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Moringa oleifera is evident to act against many neurological diseases, including muscle spasm, epilepsy, nervousness, fatigue, memory impairment, convulsion, and epilepsy. Anxiety represents the most common and disabling psychiatric condition, being often associated with depressive symptoms. This study investigated the anxiolytic-like effects of crude organic fractions of M. oleifera leaves in different behavioral paradigms that evaluate anxiety in mice. To this end, mice were administered with crude extracts (500 mg/kg, p.o.) and/or diazepam (2 mg/kg, p.o.), and submitted to behavioral tests. In the open-field test, the number of square field cross, grooming and rearing were calculated, while in light-dark and swing test were, respectively, the time spent in dark portion and number of swings. Each test was performed for 3 min. M. oleifera leaf methanol and n-hexane extracts elicited an anxiolytic-like effect observed by increased total time in the center and decreased number of rearings and groomings responses in the open field and swing tests, and residence in the dark portion in the light-dark box, similar to the diazepam group. A moderate anxiolytic effect was observed in the aqueous fraction group, while insignificant effects were recorded in the ethyl acetate fraction group in all test paradigms. In addition, both extracts potentiate the calming effects of diazepam in experimental animals. Preliminary phytochemical reports suggest that M. oleifera contains alkaloids, flavonoids, phenols, steroids, glycosides, saponins, tannin, terpenes, and gums. Of note, the results expand the understanding of M. oleifera effects in central nervous system and suggest that plant metabolites may be helpful for anxiety-related disorders management.
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Ansiolíticos/farmacología , Moringa oleifera/química , Animales , Mezclas Complejas , Diazepam/farmacología , Ratones , Fitoquímicos/análisis , Fitoquímicos/farmacología , Extractos Vegetales/química , Hojas de la Planta/químicaRESUMEN
Organic contaminants can be accumulated in aquatic systems even at trace concentrations with potential threats to the environment and human health. The present study has been performed to evaluate the effects of organochlorines and polyaromatic hydrocarbons on surface sediments of the Meliane river catchment. Their determination provides an essential scientific approach for a better understanding of the expected sources and the processes of bioaccumulation. The concentrations of saturated hydrocarbons in extractable organic matter of the dry sediment were found ranging from 0.58 to 3 83 µg kg-1 and PAHs content ranged from 63 to 131 µg kg-1. These results indicated the adherence of Oued Meliane to the pollution of the Tunis Gulf. The fraction of saturated hydrocarbons extracted from the sediments of Oued Meliane included a majority of organic compounds of biogenic nature with a small oil input. In addition, characterization with the TAR index and the LMW/HMW index confirmed that terrigenous inputs in this fraction are more abundant than aquatic inputs. The characterization of PAHs fraction has shown its pyrolitic origin with a predominance of high molecular weight PAHs.
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Monitoreo del Ambiente , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Sedimentos Geológicos , Humanos , Hidrocarburos Clorados , RíosRESUMEN
Non-renewable energy sources have remained the choice of the world for centuries. Rapid growth in population and industrialisation have caused their shortage and environmental degradation by using them. Thus, at the present rate of consumption, they will not last very long. In this prospective, this study has been conducted. The estimation of energy in terms of biogas and heat from various organic fractions of municipal solid waste is presented and discussed. The results show that organic fractions of municipal solid waste possess methane potential in the range of 3%-22% and their heat capacity ranges from 3007 to 20,099 kJ kg(-1) Also, theoretical biogas potential of different individual fruit as well as vegetable components and mixed food waste are analysed and estimated in the range of 608-1244 m(3) t(-1) Further, the share of bioenergy from municipal solid waste in the total primary energy supply in Pakistan has been estimated to be 1.82%. About 8.43% of present energy demand of the country could be met from municipal solid waste. The study leads us to the conclusion that the share of imported energy (i.e. 0.1% of total energy supply) and reduction in the amount of energy from fossil fuels can be achieved by adopting a waste-to-energy system in the country.
