Phytochemistry of Acacia—sensu lato

Inhibitory activities of selected Sudanese medicinal plants on Porphyromonas gingivalis and matrix metalloproteinase-9 and isolation of bioactive compounds from Combretum hartmannianum (Schweinf) bark

Background

Periodontal diseases are one of the major health problems and among the most important preventable global infectious diseases. Porphyromonas gingivalis is an anaerobic Gram-negative bacterium which has been strongly implicated in the etiology of periodontitis. Additionally, matrix metalloproteinases-9 (MMP-9) is an important factor contributing to periodontal tissue destruction by a variety of mechanisms. The purpose of this study was to evaluate the selected Sudanese medicinal plants against P. gingivalis bacteria and their inhibitory activities on MMP-9.

Methods

Sixty two methanolic and 50% ethanolic extracts from 24 plants species were tested for antibacterial activity against P. gingivalis using microplate dilution assay method to determine the minimum inhibitory concentration (MIC). The inhibitory activity of seven methanol extracts selected from the 62 extracts against MMP-9 was determined by Colorimetric Drug Discovery Kit. In search of bioactive lead compounds, Combretum hartmannianum bark which was found to be within the most active plant extracts was subjected to various chromatographic (medium pressure liquid chromatography, column chromatography on a Sephadex LH-20, preparative high performance liquid chromatography) and spectroscopic methods (liquid chromatography-mass spectrometry, Nuclear Magnetic Resonance (NMR)) to isolate and characterize flavogalonic acid dilactone and terchebulin as bioactive compounds.

Results

About 80% of the crude extracts provided a MIC value ≤4 mg/ml against bacteria. The extracts which revealed the highest potency were: methanolic extracts of Terminalia laxiflora (wood; MIC = 0.25 mg/ml) followed by Acacia totrtilis (bark), Ambrosia maritima (aerial part), Argemone mexicana (seed), C. hartmannianum (bark), Terminalia brownii (wood) and 50% ethanolic extract of T. brownii (bark) with MIC values of 0.5 mg/ml. T. laxiflora (wood) and C. hartmannianum (bark) which belong to combretaceae family showed an inhibitory activity over 50% at the concentration of 10 μg/ml against MMP-9. Additionally, MMP-9 was significantly inhibited by terchebulin with IC₅₀ value of 6.7 μM.

Conclusions

To the best of our knowledge, flavogalonic acid dilactone and terchebulin were isolated from C. hartmannianium bark for the first time in this study. Because of terchebulin and some crude extracts acting on P. gingivalis bacteria and MMP-9 enzyme that would make them promising natural preference for preventing and treating periodontal diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-017-1735-y) contains supplementary material, which is available to authorized users.

Comparative study of antioxidant activity and validated RP-HPTLC analysis of rutin in the leaves of different Acacia species grown in Saudi Arabia

The present study assessed the comparative antioxidant potential of the ethanol extract (EE) of leaves of four Acacia species (Acacia salicina, AS; Acacia laeta, AL; Acacia hamulosa AH; and Acacia tortilis, AT) grown in Saudi Arabia, including RP-HPTLC quantification of antioxidant biomarker rutin. In vitro DPPH radical scavenging and β-carotene-linoleic acid bleaching assays showed the promising antioxidant activities of Acacia extracts: ASEE (IC₅₀: 60.39 and 324.65 μg/ml) >ALEE (IC₅₀: 217.06 and 423.36 μg/ml) >ATEE (IC₅₀: 250.13 and 747.50 μg/ml) >AHEE (IC₅₀: 255.83 and 417.28 μg/ml). This was comparable to rutin tested at 500 μg/ml. Further, a RP- HPTLC densitometric method was developed (acetonitrile:water; 6:4; v/v) using glass-backed RP-18 silica gel F₂₅₄ plate, and scanned at UV max 254 nm. The method was validated as per the ICH guidelines. Analysis of the validated RP-HPTLC displayed an intense peak (R_f = 0.65 ± 0.004) of rutin that was estimated (μg/mg dry weight) to be highest in ASEE (10.42), followed by ALEE (2.67), AHEE (1.36) and ATEE (0.31). Taken together, presence of rutin strongly supported the high antioxidant property of the tested Acacia species, especially Acacia salicina. The developed RP-HPTLC method therefore, affirms its application in the quality control of commercialized herbal drugs or formulation containing rutin.

Natural Therapeutic Options in Endodontics - A Review

Complete eradication of microbial biofilms and elimination of the smear layer are the key factors during endodontic treatment. Various chemical irrigants have been proposed in the literature for the same. The major setback with these chemical irrigants is that they are not bio-friendly to the dental and peri-radicular tissues. In the recent years, research to use natural products for root canal disinfection has gained importance. The aim of this article is to compile various herbal products that have been used as an irrigants and intracanal medicaments in the field of Endodontics to eradicate the biofilm and remove smear layer.

Ethnomedicinal uses of plants in the treatment of paediatric geohelminth infections in Kalat district of Northern Balochistan, Pakistan

ETHNOPHARMACOLOGICAL RELEVANCE

Infection by intestinal parasitic worms (soil-transmitted helminths or geohelminths) is prevalent in many parts of the world, and poses a particular health risk to children. This paper presents findings from a preliminary study with the primary aim to document indigenous knowledge about the use of herbal medicines in the treatment of intestinal worm infections in children among the local communities of Kalat district of northern Balochistan, Pakistan.

MATERIALS AND METHODS

Ethnomedicinal data were collected through a triangulation approach, that included participant-observation and rapid appraisal methods. Prior-informed consent (PIC) was obtained from participants before conducting structured and semi-structured interviews and delivering an open ended questionnaire. A total of 94 participants, including 28 men (of whom 7 were traditional healers), and 66 women of four different age groups were interviewed. Results were analyzed using quantitative indices of Use Value citations (UVC) and Disease-Consensus Index (DCI).

