Valorisation Potential of Invasive Acacia dealbata, A. longifolia and A. melanoxylon from Land Clearings.

Acacia spp. are invasive in Southern Europe, and their high propagation rates produce excessive biomass, exacerbating wildfire risk. However, lignocellulosic biomass from Acacia spp. may be utilised for diverse biorefinery applications. In this study, attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR), high-performance anion-exchange chromatography pulsed amperometric detection (HPAEC-PAD) and lignin content determinations were used for a comparative compositional characterisation of A. dealbata, A. longifolia and A. melanoxylon. Additionally, biomass was treated with three white-rot fungi species (Ganoderma lucidum, Pleurotus ostreatus and Trametes versicolor), which preferentially degrade lignin. Our results showed that the pre-treatments do not significantly alter neutral sugar composition while reducing lignin content. Sugar release from enzymatic saccharification was enhanced, in some cases possibly due to a synergy between white-rot fungi and mild alkali pretreatments. For example, in A. dealbata stems treated with alkali and P. ostreatus, saccharification yield was 702.3 nmol mg-1, which is higher than the samples treated only with alkali (608.1 nmol mg-1), and 2.9-fold higher than the non-pretreated controls (243.9 nmol mg-1). By characterising biomass and pretreatments, generated data creates value for unused biomass resources, contributing to the implementation of sustainable biorefining systems. In due course, the generated value will lead to economic incentives for landowners to cut back invasive Acacia spp. more frequently, thus reducing excess biomass, which exacerbates wildfire risk.

Effect of polyethylene glycol 4000 supplementation on the performance of yearling male Pedi goats fed dietary mixture levels of Acacia karroo leaf meal and Setaria verticillata grass hay.

Eighteen yearling male Pedi goats weighing 21.7 ± 3.1 kg were used in a 42-day trial in a 2 (Acacia karroo leaf meal levels) × 3 (levels of PEG 4000) factorial arrangement in a completely randomized design to determine PEG 4000 supplementation levels for optimal productivity of indigenous Pedi goats fed different mixture levels of A. karroo leaf meal and Setaria verticillata (L.) P.Beauv. grass hay. Each goat was supplemented with 0, 23 or 30 g of PEG 4000 per day in addition to dietary mixture of A. karroo and S. verticillata hay. Polyethylene glycol 4000 supplementation had no effect (P > 0.05) on nutrient intake of goats. However, a diet × PEG (P < 0.05) was observed for intake of all nutrients studied. Dry matter, OM, NDF and ADF intakes per goat were optimized at PEG 4000 supplementation levels of 19.62, 19.62, 19.61 and 19.53 g/goat/day, respectively, for diets containing 20% A. karroo leaf meal. Polyethylene glycol 4000 supplementation had no effect (P > 0.05) on the apparent digestibility of all nutrients. The dietary inclusion level of A. karroo leaf meal at 20% improved (P < 0.05) DM, OM, CP, NDF and ADF digestibility of goats. Crude protein digestibility was optimized at a PEG 4000 supplementation level of 15.78 g/goat/day. Dietary mixture level and PEG 4000 supplementation had no effect (P > 0.05) on final weights of Pedi goats. Similar results were observed for blood urea and glucose concentrations of yearling male Pedi goats. However, daily body weight gain was higher (P < 0.05) in goats fed 50% A. karroo leaf meal than those on 20% inclusion level. Polyethylene glycol 4000 has potential to improve the feeding value of tanninifeorus A. karroo leaf meal.

In vitro protection of biological macromolecules against oxidative stress and in vivo toxicity evaluation of Acacia nilotica (L.) and ethyl gallate in rats.

