ETHNOPHARMACOLOGICAL RELEVANCE: Ocimum kilimandscharicum Baker ex Güerke, commonly referred to as Kapur Tulsi, is a medicinal herb that belongs to the family of Lamiaceae. It is traditionally popular for its gastroprotective effects, including its use as a digestive and anti-diarrhoeal. AIM OF THE STUDY: The present study aims to prove the anti-diarrhoeal activity of aqueous extract of leaves of Ocimum kilimandscharicum in animal models.

MATERIALS AND METHODS:

The aqueous extract was tested at three different dose levels (100, 200 and 400mg/kg, p.o. in rats and the corresponding doses in mice) against castor-oil induced diarrhoea model and castor oil induced enteropooling assay in rats; and charcoal meal test/intestinal motility test in mice. The parameters observed were the onset of defecation, cumulative faecal weight and consistency of faeces in the castor oil induced diarrhoea model; the weight of intestinal content in castor oil induced enteropooling assay; and the distance travelled by charcoal in the intestinal motility test.

RESULTS:

A significant delay in the onset of defecation (p<0.05), reduction in the cumulative faecal weight (p<0.001), along with a change in the faecal consistency from watery to solid form was observed at the dose of 200mg/kg in the castor oil-induced diarrhoea model. Similarly, the extract at the doses of 100mg/kg (p<0.01) and 200mg/kg (p<0.001) significantly decreased the weight of intestinal content in castor oil induced enteropooling assay. In the charcoal meal test the extract at the dose of 280mg/kg (corresponding to 200mg/kg in rats) significantly (p<0.01) reduced the distance travelled by charcoal.

CONCLUSION:

The aqueous extract of leaves of Ocimum kilimandscharicum showed anti-diarrhoeal activity, which may be due to its anti-motility and anti-secretory effects, which thus proved the traditional claims.

Zeolite, hematite, modified zeolite and commercial activated charcoal were examined for their ability to remove methylene blue (MB) and methyl red (MR) from their aqueous solutions. Modified zeolite and hematite were produced according to the Schwertmann and Cornell method while zeolite and commercial activated charcoal were obtained from S&B and Fluka AG companies, respectively. Adsorption experiments were conducted at three different adsorbent-to-solution ratios, namely 8, 16 and 24 g/L under environmental conditions and continuous stirring. Equilibrium isotherms of MB and MR were studied at different initial concentrations (from 5 × 10(-4) to 5 × 10(-3) g/L). MB adsorption kinetics were also studied. The maximum adsorption of MB and MR from their aqueous solutions was achieved at 24 g/L (adsorbent-to-dye solution ratio) after 1 h and was equal to 100% (MB) on modified zeolite and 99% (MR) on commercial activated charcoal, respectively. All the other materials achieved intermediate values of dye adsorption. From the applied kinetic models, the pseudo-second-order equation best described the adsorption of MB and MR. Consequently, modified zeolite showed the highest adsorption capacity for MB, while commercial activated charcoal showed the highest adsorption capacity of MR. The studied adsorbents can be used as filters to remove dyes from wastewaters.

The adsorption of crystal violet dye from aqueous solutions onto an activated carbon prepared from peanut shells was analyzed in this study. The effects of particle size, initial concentration, time and temperature on crystal violet removal were studied in batch experiments. Experimental results showed that the adsorption equilibrium was achieved within 100 min for all studied concentrations. Analysis of adsorption results showed that the adsorption isotherms could be well fitted to the Langmuir model. Kinetic parameters, rate constants, equilibrium adsorption capacities and related correlation coefficients for pseudo first-order and second-order kinetic models were calculated and discussed. The results revealed that the adsorption kinetics was in good agreement with the pseudo second-order equation. Thermodynamic parameters such as the change of Gibbs free energy (ΔG°), change of enthalpy (ΔH°) and change of entropy (ΔS°) have also been determined and it has been found that the adsorption process should be spontaneous, endothermic and physisorption in nature.