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Biocombustibles , Eliminación de Residuos/métodos , Residuos Sólidos , Biodegradación Ambiental , Ciudades , Fuentes Generadoras de Energía , Alimentos , Residuos de Alimentos , Metano/metabolismo , Pakistán , Estudios Prospectivos , Residuos Sólidos/análisisRESUMEN
As a result of their close similarities to the inorganic mineral components of human bone, hydroxyapatite nanoparticles (n-HAp) are widely used in biomedical applications and for the elaboration of biocompatible scaffold drug delivery systems for bone tissue engineering. In this context, a new efficient and economic procedure was used for the consolidation of n-HAp in the presence of various Nigella sativa (NS) fractions at a near-room temperature. The research conducted in the present study focuses on the physicochemical properties of loaded n-HAp 3D scaffolds by NS fractions and the in vitro antibacterial activity against Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 27853), and Gram-positive (Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 700603) bacteria. In order to better understand the effect of the inserted fractions on the HAp molecular structure, the elaborated samples were subject to Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectroscopic analyses. In addition, the morphological investigation by scanning electron microscope (SEM) of the loaded n-HAp 3D scaffolds demonstrated the presence of a porous structure, which is generally required in stimulating bone regeneration. Furthermore, the fabricated 3D composites exhibited significant antibacterial activity against all tested bacteria. Indeed, MIC values ranging from 5 mg/mL to 20 mg/mL were found for the HAp-Ethanol fraction (HAp-Et) and HAp-Hexane fraction (HAp-Hex), while the HAp-Aqueous fraction (HAp-Aq) and HAp-Methanol fraction (HAp-Me) showed values between 20 mg/mL and 30 mg/mL on the different strains. These results suggest that the HAp-NS scaffolds were effective as a drug delivery system and have very promising applications in bone tissue engineering.
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This study reports the emissions of condensable particulate matter (CPM) and filterable particulate matter (FPM) in two coal-fired power plants with different air pollution control devices (APCDs). The mechanisms of CPM removed by existing APCDs in coal-fired power plants were explored, and a series of analyses were also carried out on the composition and characteristics of CPM. The results show that the removal efficiencies to CPM by electrostatic-bag-precipitator (EBP) and ESP are 77.34% and 79.23%, respectively, so the difference is not obvious because the interception filtration mechanisms of baghouses for CPM have less effect on CPM compared to FPM. The mechanism of EBP/ESP to remove CPM is mainly electrostatic adsorption and FPM's adsorption. The concentration of CPM decreases when passing through WFGD. However, the WESP can increase the CPM in different ways. For example, the pollution of the circulation of the flushing fluid may cause the increase of CPM. In addition, CPM mainly includes three parts. The first part is organic fractions such as alkanes and esters; the second is the water-soluble ions that include SO42-, NH4+, and Cl-; and the third is Na, Ca, and other minerals. The research in this study is helpful to understand the impact of existing APCDs in coal-fired power plants on CPM and the sources of CPM.
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Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Carbón Mineral/análisis , Iones/análisis , Material Particulado/análisis , Centrales EléctricasRESUMEN
The Government of India (GOI) announced a nationwide lockdown starting 25th March 2020 to contain the spread of COVID-19, leading to an unprecedented decline in anthropogenic activities and, in turn, improvements in ambient air quality. This is the first study to focus on highly time-resolved chemical speciation and source apportionment of PM2.5 to assess the impact of the lockdown and subsequent relaxations on the sources of ambient PM2.5 in Delhi, India. The elemental, organic, and black carbon fractions of PM2.5 were measured at the IIT Delhi campus from February 2020 to May 2020. We report source apportionment results using positive matrix factorization (PMF) of organic and elemental fractions of PM2.5 during the different phases of the lockdown. The resolved sources such as vehicular emissions, domestic coal combustion, and semi-volatile oxygenated organic aerosol (SVOOA) were found to decrease by 96%, 95%, and 86%, respectively, during lockdown phase-1 as compared to pre-lockdown. An unforeseen rise in O3 concentrations with declining NOx levels was observed, similar to other parts of the globe, leading to the low-volatility oxygenated organic aerosols (LVOOA) increasing to almost double the pre-lockdown concentrations during the last phase of the lockdown. The effect of the lockdown was found to be less pronounced on other resolved sources like secondary chloride, power plants, dust-related, hydrocarbon-like organic aerosols (HOA), and biomass burning related emissions, which were also swayed by the changing meteorological conditions during the four lockdown phases. The results presented in this study provide a basis for future emission control strategies, quantifying the extent to which constraining certain anthropogenic activities can ameliorate the ambient air. These results have direct relevance to not only Delhi but the entire Indo-Gangetic plain (IGP), citing similar geographical and meteorological conditions common to the region along with overlapping regional emission sources. SUMMARY OF MAIN FINDINGS: We identify sources like vehicular emissions, domestic coal combustion, and semi-volatile oxygenated organic aerosol (SVOOA) to be severely impacted by the lockdown, whereas ozone levels and, in turn, low-volatility oxygenated organic aerosols (LVOOA) rise by more than 95% compared to the pre-lockdown concentrations during the last phase of the lockdown. However, other sources resolved in this study, like secondary chloride, power plants, dust-related, hydrocarbon-like organic aerosols (HOA), and biomass burning related emissions, were mainly driven by the changes in the meteorological conditions rather than the lockdown.