BACKGROUND: Recently, enormous research has been focused on natural bioactive compounds possessing potential antioxidant and anticancer properties using cell lines and animal models. Acacia nilotica (L.) is widely distributed in Asia, Africa, Australia and Kenya. The plant is traditionally used to treat mouth, ear and bone cancer. However, reports on Acacia nilotica (L.) Wild. Ex. Delile subsp. indica (Benth.) Brenan regarding its toxicity profile is limited. Hence in this study, we investigated the antioxidant capacity and acute toxicity of ethyl gallate, a phenolic antioxidant present in the A. nilotica (L.) leaf extract. METHODS: The antioxidant activity of ethyl gallate against Fenton's system (Fe3+/H2O2/ascorbic acid) generated oxidative damage to pBR322 DNA and BSA was investigated. We also studied the interaction of ethyl gallate to CT-DNA by wave scan and FTIR analysis. The amount of ethyl gallate present in the A. nilotica (L.) leaf extract was calculated using HPLC and represented in gram equivalence of ethyl gallate. The acute toxicity profile of ethyl gallate in the A. nilotica (L.) leaf extract was analyzed in albino Wistar rats. Measurement of liver and kidney function markers, total proteins and glucose were determined in the serum. Statistical analysis was done using statistical package for social sciences (SPSS) tool version 16.0. RESULTS: Ethyl gallate was found to be effective at 100 µg/mL concentration by inhibiting the free radical mediated damage to BSA and pBR322 DNA. We also found that the interaction of ethyl gallate and A. nilotica (L.) leaf extract to CT-DNA occurs through intercalation. One gram of A. nilotica (L.) leaf extract was found to be equivalent to 20 mg of ethyl gallate through HPLC analysis. Based on the acute toxicity results, A. nilotica (L.) leaf extract and ethyl gallate as well was found to be non-toxic and safe. CONCLUSIONS: Results revealed no mortality or abnormal biochemical changes in vivo and the protective effect of A. nilotica (L.) leaf extract and ethyl gallate on DNA and protein against oxidative stress in vitro. Hence, A. nilotica (L.) leaf extract or ethyl gallate could be used as potential antioxidants with safe therapeutic application in cancer chemotherapy.

Assessment of a tannin-based organic polymer to harvest Chlorella vulgaris biomass from swine wastewater digestate phycoremediation.

This study investigated the efficiency of an organic tannin polymer alone or amended with polyacrylamide to harvest Chlorella vulgaris biomass grown in a laboratory-scale photobioreactor treating swine wastewater digestate. The effect of biomass concentration, tannin (TAN) dosages and changes in pH were evaluated in jar test experiments. Among the TAN concentrations tested (11, 22, 44, 89, 178 mg L(-1)), 11 mg L(-1) showed the highest biomass recovery (97%). The highest coagulation/ flocculation efficiencies were obtained at pH 5 to 7. Flocculation efficiency improved from 50 to 97% concomitant with the increasing biomass concentrations from 45 to 165 mg L(-1), respectively. Recovery efficiencies above 95% were achieved with the same TAN dosage (11 mg L(-1)) irrespective of the concentration of organic carbon present (75 to 300 mg TOC L(-1)). Overall, the results suggest that TAN could become an interesting alternative choice of non-toxic organic polymer for harvesting Chlorella sp. from organic-rich wastewater.

Biobleaching of Acacia kraft pulp with extracellular enzymes secreted by Irpex lacteus KB-1.1 and Lentinus tigrinus LP-7 using low-cost media.

The white-rot fungi Irpex lacteus KB-1.1 and Lentinus tigrinus LP-7 have been shown in previous studies to have high biobleaching activity in vivo. The aim of this study was to investigate the activities and stabilities of extracellular enzymes, prepared from I. lacteus and L. tigrinus culture grown in three types of economical media of agricultural and forestry wastes, for biobleaching of Acacia oxygen-delignified kraft pulp using kappa number reduction as an indicator of delignification. After 3 days of incubation, the extracellular enzymes preparations from I. lacteus and L. tigrinus cultures in media of Acacia mangium wood powder supplemented with rice bran and addition 1 % glucose (WRBG), resulted in significant decrease of 4.4 and 6.7 %, respectively. A slightly higher kappa number reduction (7.4 %) was achieved with the combine extracellular enzymes from I. lacteus and L. tigrinus. One of the strategies for reducing the cost of enzyme production for treatment processes in the pulp and paper industry is the utilization of agricultural and forestry waste. Thus, WRBG has potential as a culture medium for producing stable lignolytic enzymes simply and economically.

