Antihyperglycemic and aphrodisiac effect of West African Albizia (Albizia zygia) leaves-inclusive diet in diabetes-induced erectile dysfunctional rats

ETHNOPHARMACOLOGICAL RELEVANCE

West African Albizia (Albizia zygia DC J. F. Macbr) leaves are a tropical plant that are frequently used in folkloric medicine to treat a number of illnesses, including type 2 diabetes (TY2D) and erectile dysfunction (ED), without having a complete scientific foundation.

AIM OF THE STUDY

This investigation examined the effect of action of dietary augmentation of Albizia zygia leaves (AZL) on rat sexual functioning and important enzymes related to TY2D and ED.

MATERIALS AND METHODS

Thirty matured adult Wistar rats of the weight 180-200 g were acclimatized in a lab environmental condition for two weeks prior to experiment given food and water to acclimate. Twenty-four of the rats got high fat diet (HFD) for periods of two weeks before receiving streptozotocin (STZ) intraperitoneally (i.p.), 35 mg/kg body weight single dose. Six rats got basal diets. Type 2 diabetes was identified in rats 72 h after STZ treatment. Rats were then used to evaluate the mounting number, mount delay, intromission number, and intromission latency.

RESULTS

Following that, meals supplemented with AZL (5% or 10% inclusion) were given to diabetic-ED rats for 14 days. AZL was added. Therefore, in diabetic-ED rats, AZL supplementation could significantly (p0.05) lower blood glucose levels and the activities of alpha amylase, alpha glucosidase, phosphodiesterase-5, and arginase. In the case of diabetic-ED treated rats in consideration with diabetic-ED control group, nitric oxide levels were increased along with sexual function.

CONCLUSION

Thus, experimental results of this study demonstrated rats that consumed AZL in their diets had less erectile dysfunction. In order to address ED caused by diabetes, AZL could be suggested as functional meals.

Characterization of new cellulose fiber extracted from second generation Bitter Albizia tree

The present work examines the physical, thermal tensile, and chemical properties of wood skin fibers obtained from second generation Bitter Albizia (BA) tree skin. Chemical characterization of BA fibers showed the presence of various chemical contents such as cellulose of 74.89 wt. %, hemicellulose of 14.50 wt. %, wax of 0.31 wt. %, lignin of 12.8 wt. %, moisture of 11.71 wt. %, and ash of 19.29 wt. %. The density of BA fibers (BAFs) was showed 1285 kg/m3. XRD analysis of BAFs showed a crystallinity index (CI) of 57.20% and size of crystallite of 1.68 nm. Tensile strength and strain to failure of BAFs examined through tensile test were 513-1226 MPa and 0.8-1.37% respectively. TGA portrayed the thermal steadiness of BAFs as 339 °C with 55.295 kJ/mol kinetic activation energy, its residual mass was 23.35% at 548 °C. BAFs with high CI, less wax content, and better tensile strength make more suitable for making polymer matrix composites. SEM images of the BAFs surface depicted that the fiber outer surface has more rough which shows that they can contribute to hige fiber-matrix adhesion during composites preparation.

Prediction of cell migration potential on human breast cancer cells treated with Albizia lebbeck ethanolic extract using extreme machine learning

Cancer is one of the major causes of death in the modern world, and the incidence varies considerably based on race, ethnicity, and region. Novel cancer treatments, such as surgery and immunotherapy, are ineffective and expensive. In this situation, ion channels responsible for cell migration have appeared to be the most promising targets for cancer treatment. This research presents findings on the organic compounds present in Albizia lebbeck ethanolic extracts (ALEE), as well as their impact on the anti-migratory, anti-proliferative and cytotoxic potentials on MDA-MB 231 and MCF-7 human breast cancer cell lines. In addition, artificial intelligence (AI) based models, multilayer perceptron (MLP), extreme gradient boosting (XGB), and extreme learning machine (ELM) were performed to predict in vitro cancer cell migration on both cell lines, based on our experimental data. The organic compounds composition of the ALEE was studied using gas chromatography-mass spectrometry (GC-MS) analysis. Cytotoxicity, anti-proliferations, and anti-migratory activity of the extract using Tryphan Blue, MTT, and Wound Heal assay, respectively. Among the various concentrations (2.5-200 μg/mL) of the ALEE that were used in our study, 2.5-10 μg/mL revealed anti-migratory potential with increased concentrations, and they did not show any effect on the proliferation of the cells (P < 0.05; n ≥ 3). Furthermore, the three data-driven models, Multi-layer perceptron (MLP), Extreme gradient boosting (XGB), and Extreme learning machine (ELM), predict the potential migration ability of the extract on the treated cells based on our experimental data. Overall, the concentrations of the plant extract that do not affect the proliferation of the type cells used demonstrated promising effects in reducing cell migration. XGB outperformed the MLP and ELM models and increased their performance efficiency by up to 3% and 1% for MCF and 1% and 2% for MDA-MB231, respectively, in the testing phase.

Anti-diabetic and anti-lipidepmic effect of Albizia lebbeck seeds against HepG2 cells

Albizia lebbeck has been a medicinally important plant for its pharmacological potential. This study aims to determine the in vitro antioxidant, anti-diabetic and anti-lipidemic potential of A. lebbeck seeds. The seed extracts were prepared in petroleum ether, chloroform and methanol. Crude methanolic extract (ME ext) was subjected further to sequential fractionation in increasing polarity based solvents. Extracts and fractions were analyzed for their antioxidant, anti-diabetic and anti-lipidemic potentials using hepatic cell line, HepG2. Results showed that crude extracts of A. lebbeck seeds specifically, ME ext are rich in polyphenols and flavonoids. ME ext has also shown highly significant antioxidant and alpha-amylase inhibition potential compared to petroleum ether and chloroform extracts. In vitro assays using different fractions of methanolic extract further highlighted the ethyl acetate and chloroform fractions exhibiting significant antioxidant and anti-diabetic potentials. Alpha-amylase inhibition coupled with enhanced glucose uptake of cells treated with ME ext and ethyl acetate fraction emphasized on significant anti-diabetic potential of the plant. Expression alteration of genes and reduced level of cholesterol suggested the lipid synthesis mediated anti-diabetic activity of the plant. It is therefore, concluded that A. lebbeck seed has significant antioxidant, anti-diabetic and anti-lipidemic potentials.

