Assessment of Mosquito Pollination.

Adult mosquitoes, sometimes in vast numbers, visit flowers in their search for floral nectar. However, the ability of mosquitoes to pollinate the flowers they visit is often neglected and sometimes even presumptively dismissed. Despite this, mosquito pollination has been reported in many instances, although many questions linger about its extent, importance, and the breadth of floral species or mosquito species which may be involved. In this protocol, I describe methodology to assess whether mosquitoes pollinate a flowering plant they visit, which can create a foundation for future investigations into this topic.

Global assessment of honeybee exposure to pesticides through guttation consumption: An indicator approach.

Guttation consumption is a potential pathway of pesticide residue exposure in honeybees. However, modeling tools for assessing honeybee exposure to pesticide residues in guttation drops are lacking. In this study, we propose an indicator-based approach for qualitatively or quantitatively analyzing the guttation-based exposure pathway, allowing us to conduct region-specific pesticide residue exposure assessments for honeybees. Exposure scores (the product of guttation production and residue level scores) were established to compare or rank honeybee exposure to pesticide residues via guttation intake across locations using three specified indicators (i.e., air temperature, relative humidity, and precipitation intensity). Warm, dry regions had high residue level scores (indicating high residue levels in guttation), whereas cold, wet regions had high guttation production scores (indicating high possibilities of guttation formation on leaf surfaces); their exposure scores were a combination of these two values. We evaluated and ranked honeybee exposure to imidacloprid residue across regions in Brazil, China, the United States, and selected European Union member states, revealing that pesticide application in many Brazilian federative units may raise honeybee risks due to high exposure scores. We also compared the guttation pathway to other common exposure pathways (nectar and pollen), suggesting that for some moderately lipophilic compounds, the guttation exposure pathway may not be ignored and should be further evaluated.

Floral nectar production: what cost to a plant?

Floral nectar production is central to plant pollination, and hence to human wellbeing. As floral nectar is essentially a solution in water of various sugars, it is likely a valuable plant resource, especially in terms of energy, with plants experiencing costs/trade-offs associated with its production or absorption and adopting mechanisms to regulate nectar in flowers. Possible costs of nectar production may also influence the evolution of nectar volume, concentration and composition, of pollination syndromes involving floral nectar, and the production of some crops. There has been frequent agreement that costs of floral nectar production are significant, but relevant evidence is scant and difficult to interpret. Convincing direct evidence comes from experimental studies that relate either enhanced nectar sugar production (through repeated nectar removal) to reduced ability to produce seeds, or increased sugar availability (through absorption of additional artificial nectar) to increased seed production. Proportions of available photosynthate allocated by plants to nectar production may also indicate nectar cost. However, such studies are rare, some do not include treatments of all (or almost all) flowers per plant, and all lack quantitative cost-benefit comparisons for nectar production. Additional circumstantial evidence of nectar cost is difficult to interpret and largely equivocal. Future research should repeat direct experimental approaches that relate reduced or enhanced nectar sugar availability for a plant with consequent ability to produce seeds. To avoid confounding effects of inter-flower resource transfer, each plant should experience a single treatment, with treatment of all or almost all flowers per plant. Resource allocation by plants, pathways used for resource transfer, and the locations of resource sources and sinks should also be investigated. Future research should also consider extension of nectar cost into other areas of biology. For example, evolutionary models of nectar production are rare but should be possible if plant fitness gains and costs associated with nectar production are expressed in the same currency, such as energy. It should then be possible to understand observed nectar production for different plant species and pollination syndromes involving floral nectar. In addition, potential economic benefits should be possible to assess if relationships between nectar production and crop value are evaluated.

The discriminant ability of the eating assessment tool-10 questionnaire to detect residue and aspiration in patients with mixed etiology of dysphagia.

