Micropropagation of juvenile and adult Annona squamosa

A micropropagation system for Annona squamosa L. (Sugar Apple) using hypocotyls of seedlings and nodal cuttings from 3-year-old plants was developed. Shoot proliferation was achieved with Woody Plant Medium supplemented with BA. Silver thiosulphate was added at 0.5 mg l^–1 to control leaf abscission. Rooting was obtained when subcultured shoots were preconditioned for 2 weeks in medium with 10 g l^–1 activated charcoal before treatment with 43 µm NAA or 39 µm IBA. Rooting was improved when galactose was used instead of sucrose in the rooting medium. The rooted plantlets were acclimatised successfully.Abbreviations NAA naphthaleneacetic acid - IBA indolebutyric acid - MS Murashige & Skoog Medium - WPM Woody Plant Medium - NN Nitsch Medium - Juv juvenile explant - Adu adult explant     

Vasorelaxant activity of cyclic peptide, cyclosquamosin B, from Annona squamosa

A cyclic octapeptide, cyclosquamosin B (2), isolated from the seeds of Annona squamosa showed a vasorelaxant effect on rat aorta. It showed a slow relaxation activity against norepinephrine (NE)-induced contractions of rat aorta with/without endothelium. It showed inhibition effect on vasocontraction of depolarized aorta with high concentration potassium, but moderately inhibition effect on NE-induced contraction in the presence of nicardipine. These results showed that the vasorelaxant effect by 2 might be attributed mainly to inhibition of calcium influx from extracellular space through voltage-dependent calcium channels.     

Monotetrahydrofuran annonaceous acetogenins from the seeds of Annona squamosa

Three new monotetrahydrofuran annonaceous acetogenins, Annosquamins A–C (1–3) were isolated from the 95% EtOH extract of Annona squamosa seeds, in addition to the known compounds, solamin, annotemoyin-1, uvariamicin-II, uvariamicin-III. Their structures were elucidated by spectroscopic analysis and the relative configurations of bearing tetrahydrofuran rings were established by comparing NMR data with model compounds.     

In vitro antibacterial activity in seed extracts of Manilkara zapota, Anona squamosa, and Tamarindus indica

Extracts prepared from seeds of Manilkara zapota, Anona squamosa, and Tamarindus indica were screened for their antibacterial activity by disc diffusion and broth dilution methods. Acetone and methanol extracts of T. indica seeds were found active against both gram-positive and gram-negative organisms. MIC values of potent extracts against susceptible organisms ranged from 53-380 μg/mL. Methanol extract of T. indica and acetone extract of M. zapota seeds were found to be bactericidal.     

Atmospheric-pressure plasma jet induces apoptosis involving mitochondria via generation of free radicals

The plasma jet has been proposed as a novel therapeutic method for anticancer treatment. However, its biological effects and mechanism of action remain elusive. Here, we investigated its cell death effects and underlying molecular mechanisms, using air and N₂ plasma jets from a micro nozzle array. Treatment with air or N₂ plasma jets caused apoptotic death in human cervical cancer HeLa cells, simultaneously with depolarization of mitochondrial membrane potential. In addition, the plasma jets were able to generate reactive oxygen species (ROS), which function as surrogate apoptotic signals by targeting the mitochondrial membrane potential. Antioxidants or caspase inhibitors ameliorated the apoptotic cell death induced by the air and N₂ plasma jets, suggesting that the plasma jet may generate ROS as a proapoptotic cue, thus initiating mitochondria-mediated apoptosis. Taken together, our data suggest the potential employment of plasma jets as a novel therapy for cancer.     

Development of the Anther of Annona squamosa L.