The rhizosphere effect of native legume Albizzia julibrissin on coastal saline soil nutrient availability, microbial modulation, and aggregate formation

In the coastal zones, numerous ecological shelterbelt projects were conducted to protect against natural hazards. However, it is still not fully understood whether phytoremediation with native legume Albizzia julibrissin plantation can improve saline soil structural development or microbial community structure. In this study, a field experiment was conducted to investigate the responses of rhizosphere soil salinity, nutrients, bacterial community, and aggregate structure to A. julibrissin plantation in a recently reclaimed area along Zhejiang coast, China. After ~3-year plantation, rhizosphere soil pH and EC reduced to 8.25 and 0.14 dS·m^-1, respectively, belonging to non-saline soil. Meanwhile, total organic carbon (TOC), permanganate-oxidizable carbon (POXC), total nitrogen (TN), alkali-hydrolyzable nitrogen (AN), and ammonium nitrogen (NH₄⁺-N) were significantly increased in rhizosphere soil compared with bare land (P < 0.05). Consequently, rhizosphere soil had favorable habitat condition for copiotrophic bacterial taxa (e.g., Chloroflexi, Acidobacteria, and Bacteroidates), as well as high diversity, complex co-occurrence network, and catabolism related with nutrient cycling. The soil particle size of bare land was < 0.053 mm, while microaggregate (0.053-0.25 mm) and macroaggregate (0.25-2 mm) were formed in the rhizosphere and coupled with C accumulation and Fe removal. Soil aggregates were of great importance to soil fertility with more efficient bacterial network and biogeochemical cycles of nutrients. N-fixing Rhizobiales preferred to inhabit large soil particle and might primarily contribute to N accumulation. Generally, A. julibrissin was a suitable pioneer tree for mudflat reclamation projects, which effectively improved saline soil rhizosphere environment by reducing salinity, accumulating C and N, and promoting microbial community succession, as well as aggregate structure formation.

Comprehensive analysis of chloroplast genome of Albizia julibrissin Durazz. (Leguminosae sp.)

The Albizia julibrissin chloroplasts have a classical chloroplast genome structure, containing 93 coding genes and 34 non-coding genes. Our research provides basic data for plant phylogenetic evolutionary studies. There is limited genomic information available for the important Chinese herb Albizia julibrissin Durazz. In this study, we constructed the chloroplast (Cp) genome of A. julibrissin. The length of the assembled Cp genome was 175,922 bp consisting of four conserved regions: a 5145 bp small single-copy (SSC) region, a 91,323 bp large single-copy (LSC) region, and two identical length-inverted repeat (IR) regions (39,725 bp). This Cp genome included 34 non-coding RNAs and 93 unique genes, the former contains 30 transfer and 4 ribosomal RNA genes. Gene annotation indicated some of the coding genes (82) in the A. julibrissin Cp genome classified in the Leguminosae family, with some to other related families (11). The results show that low GC content (36.9%) and codon bias towards A- or T-terminal codons may affect the frequency of gene codon usage. The sequence analysis identified 30 forward, 18 palindrome, and 1 reverse repeat > 30 bp length, and 149 simple sequence repeats (SSR). Fifty-five RNA editing sites in the Cp of A. julibrissin were predicted, most of which are C-to-U conversions. Analysis of the reverse repeat expansion or contraction and divergence area between several species, including A. julibrissin, was performed. The phylogenetic tree revealed that A. julibrissin was most closely related to Albizia odoratissima and Albizia bracteata, followed by Samanea saman, forming an evolutionary branch with Mimosa pudica and Leucaena trichandra. The research results are helpful for breeding and genetic improvement of A. julibrissin, and also provide valuable information for understanding the evolution of this plant.

Oleanane-type saponins and prosapogenins from Albizia julibrissin and their cytotoxic activities

Two undescribed oleanane-type saponins, julibrosides K-L, along with three undescribed oleanane-type prosapogenins, julibrosides M-O, were isolated from the stem bark of Albizia julibrissin Durazz. and the mild alkaline hydrolysate of the total saponin, respectively. Their structures were established by extensive analysis of 1D and 2D NMR experiments (COSY, TOCSY, HSQC, HMBC, and HSQC-TOCSY) and mass spectrometry. Furthermore, the cytotoxic activities of the isolated compounds against BGC-823, A549, HCT-116, and HepG2 cell lines were evaluated, and julibroside L showed significant cytotoxic activities against the four cancer cell lines with IC₅₀ values of 5.77, 4.80, 4.26, and 4.93 μM, respectively.

Albizia lebbeck and Albizia zygia volatile oils exhibit anti-nociceptive and anti-inflammatory properties in pain models

ETHNOPHARMACOLOGICAL RELEVANCE

Albizia lebbeck and Albizia zygia are used in Nigeria, South Africa and other countries for the treatment of flu, fever, pain, epilepsy, and inflammation.

AIM OF THE STUDY

Application of plant essence for treating ailments is common among local communities. This research was designed to characterize the volatile compounds and evaluate the toxicity, anti-inflammatory and anti-nociceptive properties of this plant species.

MATERIALS AND METHODS

The volatile oils were analysed comprehensively utilizing gas chromatography-flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS) using the HP-5 column. The toxicity was evaluated using the toxicity assay. The anti-nociceptive and anti-inflammatory assays were analysed by a hot plate, Formalin, and carrageenan-induced edema assays, respectively.

RESULTS

The essential oils were obtained in a yield of 0.1% (v/w) calculated on a dry weight basis for both oils. The main compounds of A. lebbeck were 2-pentylfuran (16.4%), (E)-geranyl acetone (15.46%), (E)-α-ionone (15.45%) and 3-Octanone (11.61%), while the oil of A. zygia is mainly hexahydrofarnesyl acetone (33.14%), (E)-methyl isoeugenol (11.7%) and 2-methyl tetradecane (6.64%). The volatile oils are non-toxic to about 5000 mg/kg dose. Albizia zygia significantly (P < 0.001) suppressed the nociceptive afferent fibres in a non-dose dependent manner in comparison to A. lebbeck in the hot plate model. Both oils inhibited nociceptive mediators at both phases of the formalin-induced assay, with a maximum inhibition (100%) at the inflammatory stage. The volatile oils inhibited the Carrageenan-induced inflammation at all phases ranging from P < 0.05 to P < 0.001. The probable pro-inflammatory inhibitory mechanism might be the suppression of some pain biomarkers such as histamine, serotonin, bradykinin, and the Interleukins (ILs) induced by the edema. Volatile constituents such as ionones, eugenol derivatives and other compounds cause the anti-nociceptive and anti-inflammatory activities reported.

CONCLUSION

This is the first report of the volatile oils and bioassays of Albizia zygia, while the study also confirms previous studies of A. lebbeck. Generally, the findings further prove the use of the plants as pain ameliorating agents.

Attenuation of oxidative stress in arthritic rats by ethanolic extract of Albizia procera benth bark through modulation of the expression of inflammatory cytokines

ETHNOPHARMACOLOGICAL RELEVANCE

Albizia procera L. (Leguminosae) commonly known as Konda vagai in Tamil, is used for the treatment of stomach and intestinal disorders. A decoction of the bark is prescribed for rheumatism and haemorrhage. Traditionally, literature claims Albizia procera as a drug to have antirheumatic properties and hence used by Tribal for the management of chronic rheumatism. Consequently, the present study has been undertaken to illustrate the beneficial outcome of Albizia procera in adjuvant induced arthritic rat model with respect to its antioxidant and anti-inflammatory activities.

