terrain, provides a distinct ecological environment for pepper cultivation. Our analysis of three major pepper-growing regions—Dafang, Guiyang, and Zunyi—demonstrates that the nitrogen, phosphorus, and potassium levels in the soil significantly impact pepper quality. Potassium plays a particularly vital role in fruit development, as deficiencies in potassium often result in flower and fruit drop and reduced yield. In Dafang, AP (available phosphorus) and TK (total potassium) were most closely linked to amino acids, reducing sugars, and capsaicinoid content, while in Bozhou, SAN (available nitrogen) was most influential, and in Qingzhen, TP (total phosphorus) and AK (available potassium) were predominant. The findings suggest that key soil elements, such as available phosphorus, available potassium, available nitrogen, and organic matter, influence the quality indicators—amino acids, reducing sugars, capsaicin, and dihydrocapsaicin—in pepper fruits. Further analysis indicates that Guizhou’s distinct soil composition significantly contributes to its peppers’ unique flavor profile. The combined effects of soil nutrients, pepper varieties, and cultivation practices underline the superior quality of Guizhou peppers. This study provides a foundation for understanding the soil–quality interaction and enhances the market recognition of Guizhou’s pepper varieties. Future research should investigate the integrated effects of environmental and soil factors to better assess Guizhou’s favorable growth conditions for peppers. Full article

To improve the mechanization levels of red cluster pepper harvesting in hilly and mountainous regions of southwest China, a crawler-type harvester is developed to suit the local planting and growth characteristics of red cluster pepper and to facilitate mechanized picking, conveying, and collecting processes. The design, supported by theoretical calculations and structural analysis, includes detailed studies of the picking, conveying, and collecting mechanisms, as well as the hydraulic system. Factors affecting picking efficiency were identified. ADAMS simulation was used to determine the optimum rotational speed range for the spring-tooth roller by analyzing its trajectory. A prototype was then built and field tested with forward speed and the spring-tooth roller’s rotational speed as variables to assess impurity, damage, loss, and hanging rates. Data from these tests were analyzed using Design Expert software, which created a mathematical model relating the test indices to the two variables. Optimum parameters were identified, resulting in a harvester configuration that achieved an average productivity of 0.21 ha·h⁻¹ at a forward speed of 1.75 m·s⁻¹ and a roller rotational speed of 181 r·min⁻¹. The impurity rate was 26.7%, the loss rate was 6.1%, the damage rate was 2.3%, and the hanging rate was 4.2%, conforming to the industry standard DG/T 114-2019. This research provides a viable solution for mechanized harvesting of red cluster pepper in hilly and mountainous regions with small planting plots. Full article

The European pepper moth (Duponchelia fovealis) is predominant in the main strawberry production areas, including Brazil, as an important invasive pest and causes substantial damage to the crop. This damage is mainly attributed to the lack of effective management strategies. A promising alternative for managing this pest is implementing biological control through releasing natural enemies. This study determined the dispersal capacity of Trichogramma pretiosum for the management of D. fovealis in a strawberry crop in a low tunnel system 24, 48, and 72 h after parasitoid release. The experiments were carried out on strawberry farms in the mountainous region of Espírito Santo. Tunnels measuring 1.20 m wide by 50 m long were selected, in which artificial infestations of 30, 60, 90, and 120 eggs of D. fovealis were made on both sides of the strawberry tunnel at distances of 3, 7, 11, and 15 m, respectively, from the central point where the parasitoids were released. After the initial 24 h, new eggs were placed to replace the infested ones; the replacement was repeated at 48 and 72 h. The results indicated that, in strawberry plantations, T. pretiosum was efficient in parasitism. There was no difference between parasitism 24 and 48 h after parasitoid release, but parasitism was substantially lower after 72 h. The dispersion capacity of T. pretiosum was 14.21 linear meters, corresponding to an area of 17.05 m². It is recommended that 93,000 T. pretiosum females be released per hectare every three days. Full article