In the stamen of Annona squamosa the initial hypodermal archesporiumcomprises a uniseriate row of cells, of which subsequently alternatecells become septal initials and sporogenous cells respectively.Morphologically the tapetum has a triple origin from the parietalcell derivatives, the connective cells and the septal initials;the tapetum derived from the former two is secretory while thelast forms a periplasmodium. Cytokinesis of microspore mothercell is by successive cytoplasmic constriction. The pollen grainsremain loosely attached as tetrads. Annona squamosa L., anther development     

Antidiabetic and antioxidative effects of Annona squamosa leaves are possibly mediated through quercetin-3-O-glucoside

Present investigation was made to reveal the involvement of a quercetin in the antidiabetic and antiperoxidative effects of Annona squamosa leaf extract. Quercetin-3-O-glucoside (characterized by UV, IR, MS and NMR analyses) was isolated from Annona squamosa leaves and examined for its potential to regulate alloxan-induced hyperglycemia and lipid peroxidation (LPO) in rats. While in alloxan treated animals, an increase in the concentration of serum glucose with a parallel decrease in insulin level was observed, administration of 15 mg/kg/day of isolated quercetin-3-O-glucoside for 10 consecutive days to the hyperglycemic animals reversed these effects and simultaneously inhibited the activity of hepatic glucose-6-phosphatase. It further decreased the hepatic and renal LPO with a concomitant increase in the activities of antioxidative enzymes, such as catalase (CAT) and superoxide dismutase (SOD) and in glutathione (GSH) content, indicating its safe and antiperoxidative effects. These findings suggest the potential of quercetin-3-O-glucoside in the amelioration of diabetes mellitus and tissue lipid peroxidation. It also appears that the antidiabetic effects of A. squamosa leaf extract is possibly mediated through the insulin stimulating and/or free radical scavenging properties of its active constituent, quercetin-3-O-glucoside.     

Annonaceous acetogenins: Precursors from the seeds of Annona squamosa

From the less polar fractions of an Annona squamosa (Annonaceae) seeds extract, four new annonaceous acetogenins, dieposabadelin (1), squamocenin (2), lepirenin (3) and dotistenin (4), were isolated, along with sixteen known acetogenins: corepoxylone, diepomuricanins A and B, dieporeticenine, tripoxyrollin, bullatencin, glabrencin B, reticulatains-1, -2, uvariamicins I, II, III, erythrosolamin, annotemoyin-1 and -2, and solamin. Fourteen are reported for the first time in this species.     

Three cytotoxic Annonaceous acetogenins from the seeds of Annona squamosa

Three new Annonaceous acetogenins, squamocin-IV (1), squamocin-V (2) and squamoxinone-E (3), together with seven other known Annonaceous acetogenins (4–10) were isolated from the seeds of Annona squamosa. The structures of all of the isolates were established and characterized through spectral and chemical methods. The new Annonaceous acetogenins 1–3 were evaluated for their cytotoxicity against the Hep-G2, SMMC-7721, BEL-7402, BGC-803 and H460 human cancer cell lines. Compound 3 exhibited the best cytotoxic activity, with IC₅₀ values of 0.103, 0.687, 4.19, 0.43 and 6.56 μg/mL, respectively for the cell lines above; meanwhile, Compound 1 showed selective cytotoxic activity against H460, with an IC₅₀ value of 0.049 μg/mL. The first mono-ACG (2) composed of 38 carbons was discovered.     

Antitumor activity of curcumin is mediated through the induction of apoptosis in AK-5 tumor cells

Curcumin, the yellow pigment of turmeric (Curcuma longa), used commonly as a spice, has been shown to possess anticarcinogenic activity. Curcumin inhibited AK-5 tumor growth and induced apoptosis in AK-5 cells. Curcumin induced apoptosis is mediated through the activation of caspase-3, which is specifically inhibited by the tetrapeptide Ac-DEVD-CHO. In addition, curcumin induced tumor cell death is caused through the generation of reactive oxygen intermediates which is inhibited by N-acetyl-L-cysteine. Our studies suggest that the apoptotic process induced by curcumin is the mechanism mediating AK-5 tumor cell death.     