AIM OF THE STUDY

The present study is aimed to investigate the oxidative stress and the expression of inflammatory markers in arthritic rats treated with ethanolic bark extract of Albizia procera.

MATERIALS AND METHODS

Ethanolic bark extract was characterized by HPTLC analysis. Acute oral toxicity study was performed according to the OECD test guideline 423 - Acute toxic class method. The anti-inflammatory effect of ETBE (100, 200 mg/kg/day/p.o.) was evaluated in complete Freund's adjuvant induced arthritic rats using diclofenac as positive control (0.3 mg/kg/day/p. o.). Plasma levels of interleukins TNF- α, IFN-α, IL-2, IL-6, myeloperoxidase and Cathepsin D levels were measured to assess the inflammatory effect of ETBE extract of Albizia procera. Further, the effect of ETBE on superoxide dismutase (SOD), glutathione peroxidase (GPX), reduced glutathione (GSH) and lipid peroxidation (LPO) were assessed in plasma.

RESULTS

HPTLC analysis showed the presence of 0.57% w/w of biochanin-A in ETBE. ETBE did not show any toxic signs up to 2000 mg/kg body weight. It exhibited the significant anti-inflammatory and antioxidant potential and did not show mortality up to 2000 mg/kg body weight. ETBE treatment significantly reduced the levels of TNF- α, IFN-α, IL-2, IL-6 and myeloperoxidase, and increased cathepsin D levels compared to vehicle treated animals. SOD, GSH and GPX levels were significantly restored to normal levels while LPO was significantly reduced at 200 mg/kg b. wt. Treated animals. Histopathological studies showed complete cartilage regeneration and near normal joint in ETBE treated arthritic rats.

CONCLUSION

ETBE demonstrated potent anti-inflammatory activity by modulating the expression of inflammatory cytokines and restoring the antioxidant enzyme levels.

Anticancer activity of saponin isolated from Albizia lebbeck using various in vitro models

ETHNOPHARMACOLOGICAL RELEVANCE

Albizia lebbeck (L.) Benth. (Family: Mimosaceae) is commonly known as Sirisha in Sanskrit. The leaves and pods of A. lebbeck were claimed to be used against cancer in traditional medicine. Previous studies using bark, leaves, seeds and pods of A. lebbeck showed cytotoxic activity against hepatic, colon, larynx, cervical and breast cancer cell lines.

AIM OF THE STUDY

To evaluate the anticancer activity of saponin rich fraction of Albizia lebbeck by using various in vitro models.

MATERIALS AND METHODS

Albiziasaponins (A-E) are oleanene triterpene presents in Albizia lebbeck were used for in silico studies. In silico testing of albiziasaponins for structure based pharmacological activity prediction using PASS Online software and docking with Autodock tool and Autodock Vina revels it's anticancer and apoptogenic potential. Antiproliferative activity of saponin rich fraction of A. lebbeck was performed using MCF-7 human breast cancer cells by MTT assay methods. Anti-angiogenic property of saponin rich fraction of A. lebbeck was evaluated in in vitro shell less chick embryo cultures with different concentrations (0.1 µg/ml, 0.5 µg/ml, and 1 µg/ml) by using ImageJ software. In vitro cultured lymphocytes chromosomal aberration assay was performed to determine the physical integrity of chromosomes in cells and effect of saponin rich fraction of A. lebbeck on cell cycle. Apoptogenic potential was evaluated using Caspases-3 and Caspase-8 ELISA assay in MCF-7 cells.

RESULTS

Result of MTT assay showed IC50 of saponin rich fraction of A. lebbeck at 1 μg/ml in MCF-7 cells. Treatment with saponin rich fraction of A. lebbeck significantly (p < 0.05) reduced angiogenic parameters. Significant chromosomal aberrations (hypodiploid, hyperdiploid, ring, premature separation, Dicentric fragments, Acentric fragment, chromatid break, and chromosomal gap) were observed in saponin rich fraction of A. lebbeck treated groups. Treatment with saponin rich fraction of A. lebbeck increased levels of Caspases-3 (optical density of 0.24 at 450 nm) and Caspase-8 (optical density of 0.31 at 450 nm) as compared to staurosporine (optical density of 2.47 and 2.65 for caspases-3 and -8 respectively at 450 nm).

CONCLUSION

In our study, saponin rich fraction of A. lebbeck showed antiproliferative, antiangiogenic and apoptogenic potential using various in-vitro models. It also found to increase chromosomal aberration and thereby may affect cell cycle.

Albizia Adianthifolia: Botany, Medicinal Uses, Phytochemistry, and Pharmacological Properties

The bark, leaves, and roots of Albizia adianthifolia are highly sought after in tropical Africa as herbal medicines. Therefore, the aim of this study was to review the botany, medicinal uses, phytochemistry, and pharmacological properties of A. adianthifolia so as to provide baseline data required for evaluating the therapeutic potential of the species. Information on the botanical profile, medicinal uses, phytochemistry, and pharmacological properties of A. adianthifolia was undertaken using databases such as ScienceDirect, SciFinder, Pubmed, Google Scholar, Medline, SCOPUS, EThOS, ProQuest, OATD, and Open-thesis. Preelectronic literature search of conference papers, scientific articles, books, book chapters, dissertations, and theses was carried out at the University library. Literature search revealed that A. adianthifolia is used as purgative and herbal medicine for diabetes, eye problems, gastrointestinal problems, haemorrhoids, headache, neurodegenerative disorders, reproductive problems in women, respiratory problems, wounds and pain, skin diseases, sexually transmitted infections, and ethnoveterinary medicine. Phytochemical compounds identified from the species include apocarotenoids, chalcone, dipeptide, elliptosides, essential oils, fatty acids, flavonoids, histamine, imidazolyl carboxylic acid, prosapogenins, steroids, triterpene saponins, and triterpenoids. Pharmacological studies revealed that A. adianthifolia extracts and compounds have acetylcholinesterase enzyme inhibitory, anthelmintic, antiamoebic, antibacterial, antimycobacterial, anti-sexually transmitted infections, antifungal, anti-inflammatory, antioxidant, anxiolytic, and antidepressant, cognitive-enhancing, haemolytic, hypoglycemic and antihyperglycemic, immunomodulatory, and cytotoxicity activities. Detailed studies on the pharmacokinetics, in vivo, and clinical research involving compounds isolated from A. adianthifolia and extracts of the species are required.