China’s Guizhou is a typical karst landscape province with high production of chili pepper, but it is mostly planted in mountainous areas, while manual harvesting of chili pepper has the deficiencies of high labor intensity, low efficiency, and high labor cost; in addition, there is no harvesting machinery applicable to the dense planting pattern of the chili pepper in mountainous areas in China. The fully hydraulic mountain track-based self-propelled pepper harvester 4JZ-1.0A is designed to solve the above problems. The pepper harvester spiral comb picking head is an important part of the whole machine design, the design of the hydraulic system of the working circuit of the picking head is the key to realizing the hydraulic control part of the whole system. In this paper, the working principle diagram of the improved load-sensitive hydraulic system is designed and analyzed for the study of whether the working circuit of the pepper picking head of the pepper machine can meet the requirements of mountain operation, taking the working circuit of the mountain pepper harvester as the research object. In addition, the load-sensitive pump model and the simulation model of the whole working circuit are established by the AMESim platform 2019.2 (Siemens simcenter amesim). The operating performance of the system under variable flow conditions, variable load conditions, and an improved sensitive system is analyzed. The simulation results show that the improved load-sensitive system can effectively reduce the oscillation and cavitation during cylinder operation and improve the system efficiency and the performance and service life of the components. The performance of the hydraulic system of the working circuit of the mountain pepper harvester was verified in the test, meeting the requirements of working use. This provides a theoretical basis for the improvement and optimal design of a mountain pepper harvester hydraulic system. Full article

The intercropping of cover crops has been adopted in several agroecosystems, including tea agroecosystems, which promotes ecological intensification. Prior studies have shown that growing cover crops in tea plantations provided different ecological services, including the biocontrol of pests. Cover crops enrich soil nutrients, reduce soil erosion, suppress weeds and insect pests, and increase the abundance of natural enemies (predators and parasitoids). We have reviewed the potential cover crops that can be incorporated into the tea agroecosystem, particularly emphasizing the ecological services of cover crops in pest control. Cover crops were categorized into cereals (buckwheat, sorghum), legumes (guar, cowpea, tephrosia, hairy indigo, and sunn hemp), aromatic plants (lavender, marigold, basil, and semen cassiae), and others (maize, mountain pepper, white clover, round-leaf cassia, and creeping indigo). Legumes and aromatic plants are the most potent cover crop species that can be intercropped in monoculture tea plantations due to their exceptional benefits. These cover crop species improve crop diversity and help with atmospheric nitrogen fixation, including with the emission of functional plant volatiles, which enhances the diversity and abundance of natural enemies, thereby assisting in the biocontrol of tea insect pests. The vital ecological services rendered by cover crops to monoculture tea plantations, including regarding the prevalent natural enemies and their pivotal role in the biocontrol of insect pests in the tea plantation, have also been reviewed. Climate-resilient crops (sorghum, cowpea) and volatile blends emitting aromatic plants (semen cassiae, marigold, flemingia) are recommended as cover crops that can be intercropped in tea plantations. These recommended cover crop species attract diverse natural enemies and suppress major tea pests (tea green leaf hopper, white flies, tea aphids, and mirid bugs). It is presumed that the incorporation of cover crops within the rows of tea plantations will be a promising strategy for mitigating pest attacks via the conservation biological control, thereby increasing tea yield and conserving agrobiodiversity. Furthermore, a cropping system with intercropped cover crop species would be environmentally benign and offer the opportunity to increase natural enemy abundance, delaying pest colonization and/or preventing pest outbreaks for pest management sustainability. Full article

Biochar is frequently utilized as a helpful amendment to sustain agricultural productivity. However, it remains uncertain whether biochar can effectively replace chemical fertilizers, especially in karst regions. To investigate the effects of co-applying biochar and chemical fertilizer on the biological characteristics and fertilizer uptake of pod peppers, as well as to determine the optimal ratio of biochar to chemical fertilizers, a two-year field experiment was conducted in southwest China. The results showed that, compared to the locally typical chemical fertilizer treatment (CF), the combined application of biochar and chemical fertilizer significantly increased the yield of both fresh and dry pod pepper. Chemical fertilizer reduction and biochar application also ameliorated fruit quality, increased nutrient accumulation, and improved fertilizer utilization efficiency. What is more, although the employment of biochar made production costs higher, the reduction in chemical fertilizers and the increase in yield improved economic efficiency, especially in the CF₇₀B treatment (70%CF + biochar). In conclusion, moderate amounts of biochar instead of chemical fertilizers may be a valid nutrient management strategy for pod pepper in the karst mountain areas, which is beneficial for maintaining yield stability, improving quality, and increasing net income. Full article

