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Ehretia asperula Zoll. & Moritzi was a common medicinal herb found in several Asian nations. This herb was found in many provinces in northern Vietnam, especially Hoa Binh province. Leaves of E. asperula cultivated in Tay Ninh Province were used to isolate compounds and evaluate their potential as antioxidants by five methods, including TAC, RP, FRAP, DPPH, and ABTS•+. Seven compounds were isolated and elucidated from the ethyl acetate fraction, including kaempferol (1), astragalin (2), nicotiflorin (3), rutin (4), caffeic acid (5), (-)-loliolide (6), and daucosterol (7), where compounds 1, 4, 6, and 7 were found from this species for the first time. All isolated compounds from E. asperula leaves exhibited antioxidant activity, consisting of 5.70 ± 0.01 to 299.13 ± 10.19 μg/mL for EC50 values. Especially compound 5 had a very strong antioxidant effect based on five methods TAC (EC50 = 8.43 ± 0.15 μg/mL), RP (EC50 = 6.79 ± 003 μg/mL), FRAP (EC50 = 12.72 ± 006 μg/mL), DPPH (EC50 = 5.57 ± 0.02 µg/mL), and ABTS•+ (EC50 = 5.70 ± 0.01 μg/mL). From our results, Tay Ninh Province's E. asperula leaves are abundant in naturally occurring antioxidants, indicating their potential use as therapeutic materials.

Piper attenuatum Buch-Ham, a perennial woody vine belonging to the Piperaceae family, is traditionally used in Southeast Asia for treating various ailments such as malaria, headache, and hepatitis. This study described the isolation and identification of three new compounds, piperamides I-III (1–3), which belong to the maleimide-type alkaloid skeletons, along with fifteen known compounds (4–18) from the methanol extract of the aerial parts of P. attnuatum. Their chemical structures were elucidated using spectroscopic methods (UV, IR, ESI-Q-TOF-MS, and 1D/2D NMR). All the isolates were evaluated for their ability to inhibit IL-6 activity in the human embryonic kidney-Blue™ IL-6 cell line and their cytotoxic activity against ovarian cancer cell lines (SKOV3/SKOV3-TR) and chemotherapy-resistant variants (cisplatin-resistant A2780/paclitaxel-resistant SKOV3). The compounds 3, 4, 11, 12, 17, and 18 exhibited IL-6 inhibition comparable to that of the positive control bazedoxifene. Notably, compound 12 displayed the most potent anticancer effect against all the tested cancer cell lines. These findings highlight the importance of researching the diverse activities of both known and newly discovered natural products to fully unlock their potential therapeutic benefits. [ABSTRACT FROM AUTHOR]

Despite increasing knowledge of the fitness costs of viability and fecundity involved in the herbicide-resistant weeds, relatively little is known about the linkage between herbicide resistance costs and phytochemical cues in weed species and biotypes. This study demonstrated relative fitness and phytochemical responses in six herbicide-resistant weeds and their susceptible counterparts. There were significant differences in the parameters of viability (growth and photosynthesis), fecundity fitness (flowering and seed biomass) and a ubiquitous phytochemical (–)-loliolide levels between herbicide-resistant weeds and their susceptible counterparts. Fitness costs occurred in herbicide-resistant Digitaria sanguinalis and Leptochloa chinensis but they were not observed in herbicide-resistant Alopecurus japonicas, Eleusine indica, Ammannia arenaria, and Echinochloa crus-galli. Correlation analysis indicated that the morphological characteristics of resistant and susceptible weeds were negatively correlated with (–)-loliolide concentration, but positively correlated with lipid peroxidation malondialdehyde and total phenol contents. Principal component analysis showed that the lower the (–)-loliolide concentration, the stronger the adaptability in E. crus-galli and E. indica. Therefore, not all herbicide-resistant weeds have fitness costs, but the findings showed several examples of resistance leading to improved fitness even in the absence of herbicides. In particular, (–)-loliolide may act as a phytochemical cue to explain the fitness cost of herbicide-resistant weeds by regulating vitality and fecundity. [ABSTRACT FROM AUTHOR]

