Inhibitors of aldose reductase and advanced glycation end-products formation from the leaves of Stelechocarpus cauliflorus R.E. Fr.

Two dihydroflavonol glycosides, engeletin and astilbin, were isolated from an EtOAc extract of the leaves of Stelechocarpus cauliflorus R.E. Fr. (Annonaceae). The inhibitory activity of engeletin against a recombinant human aldose reductase (IC50 value=1.16 microM) was twice that of quercetin as a positive control (2.48 microM), and 23 times greater than that of astilbin (26.7 microM). Engeletin inhibited the enzyme uncompetitively. Astilbin was about as potent as the positive control, quercetin, in its inhibition of advanced glycation end-products formation. These flavonoids displayed therapeutic potential in the prevention and treatment of diabetic complications.

Aldose reductase inhibitors from the leaves of Myrciaria dubia (H. B. & K.) McVaugh.

Ellagic acid (1) and its two derivatives, 4-O-methylellagic acid (2) and 4-(alpha-rhamnopyranosyl)ellagic acid (3) were isolated as inhibitors of aldose reductase (AR) from Myrciaria dubia (H. B. & K.) McVaugh. Compound 2 was the first isolated from the nature. Compound 3 showed the strongest inhibition against human recombinant AR (HRAR) and rat lens AR (RLAR). Inhibitory activity of compound 3 against HRAR (IC50 value = 4.1 x 10(-8) M) was 60 times more than that of quercetin (2.5 x 10(-6) M). The type of inhibition against HRAR was uncompetitive.

Aldose reductase inhibitors from the fruits of Caesalpinia ferrea Mart.

Aldose reductase inhibitors were isolated from an extract of the dry fruits of Caesalpinia ferrea Mart. (Leguminosae). Compound 2 was identified as ellagic acid by comparison with a reference sample. The structure of compound 1 was elucidated as 2-(2,3,6-trihydroxy-4-carboxyphenyl) ellagic acid on the basis of spectral evidence, especially 2D-NMR data (HMQC, HMBC and NOESY). These two compounds inhibited aldose reductase in a non-competitive manner.

Effects of sesquiterpenoids from "Oriental incenses" on acetic acid-induced writhing and D2 and 5-HT2A receptors in rat brain.

Six sesquiterpenoids, namely jinkoh-eremol, agarospirol, alpha- and beta-santalols, dehydrocostus lactone and costunolide, isolated from oriental incenses inhibited acetic acid-induced writhing in mice. The incidence of writhing produced by jinkoh-eremol, alpha-santalol and costunolide were revealed by administration of naloxone (mu-, kappa- and delta-antagonists). Inhibitory activities of alpha-santalol on opioid receptors were shown only by the delta antagonist, but not by the mu- and kappa-antagonists. The delta2-antagonist, but not the delta-antagonist, inhibited the activity of alpha santalol. The mechanism of inhibitory activity on the opioid receptor by alpha-santalol was different from that of morphine. Alpha-santalol was shown to be the most potent of the six as an antagonist of dopamine D2 and serotonine 5-HT2A receptor binding. The effect of alpha-santalol, was the same as that of chlorpromazine as an antipsychotic agent, although alpha-santalol was less potent than chlorpromazine.

Red ginseng ameliorated place navigation deficits in young rats with hippocampal lesions and aged rats.

Effects of hippocampal lesions and aging on spatial learning and memory and ameliorating effects of red ginseng on learning deficits were investigated in the following two experiments: performance of young rats with selective hippocampal lesions with red ginseng by mouth (p.o.; Experiment 1) and aged rats with red ginseng (p.o.; Experiment 2) in the spatial tasks was compared with that of sham-operated or intact young rats. Each rat in these two behavioral experiments was tested with the three types of spatial-learning tasks (distance movement task, DMT; random-reward place search task, RRPST; and place-learning task, PLT) in a circular open field using intracranial self-stimulation as reward. The results in the DMT and RRPST tasks indicated that motivational and motor activity of young rats with hippocampal lesions with and without ginseng were not significantly different from that of sham-operated young rats in Experiment 1. However, young rats with hippocampal lesions displayed significant deficits in the PLT task. Treatment with red ginseng significantly ameliorated place-navigation deficits in young rats with hippocampal lesions on the PLT task. Similarly, red ginseng improved performance of aged rats on the PLT task in Experiment 2. The results, along with previous studies showing significant effects of red ginseng on the central nervous system, suggest that red ginseng ameliorates learning and memory deficits through effects on the central nervous system, partly through effects on the hippocampal formation.