PURPOSE: To investigate the discriminant ability of the eating assessment tool-10 (EAT-10) to detect postswallow residue and aspiration for different consistencies. METHODS: Seventy-two consecutive patients with mixed etiology of dysphagia (42 males and 30 females, mean ± sd age of 60.42 ± 15.82) were included. After completing the EAT-10, Fiberoptic Endoscopic Evaluation of Swallowing (FEES) was performed to assess the efficiency and safety of swallowing for the following consistencies: thin liquid, nectar thick, yogurt, and solid. While swallowing efficiency was evaluated using the Yale Pharyngeal Residue Severity Rating Scale (YPRSRS), the Penetration-Aspiration Scale (PAS) was used to evaluate swallowing safety. RESULTS: The EAT-10 questionnaire significantly identified the patients with residue from those without residue for the following consistencies and anatomic locations: thin liquid residue in the pyriform sinus (cutoff score ≥ 10, p = 0.009), nectar thick residue in the vallecula (cutoff score ≥ 15, p = 0.001), yogurt residue in the vallecula (cutoff score ≥ 15, p = 0.009), yogurt residue in the pyriform sinus (cutoff score ≥ 9, p = 0.015), and solid residue in the vallecula (cutoff score ≥ 13, p = 0.016). However, the same discriminant ability of EAT-10 was not found for detecting aspiration in any consistency. CONCLUSIONS: The EAT-10 questionnaire can be used as an assessment tool to judge swallowing efficiency in patients with mixed etiology of dysphagia, but the same is not evident for swallowing safety.

Systemic assessment of the chiral insecticide pyriproxyfen in a citrus nectar source system: Stereoselective degradation, biological effect and exposure risk.

BACKGROUND: Balancing the safety and efficiency of chiral pesticides can help protect pollinators. We evaluated the stereoselective behavior, bioactivity, toxicity and exposure risk of the chiral insecticide pyriproxyfen in a citrus nectar system. RESULTS: Density functional theory (DFT) and ultra-performance liquid chromatography tandem mass spectroscopy (UPLC-MS/MS) were applied for absolute configuration appraisal and chiral analysis validation, respectively. The recoveries ranged from 72.3% to 100.5% with an relative standard deviation (RSD) ranging from 1.2% to 9.7%. In a field trial, we determined insecticide half-lives in citrus leaves and flowers, which were 7.0 and 8.6 days for R-(+)-pyriproxyfen, and 11.7 and 14.7 days for S-(-)-pyriproxyfen, respectively. We found that the bioactivity of R-(+)-pyriproxyfen was 3.39 and 2.37 times higher than S-(-)-pyriproxyfen against Unaspis yanonensis and Diaphorina citri nymphs, respectively. S-(-)-pyriproxyfen had 3.8 times higher acute toxicity than R-(+)-pyriproxyfen on Apis mellifera L., and its exposure risk was moderate based on the hazard quotient. CONCLUSION: The phenomenon of stereoselective degradation and biological effect demonstrated that the high-risk stereoisomer of S-(-)-pyriproxyfen degraded more slowly than R-(+)-pyriproxyfen, but R-(+)-pyriproxyfen with better efficiency for target. Therefore, an increased duration of R-(+)-pyriproxyfen activity on citrus was beneficial for efficacy. Our results could guide the scientific application and evaluation of chiral pesticides on nectar plants. © 2022 Society of Chemical Industry.

Modeling pesticide residues in nectar and pollen in support of pesticide exposure assessment for honeybees: A generic modeling approach.

Pesticide residues in nectar and pollen of plants can damage honeybees; however, few modeling approaches have simulated residue levels in nectar and pollen in support of exposure assessment for honeybees. This study introduced a generic modeling approach based on plant uptake models and simple partitioning rules that specifies soil incorporation and foliar spray application scenarios of pesticides and is flexible for conducting variability analysis for various environmental conditions, pesticide application patterns, chemical individuals, and plant varieties. The results indicated that, in general, systemic or moderate lipophilicity (log KOW of ~2.5) pesticides have relatively high simulated residue levels in nectar and pollen because of the enhanced residue uptake process from soil. For non-systemic or highly lipophilic pesticides, the residue uptake via leaf surface deposition pathway can be enhanced, and more residues will be bioaccumulated in pollen than nectar due to a relatively high lipid content of pollen (as compared to nectar), but the overall residue levels in nectar and pollen are lower than systemic or moderately lipophilic pesticides. The variability analysis showed that environmental conditions, pesticide application patterns, chemical properties, and plant varieties cause considerable variations in simulated residue levels in nectar and pollen, indicating that spatiotemporal, chemical, and plant-related factors must be considered in pesticide exposure assessment for honeybees. Moreover, the comparison between the simulated and measured data showed a high degree of consistency, indicating that the proposed model could be used to conduct a screening-level pesticide exposure assessment for honeybees.