Despite increasing evidence of kin recognition in natural and crop plants, there is a lack of knowledge of kin recognition in herbicide-resistant weeds that are escalating in cropping systems. Here, we identified a penoxsulam-resistant barnyardgrass biotype with the ability for kin recognition from two biotypes of penoxsulam-susceptible barnyardgrass and normal barnyardgrass at different levels of relatedness. When grown with closely related penoxsulam-susceptible barnyardgrass, penoxsulam-resistant barnyardgrass reduced root growth and distribution, lowering belowground competition, and advanced flowering and increased seed production, enhancing reproductive effectiveness. However, such kin recognition responses were not occurred in the presence of distantly related normal barnyardgrass. Root segregation, soil activated carbon amendment, and root exudates incubation indicated chemically-mediated kin recognition among barnyardgrass biotypes. Interestingly, penoxsulam-resistant barnyardgrass significantly reduced a putative signaling (–)-loliolide production in the presence of closely related biotype but increased production when growing with distantly related biotype and more distantly related interspecific allelopathic rice cultivar. Importantly, genetically identical penoxsulam-resistant and -susceptible barnyardgrass biotypes synergistically interact to influence the action of allelopathic rice cultivar. Therefore, kin recognition in plants could also occur at the herbicide-resistant barnyardgrass biotype level, and intraspecific kin recognition may facilitate cooperation between genetically related biotypes to compete with interspecific rice, offering many potential implications and applications in paddy systems. [ABSTRACT FROM AUTHOR]

Plant defense, growth, and reproduction can be modulated by chemicals emitted from neighboring plants, mainly via volatile aboveground signals. However, belowground signals and their underlying control mechanisms are largely unknown. Here, we experimentally demonstrate that the root-secreted carotenoid (–)-loliolide mediates both defensive and reproductive responses in wild-type Arabidopsis, a carotenoid-deficient Arabidopsis mutant (szl1-1), and tobacco (Nicotiana benthamiana). Wild-type Arabidopsis plants flower later than szl1-1 , and they secrete (–)-loliolide into the soil, whereas szl1-1 roots do not. When Arabidopsis and tobacco occur together, wild-type Arabidopsis induces nicotine production and defense-related gene expression in tobacco, whereas szl1-1 impairs this induction but accelerates tobacco flowering. Furthermore, nicotine production and the expression of the key genes involved in nicotine biosynthesis (QPT , PMT1), plant defense (CAT1 , SOD1 , PR-2a , PI-II , TPI), and flowering (AP1 , LFY , SOC1 , FT3 , FLC) are differently regulated by incubation with wild-type Arabidopsis and szl1-1 root exudates or (–)-loliolide. In particular, (–)-loliolide up-regulated flowering suppressors (FT3 and FLC) and transiently down-regulated flowering stimulators (AP1 and SOC1), delaying tobacco flowering. Therefore, root-secreted (–)-loliolide modulates plant belowground defense and aboveground flowering, yielding critical insights into plant–plant signaling interactions. [ABSTRACT FROM AUTHOR]

Despite increasing knowledge of the fitness costs of viability and fecundity involved in the herbicide-resistant weeds, relatively little is known about the linkage between herbicide resistance costs and phytochemical cues in weed species and biotypes. This study demonstrated relative fitness and phytochemical responses in six herbicide-resistant weeds and their susceptible counterparts. There were significant differences in the parameters of viability (growth and photosynthesis), fecundity fitness (flowering and seed biomass) and a ubiquitous phytochemical (–)-loliolide levels between herbicide-resistant weeds and their susceptible counterparts. Fitness costs occurred in herbicide-resistant Digitaria sanguinalis and Leptochloa chinensis but they were not observed in herbicide-resistant Alopecurus japonicas, Eleusine indica, Ammannia arenaria, and Echinochloa crus-galli. Correlation analysis indicated that the morphological characteristics of resistant and susceptible weeds were negatively correlated with (–)-loliolide concentration, but positively correlated with lipid peroxidation malondialdehyde and total phenol contents. Principal component analysis showed that the lower the (–)-loliolide concentration, the stronger the adaptability in E. crus-galli and E. indica. Therefore, not all herbicide-resistant weeds have fitness costs, but the findings showed several examples of resistance leading to improved fitness even in the absence of herbicides. In particular, (–)-loliolide may act as a phytochemical cue to explain the fitness cost of herbicide-resistant weeds by regulating vitality and fecundity.

