DARU, Journal of Pharmaceutical Sciences
Volume:8 Issue: 1, summer 2000

In this study the hypothesis that aminoglycoside antibiotics and lithium may influence apomorphine-induced licking via their effects on phosphoinositide pathways and calcium stores were investigated in male rats. Subcutaneous administration of apomorphine (0.1,0.25 and 0.5 mg/kg) to rats induced licking in a dose-dependent manner and the maximum response was obtained by the dose of 0.5 mg/kg of the drug. Intracerebroventricular injections of amikacin (5, 25 and 50 ug/rat) and gentamicin (10, 20 and 40 ug/rat) decreased the apomorphine-induced licking significantly. Pretreatment of animals with lithium (600 mg/1) for 7,14 and 21 days increased licking induced by apomorphine. The inhibitory effects of amikacin and high dose of gentamicin were not affected by lithium pretreatment for 14 and 28 days. These findings indicate the possible involvement of phosphoinositide cascade in alterations of apomorphine-induced licking by aminoglycoside antibiotics and lithium in the brain. Also it is suggested that type and dose of aminoglycoside antibiotics and duration of lithium administration probably have different effects on responses mediated by phosphoinositide hydrolysis.

"The composition of the volatile oil of the aerial parts of Hertia angustifolia (Compositae) was determined by GC MS and retention index. The main constituents of the monoterpene fraction of the oil were: (b-pinene (51.5%), (3-phellandrene (16.5%), a-pinene (13.9%) and a-thujene (2.7%). Percentage of the detected sesquiterpene components was relatively low.

The aim of this study was to examine various polymers considered to have mucosa-adhesive properties for the preparation of buccal-adhesive films and their in vitro evaluation. A number of materials, such as cellulose derivatives, carbopols and natural polymers, were employed for the preparation of buccal-adhesive films. Aqueous solutions containing the mucosa-adhesive polymer and a plasticizer were prepared and used to prepare films by the "solvent cast" method. Prepared films were then evaluated in terms of their physical appearance and film forming ability, in vitro mucosa-adhesive strength and duration of mucosa-adhesion. Results showed that among the various materials examined, sodium carboxymethyl cellulose (CMC) formed very flexible films with the greatest mucosa-adhesive strength. Further studies showed that the combination of carbopols and CMC, along with glycerin as the plasticizer, resulted in the formation of films with desirable appearance and a relatively stronger mucosa-adhesive strength than films containing CMC alone. In vitro studies showed that films containing carbopol 934P, CMC and glycerin gave the greatest mucosa-adhesive strength and longer mucosa-adhesion. In conclusion, this formulation is proposed as a good base for the preparation of buccal-adhesive films and patches. Furthermore, it is suggested that in the development of buccal-adhesive drug delivery systems, and in particular films and patches, duration of mucosa-adhesion determined by in vitro experiments is a critical factor in the selection of the ultimate formulation.

The essential oil from spearmint {Mentha spicata L., Labiatae) was extracted by hydrodistillation, and analysed by GC and GC/MS. Twenty eight components were identified representing 90.14% of total oil composition. The major constituents were carvone (22.40%), linalool (11.25%) and limonene (10.80%). The essential oil showed good activity against larvae of Anophel stephensi and Artemia salina.

The mechanical strength of same material composite beams of Avicel PHI02, Starch 1500 and Emcompress were assessed by three-point bending test. To provide an improved method of comparing the strength of the tablets, the tensile strength of the specimens was calculated by equations based on stress analysis. Increasing the compaction pressure led to decrease of the porosity of the compacted tablets while the overall mass of the composite tablets were kept constant. Meanwhile, the values of fracture load and strengths (including tensile and shear) raised by increasing the compaction pressure. However, when the lower layer was compacted twice, the value of tensile stress of the lower layer was more than its value in a single compacted tablet with the same material. This observation was attributed to the extent of the reduction of porosity during compaction of the single tablets which raised in their tensile strength values.

The essential oil of Salvia macrosiphon boiss (Labiatae) was prepared by steam distillation and analyzed by GC and coupled GC/MS. Twenty substances out of about thirty-three detected components were identified. The major constituents were sesquiterpenes (69.5%), a-Gurjunene (11%), P-Cubebene (10.6%), Germacrene-B (7%).

The present study examined the significance of glucocorticoid receptors (GRs) in the basolateral amygdala (BLA) on place avoidance memory in male rats. Rats were trained to avoid footshock in a 60° segment while foraging for scattered food on a circular (80-cm diameter) arena. The rats were injected bilaterally in the BLA with the specific GR antagonist RU 38486 (3 ng dissolved in 1 ul 2% ethanol) before acquisition, after training or before retrieval of the place avoidance task. Control rats were injected with vehicle. The learning in a single 30-min session was assessed 24h later by a 30 min extinction trial in which the time to first entrance and the number of entrances to the shocked area measured the avoidance memory. Acquisition and consolidation were impaired when the drug was injected 10 min before training, immediately after training, or 60 min after training (P<0.01), but not 120 min after training. In contrast, injection of the antagonist before the retrieval test was ineffective (P>0.05). These findings indicate that glucocorticoids affect memory storage at least in part by binding directly to GR in the BLA and provide further evidences for the opinion that the BLA plays an important role in integrating hormonal and neurotransmitter influences on memory storage.

The H6H gene for hyoscyamine 6B-hydroxylase (H6H), which converts hyoscyamine to scopolamine, was isolated from Hyoscyamus niger. The roots of 14 days sterile seedlings were transferred to a modified liquid B5 medium containing 1 uM indolebutyric acid, and after appearance of the lateral roots, subcultured in a free hormone medium. Following a week, its genomic DNA was extracted and PCR performed. By extraction an accurate DNA and using suitable primers, H6H gene can be isolated completely.

Two new compounds, 7-methoxycoumarin (I) and 7-hydroxyartemidin (II) were isolated from the ethanol/water (50:50, V/V) extract of Artemisia drucunculus L. leaves. Structures of the isolated compounds were elucidated on the basis of spectral data (''H NMR and MS). It is shown that compound I is devoid of anticoagulation activity in male Albino rabbits in contrast to the same activity observed in rabbits using the crude extract of the leaves.

In this study the healing properties of a medicinal plant commonly used in Iran, Onopordon acanthium known as cotton thistle was investigated. This plant has been used in the traditional Iranian medicine, as an aid in the treatment of wounds. In order to access which part of this plant contained the principle ingredient(s), hydroalcoholic extract of the roots, stems, leaves and flowers were separately prepared. The extracts were formulated into an eucerin-based ointment and applied once daily to a full thickness excision wound (2x2 cm) inflicted on the mid-dorsal area of White Newzealand rabbit. Measurement of the wound surface area was employed as the parameter by which the effectiveness of each preparation was assessed. The wound areas were traced on transparencies and the areas were quantified by placing the transparency film over graph paper and counting the squares. Compared with other extracts, the results showed that the hydroalcoholic extract from the flowers is the most effective. Dose-response curves showed that 0.2% w/w flowers extract has the optimum concentration which induced the fastest rate of healing, inducing a complete healing in 6 days compared with 17 days with the ointment base alone. The results suggest that this extract is an effective preparation in the treatment of wounds in this model.