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Contaminantes Atmosféricos , COVID-19 , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Control de Enfermedades Transmisibles , Monitoreo del Ambiente , Humanos , India , Material Particulado/análisis , SARS-CoV-2 , Estaciones del Año , Emisiones de Vehículos/análisisRESUMEN
Cropland restoration induces litter and root inputs and promotes the development of biological soil crusts (BSCs), which may promote aggregate formation and soil organic carbon (SOC) sequestration. However, litter, roots and BSCs have not been simultaneously considered when assessing soil aggregate and aggregate-associated SOC fraction responses to cropland restoration in subtropical areas. Here, we measured particulate organic carbon (POC) and mineral-associated organic carbon (MOC) in bulk soils and soil aggregates after 15 years of cropland restoration. Soil samples of cropland (CL) and four cropland restoration types (plantation forest [PF], forage grassland [FG], mixed plantation of forest and forage grassland [FF], and abandoned natural grassland [NG]) from depths of 0-30 cm were collected. Cropland restoration significantly increased SOC and POC in bulk soil at the 0-5 cm depth. However, only in FG did SOC significantly increase at depths of 5-15 cm, and POC significantly increased at depths of 5-30 cm. The large macroaggregate (5-10 mm and 2-5 mm) proportions increased significantly at the 0-15 cm depth after cropland restoration, and FG, FF and NG also increased the 5-10 mm aggregate proportions at the 15-30 cm depth. The SOC sequestration in bulk soil with cropland restoration was attributed to increases in the aggregate-associated organic carbon (AAOC) pool in large macroaggregates, which was mainly attributed to the increased aggregate amount rather than the increased AAOC concentration in large macroaggregates. Our results also indicated that an increase in aggregate-associated particulate organic carbon (AAPOC) led to an increase in AAOC. Variation partitioning indicated that the formation of large macroaggregates was controlled by the litter-moss-root interactive effect in this karst area. FG could be a better short-term cropland restoration strategy, increasing large macroaggregates in deeper soil layers better than the other vegetation types and promoting soil carbon sequestration in deeper soil layers.
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Secuestro de Carbono , Suelo , Carbono/análisis , China , Productos Agrícolas , BosquesRESUMEN
The aim of this paper was to identify the core microbes of producing lignocellulolytic enzymes during rice straw composting with functional bacterial agents inoculation. The results indicated that inoculation functional bacterial agents accelerated the degradation of organic matter and coarse fiber content by 7.58%, 8.82%, which were due to the fact that key enzymes and core microbes were stimulated. In addition, inoculation have reconstructed core microbes of producing lignocellulase. Meanwhile, inoculation functional bacterial agents not only as core bacteria to produce cellulase, xylanase and manganese peroxidase (MnP), but also increased most core microbial abundance. Redundancy analysis indicated that CMCase, xylanase, total nitrogen and MnP as key factors to affect the degradation of organic fractions in the core bacterial communities, while in the core fungal communities, were mainly affected by environmental factors (except for MnP). This study provided a theoretical basis for the efficiently degradation during agricultural wastes composting.