RESULTS

Fewer men than women agreed to be interviewed, thus overall women in the area appeared to have more ethnomedicinal knowledge. The majority of study participants belonged to the older age group (>55 years). A total of 49 plant species, belonging to 47 genera, distributed in 30 families were reported. The families Asteraceae and Lamiaceae were most frequently represented, with four species each. Trees were the most common life form, with seeds the most frequently cited plant part used (29%). Nearly a third (31%) of plant-based remedies reported in the treatment of intestinal worms were administered as a decoction. The highest UVC and DCI was reported for the species Ferula assa-foetida sL. (UVC 0.51, DCI 0.46).

CONCLUSIONS

This study provides previously unreported data on the use of medicinal plants in the treatment of geohelminth infections in children of Kalat. Eight species, Acacia modesta Wall., Asparagus capitatus Baker, Microcephala lamellata (Bunge) Pobed., Nepeta praetervisa Rech.f., Plantago ciliata Desf., Pistacia atlantica Desf., Seriphidium quettense (Podlech) Y.R.Ling and Thymus linearis Benth. are reported here as anthelmintics for the first time. Detailed studies on the anthelmintic activity of chemical constituents of these species are lacking from existing literature. Further phytochemical, pharmacological and toxicity studies are required in order to evaluate the efficacy and safety of these newly reported anthelmintic species. These plants may provide a source of novel anthelmintic drug leads, which are urgently required due to the problem of global anthelmintic resistance.

Antioxidant activity and protection against oxidative-induced damage of Acacia shaffneri and Acacia farnesiana pods extracts: in vitro and in vivo assays

BACKGROUND

Obesity is a worldwide public health issue, reaching epidemic condition in developing countries associated to chronic diseases. Oxidative damage is another side effect of obesity. Antioxidant activity from plant components regulates at some extent this imbalance. Main goal of the present study was to determine the antioxidant activity and protection against oxidative-induced damage of Acacia shaffneri (AS) and Acacia farnesiana (AF) pods extracts.

METHODS

To evaluated antioxidant activity and radical scavenging capacity of AS and AF extracts, two experiments were performed: 1) pods extracts were challenged against H2O2 using kidney cells in an in vitro assay; and 2) (Meriones unguiculatus) was employed in an in vivo assay to observe the effect of pods extracts on scavenging properties in plasma.

RESULTS

Both pods extracts presented an important protective effect on radical scavenging capacity against ABTS• + and DPPH(+), and also in TBARS formation in vitro. Vegetal pods extracts did not induce any pro-oxidative effect when added to kidney cells in DMEM. Cells damage in DMEM with addition of H2O2 was significantly higher than those when vegetal pods extracts were added at 50 (P < 0.05) or 200 ppm (P < 0.001). Plasma scavenging properties presented an important dose-dependent positive effect in those groups where pods extracts were administered.

CONCLUSIONS

The antioxidant protection of the acacia pods extracts reported in this study suggests the possible transference of antioxidant components and protective effects to animal products (milk, meat, and by-products) from Acacia pods when this vegetation is included in the diet. In order to evaluate, the possible transference of theirs antioxidant components to animal products, the incorporation of these non-conventional resources to ruminant feeding is a good opportunity of study. Profiling of Acacia farnesiana pods extract is necessary to identify the responsible bioactive compounds of protective properties.

Traditional management of diabetes in Pakistan: Ethnobotanical investigation from Traditional Health Practitioners

ETHNOPHARMACOLOGICAL RELEVANCE

The uses of anti-diabetic plants are well anchored in the traditional health care system of Pakistan. To the best of our knowledge, this is the first ethno-botanical study about the uses of plants for the treatment of diabetes. The aim of the study is to record indigenous knowledge on anti-diabetic plants from Traditional Health Practitioners (THPs) and diabetic patients. In addition, it is aimed to ascertain and validate the traditional uses of anti-diabetic plants by citing pharmacological activities and phytochemical constitutes from previously published literature.

MATERIALS AND METHODS

The ethno-medicinal data was documented during 14 field surveys, each comprising of 10 days, from 3 regions of Pakistan (Islamabad, Khyber Pukhtoonkhwa and Deserts of Sindh). In total, 113 THPs and 44 diabetic patients were interviewed using open-ended and semi-structured questionnaires. Quantitative indices, including Relative Frequency of Citation percentage (RFC %) and Disease Consensus Index (DCI) were calculated. The documented data is authenticated by comparing with 28 published articles on ethno-botanical aspects and many pharmacological studies.

RESULTS

In total, 120 plant species belonging to 50 families were reported. The ethno-botanical results indicated that Moraceae (11 species); herb (56 reports) is dominant life form; the leaves (56 reports) are the most used plant part and decoction (24%) is the preferred mode of preparation. The quantitative analysis shows that RFC% ranges from 14 to 42 and DCI varies from 0.15 to 0.74. By comparing to previous studies, 64 species are reported new in traditional treatment of DM; 40 species are new to pharmacological evidence and 3 species are new to phytochemical studies.

CONCLUSIONS

This study recoded the significant indigenous knowledge about anti-diabetic plants among the THPs and diabetic patients in Pakistan. This type of ethno-botanical knowledge on traditional use of anti-diabetic plants is an important step in designing detailed pharmacological and clinical trials for Diabetes Miletus treatment. It is recommended that further pharmacological and phytochemical analysis should be conducted on those species which lack previous references in literature and have highest Frequency of Citation (FC), Disease Consensus Index (DCI) and Relative Frequency of Citation percentage (RFC%).