[New method of near infrared spectra analysis for the content of acid soluble lignin of Acacia].

The near infrared spectra analysis model of the content of the acid soluble lignin and the model of the content of the Klason lignin were built by the iterative method separately at first. The results show that the prediction effect of the content of the Klason lignin is obviously better than that of the acid soluble lignin. Different from usual methods of building near infrared spectra analysis model, the approximate linear relation between the contents of the acid soluble lignin and the contents of the Klason lignin was used. Combined with the near infrared spectroscopy data of multi-wavelength, twenty sub models of prediction of the content of the acid soluble lignin were built with the help of the Klason lignin content whose prediction effect is better than that of the acid soluble lignin. By calculating the weighted mean value of the prediction values of these sub models, the new prediction value of the content of the acid soluble lignin of each acacia specimen was obtained at last. The prediction error of the new model is obviously less than that of the model built by the iterative method. It is possible that the method of modeling in the paper can be used to some chemical component contents when the predictions of them by usual methods are not very effective, and the effects of the near infrared spectra analysis of them will be improved.

Hemostatic, antibacterial biopolymers from Acacia arabica (Lam.) Willd. and Moringa oleifera (Lam.) as potential wound dressing materials.

Acacia arabica and Moringa oleifera are credited with a number of medicinal properties. Traditionally gum of Acacia plant is used in the treatment of skin disorders to soothe skin rashes, soreness, inflammation and burns while Moringa seed extracts are known to have antibacterial activity. In the present study the potential of the polymeric component of aqueous extracts of gum acacia (GA) and the seeds of M. oleifera (MSP) in wound management was evaluated. The results revealed that both biopolymers were hemostatic and hasten blood coagulation. They showed shortening of activated partial thromboplastin time and prothrombin time and were non-cytotoxic in nature. Both showed antibacterial activity against organisms known to be involved in wound infections with MIC ranging from 500-600 microg mL(-1) for GA and 300-700 microg mL(-1) for MSP. They were biodegradable and exhibited water absorption capacity in the range of 415 to 935%. The hemostatic character coupled to these properties envisions their potential in preparation of dressings for bleeding and profusely exuding wounds. The biopolymers have been further analysed for their composition by Gas chromatography.

The Efficacy of Gum Arabic in Managing Diseases: A Systematic Review of Evidence-Based Clinical Trials.

Gum arabic (GA) is a natural product commonly used as a household remedy for treating various diseases in the Sub-Saharan Africa region. Despite its claimed benefits, there has been a lack of research on the findings of current clinical trials (CTs) that investigated its efficacy in the treatment of various medical diseases. The aim of this systematic review was to study CTs which focused on GA and its possible use in the management of various medical diseases. A search of the extant literature was performed in the PubMed, Scopus, and Cochrane databases to retrieve CTs focusing on evidence-based clinical indications. The databases were searched using the keywords ("Gum Arabic" OR "Acacia senegal" OR "Acacia seyal" OR "Gum Acacia" OR "Acacia Arabica") AND ("Clinical Trial" OR "Randomized Controlled Trial" OR "Randomized Clinical Trial"). While performing the systematic review, data were obtained on the following parameters: title, authors, date of publication, study design, study aim, sample size, type of intervention used, targeted medical diseases, and main findings. Twenty-nine papers were included in this systematic review. The results showed that ingestion of GA altered lipid profiles, renal profiles, plaque, gingival scores, biochemical parameters, blood pressure, inflammatory markers, and adiposity. GA exhibited anti-inflammatory, prebiotic, and antibacterial properties. GA has been successfully used to treat sickle cell anemia, rheumatoid arthritis, metabolic disorders, periodontitis, gastrointestinal conditions, and kidney diseases. Herein, we discuss GA with respect to the underlying mechanisms involved in each medical disease, thereby justifying GA's future role as a therapeutic agent.

Obtaining of a rich-cellulose material from black wattle (Acacia mearnsii De Wild.) bark residues.