Glyphosate (N-phosphonomethylglycine (PMG)) is the organophosphate herbicide most widely used in the world, and industrial production of PMG generates large quantities of wastewater. A manganese dioxide-coated powdered activated carbon (MnO2/PAC) composite was synthesized and investigated for the adsorption of PMG from wastewater. The results of scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectrometry (EDAX) revealed that MnO2 was formed on the surface of the carbon during the modification process. Batch adsorption results showed that the optimal pH for glyphosate adsorption on MnO2/PAC was 3.0. In the range 0.01(-1) molL(-1), glyphosate removal by MnO2/PAC decreased with an increase in ionic strength. Among the coexistent anions, only phosphate showed significant inhibition of PMG removal due to competitive complexation. Batch studies revealed that MnO2/PAC could reach a maximum PMG adsorption capacity of 283 mg g(-1). The Langmuir equilibrium model was found to be suitable for describing PMG sorption, and kinetic studies revealed that adsorption followed second-order rate kinetics. It was also proved that the adsorbed PMG could be effectively desorbed from MnO2/PAC in 1.0 molL(-1) NaOH. All of these results implied that the MnO2/PAC composite may be used as an effective adsorbent for recycling PMG from wastewater.

Wood and coal, as low-cost sorbents, have been evaluated as an alternative to commercial granular activated carbon (GAC) for chlorophenol removal. Kinetic experiments indicated that filter coal had a significantly lower rate of uptake (approximately 10% of final uptake was achieved after three hours) than the other sorbents, owing to intra-particle diffusion limitations. The data fitted a pseudo-second-order model. Sorption capacity data showed that GAC had a high sorption capacity (294-467 mg g(-1)) compared with other sorbents (3.2-7.5 mg(g-1)). However, wood and coal had a greater sorption capacity per unit surface area than GAC. Sorption equilibrium data was best predicted using a Freundlich adsorption model. The sorption capacity for all sorbents was 2-chlorophenol < 4-chlorophenol < 2, 4-dichlorophenol, which correlates well with solute hydrophobicity, although the relative differences were much less for coal than the other sorbents. The results showed that pine, hardwood and filter coal can be used as sorbent materials for the removal of chlorophenol from water; however, kinetic considerations may limit the application of filter coal.

Maesil (the fruit of Prunus mume Siebold & Zucc.) has long been used as an alternative medicine and functional food in Korea and Japan for preventive and therapeutic purposes. We examined the laxative effect of unripe Maesil (UM) and ripe Maesil (RM) in a rat model on constipation induced by a low-fibre diet and the possible mechanisms of Maesil in the rat colon. In vivo studies were conducted on the low-fibre diet-induced constipation rat model, and isolated rat colon was used in in vitro experiments to measure the changes in spontaneous colon contraction generated by Maesil and organic acids as standard and effectual ingredients, respectively. The aqueous extract of both UM and RM applied orally (100 and 300 mg/kg) produced significant increase of faeces frequency (p < 0.05) and moisture (p < 0.001). Moreover, the number faecal pellets number was reduced (p < 0.05) in the distal colons of the Maesil-treated rats. Gastrointestinal (GI) motility, measured by charcoal meal, was activated more fully by UM than in the low-fibre diet group. Both UM and RM and its organic acids produced a dose-dependent stimulation of the spontaneous contractile amplitude (p < 0.001) and frequency (p < 0.01) of the isolated rat colon. Although both UM and RM were an effective laxative, the RM was significantly more effective than the UM in the in vivo and in vitro constipation experiments because of the changes in the composition of organic acids during the ripening of the fruit. Our results demonstrated that Maesil was effective in promoting the frequency of defaecation and contraction of the rat colon, which provided scientific basis to support the use of Maesil as potential therapeutics in treating constipation.

Aspirin overdose could lead to intoxication, with the clinical manifestations of vomit, pulmonary edema and severe dyspnea. Stomach washing, emetics and activated charcoal are the common treatments with a limited efficiency for the intoxication. In this study, an active emulsion for aspirin intoxication was prepared with the detoxifying efficiency of 100% in less than 15 min, with the conditions of dodecane used as the oil phase, 8% Abil EM90 as the surfactant and 0.1 mol/L sodium hydroxide as the inner aqueous phase in a volume ratio of 2 between internal aqueous phase and the oil phase.