Nectar Yeast Community of Tropical Flowering Plants and Assessment of Their Osmotolerance and Xylitol-Producing Potential.

Floral nectar is colonised by microbes, especially yeasts which alter the scent, temperature, and chemical composition of nectar, thereby playing an essential role in pollination. The yeast communities inhabiting the nectar of tropical flowers of India are not well explored. We isolated 48 yeast strains from seven different tropical flowering plants. Post MSP-PCR-based screening, 23 yeast isolates and two yeast-like fungi were identified, which belonged to 16 species of 12 genera viz. Candida (2 species), Aureobasidium (2 species), Metschnikowia (2 species), Meyerozyma (1 species), Saitozyma (1 species), Wickerhamomyces (1 species), Kodamaea (2 species), Pseudozyma (1 species), Starmerella (1 species), Hanseniaspora (1 species), Rhodosporidiobolus (1 species), Moesziomyces (1 species), and two putative novel species. All yeast strains were assessed for their osmotolerance abilities in high salt and sugar concentration. Among all the isolates, C. nivariensis (SRA2.2, SRA1.1 and SRA2.1), M. caribbica (SRA4.8 and SRA4.6), S. flava SRA4.2, and M. reukaufii SRA3.2 showed significant growth in high concentrations of sugar (40-50% glucose), as well as salt (12-15% NaCl). All 25 strains were also screened for their ability to utilise xylose to produce xylitol. Meyerozyma caribbica was the most efficient xylitol producer, wherein three strains of this species (SRA4.6, SRA4.1, and SRA4.8) generated 18.61 to 21.56 g l-1 of xylitol, with 0.465-0.539 g g-1 yields. Through this study, we draw attention towards the tropical floral nectar as a potential niche for the isolation of diverse, osmotolerant, and xylitol-producing yeasts. Such osmotolerant yeasts have potential applications in food industries and biofuel production.

Bene"fit" Assessment in Pollination Coevolution: Mechanistic Perspectives on Hummingbird Bill-Flower Matching.

One of the reasons why flowering plants became the most diverse group of land plants is their association with animals to reproduce. The earliest examples of this mutualism involved insects foraging for food from plants and, in the process, pollinating them. Vertebrates are latecomers to these mutualisms, but birds, in particular, present a wide variety of nectar-feeding clades that have adapted to solve similar challenges. Such challenges include surviving on small caloric rewards widely scattered across the landscape, matching their foraging strategy to nectar replenishment rate, and efficiently collecting this liquid food from well-protected chambers deep inside flowers. One particular set of convergent traits among plants and their bird pollinators has been especially well studied: the match between the shape and size of bird bills and ornithophilous flowers. Focusing on a highly specialized group, hummingbirds, we examine the expected benefits from bill-flower matching, with a strong focus on the benefits to the hummingbird and how to quantify them. Explanations for the coevolution of bill-flower matching include (1) that the evolution of traits by bird-pollinated plants, such as long and thin corollas, prevents less efficient pollinators (e.g., insects) from accessing the nectar and (2) that increased matching, as a result of reciprocal adaptation, benefits both the bird (nectar extraction efficiency) and the plant (pollen transfer). In addition to nectar-feeding, we discuss how interference and exploitative competition also play a significant role in the evolution and maintenance of trait matching. We present hummingbird-plant interactions as a model system to understand how trait matching evolves and how pollinator behavior can modify expectations based solely on morphological matching, and discuss the implications of this behavioral modulation for the maintenance of specialization. While this perspective piece directly concerns hummingbird-plant interactions, the implications are much broader. Functional trait matching is likely common in coevolutionary interactions (e.g., in predator-prey interactions), yet the physical mechanisms underlying trait matching are understudied and rarely quantified. We summarize existing methods and present novel approaches that can be used to quantify key benefits to interacting partners in a variety of ecological systems.