Black wattle (Acacia mearnsii De Wild.) barks are residues produced by tannin industries in huge quantities, which are normally discharged on environmental or used for energy production. Therefore, this study aimed to evaluate the use of black wattle bark residues as a raw material on obtaining of a rich-cellulose material by alkaline (MET1), acetosolv (MET2), and organosolv (MET3) procedures. The results obtained indicated that the alkaline methodology, followed by a bleaching step (MET1), promoted klason lignin and hemicellulose removals more efficiently. It was possible to observe that better results were achieved using NaOH concentration of 6% (wt%), at 65 °C for 2.5 h, presenting a yield of 63.24 ± 1.25%, and a reduction on klason lignin content of almost 90.45%. Regarding the bleaching step, it was possible to obtain a material free of non-cellulosic compounds with a yield of 78.28 ± 1.48%. Thermogravimetric analysis indicated the removal of lignin and hemicellulose as well as an increase in cellulose degradation temperature, due to changes in crystalline phases. According to X-ray diffraction (XRD), the procedures employed have led to an increase in crystallinity from 66.27 to 91.78% due to the removal of non-cellulosic compounds. Scanning electron microscopy (SEM) showed morphological alterations in accordance with the removal of non-cellulosic compounds.

Acacia catechu Willd. and Acacia arabica Willd. decrease the extent of anxiety behavior by reducing oxidative stress and moderating neurochemicals.

ETHNOPHARMACOLOGICAL RELEVANCE: Anxiety is a very common psychiatric problem. It affects a large group of people in the world population. Acacia genus is well known for phenolic and flavonoid content. Literature showed its potential for various biological activities and is useful in the treatment of chest pain, asthma, bronchitis, wounds, mouth ulcer, colic, vitiligo, sore throat, inflammation, diarrhoea and also used as tonic. AIM OF THE STUDY: The present study was conducted to assess the antianxiety potential of two plants Acacia catechu Willd. and Acacia arabica Willd. from the common family Fabaceae. MATERIALS AND METHODS: The stems of both plants were used for this purpose. Plants were subjected to complete exhaustive successive extraction using petroleum ether, chloroform, ethanol, and water as solvent. After pharmacognostic and phytochemical investigation, antianxiety activity was conducted on Swiss albino mice at different dose levels (100, 200, 300, & 400 mg/kg body weight p.o.) for all successive extracts of both plants. Two active extracts from each plant were further assessed for anxiolytic potential using the open-field test and mirror chamber test. One extract with the maximum response from each plant was further screened using mCPP-induced anxiety test. RESULTS: The stem of ethanol extract of A. catechu showed comparable antianxiety activity at 400 mg/kg to the standard drug diazepam (2.5 mg/kg). Improved SOD, catalase, and LPO levels were noted after administration of A. catechu ethanolic extract at 400 mg/kg. CONCLUSIONS: In conclusion, A. catechu ethanolic extract improved anxiety symptoms at dose-dependent levels in mice.

Chewable Tablets of Acacia catechu Extract, an Alternative to Betel (Paan) for Mouth Ulcers: Formulation and In vitro Evaluation.

OBJECTIVE: The objective of the current research work was to prepare chewable tablets having Acacia catechu extract useful for mouth ulcers using a 32 factorial design. METHODS: Acacia catechu heartwood extract was prepared using a reported method with some modifications. The extract was characterized using TLC against the catechin marker. Then, drug-excipient interaction studies were carried out. The mixture of drug and excipients was evaluated for pre-compression parameters. With the application of 32 factorial design, chewable tablets were prepared using direct compression technique. Prepared tablets were evaluated for post-compression parameters. RESULTS: In vitro drug release study of the developed formulations was investigated both in intact and crushed form of tablets. Based on the in vitro performance, the best formulations were selected (F6, F7 & F8 from intact and F1, F5 & F9 from the crushed group) and subjected to various kinetic models and evaluated for Chewing Difficulty Index (CDI). CONCLUSION: The overall results revealed that the formulated chewable tablets complied with the standards and exhibited the satisfactory performance in terms of drug release, chewing difficulty index and other related parameters.

Production of nanocellulose gels and films from invasive tree species.