番荔枝化学成分研究(7)

从番荔枝（Ａｎｎｏｎａ ｓｑｕａｍｏｓａ Ｌ．）种子中得到化合物１、２和４,化合物２和４分别为已知化合物ｍｏｔｒｉｌｉｎ（莫垂林,２）和ｂｕｌｌａｔａｎｏｃｉｎ（布拉他诺辛,４）。化合物１的化学结构经ＩＲ、ＭＳ、＾１Ｈ ＮＭＲ及＾１３Ｃ ＮＭＲ谱分析及其乙酰化物（１ａ）的ＭＳ、＾１Ｈ ＮＭＲ谱分析推定如（１）式并命名为２２－表－莫维查灵（２２－ｅｐｉ－ｍｏｌｖｉｚａｒｉｎ）。     

番荔枝化学成分研究(6)

自番荔枝（ ＡｎｎｏｎａｓｑｕａｍｏｓａＬ．） 种子中得到化合物１ 和２ , 化合物２ 是已知的ｂｕｌｌａｔａｃｉｎｏｎｅ （２ , ４－ 顺式和反式－ ｂｕｌｌａｔａｃｉｎｏｎｅ 的混晶） , １ 是新化合物, 命名为番荔枝塔亭丁（ｓｑｕａｍｏｓｔａｔｉｎ Ｄ） , 其结构经ＩＲ、ＭＳ、１Ｈ－ ＮＭＲ和１３ＣＮＭＲ谱解析推定如（１） 式。     

Studies on the Chemical Constituents of Annona squamosa(5)

From the seeds of Annona squamosa L.,three compounds were obtained,in which compounds i and 2 are known compounds,i.e. bullatacin and annonin I,respectively.Compounds 3 is a new non -adjacent bis -tetrahydrofuranyl annonaceous acetogenin,named squamostatin C.Based on the analysis of IR MS,1H NMR and 13 C NMR spectra,the structure of compound 3 was elucidated as (3).     

番荔枝化学成分研究(5)

自番荔枝(AnnonasquamosaL)种子中分离到3个番荔枝内酯(1～3)。化合物1和2分别是已知化合物bullatacin和annoninⅠ,化合物3系新的间双四氢呋喃环型番荔枝内酯,命名为番荔枝塔亭丙(squamostatinC),经IR、MS、1HNMR及13CNMR谱分析,其结构推定如(3)式。     

Manganese complexes and the generation and scavenging of hydroxyl free radicals

In a wide variety of biological systems non-enzyme complexes of the metals copper (Cu) and iron (Fe) have been shown to enhance oxygen radical damage by increasing the production of an oxidative species generally believed to be the hydroxyl free radical (.OH) via "Fenton" and possibly "Haber-Weiss" type reactions. However, the behavior of the chemically and biologically similar transition metal manganese (Mn) with .OH is unknown. Unlike Fe and Cu, inorganic complexes of Mn are known to exist in high concentrations in certain cells. Three different oxygen free radical generating systems and four .OH detection methods were used to investigate the activity of biologically relevant inorganic Mn complexes. These complexes were compared to compounds reported to scavenge and generate .OH. The direct and indirect effects of Mn on the .OH flux were compared by attempting to distinguish the effects of hydrogen peroxide (H2O2), superoxide (O2-), and .OH through the use of selective scavengers and generators. Mn-EDTA and biologically relevant Mn-pyrophosphates and polyphosphates, in contrast to Fe-EDTA, do not generate .OH in these systems. The results suggest that Mn in various forms does, indeed, inhibit oxy-radical damage mediated by .OH, but only if the .OH production is dependent on the presence of O2- or H2O2. Thus, with .OH, as with O2- and H2O2, Mn complexes appear to behave in a fundamentally different fashion from Cu and Fe.     