Gut reaction! Neotropical nectar-feeding bats responses to direct and indirect costs of extreme environmental temperatures.

One of the consequences of anthropogenic climate change is an increase in the frequency and intensity of extreme weather events. These events have caused mass mortality of different species of wildlife, including bats. In this study, we exposed two species of neotropical nectar-feeding bats that live in contrasting environmental conditions (A. geoffroyi and L. yerbabuenae) to extreme high and low temperatures while offering them diets with different energy content. This experimental approach allowed us to determine their thermal and behavioral responses, and to identify environmental conditions that impose high physiologic costs to these species. To determine how bats' responded, we monitored both changes in their body masses and skin temperatures. Both bat species responded differently, with L. yerbabuenae spending more time in normothermia at high temperatures than A. geoffroyi. While both species presented torpor, they used it differently. Torpor allowed A. geoffroyi to maintain and increase body mass at intermediate and low ambient temperatures. At the same time, L. yerbabuenae used torpor only when facing cold ambient temperatures and low-quality food. Understanding the mechanisms that allow species to face changes in their environment is essential given the current climate trends and the fact that the loss of these species could have significant negative consequences in tropical and subtropical ecosystems.

Multiple 1-MCP treatment more effectively alleviated postharvest nectarine chilling injury than conventional one-time 1-MCP treatment by regulating ROS and energy metabolism.

The objective of the present study was to investigate the effectiveness of different 1-MCP treatment patterns on alleviating chilling injury (CI) of postharvest nectarine stored at 0 ± 1 °C. Nectarine fruits were subjected to the following treatments: Single-High dose 1-MCP treatment (S-H): 1 µL L-1 application before storage; Multi-low dose 1-MCP treatment: (M-L) Five 0.25 µL L-1 applications after 0, 5, 10, 15, and 20 d of storage; Multi-high dose 1-MCP treatment (M-H): Five 1 µL L-1 applications after 0, 5, 10, 15 and 20 d of storage. The results showed that although all 1-MCP treatments alleviated CI, M-H 1-MCP treatment is the most effective pattern in alleviating CI of nectarine fruit in S-H, M-L, and M-H 1-MCP treatments. Moreover, this study indicated that the reduction of CI in nectarine by 1-MCP application was related to its regulations of ROS and energy metabolism.

Honeybee colonies provide foragers with costly fuel to promote pollen collection.

Honeybee pollen foragers departing the hive carry concentrated nectar to use as fuel for flight and glue for forming pollen loads. Since nectar is concentrated by in-hive bees at the cost of time and energy, using concentrated nectar increases the cost of foraging at the colony level. This experimental study explored the potential benefit to honeybees of using concentrated nectar for pollen collection by diluting nectar carried by pollen foragers from the hive. Mass feeding with 30% sugar solution successfully reduced the crop-load-sugar concentration in putative pollen foragers departing the hive, but while those bees tended to increase the crop-load volume, such increase did not fully compensate for the decreased amount of dissolved sugars in the crop load. Feeding 30% sugar solution reduced the pollen load dry weight by approx. 10-20% compared to the unfed control and to another test group fed 60% sugar solution. In addition, the pollen load size and sugar concentration of crop load remaining in returning pollen foragers was positively correlated. These results clearly show the advantage to honeybees of using concentrated nectar for pollen foraging.

Analysis on safety assessment of Tephrosia vogelii Hook to Apis cerana cerana.