Chemical composition and allelopathic potential of essential oils obtained from Acacia cyanophylla Lindl. Cultivated in Tunisia

Acacia cyanophylla Lindl. (Fabaceae), synonym Acacia saligna (Labill.) H. L.Wendl., native to West Australia and naturalized in North Africa and South Europe, was introduced in Tunisia for rangeland rehabilitation, particularly in the semiarid zones. In addition, this evergreen tree represents a potential forage resource, particularly during periods of drought. A. cyanophylla is abundant in Tunisia and some other Mediterranean countries. The chemical composition of the essential oils obtained by hydrodistillation from different plant parts, viz., roots, stems, phyllodes, flowers, and pods (fully mature fruits without seeds), was characterized for the first time here. According to GC-FID and GC/MS analyses, the principal compound in the phyllode and flower oils was dodecanoic acid (4), representing 22.8 and 66.5% of the total oil, respectively. Phenylethyl salicylate (8; 34.9%), heptyl valerate (3; 17.3%), and nonadecane (36%) were the main compounds in the root, stem, and pod oils, respectively. The phyllode and flower oils were very similar, containing almost the same compounds. Nevertheless, the phyllode oil differed from the flower oil for its higher contents of hexahydrofarnesyl acetone (6), linalool (1), pentadecanal, α-terpineol, and benzyl benzoate (5) and its lower content of 4. Principal component and hierarchical cluster analyses separated the five essential oils into four groups, each characterized by its main constituents. Furthermore, the allelopathic activity of each oil was evaluated using lettuce (Lactuca sativa L.) as a plant model. The phyllode, flower, and pod oils exhibited a strong allelopathic activity against lettuce.

Effect of acetone extract from stem bark of Acacia species (A. dealbata, A. ferruginea and A. leucophloea) on antioxidant enzymes status in hydrogen peroxide-induced HepG2 cells

Acacia species are multipurpose trees, widely used in the traditional systems of medicine to treat various ailments. The major objective of the present study was to determine the gene expression of enzymatic antioxidants by acetone extract from the stem bark of three Acacia species (Acacia dealbata, Acacia ferruginea and Acacia leucophloea) in hydrogen peroxide (H2O2)-induced human hepatoma (HepG2) cells. The expression of antioxidant enzymes such as superoxide dismutase containing copper-zinc (CuZnSOD)/manganese (MnSOD), catalase (CAT) and glutathione peroxidase (GPx) in HepG2 cells was evaluated by real-time PCR. The results of antioxidant enzyme expression in real-time PCR study revealed that the H2O2 (200 μM) challenged HepG2 cells reduced the expression of enzymes such as SOD, GPx and CAT. However, the cells pre-treated with acetone extracts of all the three Acacia species significantly (P > 0.05) up-regulated the expression of antioxidant enzymes in a concentration dependent manner (25, 50 and 75 μg/mL). In conclusion, the findings of our study demonstrated that the acetone extract of Acacia species effectively inhibited H2O2 mediated oxidative stress and may be useful as a therapeutic agent in preventing oxidative stress mediated diseases.

Acacia ferruginea inhibits inflammation by regulating inflammatory iNOS and COX-2

Inflammation is a local defensive reaction of a host to cellular injury or infection. Prolonged inflammation can contribute to pathogenesis of many disorders. Identification of naturally occurring phytoconstituents that can suppress inflammatory mediators can lead to the discovery of anti-inflammatory therapeutics. Acacia ferruginea is used traditionally to treat numerous ailments including hemorrhage, irritable bowel syndrome and leprosy. The present study evaluated the anti-inflammatory activity of A. ferruginea extract against acute (carrageenan) and chronic (formaldehyde) inflammation in Balb/c mice. Pre-treatment with A. ferruginea extract (10 mg/kg BW) for 5 consecutive days via intraperitonial (IP) administration significantly inhibited subsequent induction of paw edema in both models; the effects were comparable to that of the standard drug indomethacin. The results also showed the A. ferruginea extract significantly inhibited nitric oxide (NO) synthesis and iNOS expression (as measured in serum), diminished inflammation in - and neutrophil infiltration to - the paw tissues and led to a reduction in the number of COX-2(+) immunoreative cells (as evidenced by histologic and immunohistochemical analyses) in the paws relative to those in paws of mice that received the irritants only. Further, in vitro studies showed the extract could significantly scavenge free radicals generated as in DPPH and NO radical generating assays. Taken together, the results showed that A. ferruginea extract imparted potent anti-oxidant and -inflammatory effects, in part by maintaining oxidative homeostasis, inhibiting NO synthesis and suppressing iNOS and COX-2 expression and so could potentially be exploited as a potential plant-based medication against inflammatory disorders.

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.

Metabolomic profiling and antioxidant activity of some Acacia species

Metabolomic profiling of different parts (leaves, flowers and pods) of Acacia species (Acacia nilotica, Acacia seyal and Acacia laeta) was evaluated. The multivariate data analyses such as principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) were used to differentiate the distribution of plant metabolites among different species or different organs of the same species. A. nilotica was characterized with a high content of saponins and A. seyal was characterized with high contents of proteins, phenolics, flavonoids and anthocyanins. A. laeta had a higher content of carbohydrates than A. nilotica and A. seyal. On the basis of these results, total antioxidant capacity, DPPH free radical scavenging activity and reducing power of the methanolic extracts of studied parts were evaluated. A. nilotica and A. seyal extracts showed less inhibitory concentration 50 (IC50) compared to A. laeta extracts which means that these two species have the strongest radical scavenging activity whereas A. laeta extracts have the lowest radical scavenging activity. A positive correlation between saponins and flavonoids with total antioxidant capacity and DPPH radical scavenging activity was observed. Based on these results, the potentiality of these plants as antioxidants was discussed.