Despite increasing evidence of kin recognition in natural and crop plants, there is a lack of knowledge of kin recognition in herbicide-resistant weeds that are escalating in cropping systems. Here, we identified a penoxsulam-resistant barnyardgrass biotype with the ability for kin recognition from two biotypes of penoxsulam-susceptible barnyardgrass and normal barnyardgrass at different levels of relatedness. When grown with closely related penoxsulam-susceptible barnyardgrass, penoxsulam-resistant barnyardgrass reduced root growth and distribution, lowering belowground competition, and advanced flowering and increased seed production, enhancing reproductive effectiveness. However, such kin recognition responses were not occurred in the presence of distantly related normal barnyardgrass. Root segregation, soil activated carbon amendment, and root exudates incubation indicated chemically-mediated kin recognition among barnyardgrass biotypes. Interestingly, penoxsulam-resistant barnyardgrass significantly reduced a putative signaling (–)-loliolide production in the presence of closely related biotype but increased production when growing with distantly related biotype and more distantly related interspecific allelopathic rice cultivar. Importantly, genetically identical penoxsulam-resistant and -susceptible barnyardgrass biotypes synergistically interact to influence the action of allelopathic rice cultivar. Therefore, kin recognition in plants could also occur at the herbicide-resistant barnyardgrass biotype level, and intraspecific kin recognition may facilitate cooperation between genetically related biotypes to compete with interspecific rice, offering many potential implications and applications in paddy systems.

The improvement of performance and yield in both cultivar and species mixtures has been well established. Despite the clear benefits of crop mixtures to agriculture, identifying the critical mechanisms behind performance increases are largely lacking. We experimentally demonstrated that the benefits of rice cultivar mixtures were linked to relatedness-mediated intraspecific neighbour recognition and discrimination under both field and controlled conditions. We then tested biochemical mechanisms of responses in incubation experiments involving the addition of root exudates and a root-secreted signal, (-)-loliolide, followed by transcriptome analysis. We found that closely related cultivar mixtures increased grain yields by modifying root behaviour and accelerating flowering over distantly related mixtures. Importantly, these responses were accompanied by altered concentration of signalling (-)-loliolide that affected rice transcriptome profiling, directly regulating root growth and flowering gene expression. These findings suggest that beneficial crop combinations may be generated a-priori by manipulating neighbour genetic relatedness in rice cultivar mixtures and that root-secreted (-)-loliolide functions as a key mediator of genetic relatedness interactions. The ability of relatedness discrimination to regulate rice flowering and yield raises an intriguing possibility to increase crop production., (© 2024 John Wiley & Sons Ltd.)

Piper attenuatum Buch-Ham, a perennial woody vine belonging to the Piperaceae family, is traditionally used in Southeast Asia for treating various ailments such as malaria, headache, and hepatitis. This study described the isolation and identification of three new compounds, piperamides I-III ( 1 - 3 ), which belong to the maleimide-type alkaloid skeletons, along with fifteen known compounds ( 4 - 18 ) from the methanol extract of the aerial parts of P. attnuatum . Their chemical structures were elucidated using spectroscopic methods (UV, IR, ESI-Q-TOF-MS, and 1D/2D NMR). All the isolates were evaluated for their ability to inhibit IL-6 activity in the human embryonic kidney-Blue™ IL-6 cell line and their cytotoxic activity against ovarian cancer cell lines (SKOV3/SKOV3-TR) and chemotherapy-resistant variants (cisplatin-resistant A2780/paclitaxel-resistant SKOV3). The compounds 3 , 4 , 11 , 12 , 17 , and 18 exhibited IL-6 inhibition comparable to that of the positive control bazedoxifene. Notably, compound 12 displayed the most potent anticancer effect against all the tested cancer cell lines. These findings highlight the importance of researching the diverse activities of both known and newly discovered natural products to fully unlock their potential therapeutic benefits.