Total saponins of Albiziae Cortex show anti-hepatoma carcinoma effects by inducing S phase arrest and mitochondrial apoptosis pathway activation

ETHNOPHARMACOLOGICAL RELEVANCE

Albiziae Cortex (AC) is a widely used traditional medicine in China. It is possess various properties to treat insomnia, traumatic injuries, diuresis, sthenia, and confusion. Total saponins of Albiziae Cortex (TSAC) are the most abundant bioactive components of AC, which were reported to show significant anti-tumor effects in vivo and in vitro. But the underlying mechanism of TSAC remained to be revealed.

AIM OF STUDY

In this study, we investigated the anti-hepatoma carcinoma effects and the potential mechanism of TSAC in vivo and in vitro.

MATERIALS AND METHODS

We first purified TSAC from crude extracts and characterized the major bioactive compounds by high performance liquid chromatography (HPLC). Effects of TSAC on viability of various hepatoma carcinoma cell lines were measured by MTT. Inhibition on cell proliferation was analysed using colony formation assay. Cell cycle distribution was revealed by flow cytometry. The apoptotic cells were observed by Hoechst 33258 staining and acridine orange (AO)/ethidium bromide (EB) double staining. Microstructures of apoptotic cells were examined by Transmission electron microscopy (TEM). The mitochondrial membrane potential were determined by JC-1 staining. Western blot was used to investigate the effects of TSAC on apoptosis-related proteins, B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax), and S-phase related protein cyclin A, cyclin E and cyclin-dependent kinases 2 (CDK2). Effects on tumor growth was assessed by H22-bearing ICR mice.

RESULTS

TSAC significantly decreased the hepatoma carcinoma cell viability and inhibited HepG2 cell colony formation in a concentration-dependent manner. We also found that TSAC inhibited HepG2 cell growth via induction of S phase arrest. Further study showed that TSAC significantly down-regulated the expressions of cyclin A, cyclin E and CDK2 in HepG2 cells. Meanwhile, TSAC could effectively induce mitochondria-dependent caspase apoptosis pathway activation. Furthermore, TSAC increased the expression of pro-apoptotic protein Bax and decreased the expression of anti-apoptotic protein Bcl-2. In vivo assay showed that the anti-tumor effects of TSAC were significantly augmented without increasing toxicity in H22-bearing ICR mice.

CONCLUSION

TSAC could inhibit cell proliferation through inducing S phase arrest and activate cell apoptosis via mitochondria-dependent apoptosis pathway. Therefore, TSAC could be a promising agent in clinical trials for anti-hepatoma carcinoma treatment.

Albizia zygia (DC.) J.F. Macbr. (Leguminosae-Mimosoideae) root extract exhibits anti-nociceptive and antipyretic activities in murine models

ETHNOPHARMACOLOGICAL RELEVANCE

The root extract of Albizia zygia (DC.) J.F. Macbr. (Leguminosae-Mimosoideae) is traditionally used in the management of pain and fever. However, little scientific data exists in literature to support its use.

AIM OF STUDY

The present study evaluated the anti-nociceptive and antipyretic properties of the hydroethanolic extract of the roots of Albizia zygia in animal models.

MATERIALS AND METHODS

The analgesic effects were investigated in chemical (acetic acid-induced abdominal writhing and formalin tests), thermal (tail-immersion test) and mechanical (carrageenan-induced hyperalgesia) pain models. Possible mechanisms of anti-nociception were also assessed with antagonists in the formalin test. The anti-pyretic effect was evaluated using the baker yeast-induced pyrexia model in young rats.

RESULTS

The extract (30-300mg/kg, p.o.) and positive controls, diclofenac (3-30mg/kg, i.p.) and morphine (1-10mg/kg, i.p.), significantly (at least P<0.01) attenuated acetic acid-induced visceral pain, formalin- induced paw pain (both neurogenic and inflammatory), thermal pain as well as carrageenan-induced mechanical hyperalgesia in animals. The anti-nociceptive effect of the extract was reversed (at least P<0.05) by the pre-emptive administration of naloxone and atropine; the administration of theophylline, however, exhibited no significant (P>0.05) inhibition of anti-nociception. The extract (30-300mg/kg, p.o) and paracetamol (15-150mg/kg, p.o.) both reversed yeast-induced pyrexia in rats with ED₅₀ values of 48.59±2.59 and 26.19±1.33mg/kg respectively.

CONCLUSION

The findings indicate that the extract possesses significant anti-nociceptive and antipyretic effects which justify its traditional use in the management of pain and fever. Also, anti-nociceptive effect of the extract involves opioidergic and muscarinic cholinergic mechanisms.

Antioxidant and acetylcholinesterase inhibitory activities of leaf extract and fractions of Albizia adianthifolia (Schumach) W.F. Wright

BACKGROUND

This study was conducted to determine the antioxidant and acetylcholinesterase inhibitory activities of the leaf extract and different fractions of Albizia adianthifolia (Schumach.) W. Wright, and also to identify and quantify some phenolic compounds in the extract.

METHODS

The antioxidant and acetylcholinesterase inhibitory activities of the methanol extract (CME), ethyl acetate (EAF), chloroform (CHF), and n-hexane (NHF) fractions of A. adianthifolia leaves were subjected to in vitro chemical analyses.

RESULTS

Phytochemical screening revealed important classes of secondary metabolites. All extracts showed good antioxidant and acetylcholinesterase inhibitory activities. The EAF and CHF gave the highest total phenolic contents of 18.02±0.14 and 18.43±0.95 mg gallic acid equivalent per gram of extract, respectively. The polar extracts gave the highest activity in both assays with lower IC50 values. In the 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging activity assay, the IC50 values of CME, EAF, CHF, and NHF were 77.74±0.84, 55.76±2.30, 58.47±0.72, and 232.24±2.70 µg/mL, respectively, while in the acetylcholinesterase inhibitory assay, the IC50 values of CME, EAF, CHF, and NHF were 11.80±0.88, 10.04±1.67, 17.44±1.74, and 124.38±1.51 µg/mL, respectively.

CONCLUSIONS

The results of this study suggest that the leaf of A. adianthifolia could serve as a potential candidate for future search of antioxidant and acetylcholinesterase inhibitors for the management of neurodegenerative disorders such as Alzheimer's disease.

Sickness behaviour associated with non-lethal infections in wild primates

Non-lethal parasite infections are common in wildlife, but there is little information on their clinical consequences. Here, we pair infection data from a ubiquitous soil-transmitted helminth, the whipworm (genus Trichuris), with activity data from a habituated group of wild red colobus monkeys (Procolobus rufomitratus tephrosceles) in Kibale National Park, Uganda. We use mixed-effect models to examine the relationship between non-lethal parasitism and red colobus behaviour. Our results indicate that red colobus increased resting and decreased more energetically costly behaviours when shedding whipworm eggs in faeces. Temporal patterns of behaviour also changed, with individuals switching behaviour less frequently when whipworm-positive. Feeding frequency did not differ, but red colobus consumption of bark and two plant species from the genus Albizia, which are used locally in traditional medicines, significantly increased when animals were shedding whipworm eggs. These results suggest self-medicative plant use, although additional work is needed to verify this conclusion. Our results indicate sickness behaviours, which are considered an adaptive response by hosts during infection. Induction of sickness behaviour in turn suggests that these primates are clinically sensitive to non-lethal parasite infections.

