Morella serrata (Lam.) Killick stabilizes biomembrane and rejuvenates sexual competence in male Wistar rats

Mechanisms of inhibitory activity of root extract of Carpolobia lutea G. Don on in vitro contractile responses of rabbit corpus carvernosum

INTRODUCTION

Carpolobia lutea root extract (CLRE) has been reported to enhance penile erection. However, the mechanism involved is poorly understood. We investigated in vitro mechanisms of CLRE action on contractile activity of rabbit corpus cavernosum (CC).

METHODS

Corpus cavernosum strips from four healthy male New Zealand rabbits (2.5-3.0kg) were mounted on an organ chamber and contracted with phenylephrine (PE) (10^-9 to 10^-5M) and Potassium Chloride (KCl) (10-50mM) before treatment with various concentrations of CLRE (0.1-1.2mg/ml). Interactions between CLRE and a Nitric Oxide Synthase (NOS) inhibitor (N-nitro-l-arginine methyl ester - l-NAME 10^-4M); guanylyl cyclase inhibitors (Oxalodiazolo 4,3-a quinoxalin-1-one - ODQ 10μM, 20μM, 30μM), and (methylene blue 10-30μM); a cyclooxygenase inhibitor (10^-4M indomethacin); potassium-channel inhibitors (100μM tetraethyl ammonium TEA), (100ηM apamin) and (glibenclamide 10μM and 20μM); and a calcium-channel inhibitor (-10^-4M nifedipine) were investigated.

RESULTS

Maximal contractions of KCl and PE contracted CC strips were significantly reduced in a concentration-dependent manner (40.8±3.6% and 38.6±4.0% from 64.6±2.9% and 98.1±4.2% respectively). Relaxant effect of CLRE was significantly reduced by ODQ (38.6±4.0% to 6.4±1.3% and 38.6±4.0% to 7.2±1.2%), nifedipine (38.6±4.0% to 21.1±2.7%) and glibenclamide (40.8±3.6% to 31.5±3.3%). However l-NAME, indomethacin, methylene blue, TEA and apamin did not inhibit relaxation by CLRE.

CONCLUSION

Concentration-dependent relaxant effect of CLRE in rabbit CC involves the soluble guanylate cyclase/cyclase Guanosine Monophosphate system, and activation of ATP-dependent K⁺ channels.

Actinorhizal trees and shrubs from Africa: distribution, conservation and uses

Actinorhizal plants are a group of perennial dicotyledonous angiosperms, comprised of more than 200 species, most of which can establish root-nodule symbiosis with the nitrogen fixing actinobacteria of the genus Frankia. They are key providers of fundamental goods and services and can give a major contribution to mitigate the combined effects of climate changes, human population growth and loss of biodiversity. This aspect is particularly relevant for the developing economies of many African countries, which are highly exposed to climate and anthropogenic disturbances. In this work we have analyzed the distribution, conservation and uses of actinorhizal species native to or introduced in Africa. A total of 42 taxa distributed over six botanical families (Betulaceae, Casuarinaceae, Myricaceae, Elaeagnaceae, Rhamnaceae and Coriariaceae) were identified. The vast majority is able to thrive under a range of diverse environments and has multiple ecological and economic potential. More than half of the identified species belong to the genus Morella (Myricaceae), most of them native to Middle, Eastern and Southern Africa. Although the information about the conservation status and uses of Morella spp. is largely incomplete, the available data is indicative of their potential in e.g. forestry and agroforestry, food and medicine. Therefore, efforts should be made to upgrade actinorhizal research in Africa towards the sustainable use of biodiversity at the service of local (bio)economies.

Medicinal plant activity on Helicobacter pylori related diseases

More than 50% of the world population is infected with Helicobacter pylori (H. pylori). The bacterium highly links to peptic ulcer diseases and duodenal ulcer, which was classified as a group I carcinogen in 1994 by the WHO. The pathogenesis of H. pylori is contributed by its virulence factors including urease, flagella, vacuolating cytotoxin A (VacA), cytotoxin-associated gene antigen (Cag A), and others. Of those virulence factors, VacA and CagA play the key roles. Infection with H. pylori vacA-positive strains can lead to vacuolation and apoptosis, whereas infection with cagA-positive strains might result in severe gastric inflammation and gastric cancer. Numerous medicinal plants have been reported for their anti-H. pylori activity, and the relevant active compounds including polyphenols, flavonoids, quinones, coumarins, terpenoids, and alkaloids have been studied. The anti-H. pylori action mechanisms, including inhibition of enzymatic (urease, DNA gyrase, dihydrofolate reductase, N-acetyltransferase, and myeloperoxidase) and adhesive activities, high redox potential, and hydrophilic/hydrophobic natures of compounds, have also been discussed in detail. H. pylori-induced gastric inflammation may progress to superficial gastritis, atrophic gastritis, and finally gastric cancer. Many natural products have anti-H. pylori-induced inflammation activity and the relevant mechanisms include suppression of nuclear factor-κB and mitogen-activated protein kinase pathway activation and inhibition of oxidative stress. Anti-H. pylori induced gastric inflammatory effects of plant products, including quercetin, apigenin, carotenoids-rich algae, tea product, garlic extract, apple peel polyphenol, and finger-root extract, have been documented. In conclusion, many medicinal plant products possess anti-H. pylori activity as well as an anti-H. pylori-induced gastric inflammatory effect. Those plant products have showed great potential as pharmaceutical candidates for H. pylori eradication and H. pylori induced related gastric disease prevention.