In recent years, vermicompost (V) has been widely used as an amendment for improving crop productivity and soil quality. However, the ameliorative effect of vermicompost on the continuous cropping pepper remains unclear, particularly in the karst areas of southwestern China. A field experiment was conducted to study the effect of vermicompost application on the yield, quality, nutrient accumulation, fertilizer utilization, and economic benefits of continuous cropping pepper from 2021 to 2022. The experiment included six treatments: CK (no fertilizer), FP (the fertilization practice of local farmers), and FPV (FP combined with vermicompost of 1500, 2250, 3000, and 3750 kg·ha⁻¹). The results show that vermicompost application increased the yield of fresh pod pepper by 28.34–51.36% (2021) and 47.13–68.82% (2022), whereas the yield of dry pod pepper increased by 16.97–35.14% (2021) and 34.48–62.61% (2022), respectively, compared with the FP treatment. The application of vermicompost reduced the nitrate content and increased the vitamin C (VC) and soluble sugar content of the fruits, which is beneficial for improving their quality. Vermicompost application not only increased nutrient uptake but also significantly improved agronomic efficiency (AE) and recovery efficiency (RE). In addition, although the application of vermicompost increased production costs, the increase in yield improved net incomes (16.02–31.83% in 2021 and 35.83–62.85% in 2022), especially in the FPV4 treatment. In conclusion, the use of vermicompost amendment had a positive effect on the productivity and economic benefits of continuous cropping pepper, which may be an effective nutrient management strategy for the continuous cropping pepper in the karst mountain areas of southwest China. Full article

Global warming has driven the expansion of cultivated land to high-altitude areas. Intensive vegetable production, which is generally considered to be a high economic value and high environmental risk system, has expanded greatly in high-altitude mountainous areas of China. However, the environmental cost of vegetable production in these areas is poorly understood. In this study, pepper production at low (traditional pepper production area) and high (newly expanded area) altitudes were investigated in Shizhu, a typical pepper crop area. The output and environmental cost at the two altitudes were identified. the influence of resource inputs, climate, and soil properties on pepper production was evaluated. There were obvious differences in output and environmental cost between the two altitudes. High-altitude pepper production achieved a 16.2% lower yield, and had a higher fertilizer input, resulting in a 22.3% lower net ecosystem economic benefit (NEEB), 23.0% higher nitrogen (N) footprint and 24.0% higher carbon (C) footprint compared to low-altitude farming. There is potential for environmental mitigation with both high- and low-altitude pepper production; Compared to average farmers, high-yield farmers groups reduced their N and C footprints by 16.9–24.8% and 18.3–25.2%, respectively, with 30.6–34.1% higher yield. A large increase in yield could also be achieved by increasing the top-dress fertilizer rate and decreasing the plant density. Importantly, high-altitude pepper production was achieved despite less advanced technology and inferior conditions (e.g., a poor road system and uneven fields). It provides a reference for the study of the environmental cost of other high-altitude regions or other crop systems at high-altitude areas. Full article

Native Australian fruits and spices are enriched with beneficial phytochemicals, especially phenolic compounds, which are not fully elucidated. Therefore, this study aimed to analyze native Australian mountain-pepper berries (Tasmannia lanceolata), rosella (Hibiscus sabdariffa), lemon aspen (Acronychia acidula), and strawberry gum (Eucalyptus olida) for phenolic and non-phenolic metabolites and their antioxidant and alpha-glucosidase inhibition activities. Liquid chromatography–mass spectrometry–electrospray ionization coupled with quadrupole time of flight (LC-ESI-QTOF-MS/MS) was applied to elucidate the composition, identities, and quantities of bioactive phenolic metabolites in Australian native commercial fruits and spices. This study identified 143 phenolic compounds, including 31 phenolic acids, 70 flavonoids, 10 isoflavonoids, 7 tannins, 3 stilbenes, 7 lignans, 10 other compounds, and 5 limonoids. Strawberry gum was found to have the highest total phenolic content (TPC—36.57 ± 1.34 milligram gallic acid equivalent per gram (mg GAE/g), whereas lemon aspen contained the least TPC (4.40 ± 0.38 mg GAE/g). Moreover, strawberry gum and mountain pepper berries were found to have the highest antioxidant and anti-diabetic potential. In silico molecular docking and pharmacokinetics screening were also conducted to predict the potential of the most abundant phenolic compounds in these selected plants. A positive correlation was observed between phenolic contents and biological activities. This study will encourage further research to identify the nutraceutical and phytopharmaceutical potential of these native Australian fruits. Full article