Anti-HIV-1 integrase activity and molecular docking of compounds from Albizia procera bark

CONTEXT

Albizia procera (Roxb.) Benth. (Mimosaceae) has been traditionally used in Thai longevity preparations. Thus, searching for HIV-1 integrase (HIV-1 IN) agents from natural sources is of interest.

OBJECTIVE

The objective of this study is to examine the inhibitory activity against HIV-1 IN of compounds isolated from the stem bark of Albizia procera.

MATERIALS AND METHODS

The EtOH extract and isolated compounds of Albizia procera bark were examined for anti-HIV-1 IN activity at various concentrations (10-100 µg/mL and 10-100 µM) using the multiplate integration assay and molecular docking.

RESULTS AND DISCUSSIONS

The results showed that the ethanol extract had good anti-HIV-1 IN activity with an IC50 value of 19.5 µg/mL, whereas ethyl acetate fraction exhibited the most potent with an IC50 value of 19.1 µg/mL, followed by water fraction (IC50 value = 21.3 µg/mL), hexane and chloroform fractions (IC50 value > 100 µg/mL), respectively. From bioassay-guided isolation, the ethyl acetate fraction was further separated to give two compounds which are (+)-catechin (1) and protocatechuic acid (2), respectively. Of the tested samples, (+)-catechin (1) exhibited appreciable activity against HIV-1 IN with an IC50 value of 46.3 µM, whereas protocatechuic acid (2) showed mild activity with 46.0% inhibition at concentration of 100 µM. (+)-Catechin (1) could interact with Thr66, Gly148, and Glu152 in the core domain of IN enzyme, whereas protocatechuic acid (2) could bind with Thr66, His67, Glu152, Asn155, and Lys159. This is the first report on anti-HIV-1 IN activity of Albizia procera bark. These results may suggest that Albizia procera bark has potential as anti-HIV-1 IN agent.

In vitro anthelmintic activity of crude extracts of five medicinal plants against egg-hatching and larval development of Haemonchus contortus

ETHNOPHARMACOLOGICAL RELEVANCE

Senna occidentalis, Leonotis ocymifolia, Leucas martinicensis, Rumex abyssinicus, and Albizia schimperiana are traditionally used for treatment of various ailments including helminth infection in Ethiopia.

MATERIALS AND METHODS

In vitro egg hatch assay and larval development tests were conducted to determine the possible anthelmintic effects of crude aqueous and hydro-alcoholic extracts of the leaves of Senna occidentalis, aerial parts of Leonotis ocymifolia, Leucas martinicensis, Rumex abyssinicus, and stem bark of Albizia schimperiana on eggs and larvae of Haemonchus contortus.

RESULTS

Both aqueous and hydro-alcoholic extracts of Leucas martinicensis, Leonotis ocymifolia and aqueous extract of Senna occidentalis and Albizia schimperiana induced complete inhibition of egg hatching at concentration less than or equal to 1mg/ml. Aqueous and hydro-alcoholic extracts of all tested medicinal plants have shown statistically significant and dose dependent egg hatching inhibition. Based on ED(50), the most potent extracts were aqueous and hydro-alcoholic extracts of Leucas martinicensis (0.09 mg/ml), aqueous extracts of Rumex abyssinicus (0.11 mg/ml) and Albizia schimperiana (0.11 mg/ml). Most of the tested plant extracts have shown remarkable larval development inhibition. Aqueous extracts of Leonotis ocymifolia, Leucas martinicensis, Albizia schimperiana and Senna occidentalis induced 100, 99.85, 99.31, and 96.36% inhibition of larval development, respectively; while hydro-alcoholic extracts of Albizia schimperiana induced 99.09 inhibition at the highest concentration tested (50mg/ml). Poor inhibition was recorded for hydro-alcoholic extracts of Senna occidentalis (9%) and Leonotis ocymifolia (37%) at 50mg/ml.

CONCLUSIONS

The overall findings of the current study indicated that the evaluated medicinal plants have potential anthelmintic effect and further in vitro and in vivo evaluation is indispensable to make use of these plants.

An Active Glycoside from Albizia Species and its Action on Isolated Uterus and Ileum

An active oxytocic principle was extracted from Albizia gummifera (Lipton, 1959) by continuous percolation of the dry bark with methanol. Further purification was by dialysis, fractional extraction and precipitation with organic solvents, and by chromatography on alumina. The concentration of activity achieved was 200 times that of the dried bark, measured in vitro on strips of uterus. The active principle is a saponin, giving on hydrolysis an unsaturated triterpene acid (probably C30H48O5), and four sugars, glucose, rhamnose, xylose and arabinose. The principle has a powerful action on isolated uterine tissues from different species, resistant to atropine, antihistamines and brief boiling in aqueous or alcoholic solution, but it fails to excite guinea-pig ileum even in high concentrations. The material, for which the name ‘albitocin’ is proposed, is thought to be potentially valuable in the study of smooth muscle, particularly uterine muscle. The use of these plants by African native doctors, and their possible implication in the high incidence of uterine rupture in Uganda is discussed.

Effects on anaesthetised animals of an oxytocic glycoside extracted from certain species of Albizia

The actions on anaesthetised guinea-pigs, rabbits, cats and monkeys of a glycoside, “albitocin”, obtained from Albizia gummifera, and some other species of Albizia, used by East African witchdoctors to accelerate labour and induce abortion, are described. On intravenous injection there is a transient fall in systemic blook pressure and an increase in uterine activity, with the pregnant uterus exhibiting greater sensitivity. Both responses occur in the presence of atropine and antihistamines, and in monkeys after bilateral vagotomy and hexamethonium, but a prolonged small rise in blood pressure occurs on intraperitoneal injection of the drug. Electrocardiograph records in rabbits and monkeys exhibit no consistent acute or chronic changes in the electrical activity of the heart resulting from the injection of the drug even in lethal doses, almost up to the time of death.

In vitro antimicrobial activity of extracts and compounds of some selected medicinal plants from Cameroon

AIM OF THE STUDY

Seven extracts and eight compounds from four selected Cameroonian medicinal plants, Solanecio mannii Hook f. (Asteraceae), Monodora myristica Dunal (Annonaceae), Albizia gummifera (J.F. Gmel) C.A. Smith (Fabaceae/Mimosoideae) and Glyphaea brevis (Spreng) Monachino (Tiliaceae), traditionally used for the treatment of hepatitis, parasites and other infectious diseases, were tested in vitro for their antimicrobial activity against Gram-positive (5 species) and Gram-negative (4 species) bacteria species and pathogenic yeasts (2 Candida species), to establish whether or not they have antimicrobial activity and to validate scientifically their use in traditional medicine.

