An antioxidative role of ocular screening pigments

The action of ocular screening pigments of vertebrates (melanins) as well as those of invertebrates (ommochromes) on lipid peroxidation has been studied. Lipid peroxidation has been induced by one of the following systems: Fe2+ + ascorbic acid; Fe2+ + NADPH + liver microsomes; xanthine + xanthine oxidase; u.v. illumination; intense visible light, high concentration of O2. Measurements of the lipid peroxidation rate, as estimated from the accumulation of malonic dialdehyde, showed a sharp decrease of the lipid peroxidation rate in the presence of either melanosomes or ommochromes. Synthetic DOPA melanin was also found to exert a strong inhibiting effect on lipid peroxidation. A comparative study of lipid peroxidation in retinal pigment epithelium (RPE) of pigmented and albino rabbits demonstrated that the latter tissue is more sensitive to the effect of the above mentioned prooxidant systems. Apparently this finding is related to the presence of melanin-containing granules in the pigmented tissue rather than to differences in efficiency of other endogenous antioxidant systems. The activities of superoxide dismutase and glutathione peroxidase are practically equal in the RPE of pigmented and albino rabbits whereas the alpha-tocopherol content is higher in albinos. Possible mechanisms of inhibition of lipid peroxidation by melanosomes and ommochromes are discussed. It is proposed that their antioxidant function is one of the most important physiological features of melanins (vertebrate eye) and ommochromes (invertebrate eye).     

Preliminary psychopharmacological evaluation of Ocimum sanctum leaf extract

An ethanol extract of the leaves of Ocimum sanctum was screened for its effects on the central nervous system. It prolonged the time of lost reflex in mice due to pentobarbital, decreased the recovery time and severity of electroshock- and pentylenetetrazole-induced convulsions, and decreased apomorphine-induced fighting time and ambulation in "open field" studies. Using a behavioural despair model involving forced swimming in rats and mice, the extract lowered immobility in a manner comparable to imipramine. This action was blocked by haloperidol and sulpiride, indicating a possible action involving dopaminergic neurones. In similar studies, there was a synergistic action when the extract was combined with bromocriptine, a potent D2-receptor agonist.     

A neuropsychopharmacological profile of "Cinkara", a polyherbal preparation

"Cinkara", a polyherbal preparation reduced pentobarbitone induced hypnosis in mice, decreased apomorphine induced fighting, aggression and stereotypy and increased amphetamine induced aggregated toxicity in mice. It also increased immobility of rats in forced swimming test, an action which was not blocked by chlor-promazine, and increased ambulation in open arena test. It did not modify electrically induced convulsions or haloperidol catalepsy. It is suggested that the preparation possesses a central nervous system stimulant activity but unlike other CNS stimulants, it lowers aggressive activity in rats.     

Compounds from the pods of Astragalus armatus with antioxidant,anticholinesterase, antibacterial and phagocytic activities

Context: The phytochemical study and biological activities of Astragalus armatus Willd. subsp. numidicus (Fabaceae) pods, an endemic shrub of Maghreb, are reported.

Objective: This study isolates the secondary metabolites and determines the bioactivities of Astragalus armatus pods.

Materials and methods: The chloroform, ethyl acetate and n-butanol extracts of hydro-ethanolic extracts were studied. Antioxidant activity was investigated using DPPH and ABTS radical scavenging, CUPRAC and ferrous chelating assays at concentrations ranging from 3 to 200?μg/mL. Anticholinesterase activity was determined against acetylcholinesterase and butyrylcholinesterase enzymes at 50, 100 and 200?μg/mL. Antibacterial activity was performed according to minimum inhibitory concentration (MIC) method. Carbon clearance method in albino mice was used for the phagocytic activity at concentrations 50, 70 and 100?mg/kg body weight. Spectroscopic techniques were used to elucidate the compounds.

Results: Ethyl acetate extract afforded a flavonoid (1) while the n-butanol extract gave four flavonoids (2–5), a cyclitol (6) and a cycloartane-type saponin (7). The ethyl acetate extract exhibited highest antioxidant activity in DPPH (IC₅₀: 67.90?±?0.57?μg/mL), ABTS (IC₅₀: 11.30?±?0.09?μg/mL) and CUPRAC (A_0.50: 50.60?±?0.9?μg/mL) assays. The chloroform extract exhibited the best antibacterial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, each with 80?μg/mL MIC values. The n-butanol extract enhanced phagocytic activity.

Discussion and conclusion: Isorhamnetin (1), isorhamnetin-3-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-galactopyranoside (2), isorhamnetin-3-O-β-d-apiofuranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 6)]-β-d-galactopyranoside (3), kaempferol-3-O-(2,6-di-O-α-l-rhamnopyranosyl)-β-d-galactopyranoside (4), kaempferol-3-O-(2,6-di-O-α-l-rhamnopyranosyl)-β-d-glucopyranoside (5), pinitol (6) and cyclomacroside D (7) were isolated whereas 1, 2, 6 and 7 are reported for the first time from A. armatus.     

A double-blind comparison of sexual functioning, antidepressant efficacy, and tolerability between agomelatine and venlafaxine XR

Impaired sexual function is associated with major depressive disorder in the untreated state and is often more prevalent during antidepressant therapy, which frequently results in poor treatment compliance. In this double-blind, multicenter study, the effects of agomelatine (an MT1 and MT2 agonist and 5HT-2C antagonist) and venlafaxine XR on sexual function were compared using the Sex Effects Scale in depressed patients. A total of 276 male and female patients received either agomelatine (50 mg) or venlafaxine XR (titrated to a target dose of 150 mg/d) for 12 weeks. Those who were sexually active at baseline (n = 193) and those who, in addition, achieved remission (n = 111) were defined a priori for analyses of change in sexual function. Treatment-emergent sexual dysfunction was significantly less prevalent among patients who received agomelatine, and venlafaxine XR was associated with significantly greater deterioration on the Sex Effects Scale domains of desire and orgasm. Both treatments resulted in equivalently high rates of remission (agomelatine, 73%; venlafaxine XR, 66.9%), although fewer patients in the agomelatine group discontinued treatment because of adverse events (agomelatine, 2.2%, vs venlafaxine XR, 8.6%). Agomelatine seems to be an efficacious antidepressant with a superior sexual side effect profile compared with venlafaxine XR, although superiority to placebo was not evaluated in this trial.     

Thermal Kinetics of Monocationic and Dicationic Pyrrolidinium-Based Ionic Liquids

This work presents an in-depth kinetic thermal degradation comparison between traditional monocationic and the newly developed dicationic ionic liquid (IL), both coupled with a bromide (Br⁻) anion by using non-isothermal thermogravimetric analysis. Thermal analyses of 1-butyl-1-methylpyrrolidinium bromide [C₄MPyr][Br] and 1,4-bis(1-methylpyrrolidinium-1-yl)butane dibromide [BisC₄MPyr][Br₂] were conducted at a temperature range of 50–650 °C and subjected to various heating rates, which are 5, 10, 15, 20 and 25 °C/min. Thermogravimetric analysis revealed that dicationic IL, [BisC₄MPyr][Br₂] is less thermally stable compared to monocationic [C₄MPyr][Br]. A detailed analysis of kinetic parameters, which are the activation energy (E_a) and pre-exponential factor (log A), was calculated by using Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO) and Starink. This study revealed that the average E_a and log A of [BisC₄MPyr][Br₂] are lower than [C₄MPyr][Br], which may be contributed to by its low thermal stability. Conclusively, it proved that the E_a and log A of ILs are strongly related to the thermal stability of ILs.