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Compostaje , Oryza , Agricultura , Nitrógeno/análisis , SueloRESUMEN
It has been proven that the raw wastewater, secondary effluent and even reclaimed water may have toxic effects on aquatic organisms. In the present study, fractionation procedures combined with bioassays using luminescent bacteria were conducted to identify the fractions that contributed to the acute and long-term toxicity of municipal wastewater. Solid phase extraction was used to divide dissolved organic matter from the wastewater into three fractions, including non-polar, medium-polar and polar fraction. Among these fractions, although the acute toxicity of municipal wastewater was mainly caused by polar and medium-polar chemicals, the acute toxicity induced by the unit mass of the medium-polar fraction was the greatest. Using three kinds of resins, the organic substances in municipal wastewater were classified into six fractions, and the long-term toxicity of these fractions was further identified. The long-term toxicity of the hydrophobic neutrals, which were the primary toxic substances in raw wastewater, decreased after the conventional secondary biological treatment. Hydrophilic neutrals, which accounted for the majority of organic substances in the secondary effluent, were the main substances with long-term toxicity in the secondary effluent. The identification of fractions with acute and long-term toxicity in municipal wastewater is beneficial for further treatment to attenuate the ecotoxicity of wastewater before discharge into the aquatic environment.
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Aguas Residuales , Contaminantes Químicos del Agua , Fraccionamiento Químico , Monitoreo del Ambiente , Eliminación de Residuos LíquidosRESUMEN
This study aims to explore the effect of Fenton pretreatment on organic fractions, enzymes activities and microbial communities during composting. In this study, rice straw was chosen to be composted after pretreatment. The results indicated that Fenton pretreatment significantly increased the degradation of organic matter and coarse fiber contents, which might be the reason that Fenton pretreatment enhanced lignocellulose-degrading enzymes activities during composting, including CMCase, FPase, xylanase, manganese peroxidase, lignin peroxidase and laccase. Additionally, Fenton pretreatment reshaped bacteria community. The key enzymes and environmental factors, which affected organic fractions degradation were identified by redundancy analysis. Furthermore, structural equation modeling and variation partitioning analysis further revealed possible mechanisms of organic fractions degradation in different treatments during composting. In summary, the combined application Fenton pretreatment and composting improved lignocellulose degradation efficiency, which provided for an effective and environment-friendly way to manage lignocellulose wastes.
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Compostaje , Oryza , Lignina , SueloRESUMEN
BACKGROUND: The herb, Commelina paludosa (CP) Blume (Family-Commelinaceae) is medicinally used by the traditional practitioners in Bangladesh. However, there is a lack of scientific evidence on this medicinal herb. AIM AND OBJECTIVES: This study aimed to evaluate the phytochemical and pharmacological activities of CP (ethanol [ECP], chloroform [CCP] and n-hexane [NHCP] of whole-plant extracts). MATERIALS AND METHODS: For this antioxidant, antimicrobial, antidiarrheal and antipyretic activities of crude extracts of CP were conducted by 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, disc diffusion and serial dilution, castor oil-induced diarrhea and yeast powder-induced pyrexia methods respectively. RESULTS AND OBSERVATION: The results suggest that all the fractions significantly scavenged DPPH radicals. In the disc diffusion test, the zones of inhibition were observed within the range of 7 mm to 30.67 mm at 500 mg/disc. The highest zones of inhibition were observed by ECP, CCP and NHCP against Bacillus azotoformans, Lactobacillus coryifomis and Salmonella typhi respectively. NHCP was found to exert stronger antibacterial effect than the ECP and CCP. CONCLUSION: Minimum inhibitory concentrations were detected within the range of 31.25 and 250 µg/ml. Moreover, the crude fractions also showed significant (P < 0.05) antidiarrheal and antipyretic activities in Swiss mice. CP may be a good source of therapeutic components.