Tephrosia vogelii Hook was excellent insecticidal plant, it was introduced into China and planted over a large area in Guangdong province. The main active components of T. vogelii was rotenone and it widely found in leaves and pods of T. vogelii. This paper study of the safety assessment of T. vogelii flowers to worker bees. In this paper, the content of rotenone in T. vogelii petal, nectar, pollen, pistil, and stamen samples were investigated by HPLC, and tested the toxicity of T. vogelii flowers for Apis cerana cerana during 24 h. The dissipation and dynamic of rotenone in A. c. cerana different biological compartments were investigated under indoor conditions during 24 h. The results showed, The LT50 of T. vogelii flowers to worker bees were collected from the eastern, western, southern, northern and top were 13.95, 24.17, 12.55, 26.48, and 18.84 h, the haemolymph of worker bees have the highest content of rotenone, the least accumulation of rotenone in workers bee's thorax, and the rate of dissipation was slowly during the whole study. In conclusion, the results showed the T. vogelii create security risks to worker bees under some ecosystems.

Nectar quality changes the ecological costs of chemically defended pollen.

Plants often compete in a marketplace that involves the exchange of floral rewards for pollination service [1]. This marketplace is frequently viewed as revolving around a single currency, typically nectar. While this focus has established pollinators such as bees as classic models in foraging ecology, in reality many plants provide both pollen and nectar, which vary in composition within and across species [2]. How this complexity impacts interactions between plants, pollinators, and co-flowering competitors is unknown. We explored how variation in two axes of reward chemistry - nectar sugar and pollen alkaloid content - impacted competition for bumblebee visits. The effect of variation in one reward depended on the presence and quality of the other - bees discriminated against flowers with more defended pollen when all flowers offered the same quality nectar. However, bees preferred flowers with highly defended pollen when they offered higher quality nectar, suggesting that attractive nectar can overcome the ecological costs of defended pollen. Recognizing the interdependence of these floral currencies may help identify traits that drive indirect interactions between plants and clarify broader evolutionary patterns of floral reward phenotypes.

Foraging Economics of the Hunt Bumble Bee, a Viable Pollinator for Commercial Agriculture.

Globally, there are only five bumble bee (Hymenoptera: Apidae, Bombus) species that have been successfully commercialized for agriculture. The Hunt bumble bee, Bombus huntii Green, 1860, has been recognized as a suitable pollinator of crops and has a broad distribution in western North America, making it a viable candidate for commercialization. In this study, our goal was to characterize the foraging dynamics of B. huntii female workers under open field conditions. To accomplish this goal, we monitored three B. huntii colonies over an 8-wk period in the summer of 2012 in northern Utah. Using marked bees, we studied the relationship between foraging duration/offloading and pollen/nonvisible pollen collection. In total, we observed 921 foraging events across all three colonies. Of our observations, 82% (n = 756) were foraging events that included both a departure and arrival time observation. Average duration of pollen and nonpollen (i.e., nectar) trips across foragers is 41.86 ± 5.65 min (±SE) and 32.18 ± 5.89 min, respectively. Workers spent a significantly longer time offloading pollen in the nest after a foraging trip relative to workers without pollen present on their corbicula. Pollen foraging rate increases over the course of the day, likely due to the time it takes to learn how to forage on a diverse array of flower morphologies. Our study provides data on how long it takes for B. huntii to forage in open field conditions and will be useful when comparing foraging rates in controlled crop systems.

NMR assessment of European acacia honey origin and composition of EU-blend based on geographical floral markers.

A geographical discrimination of honey is an important prerequisite for quality and authenticity control. Here, we present a method based on an NMR-metabolomic analysis of organic extracts for a geographical discrimination of commercial European acacia honeys found on the Italian market. All 234 analysed samples show the characteristic 1H NMR profile of acacia (Robinia pseudoacacia) honey. However, a PLS2-DA model revealed variations among production zones allowing the successful geographical differentiation with a 100% of overall correct classification rate. Moreover, a PLS2 model is able to predict the proportions in binary blends of Italian and Eastern European acacia honeys. The geographical distinction and the possibility to characterize the content of blends derive from different markers content originating from minor nectar contributions of the acacia-accompanying flora.

Thiamethoxam: Long-term effects following honey bee colony-level exposure and implications for risk assessment.