Neighbor detection and allelochemical response are important mediators in plant–plant interactions. Although there is increasing knowledge about plant allelochemicals released in response to the presence of competitors and involved in neighbor-derived signaling, less is known about which signaling chemicals are responsible for the neighbor-induced allelochemical response. Here, we experimentally demonstrate that (–)-loliolide, a carotenoid metabolite, acts as a signaling chemical in barnyardgrass–rice allelopathic interactions. The production of the rice allelochemicals momilactone B and tricin was increased in the presence of five biotypes of barnyardgrass. (–)-Loliolide was found in all the biotypes of barnyardgrass and their root exudates and rhizosphere soils. There were significant positive relationships between rice allelochemicals and (–)-loliolide concentrations across the biotypes of barnyardgrass. Furthermore, (–)-loliolide elicited the production of momilactone B and tricin. Comparative transcriptomic analysis revealed regulatory activity of (–)-loliolide on the diterpenoid and flavonoid biosynthesis pathway. The expression of key genes involved in the biosynthesis of momilactone B (CPS4 , KSL4 , and MAS) and tricin (CYP75B3 and CYP75B4) was up-regulated by (–)-loliolide. These findings suggest that (–)-loliolide acts as a signaling chemical and participates in barnyardgrass-rice allelopathic interactions. Allelopathic rice plants can detect competing barnyardgrass through the presence of this signaling chemical and respond by increasing levels of their allelochemicals to achieve an advantage for their own growth. [ABSTRACT FROM AUTHOR]

The present study evaluated the effects of (–)-loliolide isolated from Sargassum horneri (S. horneri) against oxidative stress and inflammation, and its biological mechanism in interferon (IFN)-γ/tumor necrosis factor (TNF)-α-stimulated HaCaT keratinocytes. The results showed that (–)-loliolide improved the cell viability by reducing the production of intracellular reactive oxygen species (ROS) in IFN-γ/TNF-α-stimulated HaCaT keratinocytes. In addition, (–)-loliolide effectively decreased the expression of inflammatory cytokines (interleukin (IL)-4 IL-6, IL-13, IFN-γ and TNF-α) and chemokines (CCL11 (Eotaxin), macrophage-derived chemokine (MDC), regulated on activation, normal T cell expressed and secreted (RANTES), and thymus and activation-regulated chemokine (TARC)), by downregulating the expression of epidermal-derived initial cytokines (IL-25, IL-33 and thymic stromal lymphopoietin (TSLP)). Furthermore, (–)-loliolide suppressed the activation of mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling, whereas it activated nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling. Interestingly, the cytoprotective effects of (–)-loliolide against IFN-γ/TNF-α stimulation were significantly blocked upon inhibition of HO-1. Taken together, these results suggest that (–)-loliolide effectively suppressed the oxidative stress and inflammation by activating the Nrf2/HO-1 signaling in IFN-γ/TNF-α-stimulated HaCaT keratinocytes.