Effects of Ayahuasca on the human EEG.

EEG data were recorded under field conditions from 11 members of the Santo Daime Doctrine, a Brazilian shamanistic religion, before and after ingesting the psychoactive alkaloid preparation, ayahuasca, or daime, as they term it. Post-ingestion, we observed increases in power in the 36-44 Hz frequency band ("40 Hz") from the left occipital-temporal-parietal scalp electrodes in the eyes-closed condition, which extended to most of the posterior scalp in the eyes-open condition. The results are consistent with many reports that ayahuasca intensifies visual imagery. These results are discussed in terms of a thalamocortical model of the role of 40 Hz activity in brain function and conscious experience. We also noted tendencies toward decreases in the power of slow (theta and alpha) brain rhythms, and increases in the 14-30 Hz beta band, in accord with studies reported 30 years ago with other consciousness-altering compounds. Analysis of four ayahuasca samples yielded an average composition per ingested dose (75 ml) of 55.6 mg harmine, 43.9 mg tetrahydroharmine, 41.3 mg N,N-dimethyltryptamine (DMT), 4.6 mg harmaline, and 3.1 mg harmol. The DMT appeared to be of sufficient concentration to promote psychoactive effects, while the ß-carbolines functioned to supply MAO inhibitors necessary to prevent degradation of DMT and to maintain its oral activity.

Effect of jinkoh-eremol and agarospirol from agarwood on the central nervous system in mice.

Agarwood (Jinkoh in Japanese), one of the Oriental medicines, is used as a sedative. The benzene extract of this medicine showed a prolonged effect on the hexobarbital-induced sleeping time, and hypothermic effects in terms of rectal temperature, a suppressive effect on acetic acid-writhing, and a reduction of the spontaneous motility in mice. By repeated fractionation, oral administration in mice, and pharmacological screening, the active principles, jinkoh-eremol and agarospirol, were obtained from the benzene extract. They also gave positive effects on the central nervous system by peritoneal and intracerebroventricular administration. They decreased both methamphetamine- and apomorphine-induced spontaneous motility. The level of homovanillic acid in the brain was increased by them, while the levels of monoamines and other metabolites were unchanged. Similar results were seen in chlorpromazine-administered mice. Therefore, jinkoh-eremol and agarospirol can be considered to be neuroleptic.

Mitogenic activities in African traditional herbal medicines (Part II).

Mitogenic activities in African traditional herbal medicines were examined on human peripheral blood lymphocytes and mouse spleen cells using protein fractions obtained from their extracts by precipitation with ammonium sulfate. Target specificity for these mitogens was investigated by using isolated T cells and lymphocytes from athymic nude mice. Among 20 plants investigated, potent mitogenic activities for both human and mouse lymphocytes were found in 7 plants: Monanthotaxis sp. (Annonaceae), Uvaria lucida (Annonaceae), Maytenus buchananii (Celastraceae), Lonchocarpus bussei (Leguminosae), Phytolacca dodecandra (Phytolaccaceae), Phytolacca octandra (Phytolaccaceae), and Toddalia asiatica (Rutaceae). The U. lucida stem demonstrated the highest activity among all and induced mitogenesis both in human and mouse isolated T cells, but not in lymphocytes from athymic nude mice.

Effect of dehydrocostus lactone and costunolide from Saussurea root on the central nervous system in mice.

Saussurea root (Mokko in Japanese; root of Saussurea lappa, Compositae) is an aromatic stomachic and sedative in Oriental medicine. Four extracts of saussurea root were obtained by successively extracting with benzene, chloroform, methanol and water. Each of these extracts was tested for effects on the central nervous system (CNS) of mice by intraperitoneal administration, i. e. potentiation of hexobarbital sleeping time, body temperature alterations, antinociceptive effects, and spontaneous locomotor activity changes. The benzene extract was the most active and was then separated further into five fractions, 1,2,3,4, and 5 by column chromatography. Fraction 2 was shown to be the most active in the aforementioned assays. From this fraction dehydrocostus lactone and costunolide were isolated as the CNS active constituents. They were both active by the intraperitoneal, intragastric and intracerebroventricular routes of administration. They decreased both methamphetamine- and apomorphine-induced spontaneous motility. The level of homovanillic acid in the brain was increased following their administration, while the levels of monoamines and other metabolites were unchanged. Similar results were seen in chlorpromazine-treated mice. These results show that dehydrocostus lactone and costunolide can be considered as neuroleptics by resemblance of their pharmacological activities to chlorpromazine.