Diminution of hepatic response to 7, 12-dimethylbenz(α)anthracene by ethyl acetate fraction of Acacia catechu willd. through modulation of xenobiotic and anti-oxidative enzymes in rats

BACKGROUND

Liver is the primary metabolizing site of body and is prone to damage by exogenous as well as endogenous intoxicants. Polycyclic aromatic hydrocarbons such as 7, 12- dimethylbenz(α)anthracene (DMBA) is an exogenous hepatotoxin, which is well known for modulating phase I, II and anti-oxidative enzymes of liver. Plants contain plethora of polyphenolic compounds which can reverse the damaging effect of various xenobiotics. The present study investigated protective role of the ethyl acetate fraction of Acacia catechu Willd. (EAF) against DMBA induced alteration in hepatic metabolizing and anti-oxidative enzymes in rats.

METHODOLOGY AND PRINCIPAL FINDINGS

The rats were subjected to hepatic damage by treating with DMBA for 7 weeks on alternative days and treatment schedule was terminated at the end of 14 weeks. The rats were euthanized at the end of protocol and livers were homogenized. The liver homogenates were used to analyse phase I (NADPH-cytochrome P450 reducatse, NADH-cytochrome b5 reductase, cytochrome P420, cytochrome b5), phase II (glutathione-S-transferase, DT diaphorase and γ-Glutamyl transpeptidase) and antioxidative enzymes (catalase, superoxide dismutase, ascorbate peroxidase, glutathione reductase, guiacol peroxidase and lactate dehydrogenase). Furthermore, other oxidative stress parameters (thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes and reduced glutathione) and liver marker enzymes (serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase and alkaline phosphatase) were also studied. The DMBA induced significant changes in activity of hepatic enzymes that was reversed by treatment with three dose levels of EAF.

CONCLUSION

It is concluded that EAF affords hepato-protection against DMBA in rats through modulation of phase I, II and anti-oxidative enzymes.

Significance of the natural occurrence of L- versus D-pipecolic acid: a review

Pipecolic acid naturally occurs in microorganisms, plants, and animals, where it plays many roles, including the interactions between these organisms, and is a key constituent of many natural and synthetic bioactive molecules. This article provides a review of current knowledge on the natural occurrence of pipecolic acid and the known and potential significance of its L- and D-enantiomers in different scientific disciplines. Knowledge gaps with perspectives for future research identified within this article include the roles of the L- versus the D-enantiomer of pipecolic acid in plant resistance, nutrient acquisition, and decontamination of polluted soils, as well as rhizosphere ecology and medical issues.

Omani propolis: chemical profiling, antibacterial activity and new propolis plant sources

Background

Propolis (bee glue) is a resinous honeybee product having a long history of application in many countries as a traditional remedy for treating wounds, burns, soar throat, stomach disorders, etc. It has been proved to possess beneficial biological effects, including antimicrobial, antioxidant, anti-inflammatory, cytotoxic, antiulcer, and many others. Bees gather propolis from diverse resinous plant parts and in different phytogeographic regions its chemical composition might vary significantly. In this article we report the results of the first study on the chemical profiles of propolis from Oman, its plant origin and antibacterial activity.

Results

The chemical profiles of Omani propolis extracts were obtained by GC-MS analysis after silylation. Over 50 individual compounds were identified in the samples, belonging to different compound types: sugars, polyols, hydroxy acids, fatty acids, cardanols and cardols, anacardic acids, flavan derivatives, triterpenes, prenylated flavanones and chalcones. The profiles were dissimilar from other known propolis types. They demonstrate that although Oman is not a large country, the plant sources of propolis vary significantly, even in the same apiary and the same season. Based on chemical profiles, and isolation and identification of major marker compounds (new propolis constituents), new plant sources of propolis were found: Azadiracta indica (neem tree) and Acacia spp. (most probably A. nilotica). The ethanol extracts of the studied propolis samples demonstrated activity against S. aureus (MIC < 100 μg. mL^-1) and E. coli (MIC < 380 μg. mL^-1).

Conclusion

Omani propolis is different form the known propolis types and demonstrates significant chemical diversity. Its most important plant source is the resin of Azadirachta indica, and as a result its typical components are С₅-prenyl flavanones. Other plant sources have been identified, too, playing some role in resin collection by bees in Oman: Acacia spp. (most probably A. nilotica) and Mangifera indica. The results demonstrate also the potential of Omani propolis as antimicrobial.

Protective Effect of Acacia nilotica (L.) against Acetaminophen-Induced Hepatocellular Damage in Wistar Rats

The potential biological functions of A. nilotica have long been described in traditional system of medicine. However, the protective effect of A. nilotica on acetaminophen-induced hepatotoxicity is still unknown. The present study attempted to investigate the protective effect of A. nilotica against acetaminophen-induced hepatic damage in Wistar rats. The biochemical liver functional tests Alanine transaminase (ALT), Aspartate transaminase (AST), Alkaline phosphatase (ALP), total bilirubin, total protein, oxidative stress test (Lipid peroxidation), antioxidant parameter glutathione (GSH), and histopathological changes were examined. Our results show that the pretreatment with A. nilotica (250 mg/kg·bw) orally revealed attenuation of serum activities of ALT, AST, ALP, liver weight, and total bilirubin levels that were enhanced by administration of acetaminophen. Further, pretreatment with extract elevated the total protein and GSH level and decreased the level of LPO. Histopathological analysis confirmed the alleviation of liver damage and reduced lesions caused by acetaminophen. The present study undoubtedly provides a proof that hepatoprotective action of A. nilotica extract may rely on its effect on reducing the oxidative stress in acetaminophen-induced hepatic damage in rat model.