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The production of oil from oil sands in northern Alberta has led to the generation of large volumes of oil sands process-affected water (OSPW) that was reported to be toxic to aquatic and other living organisms. The toxicity of OSPW has been attributed to the complex nature of OSPW matrix including the inorganic and organic compounds primarily naphthenic acids (NAs: CnH2n+ZOx). In the present study, granular activated carbon (GAC) adsorption was investigated for its potential use to treat raw and ozonated OSPW. The results indicated that NA species removal increased with carbon number (n) for a fixed Z number; however, the NA species removal decreased with Z number for a fixed carbon number. The maximum adsorption capacities obtained from Langmuir adsorption isotherm based on acid-extractable fraction (AEF) and NAs were 98.5â¯mg and 60.9â¯mg AEF/g GAC and 60â¯mg and 37â¯mg NA/g GAC for raw and ozonated OSPW, respectively. It was found that the Freundlich isotherm model best fits the AEF and NA equilibrium data (r2â¯≥â¯0.88). The adsorption kinetics showed that the pseudo-second order and intraparticle diffusion models were both appropriate in modeling the adsorption kinetics of AEF and NAs to GAC (r2â¯≥â¯0.97). Although pore diffusion was the rate limiting step, film diffusion was still significant for assessing the rate of diffusion of NAs. This study could be helpful to model, design and optimize the adsorption treatment technologies of OSPW and to assess the performance of other adsorbents.
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Carbón Orgánico/química , Yacimiento de Petróleo y Gas/química , Compuestos Orgánicos/química , Contaminantes Químicos del Agua/química , Adsorción , Alberta , Restauración y Remediación Ambiental , CinéticaRESUMEN
The impact of long-term (>2 years) biological activated carbon (BAC) treatment for mitigating organic fouling in the microfiltration of biologically treated secondary effluent was investigated. Correlation between the organic constituents and hydraulic filtration resistance was investigated to identify the major components responsible for fouling. Over two years operation, the removal efficiency for dissolved organic carbon (DOC) by the BAC treatment was fairly consistent (30 ± 3%), although the reduction in UVA254 gradually decreased from 56 to 34%. BAC treatment effectively decreased the organic foulants in the effluent and so contributed to the mitigation of membrane fouling as shown by reduction in the unified membrane fouling index (UMFI). BAC consistently removed biopolymers whereas the removal of humic substances decreased from 52 to 25% after two years of BAC operation, and thus led to a gradual decrease in UMFI reduction efficiency from 78 to 43%. This was due to gradual reduction in adsorption capacity of the activated carbon as confirmed by analysis of its pore size distribution. Hence humics also played an important role in membrane fouling. However, there was a good correlation between protein and carbohydrate contents with hydraulically reversible and irreversible filtration resistance, compared with UVA254, turbidity and DOC. Although the mitigation of membrane fouling decreased over time, this study demonstrated that the long-term use of BAC pre-treatment of biologically treated secondary effluent prior to microfiltration has potential to reduce the need for frequent chemical cleaning and so increase membrane life span.
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Biopolímeros/química , Carbón Orgánico/química , Filtración/métodos , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Adsorción , Carbohidratos/química , Cromatografía/métodos , Sustancias Húmicas , Membranas Artificiales , Peso Molecular , Proteínas/química , Espectrometría de Fluorescencia , Contaminantes Químicos del Agua/análisisRESUMEN
Pre-aeration is effective on regulating subsequent anaerobic degradation of municipal solid waste (MSW) with high organic fractions during landfilling. The strength of pre-aeration should be optimized to intentionally remove some easily biodegradable fractions while conserve bio-methane potential as much as possible. This study investigates the evolution of organic components in MSW during 2-14days pre-aeration process and its impacts on subsequent anaerobic degradation in simulated landfill bioreactors. Results showed that a 6-day pre-aeration enabled to develop a thermophilic stage, which significantly accelerated biodegradation of organics except lignocelluloses, with removal rates of 42.8%, 76.7% and 25.1% for proteins, carbohydrates and lipids, respectively. Particularly, ammonia from accelerated ammonification in the thermophilic stage neutralized VFAs generated from anaerobic landfilling. As a result, the MSW with 6-day pre-aeration obtained the highest methane yield 123.4NL/kg dry matter. Therefore, it is recommended to interrupt pre-aeration before its cooling stage to switch to anaerobic landfilling.