Wood from invasive tree species Acacia dealbata and Ailanthus altissima was used to produce high value-added nanocellulose. Firstly, bleached pulps were produced from the wood of these tree species after kraft cooking. Afterwards, the resultant pulps were pre-treated by TEMPO-mediated oxidation (Acacia dealbata) or enzymatic hydrolysis (Ailanthus altissima) followed by high-pressure homogenization. Hydrogels were obtained and characterized for their main physical and chemical properties, including rheology measurements. After freeze-drying, the surface properties of the materials were evaluated by inverse gas chromatography. Results showed that nano/micro fibrils could be obtained from the wood of these invasive species. Rheometry studies showed that Acacia-TEMPO cellulose nanofibrils form strong gels with high yield stress point and viscosities (reaching ca. 100,000 Pa·s). Additionally, the surfaces of the obtained nanocelluloses showed a dispersive component of the surface energy near 40 mJ/m2 and a prevalence of the Lewis acidic character over the basic one, as typical for cellulose-based materials. Finally, films with good mechanical and optical properties could be obtained from the cellulose hydrogels. Acacia-TEMPO film (produced by filtration/hot pressing) showed a tensile strength of 79 MPa, Young's modulus of 7.9 GPa, and a transparency of 88%. The water vapor barrier, however, was modest (permeability of 4.9 × 10-6 g/(Pa·day·m)).

Polymer functionalization through an enzymatic process: Intermediate products characterization and their grafting onto gum Arabic.

The modification of gum Arabic with ferulic acid oxidation products was performed in aqueous medium, at 30 °C and pH 7.5, in the presence of Myceliophthora thermophila laccase as biocatalyst. First, this study aimed to investigate the structures of the oxidation products of ferulic acid that could possibly be covalently grafted onto gum Arabic. HPLC analyses revealed that this reaction produced several oxidation products, whose structures were investigated using LC-MS/MS analyses (liquid chromatography-mass spectrometry with mass fragmentation analyses) and NMR experiments. The chemical structure of one intermediate reaction product was fully elucidated as the 2-(4-hydroxy-3-methoxyphenyl)-4-[(4-hydroxy-3-methoxyphenyl) methylidene] cyclobutane-1, 3-dione, called by the authors cyclobutadiferulone. Secondly, this study aimed to locate the grafting of the oxidation products onto gum Arabic by performing several NMR experiments. This study did not determine how much and specifically which oxidation products were grafted but some of them were undeniably present onto modified gum Arabic, close to the glucuronic acid C5 carbon or close to the galactose C6 carbon.

Balancing the effect of pretreatment severity on hemicellulose extraction and pulping performance during auto-hydrolysis prior to kraft pulping of acacia wood.

When using a combination of pre-extraction and chemical pulping, a high yield of sugar recovery and minimal negative effect on the subsequent pulping step are expected. In this work, the P factor was utilized to investigate the effect of auto-hydrolysis severity on sugar recovery, removal of the main component, and impact on the kraft pulping of acacia wood chips. Using a P factor of 235, 84.34% of the polysaccharides in 14.05 g L-1 of dissolved sugars could be obtained. In addition, the soluble sugars were easily separated with a recovery yield of 3.54 g ·L-1 and Mw of 4,690 g mol-1 by direct precipitation using organic solvents. However, a maximum of 22.14 g L-1 of dissolved sugars was obtained with approximately 72.53% polysaccharides and Mw of 2,198 g mol-1 for a P factor of 601. Moreover, nearly 50% of the degraded carbohydrates remained in the auto-hydrolyzed wood chips. The decrease in the mass of pentosan, holocellulose, and klason lignin was 62, 30, and 8.76%, respectively. With intensifying severity, the screened yield and viscosity of pulps decreased markedly, whileas the Kappa number increased. No significant differences were observed in the morphology of the resultant fibers. Moreover, there was a decrease in the physical strength of the pulps due to the loss of the intrinsic strength of the pulp fibers, which in turn resulted from the cellulose damage. The combustion performance of the resultant pulping black liquor is improved due to the higher lignin content.