MATERIALS AND METHODS

The agar disc diffusion and the microbroth dilution methods were used to determine the zone of inhibition between the edge of the filter paper and the edge of the inhibition area (IZ) and the minimal inhibitory concentration (MIC) respectively.

RESULTS

The most active extracts against Candida albicans and Candida krusei were respectively the cyclohexane extract from the fruits of Monodora myristica and the ethyl acetate extract from the stem bark of Albizia gummifera (MIC=6.3 microg/ml for both extracts). The lowest MIC value (1.6 microg/ml) for purified compounds was obtained on Candida albicans with a mixture of linear aliphatic primary alcohols (n-C24H50O to n-C30H62O), with n-hexacosanol (1b) as major compound and mixture of fatty acid esters of diunsaturated linear 1,2-diols (6).

CONCLUSION

These results afford ground informations for the potential use of the crude extracts of these species as well as of some of the isolated compounds in bacterial and fungal infections.

Anti-inflammatory activity of Albizia lebbeck Benth., an ethnomedicinal plant, in acute and chronic animal models of inflammation

AIM OF THE STUDY

Albizia lebbeck Benth. is used both in Indian traditional system and folk medicine to treat several inflammatory pathologies such as asthma, arthritis and burns. The aim of the present study was to evaluate the scientific basis of anti-inflammatory activity of different organic solvent extracts of Albizia lebbeck.

MATERIALS AND METHODS

The anti-inflammatory activity of Albizia lebbeck was studied using the carrageenan, dextran, cotton pellet and Freund's complete adjuvant induced rat models. The extracts obtained using petroleum ether, chloroform and ethanol were administered at the concentrations of 100, 200 and 400mg/kg body weight.

RESULTS

The petroleum ether and ethanol extracts at 400mg/kg, showed maximum inhibition of inflammation induced by carrageenan (petroleum ether-48.6%; ethanol-59.57%), dextran (petroleum ether-45.99%; ethanol-52.93%), cotton pellet (petroleum ether-34.46%; ethanol-53.57%) and Freund's adjuvant (petroleum ether-64.97%; ethanol-68.57%).

CONCLUSION

The marked inhibitory effect on paw edema shows that Albizia lebbeck possesses remarkable anti-inflammatory activity, supporting the folkloric usage of the plant to treat various inflammatory diseases.

The analgesic and anti-inflammatory activities of the extract of Albizia lebbeck in animal model

The extract of the bark of Albizia lebbeck Benth. obtained by cold extraction of mixture of equal proportions of petroleum ether, ethyl acetate and methanol was chosen for pharmacological screening. In rat paw edema model induced by carrageenan, the extract at the 400 mg/kg dose level showed 36.68% (p<0.001) inhibition of edema volume at the end of 4h. In the acetic acid-induced writhing test, the extract at the 200 and 400 mg/kg dose level showed 39.9% and 52.4 % inhibition of writhing, respectively. In radiant heat tail-flick method the crude extract produced 40.74% (p<0.001) and 61.48% (p<0.001) elongation of tail flicking time 30 minutes after oral administration at the 200 and 400 mg/kg dose level, respectively.

The antiplasmodial activity of spermine alkaloids isolated from Albizia gummifera

In the present study the methanolic extract of Albizia gummifera was fractionated into various fractions. These fractions were tested against choroquine sensitive (NF54) and resistant (ENT30) strains of Plasmodium falciparum. All other fractions apart from the alkaloidal fraction showed low activity with IC 50 above 3 microg/ml. The alkaloidal fraction exhibited strong activity against NF54 and ENT30 with IC 50 of 0.16+/-0.05 and 0.99+/-0.06 microg/ml, respectively. Five known spermine alkaloids were isolated from the alkaloidal fraction. These alkaloids exhibited activities against NF54 and ENT30 with IC 50 ranging from 0.09+/-0.02 to 0.91+/-0.10 microg/ml. Four of the alkaloids were further evaluated for in vivo activity against rodent malaria parasite Plasmodium berghei. The alkaloids showed percentage chemosuppression of parasitaemia in mice ranging from 43 to 72%. The use of the extracts A. gummifera for treatment of malaria in traditional medicine seems to have a scientific basis.

In vitro antiprotozoal activities and cytotoxicity of some selected Cameroonian medicinal plants

Eight extracts from seven selected Cameroonian medicinal plants, traditionally used to treat malaria and other protozoal diseases, were tested in vitro for their antiprotozoal activities against Plasmodium falciparum K1 chloroquine-resistant strain, Leishmania donovani, Trypanosoma cruzi and Trypanosoma brucei rhodesiense, protozoa responsible for malaria, visceral leishmaniasis, Chagas disease and African trypanosomiasis, respectively. The most active extract against Plasmodium falciparum K1 strain and Trypanosoma brucei rhodesiense was the methanolic extract of Albizia zygia (Fabaceae) stem bark with IC(50) values of 1.0 microg/ml and 0.2 microg/ml, respectively. Five extracts showed IC(50) values below 5mug/ml against Leishmania donovani, with the methanolic seed extract of Harungana madagascarensis showing the highest activity, but only the methanolic extract of Albizia zygia showed activity against Trypanosoma cruzi. Cytotoxicity and selectivity indexes were estimated for the most active extracts. The best ratio of cytotoxicity to antiplasmodial activity (SI(a)=14) was established for the methanolic leaf extract of Symphonia globulifera (Clusiaceae), while the methanolic stem bark extract of Albizia zygia showed the best ratio of cytotoxicity to antitrypanosomal activity (SI(b)=22.5).

Antimicrobial activity of some ethnomedicinal plants used by Paliyar tribe from Tamil Nadu, India

Background

Antimicrobial activity of 18 ethnomedicinal plant extracts were evaluated against nine bacterial strains (Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Ervinia sp, Proteus vulgaris) and one fungal strain (Candida albicans). The collected ethnomedicinal plants were used in folk medicine in the treatment of skin diseases, venereal diseases, respiratory problems and nervous disorders.

Methods

Plants were collected from Palni hills of Southern Western Ghats and the ethnobotanical data were gathered from traditional healers who inhabit the study area. The hexane and methanol extracts were obtained by cold percolation method and the antimicrobial activity was found using paper disc diffusion method. All microorganisms were obtained from Christian Medical College, Vellore, Tamil Nadu, India.