Protective effect of ethyl acetate fraction of Acacia ferruginea DC. against ethanol-induced gastric ulcer in rats

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional systems of medicine, stem bark of Acacia ferruginea DC. is used for the treatment of itching, leucoderma, ulcers, stomatitis and diseases of the blood. In the present study, we determined antioxidant and anti-ulcerogenic activities of Acacia ferruginea stem bark.

MATERIALS AND METHODS

Acetone extract and its sub-fractions of Acacia ferruginea stem bark were subjected to assess their antioxidant potential using various in vitro systems such as DPPH(•), ABTS(•+) scavenging, FRAP and phosphomolybdenum reduction activities. Based on the antioxidant potential, the ethyl acetate fraction was used to evaluate the protective effect of ethanol-induced gastric damage in rat model. Enzyme activities such as superoxide dismutase, glutathione, catalase and lipid peroxidation were also determined in the stomach tissues.

RESULTS

Ethyl acetate fraction (AFE) of Acacia ferruginea stem bark registered higher antioxidant and free radical scavenging activities than the crude acetone extract and other fractions. In addition, AFE exhibited that the IC50 values of DPPH (2.5µg/ml) and ABTS (1.8µg/ml) were lower when compared to the standard quercetin (12.4µg/ml and 4.7µg/ml, respectively). In ethanol induced gastric ulcer, administration of AFE at doses of 10mg/kg, 50mg/kg and 100mg/kg body weight prior to ethanol ingestion significantly protected the stomach ulceration. Consequently significant changes were observed in enzyme activities such as SOD, CAT, GSH and LPO in the stomach tissues when compared with ethanol control group.

CONCLUSION

It is concluded that the ethyl acetate fraction of Acacia ferruginea stem bark possessed higher antioxidant and anti-ulcerogenic activities. Based on the results, we suggest that Acacia ferruginea stem bark has potential to provide a therapeutic approach to ethanol mediated ulcer as an effective anti-ulcer agent.

Anticancer activity of Acacia nilotica (L.) Wild. Ex. Delile subsp. indica against Dalton's ascitic lymphoma induced solid and ascitic tumor model

The aim of the present investigation was to evaluate the effect of A. nilotica extract against Dalton's ascitic lymphoma (DAL) induced solid and ascitic tumors in BALB/c mice. Experimental animals received A. nilotica extract (10 mg/kg.bw) intraperitoneally for 10 and 14 consecutive days before induction of solid and ascitic tumors, respectively. Treatment with A. nilotica extract significantly decreased the development of tumor and percentage increase in body weight when compared to DAL induced solid tumor control group, also increasing the life span, restoring the total white blood cell count and hemoglobin content and significantly decreasing the levels of serum aspartate transaminase (SGPT), alanine transaminase (SGOT), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT) and nitric oxide (NO) when compared to DAL induced ascitic tumor controls. The treatment also reduced significantly the cellular glutathione (GSH) and nitric oxide levels in treated animals. Histopathological studies also confirmed protective influence. The outcome of the present work indicates that A. nilotica extract could be used as natural anticancer agent for human health.

Therapeutic effect of Acacia nilotica pods extract on streptozotocin induced diabetic nephropathy in rat

The aim of the present study was to examine the effect of aqueous methanol extract (150 and 300 mg/kg body weight) of Acacia nilotica pods in streptozotocin-induced diabetic rats for 60 days, and its biochemical, histopathological and histochemical study in the kidney tissues. Diabetic rats exhibited hyperglycemia, elevated of serum urea and creatinine. Significant increase in lipid peroxidation (LPO), superoxide dismutase (SOD) and reduced glutathione (GSH) was observed in diabetic kidney. Histopathological examination revealed infiltration of the lymphocytes in the interstitial spaces, glomerular hypertrophy, basement membrane thickening and tubular necrosis with loss of their brush border in some of the proximal convoluted tubules in diabetic rats. Acacia nilotica extract lowered blood glucose levels, restored serum urea and creatinine. In addition, Acacia nilotica extract attenuated the adverse effect of diabetes on LPO, SOD and GSH activity. Treatment with Acacia nilotica was found to almost restore the normal histopathological architecture of kidney of streptozotocin-induced diabetic rats. However, glomerular size and damaged area showed ameliorative effect after treatment with the extract. In conclusion, the antioxidant and antihyperglycemic properties of Acacia nilotica extract may offer a potential therapeutic source for the treatment of diabetes.

Minor lipid components of some Acacia species: potential dietary health benefits of the unexploited seeds

BACKGROUND

Oilseed samples from four Acacia species ( A. cyclops, A. ligulata, A. salicina and A. cyanophylla) were analyzed in order to evaluate the potential nutritional value of their unexploited seeds.

METHODS

Samples were collected from different Tunisian geographic locations. Seed oils were extracted and carotenoids, tocopherols and sterols were analyzed using chromatographic methods.

RESULTS

The studied Acacia seeds seem to be quite rich in lipids (from 6% to 12%). All Acacia species contain mainly the xanthophylls zeaxanthin and lutein compounds: from ca. 38 mg.kg⁻¹ of total lipids (A. cyclops) to ca. 113 mg.kg⁻¹ of total lipids (A. cyanophylla). Total tocopherols varied from ca. 221 mg.kg⁻¹ of total lipids (A. cyclops) to ca. 808 mg.kg-1 of total lipids (A. ligulata). Sterols are highly present and their contents ranged between ca. 7 g. kg⁻¹ of total lipids (A. salicina) and 11 g. kg⁻¹ of total lipids (A. cyclops).

CONCLUSION

This study highlights that these unexploited seeds might have a potential nutritional value and encourages researchers to more explore and find developments for these plants for healthy purposes.