At present air pollution in parts of East Asia is at an alarming level due to elevated levels of fine dust (FD). Other than pulmonary complications, FD was found to affect the pathogenesis of ROS-dependent inflammatory responses via penetrating barrier-disrupted skin, leading to degradation of extracellular matrix components through the keratinocyte-fibroblast axis. The present study discloses the evaluation of human dermal fibroblast (HDF) responses to FD preconditioned human keratinocyte media (HPM) primed without and with (-)-loliolide (HTT). HPM-FD treatment increased the ROS level in HDFs and activated mitogen-activated protein kinase-derived nuclear factor (NF)-κB inflammatory signaling pathways with a minor reduction of viability. The above events led to cell differentiation and production of matrix metalloproteinases (MMP), increasing collagenase and elastase activity despite the increase of tissue inhibitors of metalloproteinases (TIMP). Media from HTT primed keratinocytes stimulated with FD indicated ameliorated levels of MMPs, inflammatory cytokines, and chemokines in HDFs with suppressed collagenase and elastase activity. Present observations help to understand the factors that affect HDFs in the microenvironment of FD exposed keratinocytes and the therapeutic role of HTT as a suppressor of skin aging. Further studies using organotypic skin culture models could broaden the understanding of the effects of FD and the therapeutic role of HTT.

The emergence of fine dust (FD) among air pollutants has taken a toll during the past few decades, and it has provided both controversy and a platform for open conversation amongst world powers for finding sustainable solutions and effective treatments for health issues. The present study emphasizes the protective effects of (–)-loliolide (HTT) isolated from Sargassum horneri against FD-induced oxidative stress in human HaCaT keratinocytes. The purification of (–)-loliolide was carried out by centrifugal partition chromatography. HTT did not show any cytotoxicity, and it further illustrated the potential to increase cell viability by reducing the reactive oxygen species (ROS) production in FD-stimulated keratinocytes. Furthermore, HTT suppressed FD-stimulated DNA damage and the formation of apoptotic bodies, and it reduced the population of cells in the sub-G1 apoptosis phase. FD-induced apoptosis was advancing through the mitochondria-mediated apoptosis pathway. The cytoprotective effects of the HTT against FD-stimulated oxidative damage is mediated through squaring the nuclear factor E2-related factor 2 (Nrf2)-mediated heme oxygenase-1 (HO-1) pathway, dose-dependently increasing HO-1 and NAD(P)H dehydrogenase (quinone) 1 (NQO1) levels in the cytosol while concomitantly improving the nuclear translocation of Nrf2. Future studies could implement the protective functionality of HTT in producing pharmaceuticals that utilize natural products and benefit the diseased.

The present study evaluated the effects of (–)-loliolide isolated from Sargassum horneri (S. horneri) against oxidative stress and inflammation, and its biological mechanism in interferon (IFN)-γ/tumor necrosis factor (TNF)-α-stimulated HaCaT keratinocytes. The results showed that (–)-loliolide improved the cell viability by reducing the production of intracellular reactive oxygen species (ROS) in IFN-γ/TNF-α-stimulated HaCaT keratinocytes. In addition, (–)-loliolide effectively decreased the expression of inflammatory cytokines (interleukin (IL)-4 IL-6, IL-13, IFN-γ and TNF-α) and chemokines (CCL11 (Eotaxin), macrophage-derived chemokine (MDC), regulated on activation, normal T cell expressed and secreted (RANTES), and thymus and activation-regulated chemokine (TARC)), by downregulating the expression of epidermal-derived initial cytokines (IL-25, IL-33 and thymic stromal lymphopoietin (TSLP)). Furthermore, (–)-loliolide suppressed the activation of mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling, whereas it activated nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling. Interestingly, the cytoprotective effects of (–)-loliolide against IFN-γ/TNF-α stimulation were significantly blocked upon inhibition of HO-1. Taken together, these results suggest that (–)-loliolide effectively suppressed the oxidative stress and inflammation by activating the Nrf2/HO-1 signaling in IFN-γ/TNF-α-stimulated HaCaT keratinocytes. [ABSTRACT FROM AUTHOR]