Evaluation of mosquitocidal activity of Annona squamosa leaves against filarial vector mosquito,Culex quinquefasciatus Say

Methanolic extract of leaves of A. squamosa was tested for mosquitocidal effect against C. quinquefasciatus. A liquid mosquito insecticide formulation was prepared with the extract (1, 3 and 5 %w/w) using deodorized kerosene as solvent and investigated for its knock-down and 24 hr mortality. The extract formulation produced dose dependent activity, exhibited significantly shorter knock down KD50 and KD90 values and produced significant mortality. The results suggest the potential mosquitocidal effect of A. squamosa on C. quinquefasciatus.     

Three Novel Chemical Compounds of Annonaceous Acetogenins from the Seeds of Annona squamosa

Seven compounds (A1--A7) were isolated from the seeds of Annona squamosa L. Three of them, A2, A3, and A5, are new compounds of annonaeeous aeetogenins, and they were name neo-desacetyluvaricin (A2), neo-annonin B (A3) and neo-reticulatacin A (A5), respectively.     

The generation of free radicals by nitric oxide synthase

Nitric oxide synthase (NOS) is an example of a family of heme-containing monooxygenases that, under the restricted control of a specific substrate, can generate free radicals. While the generation of nitric oxide (NO*) depends solely on the binding of L-arginine, NOS produces superoxide (O(2)*(-)) and hydrogen peroxide (H(2)O(2)) when the concentration of the substrate is low. Not surprisingly, effort has been put forth to understand the pathway by which NOS generates NO*, O(2)*(-) and H(2)O(2), including the role of substrate binding in determining the pathways by which free radicals are generated. By binding within the distal heme pocket near the sixth coordination position of the NOS heme iron, L-arginine alters the coordination properties of the heme iron that promotes formation of the perferryl complex NOS-[Fe(5+)=O](3+). This reactive iron intermediate has been shown to abstract a hydrogen atom from a carbon alpha to a heteroatom and generate carbon-centered free radicals. The ability of NOS to produce free radicals during enzymic cycling demonstrates that NOS-[Fe(5+)=O](3+) behaves like an analogous iron-oxo complex of cytochrome P-450 during aliphatic hydroxylation. The present review discusses the mechanism(s) by which NOS generates secondary free radicals that may initiate pathological events, along with the cell signaling properties of NO*, O(2)*(-) and H(2)O(2).     

Saturated free fatty acid release and intracellular ceramide generation during apoptosis induction are closely related processes

Apoptosis induced by cells from the immune system is frequently associated with an increase in the ceramide content of target cells, due to the activation of sphingomyelinases (SMase). Some studies have also reported the release of saturated and monounsaturated free fatty acids (FFA) from apoptotic cells. However, the possible relationship between these lipid biochemistry events has not been characterized. We have analysed for the first time the release of FFA triggered by tumor necrosis factor-alpha (TNF-alpha), Fas/CD95 or the perforin/granzyme system of cytotoxic T lymphocytes (CTL) and their relationship to intracellular ceramide generation. TNF-alpha- and Fas-induced apoptosis are associated with both intracellular ceramide generation from sphingomyelin (SM) and release of palmitic-derived FFA, with similar kinetics. Intracellular SMase activation and FFA release from target cells during Fas-induced apoptosis are much more rapid and efficient if Fas-based cytotoxicity is exerted by alloantigenic CTL. In the case of perforin/granzyme-based cytotoxicity exerted by CTL, intracellular ceramide generation and FFA release from target cells seem to depend on the type of lysis induction used. Importantly, the correlation between intracellular SMase activation and the release of palmitic acid-derived FFA from target cells has been observed in all types of cytotoxicity assayed. In addition, exogenous natural ceramide induces the rapid release of the same FFA, well before any apoptotic sign is detected, and FFA release during Fas-induced apoptosis is inhibited in SM-depleted cells by chronic fumonisin-B(1) treatment. These results demonstrate a novel connection between the release of palmitic acid-derived FFA and intracellular ceramide accumulation during apoptosis induction.