Relationship between wood color parameters measured by the CIELab system and extractive and phenol content in Acacia mangium and Vochysia guatemalensis from fast-growth plantations

The heterogeneity of color distribution between sapwood and heartwood limits the market for wood from fast-growth plantations of tropical species. Wood color is associated with wood extractives contents. This study presents the relationship between wood color parameters measured by the CIELab color system and total amount of extractives and phenolic-type extractives in ethanol-toluene and hot water extracts of wood from two fast-growth plantation species. The results demonstrated that the difference in sapwood and hardwood color in Vochysia guatemalensis and Acacia mangium is caused by lower concentrations of extractives in sapwood of both species. Additionally, variations in total extractive and phenolic content have different effects on the color parameters (L*, a* and b*) of both species studied. In Vochysia guatemalensis wood, parameter L* decreases as total extractive and phenolic content increases; however, parameter a* increases as the content of extractives and phenols increases. In Acacia mangium, the amount of phenols showed no relationship with the color parameters. The ethanol-toluene total extractive content, however, shows a relationship with several color parameters. An increase in the content of total extractives in water and ethanol-toluene increases parameter a*, but decreases parameter L*.

Antioxidant and cytotoxic activity of polyphenolic compounds isolated from the leaves of Leucenia leucocephala

CONTEXT

Cancer is a serious clinical problem to the health care system. Anticancer drugs have been extracted from plants containing phenolic compounds. Leucenia species (Fabaceae) contain a variety of bioactive components of numerous biological and pharmacological properties.

OBJECTIVE

This study explored the constitutive polyphenols of Leucenia leucocephala Lam. growing in Egypt and evaluated the antioxidant and cytotoxic activity.

MATERIALS AND METHODS

Chemical structures of the isolated compounds from the leaves of L. leucocephala were established by spectral techniques (UV, (1)H, and (13)C NMR, MS).

RESULTS

Chromatographic separation of 80% MeOH extract of the leaves of L. leucocephala have resulted in a novel flavonoid-galloyl glycoside [myricetin 3-O-(2',3'4'-tri-O-galloyl)-α-L-rhamnopyranoside] with three known polyphenolic compounds isolated for the first time from this species (apigenin 7-O-β-D-glucuronopyranoside methyl ester, luteolin 7-O-β-D-glucuronopyranoside methyl ester, and 1,3,6-tri-O-galloyl-β-D-glucopyranose) and seven known previously isolated compounds. Also, 80% methanol extract exhibited high antioxidant activity (SC(50) = 3.94 µg/ml), which is correlated with its phenolic content. The extract also showed cytotoxic activity against Hep G2 (IC(50) value 1.41 µg/ml) confirming its anticancer activity against hepatocellular carcinoma. Among the tested compounds (4-8) for antioxidant property, compound 7 was the most active compound (SC(50) = 2.49 µg/ml). Also compounds 7 and 8 exhibited high cytotoxic activity (IC(50) = 2.41 and 2.81 µg/ml, respectively).

DISCUSSION AND CONCLUSION

These findings demonstrate that the leaves of L. leucocephala contain a considerable amount of polyphenolic compounds with high antioxidant properties, thus it has great potential as a source for natural health products.

Responses to water stress of gas exchange and metabolites in Eucalyptus and Acacia spp

Studies of water stress commonly examine either gas exchange or leaf metabolites, and many fail to quantify the concentration of CO₂ in the chloroplasts (C(c)). We redress these limitations by quantifying C(c) from discrimination against ¹³CO₂ and using gas chromatography-mass spectrometry (GC-MS) for leaf metabolite profiling. Five Eucalyptus and two Acacia species from semi-arid to mesic habitats were subjected to a 2 month water stress treatment (Ψ(pre-dawn) = -1.7 to -2.3 MPa). Carbohydrates dominated the leaf metabolite profiles of species from dry areas, whereas organic acids dominated the metabolite profiles of species from wet areas. Water stress caused large decreases in photosynthesis and C(c), increases in 17-33 metabolites and decreases in 0-9 metabolites. In most species, fructose, glucose and sucrose made major contributions to osmotic adjustment. In Acacia, significant osmotic adjustment was also caused by increases in pinitol, pipecolic acid and trans-4-hydroxypipecolic acid. There were also increases in low-abundance metabolites (e.g. proline and erythritol), and metabolites that are indicative of stress-induced changes in metabolism [e.g. γ-aminobutyric acid (GABA) shunt, photorespiration, phenylpropanoid pathway]. The response of gas exchange to water stress and rewatering is rather consistent among species originating from mesic to semi-arid habitats, and the general response of metabolites to water stress is rather similar, although the specific metabolites involved may vary.

Phenolic compounds from the aqueous extract of Acacia catechu

Two new phenolic compounds, 5-hydroxy-2-[2-(4-hydroxyphenyl) acetyl]-3-methoxylbenzoic acid (1) and (2S,3S)-3,7,8,3',4'-pentahydroxyflavane (2), were obtained from the aqueous extract of Acacia catechu, along with four known compounds identified as rhamnetin (3), 4-hydroxyphenyl ethanol (4), 3,3',5,5',7-pentahydroxyflavane (5), and fisetinidol (6). Their structures were determined on the basis of spectroscopic analysis. Free radical-scavenging activities of the new compounds were evaluated.

Medicinal plants used for traditional veterinary in the Sierras de Córdoba (Argentina): an ethnobotanical comparison with human medicinal uses

BACKGROUND

This is a first description of the main ethnoveterinary features of the peasants in the Sierras de Córdoba. The aim of this study was to analyze the use of medicinal plants and other traditional therapeutic practices for healing domestic animals and cattle. Our particular goals were to: characterize veterinary ethnobotanical knowledge considering age, gender and role of the specialists; interpret the cultural features of the traditional local veterinary medicine and plant uses associated to it; compare the plants used in traditional veterinary medicine, with those used in human medicine in the same region.