Neonicotinoid insecticides have been used in a wide range of crops through seed treatment, soil and foliar applications and a large database exists on both their lethal and sub-lethal effects on honey bees under controlled laboratory conditions. However, colony-level studies on the effects of neonicotinoids in field studies are limited, primarily due to their complexity and the resources required. This paper reports the combined results of two large-scale colony-feeding studies, each with 6 weeks of continuous dosing of 12 colonies per treatment (24 control) to 12.5, 25, 37.5, 50 or 100 ng thiamethoxam/g sucrose solution. Exposure continued beyond dosing with residues present in stored nectar and bee-bread. The studies were conducted in an area with limited alternative forage and colonies were required to forage for pollen and additional nectar The studies provide colony-level endpoints: significant effects (reductions in bees, brood) were observed after exposure to the two highest dose rates, colony loss occurred at the highest dose rate, but colonies were able to recover (2-3 brood cycles after the end of dosing) after dosing with 50 ng thiamethoxam/g sucrose. No significant colony-level effects were observed at lower dose rates. The data reported here support the conclusions of previous colony-level crop-based field studies with thiamethoxam, in which residues in pollen and nectar were an order of magnitude below the colony-level NOEC of 37.5 ng thiamethoxam/g sucrose. The feeding study data are also compared to the outcomes of regulatory Tier 1 risk assessments conducted using guidance provided by the USA, Canada, Brazil and the EU regulatory authorities. We propose an adaptation of the European chronic adult bee risk assessment that takes into account the full dataset generated in laboratory studies while still providing an order of magnitude of safety compared with the colony feeding study NOEC.

Species coexistence through simultaneous fluctuation-dependent mechanisms.

Understanding the origins and maintenance of biodiversity remains one of biology's grand challenges. From theory and observational evidence, we know that variability in environmental conditions through time is likely critical to the coexistence of competing species. Nevertheless, experimental tests of fluctuation-driven coexistence are rare and have typically focused on just one of two potential mechanisms, the temporal storage effect, to the neglect of the theoretically equally plausible mechanism known as relative nonlinearity of competition. We combined experiments and simulations in a system of nectar yeasts to quantify the relative contribution of the two mechanisms to coexistence. Resource competition models parameterized from single-species assays predicted the outcomes of mixed-culture competition experiments with 83% accuracy. Model simulations revealed that both mechanisms have measurable effects on coexistence and that relative nonlinearity can be equal or greater in magnitude to the temporal storage effect. In addition, we show that their effect on coexistence can be both antagonistic and complementary. These results falsify the common assumption that relative nonlinearity is of negligible importance, and in doing so reveal the importance of testing coexistence mechanisms in combination.

Costs and benefits of alternative food handling tactics help explain facultative exploitation of pollination mutualisms.

Many mutualisms are taken advantage of by organisms that take rewards from their partners but provide no benefit in return. In the absence of traits that limit exploitation, facultative exploiters (partners that can either exploit or cooperate) are widely predicted by mutualism theory to choose an exploitative strategy, potentially threatening mutualism stability. However, it is unknown whether facultative exploiters choose to exploit, and, if so, make this choice because it is the most beneficial strategy for them. We explored these questions in a subalpine plant-insect community in which individuals of several bumble bee species visit flowers both "legitimately" (entering via the flower opening, picking up and depositing pollen, and hence behaving mutualistically) and via nectar robbing (creating holes through corollas or using an existing hole, bypassing stigmas and anthers). We applied foraging theory to (1) quantify handling costs, benefits and foraging efficiencies incurred by three bumble bee species as they visited flowers legitimately or robbed nectar in cage experiments, and (2) determine whether these efficiencies matched the food handling tactics these bee species employed in the field. Relative efficiencies of legitimate and robbing tactics depended on the combination of bee and plant species. In some cases (Bombus mixtus visiting Corydalis caseana or Mertensia ciliata), the robbing tactic permitted more efficient nectar removal. As both mutualism and foraging theory would predict, in the field, B. mixtus visiting C. caseana were observed more frequently robbing than foraging legitimately. However, for Bombus flavifrons visiting M. ciliata, the expectation from mutualism theory did not hold: legitimate visitation was the more efficient tactic. Legitimate visitation to M. ciliata was in fact more frequently observed in free-flying B. flavifrons. Free-flying B. mixtus also frequently visited M. ciliata flowers legitimately. This may reflect lower nectar volumes in robbed than unrobbed flowers in the field. These results suggest that a foraging ecology perspective is informative to the choice of tactics facultative exploiters make. In contrast, the simple expectation that exploiters should always have an advantage, and hence could threaten mutualism persistence unless they are deterred or punished, may not be broadly applicable.