In vitro larval migration and kinetics of exsheathment of Haemonchus contortus larvae exposed to four tropical tanniniferous plant extracts.

As for some temperate forage, some tropical tanniniferous plants (TTP) from browsing might represent an alternative to chemical anthelmintic. The anthelmintic effect of four TTP (Acacia pennatula, Lysiloma latisiliquum, Piscidia piscipula, Leucaena leucocephala) on Haemonchus contortus was measured using two in vitro assays. First, the effects of increasing concentrations of lyophilized extracts (150, 300, 600, 1200 microg/ml PBS) were tested on H. contortus larvae (L(3)) using the larval migration inhibition (LMI) test. An inhibitor of tannin, polyvinyl polypyrrolidone (PVPP), was used to verify whether tannins were responsible for the AH effect. Secondly, the effects of extracts on larval exsheathment were examined. Larvae (L(3)) were in contact with extracts (1200 microg/ml) for 3h, and then were exposed to an artificial exsheathment procedure with observations of the process at 10 min intervals. A general lineal model (GLM) test was used to determine the dose effect in the LMI test and the difference of the percentage of exsheathed larvae between the control and the treatment groups. A Kruskal Wallis test was used to determine the effect of PVPP on LMI results. The LMI test showed a dose-dependent anthelmintic effect for A. pennatula, L. latisiliquum and L. leucocephala (P<0.01), which disappeared after PVPP addition, confirming the role of tannins. No effect was found for P. piscipula on H. contortus in the LMI test. However, all four plant extracts interfered with the process of L(3) exsheathment which might be involved as a mechanism of action of tannins on H. contortus larvae. A. pennatula, L. latisiliquum and L. leucocephala could be used as an anthelmintic for the control of H. contortus after confirmation based on in vivo studies.

Formation and evaluation of casein-gum arabic coacervates via pH-dependent complexation using fast acidification.

The formation of complex coacervation using fast acidification at 25 °C for 0.5 h between casein (CAS) and gum arabic (GA) was investigated by turbidity, particle size distribution (PSD), zeta potential (ZP), and Fourier transform infrared (FTIR). When the mass ratio of CAS and GA was 1:1 and the total biopolymer concentration (CT) was 0.5% (w/v), an optimum pH (pHopt) of complex coacervation was found at pH 3.5. Particle size distribution (PSD) of homogenous CAS and GA solutions, and mixture solution of CAS-GA at critical pH values revealed the association and disassociation processes during complex coacervation. Meanwhile, ZP and FTIR spectra analyses indicated that the complexation between CAS and GA was ascribed to electrostatic interaction and hydrogen bonding. The CAS-GA coacervates were characterized by X-ray diffraction (XRD), thermogravimetric analyzer (TGA), and differential scanning calorimetry (DSC). Two XRD peaks (2θ = 8° and 23°) differing from CAS and GA indicated the characteristic of CAS-GA coacervates. Moreover, the thermal stability of CAS-GA coacervates was superior to CAS and GA below 220 °C. The good performance of CAS-GA coacervates predicts a bright future in application of food and pharmacy industries.

Antimicrobial Efficacy of Acacia nilotica, Murraya koenigii L. Sprengel, Eucalyptus hybrid, Psidium guajava extracts and their combinations on Fusobacterium nucleatum and Porphyromonas gingivalis.

BACKGROUND: The herbal extracts have been effectively tried in the treatment and prevention of many oral diseases. AIM: The aim is to assess the antimicrobial efficacy of Acacia nilotica, Murraya koenigii L. Sprengel, Eucalyptus hybrid, Psidium guajava extracts and their combinations on Fusobacterium nucleatum (Fn) and Porphyromonas gingivalis (Pg). MATERIALS AND METHODS: The extraction process was carried out by Soxhlet apparatus using ethanol as solvent. The combinations of the four plant extracts were prepared by combining an equal quantity of 10% solution of each of the four plant extracts. The antimicrobial efficacy testing of the plant extracts and their combinations on Fn and Pg was performed using agar well diffusion method. Columbia 5% of sheep blood agar plates were used for antimicrobial efficacy testing under anaerobic conditions. The qualitative assay was carried out to identify the various phytochemical constituents. Dimethyl sulfoxide and 0.2% chlorhexidine acted as negative and positive controls, respectively. The mean diameter of inhibition zone between different categories was compared using one-way analysis of variance. RESULTS: All the individual plant extracts and their double, triple, and quadruple combinations were effective in inhibiting the growth of these bacteria. However, 0.2% chlorhexidine produced the highest mean diameter of inhibition zone. CONCLUSION: The plant extracts in combinations offer enhanced antimicrobial efficacy due to their synergistic action besides slowing the development of bacterial resistance. Hence, these extracts in combinations could be used tried as effective alternates to chlorhexidine.