Induction of Fos protein in the rat hypothalamus elicited by insulin-induced hypoglycemia.

To evaluate the responses to insulin-induced hypoglycemia of neurons in vivo, we studied Fos protein induction in the brain by means of immunohistochemistry. The induction of Fos protein was maximum after the first injection of insulin for 3 h. This induction was found in the parvocellular division of paraventricular nucleus (PVN), the periventricular, dorsomedial and arcuate nuclei and the lateral hypothalamic area of the hypothalamus. These findings show the activation of specific subsets of neurons in areas of the hypothalamus following hypoglycemic stimulation.

Effect of α-santalol and ß-santalol from sandalwood on the central nervous system in mice.

Sandalwood (Byakudan in Japanese; Santalum album L.) is used as a popular sedative in Oriental medicine. Extracts of the wood of Santalum album were obtained by successively extracting with benzene, chloroform, methanol and water. Each of these fractions was tested for activity on the central nervous system of mice following intraperitoneal administration, i.e. potentiation of hexobarbital sleeping time, body temperature alterations, antinociceptive and spontaneous motor activity changes. The benzene extract was active in these assays and was then separated further into fractions 1, 2 and 3. Fraction 2 was shown to be the most active in the aforementioned assays, α- and ß-Santalols were isolated from this active fraction as the major CNS active constituents. They were both active by the intragastric and intracerebroventricular routes of administration. Thus, it can be considered that α- and ß-santalols contribute to the reputed sedative effect of sandalwood preparations in Oriental medicine. Additionally, α- and ß-santalols significantly increased the levels of homovanillic acid, 3,4-dihydroxyphenylacetic acid and/or 5-hydroxyindoleacetic acid in the brain of mice, and chlorpromazine did the ones of homovanillic acid and 3,4-dihydroxyphenylacetic acid. These results showed that α- and ß-santalols could be considered as neuroleptic by resemblance to the pharmacological activities of chlorpromazine.

Mitogenic activities in African traditional herbal medicines.

Mitogenic activities in African traditional herbal medicines were examined using protein fractions obtained from their extracts by precipitation with ammonium sulfate. Potent mitogenic activities for human and mouse lymphocytes were found in the three plants: Croton macrostachyus, Croton megalocarpus (Euphorbiaceae), and Phytolacca dodecandra (Phytolaccaceae). All the gel chromatographic patterns of these protein fractions progressed toward the smaller molecule site with pronase treatment, while their mitogenic activities decreased significantly. Protein fractions from these three plants induced mitogenesis both in human and mouse isolated T cells, but not in lymphocytes from athymic nude mice. By testing further fractionated protein fractions with gel filtration chromatography, it was found that all three plants contained several mitogens having different molecule sizes.

Identification of galanin-immunoreactive cells in the anterior pituitary of male monkeys (Macaca fascicularis).

The localization of galanin (GAL) was studied in the anterior pituitary of adult male macaque monkeys immunohistochemically. GAL-immunoreactive fiber bundles were noted in the posterior lobe of the pituitary. Cells immunoreactive for GAL were observed in the anterior lobe, and colocalization studies revealed that GAL-like immunoreactivity was present in gonadotrophs and thyrotrophs. The differences among the monkey, human and rat in GAL-immunoreactive localization may indicate that the regulation of GAL in the three species differs.

Effects of agarwood extracts on the central nervous system in mice.

Agarwood (Jinkoh in Japanese) is an Oriental medicine for use as a sedative. Neuropharmacological studies have been conducted with the extracts of petroleum ether, benzene, chloroform, and water from agarwood (Aquilaria sp.; probably Aquilaria malaccensis Benth.) in mice. The benzene extract showed a reducing effect in spontaneous motility, a prolonging effect on hexobarbiturate-induced sleeping time, a hypothermic effect in terms of rectal temperature, and a suppressive effect on acetic acid-writhing by oral administration. Fr. 1 of the three fractions which were obtained from the benzene extract by column chromatography was found to produce more positive effects on these neuropharmacological tests than the original benzene extract. These facts suggest that the benzene extractable compounds of agarwood possess potent central nervous system depressant activities.