The inhibitory effect of Manuka honey on human colon cancer HCT-116 and LoVo cell growth. Part 1: the suppression of cell proliferation, promotion of apoptosis and arrest of the cell cycle.

Numerous investigations have been made on plant phenolic compounds and cancer prevention in recent decades. Manuka honey (MH) represents a good source of phenolic compounds such as luteolin, kaempferol, quercetin, gallic acid and syringic acid. The aim of this work was to evaluate the chemopreventive effects of MH on human colon cancer HCT-116 and LoVo cells. Both cells were exposed to different concentrations of MH (0-20 mg mL-1 for HCT-116 cells and 0-50 mg mL-1 for LoVo cells) for 48 h to measure apoptosis and cell cycle arrest as well as apoptosis and cell cycle regulatory gene and protein expression. MH exhibited profound inhibitory effects on cellular growth by reducing the proliferation ability, inducing apoptosis and arresting the cell cycle in a dose-dependent manner. Interestingly, MH treatment in non-malignant cells did not exert any significant toxicity at similar concentrations. The apoptosis event was associated with the increasing expression of p53, cleaved-PARP and caspase-3 and with the activation of both intrinsic (caspase-9) and extrinsic (caspase-8) apoptotic pathways. MH induced cell cycle arrest in the S phase in HCT-116 cells, and simultaneously, in LoVo cells, it occurred in the G2/M phase through the modulation of cell cycle regulator genes (cyclin D1, cyclin E, CDK2, CDK4, p21, p27 and Rb). The expression of p-Akt was suppressed while the expression of p-p38MAPK, p-Erk1/2 and endoplasmic stress markers (ATF6 and XBP1) was increased for apoptosis induction. Overall, these findings indicate that MH could be a promising preventive or curative food therapy for colon cancer.

Assessment of Multiple Solvents for Extraction and Direct GC-MS Determination of the Phytochemical Inventory of Sansevieria Extrafoliar Nectar Droplets.

Considerable effort has been devoted to analytical determinations of sugar and amino acid constituents of plant nectars, with the primary aim of understanding their ecological roles, yet few studies have reported more exhaustive organic compound inventories of plant nectars or extrafoliar nectars. This work evaluated the efficacy of four solvents (ethyl acetate, dichloromethane, toluene and hexane) to extract the greatest number of organic compound classes and unique compounds from extrafoliar nectar drops produced by Sansevieria spp. Aggregation of the results from each solvent revealed that 240 unique compounds were extracted in total, with 42.5% of those detected in multiple extracts. Aliphatic hydrocarbons dominated in all but the ethyl acetate extracts, with 44 unique aliphatic hydrocarbons detected in dichloromethane (DCM) extracts, followed by 41, 19 and 8 in hexane, toluene and ethyl acetate extracts, respectively. Hexane extracted the most unique compounds (79), followed by DCM (73), ethyl acetate (56) and toluene (32). Integrated total ion chromatographic peak areas of extracted compound classes were positively correlated with numbers of unique compounds detected within those classes. In addition to demonstrating that multi-solvent extraction with direct GC-MS detection is a suitable analytical approach for determining secondary nectar constituents, to the best of our knowledge, this study also represents: (i) the first attempt to inventory the secondary phytochemical constituents of Sansevieria spp. extrafoliar nectar secretions and (ii) the largest organic solvent extractable compound inventory reported for any plant matrix to date.