Huperzia saururus Lam. Trevis. (Lycopodiaceae) facilitates ejaculation in spinal cord transected male rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Huperzia saururus (Lam.) Trevis. has an extensive ethnopharmacological use, mainly because of its aphrodisiac properties. The species is consumed as decoctions or infusions in traditional medicine. The purpose of the present research was to determine if Huperzia saururus is able to increase sexual potency by evaluating the ejaculatory response, in the presence of a decoction in spinal cord transected male rats. MATERIALS AND METHODS: The fictive ejaculation model to record the rhythmic contractions of the bulbospongiosus muscles that accompany ejaculation as an indicator of ejaculation occurrence was used. Sexually experienced male Wistar rats were used. The activation of the fictive ejaculation by the i.v. administration of a decoction was tested, as well as the effects of the oxytocinergic, cholinergic, adrenergic and nitrergic antagonism upon the pro-ejaculatory activity of Huperzia saururus. RESULTS: Decoction (3µg/animal) was able to activate the fictive ejaculation in spinal male rats, producing a statistically significant diminution on the latency of discharge parameter and a statistically significant augment for the number of discharges. Moreover, when sequential treatments using antagonists plus decoction were administered, the effects produced showed that prazosin prevent the pro-ejaculatory effect of the decoction and that the four antagonists assayed blocked the facilitatory effect of Huperzia saururus since the facilitation in the latency of response was prevented, and the number of discharges was reduced. Together these findings support the notion that the decoction exerts an aphrodisiac effect influencing the ejaculatory potency which is partially mediated by oxytocinergic, cholinergic, adrenergic and nitrergic spinal mechanisms. CONCLUSION: In agreement to the ethnopharmacological uses, Huperzia saururus decoction has aphrodisiac properties by influence on the ejaculatory potency.

Quercetin 3,7,3',4'-tetrasulphated isolated from Flaveria bidentis inhibits tissue factor expression in human monocyte.

Sulphated esters of the flavonoids sulphated quercetin 3,7,3',4'-tetrasulphated (QTS) and quercetin 3-acetyl-7,3,4'-trisulphate (ATS), isolated from Flaveria bidentis, have demonstrated anticoagulant and antiplatelet properties. In this study, we examined if both compounds affected the expression of the procoagulant tissue factor (TF) induced by lipopolysaccharide (LPS) on human monocyte. Monocytes were pretreated with different concentrations of each flavonoid (0.1-500 µM), followed by a 4h incubation with LPS in order to induce TF expression. Results of the TF expression showed different behaviors for the two flavonoids studied. A slight inhibitory effect on the TF expression was detected at a QTS concentration of 0.1 µM, but from 1 µM onwards a significant inhibitory effect that remained up to 500 µM could be observed. In contrast, ATS induced a poor inhibitory effect on TF expression at all concentrations tested. These results suggest that QTS has another antithrombotic property, to be added to its already renowned ability as an anticoagulant and antiplatelet compound.

Huperzia saururus increases memory retention in rats.

Huperzia saururus is reported in Argentinean popular medicine as a memory improver. Chemical studies have shown that the main constituents of the species are Lycopodium alkaloids. On the basis of this information, a purified alkaloid extract was obtained by alkaline extraction of the aerial parts. The aim of this work was to investigate the effects of intra-hippocampal administration of the purified alkaloid extract (AE) on memory retention in vivo, using a step down test, in order to correlate with previous results obtained in vitro in an electrophysiological model. The AE administration significantly increased the latency time in comparison to control animals. For treated animals the latency time was 37.61 +/- 2.84, 80.94 +/- 2.37, and 180.00 +/- 5.74 s for 1, 5, and 10 ng/rat, respectively versus 14.89 +/- 2.38 s for controls. According to these results there is a good relationship between the ethnopharmacological use and the effects hereby showed.

Huperzia saururus, activity on synaptic transmission in the hippocampus.

Huperzia saururus (Lam.) Trevis. (Lycopodiaceae) known as cola de quirquincho is used in folk medicine to improve memory. The cholinergic neurons of the basal forebrain, including those in the medial septum, and in the vertical limbs of the diagonal band of Broca and the nucleus basalis of Meynert, provide a major source of cholinergic enervation of the cortex and hippocampus. These neurons have also been shown to play an important role in learning and memory processes. Thus, the effects of this traditional Argentinean species were studied in relation to its activity on synaptic transmission in the hippocampus. The alkaloid extract obtained first by decoction of the aerial parts and by subsequent alkaline extraction, was purified by using a Sephadex LH 20 packed column. Electrophysiological experiments were developed with the purified extract (E(2)) on rat hippocampus slices, thus eliciting long-term potentiation (LTP). Results show a marked increase in the hippocampal synaptic plasticity. The threshold value for generation of LTP was 22 +/- 1.01 Hz on average for E(2), while for controls it was 86 +/- 0.92 Hz. All of these factors could explain the use of Huperzia saururus as a memory improver as is reported in the ethnomedicine.

Anticholinesterase activity in an alkaloid extract of Huperzia saururus.