Results

The results indicated that out of 18 plants, 10 plants exhibited antimicrobial activity against one or more of the tested microorganisms at three different concentrations of 1.25, 2.5 and 5 mg/disc. Among the plants tested, Acalypha fruticosa, Peltophorum pterocarpum, Toddalia asiatica,Cassia auriculata, Punica granatum and Syzygium lineare were most active. The highest antifungal activity was exhibited by methanol extract of Peltophorum pterocarpum and Punica granatum against Candida albicans.

Conclusion

This study evaluated the antimicrobial activity of the some ethnomedicinal plants used in folkloric medicine. Compared to hexane extract, methanol extract showed significant activity against tested organisms. This study also showed that Toddalia asiatica, Syzygium lineare, Acalypha fruticosa and Peltophorum pterocarpum could be potential sources of new antimicrobial agents.

Induction of apoptosis in human acute leukemia Jurkat T cells by Albizzia julibrissin extract is mediated via mitochondria-dependent caspase-3 activation

To understand antitumor activity of Albizzia julibrissin Durazz (Leguminosae), which has been used as a traditional oriental medicine, the mechanism underlying cytotoxic effect of its extract on human acute leukemia Jurkat T cells were investigated. The methanol extract of the stripped barks (3kg) of Albizzia julibrissin was evaporated, dissolved in water, and then sequentially extracted by chloroform, ethyl acetate, and n-butanol. The substance in the butanol extract containing the most cytotoxic activity was further purified by a series of preparative column chromatography. The active substance obtained (723mg) was designated as HaBC18. When Jurkat T cells were treated with HaBC18 (0.5-2microg/ml), apoptosis along with several biochemical events such as mitochondrial cytochrome c release, activation of caspase-9 and -3, degradation of PARP, and DNA fragmentation was induced in a dose-dependent manner. However, the HaBC18-induced apoptosis was abrogated by an ectopic overexpression of Bcl-xL, which is known to block mitochondrial cytochrome c release. Primary cultures of human PBMC were less sensitive to the cytotoxicity relative to Jurkat T cells. These results demonstrate that the cytotoxicity of HaBC18 toward Jurkat T cells is attributable to apoptosis mediated by mitochondria-dependent death-signaling pathway regulated by Bcl-xL.

Julibroside J8-induced HeLa cell apoptosis through caspase pathway

The julibroside J8 was isolated from the Albizia julibrissin and evaluated for antiproliferatived on six cancer cell lines (BGC-823, Bel-7402, HeLa, PC-3MIE8, MDA-MB-435 and LH-60) in vitro. Julibroside J8 at 100 microg mL- 1 (46.08 micromol.L- 1) significantly inhibited growth in the first three cell lines. In addition, in HeLa cells typical apoptotic changes in morphology were observed, and further, nuclear damage was observed by Giemsa staining and DNA fragmentation was exhibited. Effects of julibrosideJ8 on induction of DNA fragmentation, caspase-3 activation and downregulation of ICAD expression were effectively inhibited by a caspase-3 inhibitor, z-DEVD-fmk. In addition, apoptosis induced with julibroside J8 was associated with an increase in expression of the apoptosis inducer Bax, and a significant reduction in expression of the apoptosis suppressor Bcl-2 in mitochondria. These results suggest that julibroside J8 induces HeLa death through caspase pathway.

Effect of Cha-em Thai mouthwash on salivary levels of mutans streptococci and total IgA

The aim of this study was to investigate the effect of Cha-em Thai (Albizia myriophylla) mouthwash on the mutans streptococci (MS) and immunoglobulin A (IgA) level in saliva. Sixty-seven schoolchildren, age 6-12 years, with MS more than 1x10(5) cfu per milliliter of saliva were entered in this study. They were divided into two balanced groups according to their baseline MS counts (> or = 10(5) cfu/ml). Each group was randomly assigned to use either the Cha-em Thai mouthwash or the placebo mouthwash. After twice daily rinses with their mouthwash for 2 weeks, stimulated saliva were collected and analysed. The MS counts and IgA levels for the two groups were compared. Those rinsing with Cha-em Thai mouthwash showed a significant reduction in MS counts (p<0.05), but the IgA levels were not different. Those rinsing with the placebo mouthwash showed no statistically significant differences in the MS counts or the IgA levels (p>0.05). The results indicate that twice daily use of Cha-em Thai mouthwash can reduce the levels of MS in saliva.

Screening of Tanzanian medicinal plants for anti-Candida activity

Background

Candida albicans has become resistant to the already limited, toxic and expensive anti-Candida agents available in the market. These factors necessitate the search for new anti-fungal agents.

Methods

Sixty-three plant extracts, from 56 Tanzanian plant species obtained through the literature and interviews with traditional healers, were evaluated for anti-Candida activity. Aqueous methanolic extracts were screened for anti-Candida activity by bioautography agar overlay method, using a standard strain of Candida albicans (ATCC 90028).

Results

Twenty- seven (48%) out of the 56 plants were found to be active. Extracts of the root barks of Albizia anthelmintica and Balanites aegyptiaca, and roots of Plectranthus barbatus showed strong activity.

Conclusion

The extracts that showed strong anti-Candida activity are worth of further investigation in order to isolate and identify the active compounds.

Effect of chronic treatment on 5-hydroxytryptamine receptors in rat brain

Quantitative receptor autoradiography and behavioral studies were employed to investigate whether the aqueous extract of Albizzia julibrissin (AEAJ) specifically targets serotonergic systems in rat brain. AEAJ was orally administered at 50 and 200 mg/kg to adult male SD rats for 7 days. Treatment with AEAJ (200 mg/kg) significantly increased time-spent in open arms and the number of open arm entries in an elevated plus-maze (EPM) versus saline controls (P<0.05). Moreover, those effects of AEAJ were blocked by WAY 100635, a 5-HT1A receptor antagonist. Following behavioral evaluation, the binding of [3H]8-hyroxy-2-(di-n-propylamino) tertalin ([3H]8-OH-DPAT) to 5-HT1A receptors in rat brain was investigated. [3H]8-OH-DPAT binding after AEAJ (200 mg/kg) treatment showed a marked increase in the frontal cortex, hippocampus (CA2 and CA3 regions) and in the lateral septum versus vehicle-treated controls. No changes of [3H]8-OH-DPAT binding were observed in the caudate putamen, dentate gyrus and CA1 areas of the hippocampus or in the hypothalamus. In the dorsal raphe region, [3H]8-OH-DPAT binding was significantly reduced by AEAJ (50 mg/kg) treatment but was unchanged by AEAJ (200 mg/kg). These results suggest that the anxiolytic-like effect of A. julibrissin is mediated by the changes of serotonergic nervous system, especially 5-HT1A receptors.