METHODS

Fieldwork was carried out as part of an ethnobotanic regional study where 64 informants were interviewed regarding medicinal plants used in veterinary medicine throughout 2001-2010. Based participant observation and open and semi-structured interviews we obtained information on the traditional practices of diagnosis and healing, focusing on the veterinary uses given to plants (part of the plant used, method of preparation and administration). Plants speciemens were collected with the informants and their vernacular and scientific names were registered in a database. Non-parametric statistic was used to evaluate differences in medicinal plant knowledge, use, and valorization by local people. A comparison between traditional veterinary medicine and previous human medicine studies developed in the region was performed by analyzing the percentages of common species and uses, and by considering Sorensen's Similarity Index.

RESULTS

A total of 127 medicinal uses were registered, corresponding to 70 species of plants belonging to 39 botanic families. Veterinary ethnobotanical knowledge was specialized, restricted, in general, to cattle breeders (mainly men) and to a less degree to healers, and was independent of the age of the interviewees. Native plants were mostly used as skin cicatrizants, disinfectants or for treating digestive disorders. Together with a vast repertoire of plant pharmacopoeia, the therapies also involve religious or ritualistic practices and other popular remedies that evidence the influence of traditional Hispanic-European knowledge. Although the traditional veterinary knowledge seems to be similar or else is inlcuded in the local human ethnomedicine, sharing a common group of plants, it has distinct traits originated by a constant assessment of new applications specifically destined to the treatment of animals.

CONCLUSIONS

Veterinary medicine is a fountain of relevant vernacular knowledge, a permanent source for testing new applications with valuable ethnobotanical interest. Knowledge on medicinal applications of native plants will allow future validations and tests for new homeopathic or phytotherapeutic preparations.

Free Radical Scavenging, Cytotoxic and Hemolytic Activities from Leaves of Acacia nilotica (L.) Wild. ex. Delile subsp. indica (Benth.) Brenan

Dietary intake of phytochemicals having antioxidant activity is associated with a lower risk of mortality from many diseases. Therefore, the aim of this study was to determine the free radical scavenging, cytotoxic and hemolytic activities of leaves of Acacia nilotica by using various methods. The results of the present study revealed that ethanol extract was the most effective and IC₅₀ value was found to be 53.6 μg mL⁻¹ for Vero cell lines and 28.9 μg mL⁻¹ for Hela cell lines in cytotoxicity assays. The zone of color retention was 14.2 mm in β-carotene bleaching assay, which was as significant as positive control, butylated hydroxy toluene. None of the tested extracts possessed any hemolytic activity against rat and human erythrocytes revealing their cytotoxic mechanism and non-toxicity. Thus, only the ethanol extract could be considered as a potential source of anticancer and antioxidant compounds. Further phytochemical studies will be performed for specification of the biologically active principles.

Phytochemicals from Acacia confusa heartwood extracts reduce serum uric acid levels in oxonate-induced mice: their potential use as xanthine oxidase inhibitors

In this study, the antihyperuricemic effect of Acacia confusa heartwood extracts and their phytochemicals on potassium oxonate (PO)-induced acute hyperuricemia was investigated for the first time. All treatments at the same dosage (100 mmol/kg) were administered to the abdominal cavity of PO-induced hyperuricemic mice, and serum uric acid level was measured at 3 h after administration. In experimental mice, serum uric acid level was significantly suppressed by the administration of A. confusa heartwood extracts and their major phytochemicals, (-)-2,3-cis-3,4-cis-3,3',4,4',7,8-hexahydroxyflavan, (-)-2,3-cis-3,4-cis-4'-methoxy-3,3',4,7,8-pentahydroxyflavan, melanoxetin, transilitin, and okanin, relative to the PO group. The direct inhibitory effect of these five compounds on xanthine oxidase (XOD) activity was examined using isothermal titration calorimetry (ITC). Among them, melanoxetin showed a more remarkable inhibitory effect on XOD activity than allopurinol, a clinical drug used for XOD inhibitor. To further understand the stereochemistry between XOD and melanoxetin (or allopurinol), structure-based molecular modeling was performed. Melanoxetin undergoes extended interactions in the hydrophobic region via the 3',4'-dihydroxyphenyl moiety, thus accounting for its higher binding affinity to XOD than allopurinol. These results indicate that A. confusa heartwood extracts and their major phytochemicals exhibit strong XOD inhibitory effects, which reduce serum uric acid levels while inhibiting uric acid generation in purine metabolism.

Woody legumes: a (re)view from the South

This review is focused on woody legumes from the southern continents. We highlight that the evolution of the Caesalpinioideae and Mimosoideae with old soils, with variable supplies of water and also with fire has produced a suite of advantageous physiological characteristics. These include good potential for nitrogen fixation and mechanisms for acquiring P. The latter includes the ability to form cluster roots and produce extracellular phosphatase enzymes. Further, many of the species in these subfamilies are known to synthesize in significant amounts osmotically compatible solutes, such as pinitol and other cyclitols/polyols, that help them cope with even severe drought conditions. In many cases, these species regenerate prolifically after fire from seed. Such species and their beneficial characters can now be better exploited to help sequester carbon, provide key nutrients such as nitrogen and phosphorus for companion crops and other plants and provide feedstocks for a range of industries, including energy industries.