At present air pollution in parts of East Asia is at an alarming level due to elevated levels of fine dust (FD). Other than pulmonary complications, FD was found to affect the pathogenesis of ROS-dependent inflammatory responses via penetrating barrier-disrupted skin, leading to degradation of extracellular matrix components through the keratinocyte-fibroblast axis. The present study discloses the evaluation of human dermal fibroblast (HDF) responses to FD preconditioned human keratinocyte media (HPM) primed without and with (-)-loliolide (HTT). HPM-FD treatment increased the ROS level in HDFs and activated mitogen-activated protein kinase-derived nuclear factor (NF)-κB inflammatory signaling pathways with a minor reduction of viability. The above events led to cell differentiation and production of matrix metalloproteinases (MMP), increasing collagenase and elastase activity despite the increase of tissue inhibitors of metalloproteinases (TIMP). Media from HTT primed keratinocytes stimulated with FD indicated ameliorated levels of MMPs, inflammatory cytokines, and chemokines in HDFs with suppressed collagenase and elastase activity. Present observations help to understand the factors that affect HDFs in the microenvironment of FD exposed keratinocytes and the therapeutic role of HTT as a suppressor of skin aging. Further studies using organotypic skin culture models could broaden the understanding of the effects of FD and the therapeutic role of HTT. [ABSTRACT FROM AUTHOR]

The emergence of fine dust (FD) among air pollutants has taken a toll during the past few decades, and it has provided both controversy and a platform for open conversation amongst world powers for finding sustainable solutions and effective treatments for health issues. The present study emphasizes the protective effects of (–)-loliolide (HTT) isolated from Sargassum horneri against FD-induced oxidative stress in human HaCaT keratinocytes. The purification of (–)-loliolide was carried out by centrifugal partition chromatography. HTT did not show any cytotoxicity, and it further illustrated the potential to increase cell viability by reducing the reactive oxygen species (ROS) production in FD-stimulated keratinocytes. Furthermore, HTT suppressed FD-stimulated DNA damage and the formation of apoptotic bodies, and it reduced the population of cells in the sub-G1 apoptosis phase. FD-induced apoptosis was advancing through the mitochondria-mediated apoptosis pathway. The cytoprotective effects of the HTT against FD-stimulated oxidative damage is mediated through squaring the nuclear factor E2-related factor 2 (Nrf2)-mediated heme oxygenase-1 (HO-1) pathway, dose-dependently increasing HO-1 and NAD(P)H dehydrogenase (quinone) 1 (NQO1) levels in the cytosol while concomitantly improving the nuclear translocation of Nrf2. Future studies could implement the protective functionality of HTT in producing pharmaceuticals that utilize natural products and benefit the diseased. [ABSTRACT FROM AUTHOR]

The emergence of fine dust (FD) among air pollutants has taken a toll during the past few decades, and it has provided both controversy and a platform for open conversation amongst world powers for finding sustainable solutions and effective treatments for health issues. The present study emphasizes the protective effects of (-)-loliolide (HTT) isolated from Sargassum horneri against FD-induced oxidative stress in human HaCaT keratinocytes. The purification of (-)-loliolide was carried out by centrifugal partition chromatography. HTT did not show any cytotoxicity, and it further illustrated the potential to increase cell viability by reducing the reactive oxygen species (ROS) production in FD-stimulated keratinocytes. Furthermore, HTT suppressed FD-stimulated DNA damage and the formation of apoptotic bodies, and it reduced the population of cells in the sub-G 1 apoptosis phase. FD-induced apoptosis was advancing through the mitochondria-mediated apoptosis pathway. The cytoprotective effects of the HTT against FD-stimulated oxidative damage is mediated through squaring the nuclear factor E2-related factor 2 (Nrf2)-mediated heme oxygenase-1 (HO-1) pathway, dose-dependently increasing HO-1 and NAD(P)H dehydrogenase (quinone) 1 (NQO1) levels in the cytosol while concomitantly improving the nuclear translocation of Nrf2. Future studies could implement the protective functionality of HTT in producing pharmaceuticals that utilize natural products and benefit the diseased.