Preparation and characterization of nanocrystalline cellulose from Acacia mangium and its reinforcement potential.

Acacia mangium, a fast growing tree is widely planted in Malaysia. Converting Acacia wood into nanocellulose could create new value added products for forest-based industry. Nanocrystalline cellulose (NCC) was prepared from Acacia mangium wood pulp via 64wt% sulfuric acid hydrolysis. Prior to acid hydrolysis, Acacia mangium was subjected to pulping followed by bleaching in order to remove non-cellulosic fragments. Acid hydrolysis was carried out on bleached pulp to produce the needle-like NCC with 79% crystallinity and aspect ratio of 26. The resulting NCC was mixed with PVA as a reinforcement material. Incorporation of 2% NCC improved the tensile of the NCC-PVA film by 30%.

Cellulose nanocrystals from acacia bark-Influence of solvent extraction.

The isolation of cellulose nanocrystals from different lignocellulosic materials has shown increased interest in academic and technological research. These materials have excellent mechanical properties and can be used as nanofillers for polymer composites as well as transparent films for various applications. In this work, cellulose isolation was performed following an environmental friendly procedure without chlorine. Cellulose nanocrystals were isolated from the exhausted acacia bark (after the industrial process of extracting tannin) with the objective of evaluating the effect of the solvent extraction steps on the characteristics of cellulose and cellulose nanocrystals. It was also assessed the effect of acid hydrolysis time on the thermal stability, morphology and size of the nanocrystals, through TGA, TEM and light scattering analyses. It was concluded that the extraction step with solvents was important in the isolation of cellulose, but irrelevant in the isolation of cellulose nanocrystals. Light scattering experiments indicated that 30min of hydrolysis was long enough for the isolation of cellulose nanocrystals.

Comparison of the in vitro anthelmintic effects of Acacia nilotica and Acacia raddiana.

Gastrointestinal nematodes are a major threat to small ruminant rearing in the Sahel area, where farmers traditionally use bioactive plants to control these worms, including Acacia nilotica and Acacia raddiana. The main aim of this study was to screen the potential anthelmintic properties of aqueous and acetone extracts of leaves of these two plants based on three in vitro assays: (1) the egg hatch inhibition assay (EHA); (2) the larvae exsheathment inhibition assay (LEIA) using Haemonchus contortus as a model; and (3) an adult mortality test (AMT) applied on Caenorhabditis elegans. For the EHA, only A. raddiana was effective with IC50 = 1.58 mg/mL for aqueous extract, and IC50 = 0.58 mg/mL for acetonic extract. For the LEIA, all extracts inhibited the exsheathment of larvae compared to the controls, and the aqueous extract of A. nilotica was more larvicidal with IC50 = 0.195 mg/mL. In general, all responses to the substances were dose-dependent and were significantly different from the control group (p < 0.05). For the AMT, the extracts of the two Acacia species were effective but A. raddiana showed greater efficacy with 100% mortality at 2.5 mg/mL and LC50 = 0.84 mg/mL (acetonic extract). The addition of polyvinyl polypyrrolidone (PVPP) to the extracts suggested that tannins were responsible for blocking egg eclosion and inducing adult mortality but were not responsible for exsheathment inhibition. These results suggest that the leaves of these Acacia species possess ovicidal and larvicidal activities in vitro against H. contortus, and adulticidal effects against C. elegans.