This study examined the effect of five types of carbonaceous materials (CMs) in sediment on bioaccumulation of perfluorochemicals (PFCs) by Chironomus plumosus larvae. The CMs included two multiwalled carbon nanotubes (MWCNT10 and MWCNT50), maize straw- and willow-derived chars, and maize straw-origin ash. The PFCs included perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorododecanoic acid (PFDoA). The CMs with different concentrations (0-1.5% dry weight) were amended into sediments spiked with PFCs and aged for 60 d. The uptake rate constants (k(s)) for each PFC to larvae differed with different CM amendments (p < 0.05), while elimination rate did not change significantly (p > 0.05). Decreasing PFC concentration in larvae (C(B)) was found with increasing CM concentration (f(CM)) in the sediments, and a linear positive correlation existed between 1/C(B) and f(CM) (p < 0.05). The effect of CMs on PFC bioaccumulation agreed well with the CM properties; MWCNT10 with the highest specific surface area resulted in the lowest k(s) values and biota-sediment accumulation factors (BSAF), with a BSAF reduction of 66%-97% by a 1.5% amendment. The mechanism was explored by analyzing the aqueous phase concentrations of PFCs and the sorption of PFCs on sediments amended with CMs. The results suggested that the decreasing trend of PFCs in larvae was caused by the decreasing aqueous phase concentration with increasing CM concentration. In the studied conditions with low PFC concentrations, the bioaccumulation of PFCs was a linear partitioning between pore water and biota, and the sorption of PFCs to the sediment/CM mixtures was a two domain linear distribution. This study suggests that both the type and concentration of carbonaceous materials in sediment can affect the bioaccumulation of PFCs to benthic organisms through changing their aqueous phase concentrations.

The adsorbent, based on the thermal modification of activated carbon impregnated by iron(III) nitrate(V), has been prepared and applied for selenium enrichment from aqueous solution. Various ratios of the impregnating agent to carbon mass were carefully examined with respect to selenium adsorption capacity and selectivity. The basic Se(VI) ions adsorption parameters affecting the adsorption ability onto the prepared activated carbons were studied. The carbon impregnated by 10% Fe(NO(3))(2) and thermally treated at 200 °C possessed the highest adsorption capacity and selectivity towards selenium ions. The physico-chemical characterization of the prepared adsorbents before and after selenium uptake were carried out using scanning electron microscopy (SEM) equipped with an energy dispersive X-ray detector (EDX) and X-ray photoelectron spectroscopy (XPS). The studies confirmed the surface complexation reactions of iron species and selenium on the Fe-loaded activated carbon. Due to its high adsorption capacity enrichment of selenium on the studied adsorbent has been successfully applied for its determination in the complementary feeds, using the carbon slurry sampling graphite furnace atomic absorption spectrometry technique (GFAAS) and standard calibration method.

The adsorption kinetics and thermodynamics of nitrogen-heterocyclic compounds (NHCs), pyridine, indole and quinoline, in aqueous solutions on bamboo charcoal (BC), as well as the regeneration of spent BC by microwave radiation, are investigated. BC is produced by incomplete combustion of moso bamboo at high temperature and nitrogen atmosphere. Adsorption kinetics is analyzed using pseudo-first-order and pseudo-second-order as well as Weber-Morris model. The results show that NHC adsorption on BC is predominantly regulated by surface diffusion in initial 1h followed by intraparticle diffusion in later stage. BC exhibits a strong adsorption affinity to NHCs, and the adsorption isotherms are well described by Freundlich model. Thermodynamic analysis indicates that the adsorption is spontaneous and endothermic. Adsorption site energy analysis illustrates a distribution of adsorption energy, which indicates the heterogeneous sites on BC for NHC adsorption. Furthermore, spent BC with NHC adsorption can be effectively regenerated by MW radiation. The adsorption capacity becomes even higher than that of virgin BC after five times of adsorption-regeneration cycles. This study proves BC is a promising adsorbent for NHC removal in wastewater.