Prostate cancer (PCa) is the second leading cause of cancer death among men in the United States. Surgery, radiation therapy, chemotherapy, and androgen deprivation therapy are currently the standard treatment options for PCa. These have poor outcomes and result in the development of castration-resistant prostate cancer (CRPC), which is the foremost underlying cause of mortality associated with PCa. Taxanes, diterpene compounds approved to treat hormonal refractory PCa, show poor outcomes in CRPC. Polygodial (PG) is a natural sesquiterpene isolated from water pepper (Persicaria hydropiper), Dorrigo pepper (Tasmannia stipitata), and mountain pepper (Tasmannia lanceolata). Previous reports show that PG has an anticancer effect. Our results show that PG robustly inhibits the cell viability, colony formation, and migration of taxane-resistant CRPC cell lines and induces cell cycle arrest at the G0 phase. A toxicity investigation shows that PG is not toxic to primary human hepatocytes, 3T3-J2 fibroblast co-cultures, and non-cancerous BPH-1 cells, implicating that PG is innocuous to healthy cells. In addition, PG induces oxidative stress and activates apoptosis in drug-resistant PCa cell lines. Our mechanistic evaluation by a proteome profiler–human apoptotic array in PC3-TXR cells shows that PG induces upregulation of cytochrome c and caspase-3 and downregulation of antiapoptotic markers. Western blot analysis reveals that PG activates apoptotic and DNA damage markers in PCa cells. Our results suggest that PG exhibits its anticancer effect by promoting reactive oxygen species generation and induction of apoptosis in CRPC cells. Full article

The dynamic variation in the water surfaces of the river networks within the Qinghai-Tibet Plateau affects the water resource availability for downstream ecosystems and human activities. Small rivers (with a river width less than 30 m) are an important component of this network, but are difficult to map in the Qinghai-Tibet Plateau. Firstly, the width of most rivers is very narrow, at around 20 m, which appears as only one or two pixels in Sentinel-2 images and thus is susceptible to salt-and-pepper noise. Secondly, local mountain shadows, cloud shadows, and snow pixels have spectral characteristics similar to those of rivers, leading to misclassification. Therefore, we propose an automated small river mapping (ASRM) method based on Sentinel-2 imagery to address these two difficulties. A preprocessing procedure was designed to remove the salt-and-pepper noise and enhance the linear characteristic of rivers with specific widths. A flexible digital elevation model (DEM)-based post-processing was then imposed to remove the misclassifications caused by mountain shadows, cloud shadows, and snow pixels. The ASRM results achieved an overall accuracy of 87.5%, outperforming five preexisting remote sensing-derived river network products. The proposed ASRM method has shown great potential for small river mapping in the entire Qinghai-Tibet Plateau. Full article

Plants play a pivotal role in drug discovery, constituting 50% of modern pharmacopeia. Many human diseases, including age-related degenerative diseases, converge onto common cellular oxidative stress pathways. This provides an opportunity to develop broad treatments to treat a wide range of diseases in the ageing population. Here, we characterize and assess the toxicological effects of finger lime (Citrus australasica), mountain pepper (Tasmannia lanceolata), and small-leaved tamarind (Diploglottis australis) extracts. The characterization demonstrates that these Australian native plants have antioxidant potential and, importantly, they have high concentrations of distinct combinations of different antioxidant classes. Using zebrafish larvae as a high-throughput pre-clinical in vivo toxicology screening model, our experiment effectively discriminates which of these extracts (and at what exposure levels) are suitable for development towards future therapies. The LC50-96h for finger lime and tamarind were >480 mg/L, and 1.70 mg/L for mountain pepper. Critically, this work shows that adverse effects are not correlated to the properties of these antioxidants, thus highlighting the need for combining characterization and in vivo screening to identify the most promising plant extracts for further development. Thus, we present a high-throughput pre-clinical screening that robustly tests natural plant products to utilize the diversity of antioxidant compounds for drug development. Full article