Heavy metal concentrations in redeveloping soil of mine spoil under plantations of certain native woody species in dry tropical environment, India

Total concentration of heavy metals (Cd, Cr, Cu, Fe, Pb, Ni, Mn and Zn) was estimated in the redeveloping soil of mine spoil under 5-yr old plantations of four woody species namely: Albizia lebbeck, Albizia procera, Tectona grandis and Dendrocalamus strictus. The data recorded in the present study were compared with other unplanted coal mine spoil colliery, which was around to the study site and adjoining area of dry tropical forest. Among all the heavy metals, the maximum concentration was found for Fe and minimum for Cd. However, among all four species, total concentrations of these heavy metals were recorded maximally in the plantation plots of T. grandis except for Fe, while minimally in A. lebbeck except for Zn, whereas, the maximum concentration of Fe and Zn was in the plantation plots of D. strictus and A. procera. Statistical analysis revealed significant differences due to species for all the heavy metals except Cu. Among four species, A. lebbeck, A. procera and D. strictus showed more efficient for reducing heavy metal concentrations whereas T. grandis was not more effective to reduce heavy metal concentrations in redeveloping soil of mine spoil.

Efficacy of Myrsine africana, Albizia anthelmintica and Hilderbrantia sepalosa herbal remedies against mixed natural sheep helminthosis in Samburu district, Kenya

Traditional livestock healers from Samburu and Turkana communities in Samburu District of Kenya were identified and recruited for participation in this study. Sheep with mixed gastrointestinal helminthosis were purchased from nomadic livestock owners in the area. Three herbal anthelmintic remedies, viz. Myrsine africana, Albizia anthelmintica and Hilderbrantia sepalosa were administered in the traditional way by the healers and their efficacy determined using percent fecal egg count reduction (percent FECR) test. The results indicate that all the herbal remedies had some efficacy against both nematodes and Monezia species of helminths. The group effect against nematodes was significantly different (P=0.002). Compared to an untreated control group, the efficacy against nematodes was 77, 89.8 and 90% for Myrsine afriacana, Albizia antihelmintica and Hilderbrantia sepalosa, respectively, while albendazole had 100% efficacy. The main nematodes encountered included Haemonchus spp., Trichostrogylus spp. and Oesophagostomum spp. With regard to Monezia species herbal remedies performed better than albendazole with an efficacy of 100% compared to 63% for albendazole. The group of sheep treated with Albizia anthelmintica showed a significant increase (P=0.003) in packed cell volume (PCV).

Calcium mobilization as the endothelium-independent mechanism of action involved in the vasorelaxant response induced by the aqueous fraction of the ethanol extract of Albizia inopinata G. P. Lewis (AFL) in the rat aorta

In a previous work, we demonstrated that, in normotensive rats, AFL induced a marked hypotension due to a decrease in total peripheral resistances (TPR), partially secondary to the release of NO by the endothelium. NO did not, however, account for the total vasodilation produced by AFL in these rats. The aim of this study was to determine the involvement of the intracellular calcium mobilization in the vasorelaxant action induced by AFL in the rat aorta. In aorta of normotensive rats AFL (10, 20, 40 and 80 microg/ml) inhibited the sustained contractions induced by KCl (80 and 30 mM) and phenylephrine (Phe, 1 microM) with similar IC50 values (54 +/- 6, 52 +/- 4 and 65 +/- 4 microg/ml, respectively). The relaxing response induced by AFL against Phe-induced contractions was modified significantly by the endothelium removal (IC50 = 132 +/- 23 and 65 +/- 4 microg/ml, endothelium removed and intact endothelium aortic rings, respectively). Nevertheless, removal of the endothelium did not significantly change IC50 values when KCl (30 and 80 mM) was used as the contractile agent. The inhibitory effect induced by AFL on high (64.5 mM) K+-induced contraction was potentiated slightly (p < 0.05) by the decrease (from 2.5 to 0.3 mM, Ca2+) and attenuated by the increase (from 2.5 to 7.5 mM Ca2+) in the external [Ca2+]. In addition, in aortas from normotensive rats, AFL antagonized transient contractions induced in Ca2+-free media induced by 1 microM noradrenaline in a concentration-dependent manner, but not those induced by 20 mM caffeine. It is suggested that the remaining vasodilator effect of AFL in normotensive rats is probably due to an inhibition of Ca2+ influx and/or inhibition of intracellular Ca2+ mobilization from the noradrenaline-sensitive stores.

Acid deposition and critical load analysis in Agra, India

The deposition of sulphur (161.1 eq.ha(-1) per year), nitrogen(49.9 eq.ha(-1) per year), and ammonium (176.8 eq.ha(-1) per year) from the atmosphere were calculated for both wet and dry deposition in Agra region of India. Seven sampling sites located at Bichpuri, Bah, Fatehabad, Shamsabad, Nunhai, Dayalbagh, and St. John's College were used. The values for critical load of sulphur and nitrogen for soil with respect to Hibiscus (Hibiscus rosa-sinensis) and Black siris (Albizzia odoratissima) were calculated. The methodology employed involved the steady state mass balance (SSMB) method. The values of actual acidity were compared with the RAINS-Asia model. On comparing the acidity, it was found that the values computed by RAINS-Asia model are higher for this area.

Antioxidant activity from the stem bark of Albizzia julibrissin

The antioxidant activity of the stem bark from Albizzia julibrissin was evaluated for its potential to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, to inhibit the generation of the hydroxyl radical (*OH), total reactive oxygen species (ROS) and to scavenge authentic peroxynitrites (ONOO-). The methanol extract of A. julibrissin exhibited strong antioxidant activity in the tested model systems. Therefore, it was further fractionated using several solvents. The antioxidant activity of the individual fractions were in the order of ethyl acetate (EtOAc) > n-butanol (n-BuOH) > dichloromethane (CH2Cl2) > and water (H2O). The ethyl acetate soluble fraction, which exhibited strong antioxidant activity, was further purified by repeated silicagel, Sephadex LH-20 and RP-18 gel column chromatography. Sulfuretin (1) and 3',4',7-trihydroxyflavone (2) were isolated as the active principles. Compounds 1 and 2 exhibited good activity in all tested model systems. Compound 1 exhibited five times more inhibitory activity on the total ROS than Trolox. Compound 2 showed six times stronger DPPH radical scavenging activity than L-ascorbic acid. These results show the possible antioxidant activity of the A. julibrissin crude extract and its major constituents.

A new (E)4-hydroxy-dodec-2-enedioic acid from the stem bark of Albizzia julibrissin

A new unsaturated hydroxy acid was isolated from the stem bark extract of Albizzia julibrissin through repeated silica gel and Sephadex LH-20 column chromatography. The chemical structure of the new acid was determined as (E)-4-hydroxy-dodec-2-enedioic acid on the basis of several spectral data including 2D-NMR. The stereochemical feature of the double bond was determined to be E on the basis of the coupling pattern of related proton signals in the 1H-NMR and COSY experiments.