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Biodegradación Ambiental , Reactores Biológicos , Eliminación de Residuos/métodos , Residuos Sólidos , Instalaciones de Eliminación de ResiduosRESUMEN
A long-term evaluation of a mesophilic up-flow intermittently stirred tank reactor (UISTR) for hydrogen production from the organic fraction of municipal solid waste was investigated. UISTR was operated at five different hydraulic retention times (HRTs) of 10, 7.5, 5, 3 and 2days. This corresponds to organic loading rates (OLRs) of 18.1, 26.2, 41.3, 61.0, and 97.2gCOD/L/day, respectively. The highest volumetric H2 production of 2.20±0.19L/L/d and H2 yield of 2.05±0.33molH2/molCarbohydrate were achieved at HRT of 3days and OLR of 61.0gCOD/L/day. This revealed a higher sCOD/tCOD ratio of 0.46±0.08 and a lower particle size diameter of 307.6µm in the digestate, with a reduction of 72.0%. The maximum carbohydrates, proteins, and lipids conversions amounted to 68.2±13.0%, 37.5±6.7% and 48.6±4.7%, respectively recorded at HRT of 10days and OLR of 18.1gCOD/L/day.
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Biocombustibles/análisis , Reactores Biológicos , Hidrógeno/análisis , Compuestos Orgánicos/análisis , Residuos Sólidos , Anaerobiosis/efectos de los fármacos , Biodegradación Ambiental/efectos de los fármacos , Cinética , Modelos Teóricos , Tamaño de la Partícula , Proyectos Piloto , Reología , Bicarbonato de Sodio/farmacología , Factores de TiempoRESUMEN
Soluble algal products (SAP) accumulated in culture medium via water reuse may affect the growth of microalga during the cultivation. Scenedesmus sp. LX1, a freshwater microalga, was used in this study to investigate the effect of SAP on growth and lipid production of microalga. Under the SAP concentrations of 6.4-25.8 mg L(-1), maximum algal density (K) and maximum growth rate (Rmax) of Scenedesmus sp. LX1 were decreased by 50-80% and 35-70% compared with the control group, respectively. The effect of SAP on lipid accumulation of Scenedesmus sp. LX1 was non-significant. According to hydrophilic-hydrophobic and acid-base properties, SAP was fractionized into six fractions. All of the fractions could inhibit the growth of Scenedesmus sp. LX1. Organic bases (HIB, HOB) and hydrophilic acids (HIA) showed the strongest inhibition. HIA could also decrease the lipid content of Scenedesmus sp. LX1 by 59.2%. As the inhibitory effect, SAP should be seriously treated before water reuse.
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Biocombustibles , Biomasa , Lípidos/química , Scenedesmus/metabolismo , Medios de Cultivo/química , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Microalgas/química , Análisis de Regresión , Espectrometría de Fluorescencia , Factores de Tiempo , Agua/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodosRESUMEN
Mondia whitei root was evaluated to validate its anecdotal use and determine its possible mode of action in the management of erectile dysfunction. Rabbits were administered with daily oral doses of 100-400 mg kg(-1) crude ethanolic extract of M. whitei and sildenafil (50 mg kg(-1)) as positive control for 6 weeks. Cavernosal tissue NOS activity and levels of NO and cGMP, and NOS and PDE protein expressions were investigated. The effect of the crude extract, chloroform and petroleum ether fractions in vitro on cavernosal tissue NOS activity and levels of NO and cGMP at 0.01 and 0.10 mg g(-1) tissue were also investigated. Results indicate that the crude extract increased NOS activity by 7% at 200 mg kg(-1) with corresponding increases in NO (88%) and cGMP (480%) levels. No significant changes in these measurements were observed with the 100 and 400 mg kg(-1) doses whilst sildenafil slightly reduced them (15.9-37.5%). NOS and PDE protein expressions in test animals were not different from controls. Pre-incubation of cavernosal tissue in vitro with the crude extract of M. whitei and its chloroform fraction markedly increased NOS activity (26-132%) and levels of NO (25%) and cGMP (50-400%) at 0.01 mg g(-1) tissue but these were reduced to near control levels when their concentrations were increased to 0.10 mg g(-1) tissue whilst the petroleum ether fraction had no effect. These findings suggest that M. whitei may influence erectile function through activation/stimulation of NOS with corresponding increases in tissue NO and cGMP levels and that certain chemical constituents present in the chloroform fraction may be responsible for biological activity.