Mitogenic activities in the protein fractions of crude drugs.

Eighteen different crude drugs were extracted with hot water and saline, and protein fractions were prepared from the extracts by ammonium sulfate precipitation. Mitogenic activities of the protein fractions were examined both on human peripheral blood lymphocytes and on mouse spleen cells. Potent mitogenic activities for both human and/or mouse lymphocytes were found in the protein fractions of four crude drugs, namely, Bupleuri radix, Pinelliae tuber, Sophorae radix, and Zedoariae rhizoma. Target specificities of these mitogens were investigated by using isolated T and B cells and lymphocytes from athymic nude mice. Sensitivity to protease digestion as well as water-soluble, ammonium sulfate precipitable nature assures that the substances responsible for the mitogenic activities are proteins.

[Multicenter clinical evaluation of red cell concentrates stored up to 6 weeks in MAP, a new additive solution].

The clinical safety and efficacy of transfusion of red cell concentrates stored in MAP solution (MAP-CRC) containing mannitol, adenine, glucose, phosphate and citrate, into 39 anemic patients were evaluated. In 23 patients, infusion of MAP-CRC was alternated with infusion of ordinary CRC as a control. The MAP-CRC and CRC used in this study were stored at 4 degrees C for an average of 38.2 +/- 2.6 days (n = 52) and 18.1 +/- 2.2 days (n = 26), respectively. Red cell recovery was 77.5% for MAP-CRC and 82.5% for CRC, based on calculation of the increase in hemoglobin level one day after transfusion. There were no differences between patients transfused with MAP-CRC and those transfused with CRC in clinical findings or biochemical data. No major side-effects other than pyrexia associated with the underlying infections were seen in patients transfused with MAP-CRC. MAP-CRC stored up to 42 days is apparently as safe and effective as stored CRC. This new additive solution may therefore be useful for the future expansion of the indications for autologous blood transfusion by facilitating the collection and storage of more blood in the liquid state for a longer period, and may also be useful in obtaining more plasma from whole blood as source plasma.

Periandradulcins A, B and C: phosphodiesterase inhibitors from Periandra dulcis Mart.

During the course of our screening of bioactive natural products, three new saponins named periandradulcins A (1), B (2) and C (3) were isolated as phosphodiesterase (PDE, EC 3.1.4.17) inhibitors from 80% MeOH extract of the roots of Periandra dulcis Mart. (Leguminosae) by a combination of column chromatography and reversed- and normal-phase high-performance liquid chromatography (HPLC). On the basis of 1H-, 13C- and two-dimensional nuclear magnetic resonance (NMR) spectral data and chemical evidence, their chemical structures were characterized as 3-O-beta-[alpha-L-rhamnopyranosyl(1----2)-beta-D-xylopyranosyl(1----2)-b eta-D- glucuronopyranosyl]-30-hydroxyl-25-formylolean-18-ene-22 beta-O-syringate, 3-O-beta-[alpha-L-rhamnopyranosyl(1----2)-beta-D- xylopyranosyl(1----2)-beta-D-glucuronopyranosyl]-22 beta-hydroxyl-25- formylolean-12-ene and 3-O-beta-[alpha-L-rhamnopyranosyl(1----2)-beta-D- glucopyranosyl(1----2)-beta-D-glucuronopyranosyl]-22 beta-hydroxyl-25-formylolean-18-ene, respectively. The concentrations of periandradulcins A, B and C required to give 50% inhibition (IC50 values) of PDE from bovine heart, were 0.033, 7.6 and 7.7 microM, respectively. Compound 1 was the most potent among the known PDE inhibitors; it inhibited PDE-I (IC50:0.0022 microM) twenty and forty times more effectively than PDE-II and -III, respectively.

Sites of origin of growth hormone-releasing factor-containing neurons projecting to the stalk-median eminence of the rat.

The topographical location of neurons containing GRF which project to the median eminence were studied with immunofluorescence for GRF in combination with the retrograde transport of True blue. After the injection of True blue into the median eminence, retrogradely-labeled GRF neurons were identified in the arcuate nucleus and the lateral basal hypothalamus. GRF neurons in the perifornical area contained no positive dye. We concluded that the location of neurons containing hypophysiotrophic GRF are confined within the arcuate nucleus and the lateral basal hypothalamus.