Huperzia saururus (Lam.) Trevis. (Lycopodiaceae) is used widely in Argentinian traditional medicine as an aphrodisiac and for memory improvement. An aqueous extract from the aerial parts was obtained by decoction, revealing the presence of alkaloids, among other constituents. By partition with organic solvent in alkaline media, alkaloids were extracted and then purified by gel permeation. We studied the anticholinesterase activity in vitro of the alkaloid extract using erythrocyte membranes and human serum as sources of acetylcholinesterase and pseudocholinesterase, respectively. The results show a marked inhibition of true acetylcholinesterase with an IC50 value of 0.58 microg/ml. Low inhibition of pseudocholinesterase was observed (IC50 value = 191 microg/ml). This shows a selectivity of the extract for the true acetylcholinesterase. Furthermore, chemical study of the bioactive extract was performed by GC-MS, revealing the presence of seven Lycopodium alkaloids, including some not identified previously: sauroxine, 6-hydroxylycopodine, N-acetyllycodine, lycopodine, lycodine, N-methyllycodine, and clavolonine. Further investigations will be undertaken in order to discover which compound/s are responsible for the aqueous extract's acetylcholinesterase activity.

Pharmacological and toxicological activity of Heterophyllaea pustulata anthraquinone extracts.

Benzenic extracts from both stems and leaves of Heterophyllaea pustulata showed the most significant activity in vivo in the Brine Shrimp Lethally Test (BST), relative to others of different polarity. They were therefore selected for in vitro antimicrobial activity studies. Bacteriostatic activity against Micrococcus luteus ATCC 9341 was detected, selectively inhibiting both oxacillin-sensitive and -resistant Staphylococcus aureus, among several gram-positive and gram-negative bacterial species tested. Antifungal activity against important opportunist microorganisms and against those involved in superficial mycosis, all from nosocomial origin was also detected. A chemical screening revealed the presence of anthraquinones as major compounds. Among them, we identified damnacanthal, rubiadin, 2-hydroxy-3-methyl anthraquinone, soranjidiol, rubiadin-1-methyl ether, and damnacanthol in the benzenic stem extract. The benzenic leaf extract shows a similar chemical composition, except for damnacanthal, damnacanthol, soranjidiol-1-methyl ether, and 3 anthraquinones whose structures have not yet been elucidated. Acute toxicity studies revealed a low toxicity in mice for the anthraquinonic extracts, as measured in the LD50 value (123 mg/kg body wt. i.v.), and death was not observed at doses of up to 4000 mg/kg body wt. s.c.

Adesmia aegiceras: antimicrobial activity and chemical study.

The antimicrobial activity of the ethanolic extract of Adesmia aegiceras was studied by the agar-well diffusion method. Antibacterial activity against Micrococcus luteus and eight pathogenic bacterial strains as well as antifungal activity against Candida albicans, was detected. Bacterial and fungal strains exhibited similar concentration-response curves (EC50 and Rmax values) and similar MIC. The MBC/MIC was about 8. These data would indicate the potential usefulness of the A. aegiceras extract as a microbiostatic, antiseptic or disinfectant agent. Furthermore, chemical study of the bioactive alcoholic extract was performed, which revealed quercetin, isorhamnetin-3-rutinoside, isovitexin, pinitol and chlorogenic acid as its main components.

The essential oil of Senecio graveolens (Compositae): chemical composition and antimicrobial activity tests.

The chemical composition of the essential oil obtained from Senecio graveolens (Compositae) was analyzed by GLC-MS and the components identified were: isovaleraldehyde, alpha-pinene, alpha-phellandrene, alpha-terpinene, p-cymene, sabinene, gamma-terpinene, 1-methyl-4-isopropenylbenzene, terpinolene, terpinen-4-ol, piperitenone, alpha- and beta-eudesmol. The investigation by the agar-well diffusion method of the antimicrobial activity of the essential oil proved that it has antibacterial effects on Micrococcus luteus ATCC 9341, oxacillin-sensitive and oxacillin-resistant Staphylococcus aureus, as well as antifungal effects on clinically isolated Candida albicans. The minimal inhibitory concentration (MIC) values for M. luteus, oxacillin-sensitive S. aureus and C. albicans were 8.73, 10.91 and 2.13 x 10(-2) mg/ml, respectively. The antimicrobial activity related to known antibiotics was calculated. These results would be compatible with a potential concentration-dependent selectivity of antifungal effect of S. graveolens essential oil. Minimal bactericidal concentration (MBC) is above 87.3 mg/ml. Thus the MBC:MIC ratio would be clearly higher than 1 (above 8), indicating a bacteriostatic effect of the essential oil.

Microcystis aeruginosa: behaviour and toxic features in San Roque Dam (Argentina).

M. aeruginosa is a cyanophyte frequently found in the water at the San Roque Dam (raw water supply conditioned for human use in Córdoba city) that causes a bad smell and taste, as well as potential toxic hazards of a still unknown extent. A heavy bloom tested by mouse bioassay (i.p.) for the first time on January 27, 1989, revealed toxicity. The dominant cyanobacterial species in the water sample was M. aeruginosa. The lyophilized bloom material (LD50: 14.5 mg/kg body weight) and the toxin isolated (LD50 estimated: 500 micrograms/kg), when administered to mice i.p., induced clinical signs similar to those induced by peptide toxins produced by M. aeruginosa. HPLC detected toxin traces from a sample of drinking water collected on the same day as the bloom. A seasonal follow-up was carried out for the next 4 years in order to compare bloom toxicity values during the most significant water blooms; these never yielded LD50 values lower than 200 mg liophilized bloom material/kg mice.