Extracts of edible and medicinal plants damage membranes of Vibrio cholerae

The use of natural compounds from plants can provide an alternative approach against food-borne pathogens. The mechanisms of action of most plant extracts with antimicrobial activity have been poorly studied. In this work, changes in membrane integrity, membrane potential, internal pH (pH(in)), and ATP synthesis were measured in Vibrio cholerae cells after exposure to extracts of edible and medicinal plants. A preliminary screen of methanolic, ethanolic, and aqueous extracts of medicinal and edible plants was performed. Minimal bactericidal concentrations (MBCs) were measured for extracts showing high antimicrobial activity. Our results indicate that methanolic extracts of basil (Ocimum basilicum L.), nopal cactus (Opuntia ficus-indica var. Villanueva L.), sweet acacia (Acacia farnesiana L.), and white sagebrush (Artemisia ludoviciana Nutt.) are the most active against V. cholera, with MBCs ranging from 0.5 to 3.0 mg/ml. Using four fluorogenic techniques, we studied the membrane integrity of V. cholerae cells after exposure to these four extracts. Extracts from these plants were able to disrupt the cell membranes of V. cholerae cells, causing increased membrane permeability, a clear decrease in cytoplasmic pH, cell membrane hyperpolarization, and a decrease in cellular ATP concentration in all strains tested. These four plant extracts could be studied as future alternatives to control V. cholerae contamination in foods and the diseases associated with this microorganism.

Phytochemical, antibacterial, antiproliferative, and antioxidant potentials and DNA damage-protecting activity of Acacia salicina extracts

The extract enriched in total oligomer flavonoids (TOF), and the aqueous, methanol, and ethyl acetate extracts of Acacia salicina were investigated for their polyphenolic compound content, antioxidative activity in the nitro blue tetrazolium/riboflavin assay system, antibacterial activity against Gram-positive and Gram-negative bacterial reference strains, antigenotoxic activity tested with the Ames assay, and cytotoxic activity against the K562 human chronic myelogenous leukemia cell line and L1210 leukemia murine cells. TOF extract was effective at inhibiting nitro blue tetrazolium reduction by superoxide radical in a nonenzymatic O(2)(*-)-generating system. Significant activity against bacterial reference strains Staphylococcus aureus, Enterococcus faecalis, Salmonella enteritidis, and Salmonella typhimurium was shown with all the tested extracts. These extracts significantly decreased the genotoxicity induced by sodium azide and 4-nitro-o-phenylenediamine. A pronounced cytotoxic effect on both leukemia cell lines was detected in TOF, methanolic and ethyl acetate extracts. The antioxidant, antimicrobial, antigenotoxic, and cytotoxic activities exhibited by A. salicina depended on the chemical composition of the tested extracts.

Characteristic Flavonoids from Acacia burkittii and A. Acuminata Heartwoods and their Differential Cytotoxicit to Normal and Leukemia Cells

Bioassay-guided fractionation of extracts from Acacia burkittii and A. acuminata heartwoods against an L1210 (mouse lymphoma) cell line led to the isolation of two flavan-3,4-diols, melacacidin (1) and isomelacacidin (2), and three flavonoids, 3,7,8,3′,4′-pentahydroxyflavone (3), 7,8,3′,4′-tetrahydroxyflavanone (4) and 3,7,8,3′,4′-pentahydroxyflavanone (5). HPLC analyses (280 nm) of the 70% acetone extracts of the two plants showed different profiles in terms of the relative concentration of the five identified compounds. When tested against L1210, compounds 1 and 2 were the most active, giving ID50 values of 2.5 and 4.5 μg/mL, respectively. The lower activity of the other isolated compounds indicated the importance of the 3,4-hydroxyl groups for the cytotoxic activity of these flavonoids. The isolated compounds were either non-toxic or had very low toxicities against the “normal” CV-1 cell line (green monkey kidney cells). The O-methyl and O-acetyl derivatives of these compounds were inactive. Ten commercially available phenolic compounds (6-15) were also tested for their activity against both CV-1 and L1210 cell lines. Flavan-3,4-diols 1 and 2 were more cytotoxic to L1210 cells than all tested compounds, including catechin and epicatechin, the most abundant flavan-3-ols in many fruits and vegetable.

Effect of phytocompounds from the heartwood of Acacia confusa on inflammatory mediator production

Acacia confusa Merr. (Leguminosae) is traditionally used as a medicinal plant in Taiwan. In the present study, anti-inflammatory activity of extracts from the heartwood of A. confusa were investigated for the first time. Results demonstrated that ethanolic extracts of A. confusa heartwood strongly suppressed NO production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Among all fractions derived from ethanolic extracts, the EtOAc fraction exhibited the best inhibitory activity. Following column chromatography and reverse-phase high-performance liquid chromatography, 13 specific phytocompounds including 5 new flavonoids (i.e., 7,8,3',4'-tetrahydroxy-4-methoxyflavan-3-ol, 7,8,3',4'-tetrahydroxyflavone, 7,8,3'-trihydroxy-3,4'-dimethoxyflavone, 7,3',4'-trihydroxyflavone, and 7,3',4'-trihydroxy-3-methoxyflavone) were isolated and identified from the EtOAc fraction. In addition, melanoxetin (3,7,8,3',4'-pentahydroxyflavone), a major compound in the EtOAc fraction, markedly suppressed LPS-induced NO and prostaglandin E 2 (PGE 2) production. Moreover, melanoxetin completely suppressed gene expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) at 50 and 100 microM, respectively. This is the first report to identify the inhibitory bioactivities of melanoxetin on iNOS and COX-2.

Demonstration of long-chain n-alkyl caffeates and delta7-steryl glucosides in the bark of Acacia species by gas chromatography-mass spectrometry

The GC-MS identification of several abundant long-chain aliphatic n-alkyl caffeates, together with other phydroxycinnamic acid esters, in the dichloromethane extracts of the bark of Acacia dealbata and A. melanoxylon, is reported. In addition, the unambiguous differentiation between two delta7-steryl glucosides (namely, spinasteryl glucoside and dihydrospinasteryl glucosides) and the homologous delta5-steryl glucosides was achieved based on the EI-MS fragmentation features of their trimethylsilyl derivatives.