Avicenna Journal of Phytomedicine
Volume:2 Issue: 1, Winter 2012

In the previous issue of AJP an article under the title of «Reduction of serum cholesterol in hypercholesterolemic rats by Guar gum» was published (Samarghandian et al., 2011), which raised some question to be discussed more. In the “Animal Experimental Procedure” section, for induction of hypercholesterolemia, rats have been fed a chow supplemented with 18% corn oil. This diet is absolutely a high fat diet but it could not induce hypercholesterolemia because cholesterol is an animal or fungus steroid and oils with plant origin have no or little amount of cholesterol (Horton et al., 2002, Behrman et al. 2005). Therefore plant oils could not increase cholesterol levels in rats and are not used routinely for induction of hypercholesterolemia. Authors have cited five studies in order to support their protocol (Pratchayasakul et al., 2011, Guo et al., 2011, Bajerska et al., 2011, Suanarunsawat et al., 2010, Zhao et al., 2011). However in all cited references (except for Zhao et al that has not been listed in references list), animal fat such as lard with or without corn oil were used as the hypercholesterolemic diet that is not used in the current study. It is clear that authors and coworkers have not followed the exact procedure mentioned in the articles they cited, therefore elevation of serum total cholesterol levels mentioned in the figure 2 (results section) may not be possible. In my opinion this can be a typing error, but there is not any animal fat as an ingredient of the diet of hypercholestrolemic group (control) as detailed in table 2 either. In conclusion the exact model of hypercholesterolemia has not been produced by the mentioned procedure and none of the provided results in the remaining paper could be accurate. However there is an article cited in the body of the manuscript (Zhao et al., 2011) which has not been listed in the references section. In my opinion the above-mentioned issues warrant further clarification by the authors.

This study was planned to investigate whether Coriandrum sativum (C. sativum) is capable of protecting neurons against glucose/serum deprivation (GSD)-induced cytotoxicity. The PC12 cells were cultivated for 24 h in standard media (high-glucose DMEM containing Fetal Bovine Serum) or for 6 h in GSD condition (glucose-free DMEM, without serum) in the absence or presence of various concentrations (0.1, 0.2, 0.4, 0.8 and 1.6 mg/ml) of hydro-alcoholic extract (HAE), water fraction (WF), ethyl acetate fraction (EAF) or N-butanol fraction (NBF) of this plant. At the end of the treatments, the cell viability was determined using MTT assay. With the exception of 1.6 mg/ml of EAF or NBF which decreased cell survival, the HAE and its fractions exhibited no cytotoxicity under standard condition. Exposure of the cells to GSD condition showed 52% decrease in the viability. In this condition, the HAE, EAF and NBF not only failed to increase cell viability but also increased the toxicity. On the other hand, WF at 0.4, 0.8 and 1.6 mg/ml significantly attenuated the GSD-induced decrease in cell survival. The present study revealed that C. sativum bearing water-soluble compound(s) could induce neuroprotective activity. Also, we showed that some constituents from this plant may serve as cytotoxic agents under stressful conditions like hypoglycemia and serum limitation.

Asafoetida (Ferula assa-foetida) is known as a valuable remedy for whooping cough, pneumonia, bronchitis in children and asthma treatment in folk medicine. In the present study the relaxant effects of the asafoetida on tracheal smooth muscle of guinea pigs and its probable mechanism(s) were examined. The relaxant effects of three cumulative concentrations of the aqueous extract (2, 5 and 10 mg/ml), theophylline (0.25, 0.5 and 0.75 mM) and saline were examined on non-incubated tracheal smooth muscle of guinea pig precontracted by 10 µM methacholine (group 1); preincubated tissues by propranolol and chlorpheniramine, contracted by methacholine (group 2) and preincubated tissues by propranolol, contracted by methacholine (group 3), (n=6 for each group). All concentrations of theophylline in group 1 and all concentrations of the extract in the other three groups showed significant relaxant effects compared to that of saline (p<0.001 for all cases). There was not significant difference in the relaxant effect of the extract between three groups. The relaxant effects of two last concentrations of the extract (5 and 10 mg/ml) only in group 2 were significantly lower than that of theophylline (p<0.05 for both case). There was no significant difference between relaxant effects of the extract and theophylline in group 2. There were significant positive correlations between the relaxant effects of the extract with their concentrations in all three groups (p<0.001 for all cases). These results showed a potent relaxant effect for the asafoetida extract on tracheal smooth muscle which is perhaps due to muscarinic receptor blockade.

Platycladus orientalis or Thuja orientalis is a native plant of Iran different parts of which are used in the treatment of various diseases such as: gout, rheumatoid arthritis, common cold, cough, bronchitis, asthma, high blood pressure and hormonal disorders like hirsutism and baldness. Also, various organs of this species have been used as appetizer. The purpose of this study was to prepare and characterize liposomal formulations that contain methanol extract of aerial parts of P. orientalis for hirsutism treatment. Plant’s leaves were dried in room temperature, and powdered by grinding. Then, methanol extract was prepared by maceration method. Liposomes containing mathanol extract were produced by two methods of fusion and solvent evaporation. To evaluate mathanol extract and encapsulation efficiency of liposomes, quercetin was chosen as standard. The amount of quercetin in samples was determined by high pressure liquid chromatography (HPLC) method. Mean size of liposomes prepared by solvent evaporation and fusion methods was 373 and 320 nm, respectively. According to the quercetin concentration, encapsulation efficiency of liposomes containing menthanol extract was 69.3±3.1% for solvent evaporation and 62.2±4.9% for fusion method. In the current study, a suitable liposomal formulation was prepared. The pharmacological activity of these carriers should be evaluated in the future study.

In the present study, the effects of aqueous saffron extract (Crocus sativus L.) on the acquisition and reinstatement of morphine-induced conditioned place preference (CPP) in mice were investigated. Subcutaneous administration of morphine (40 mg/kg for four days) produced place preference. Intraperitoneal administration of aqueous extract (40 and 80 mg/kg for four days) 30 min before the morphine administration decreased the acquisition of morphine CPP. In other groups of animal, following extinction of a place preference induced by morphine (40 mg/kg), single administration of morphine (10 mg/kg) reinstated the place reference. The aqueous extract (80 mg/kg) 30 min before this priming dose of morphine blocked morphine-induced reinstatement of place preference. These results show that aqueous saffron extract can reduce the acquisition and reinstatement of morphine-induced conditioned place preference.

This study investigates the effects of hydro-alcoholic extract of Prangos ferulacea (L.) Lindle (P.f) on rats'' pancreas structure changes and diabetic treatment after streptozotocin injection. In this research forty male Wistar rats with body weights of 100±20 gram, were randomly divided into 5 groups with 8 rats per each group. Diabetes was induced in rats by streptozotocin at a dose of 75 mg/kg body weight (B.W) injected intraperitoneally. Root and leaves with stems hydroalcoholic extract of P.f at a dose of 100 mg/kg B.W have been injected orally in diabetic rats, daily for a month. Significant decrease in blood glucose, WBC and HbA1c and increase in body weight were observed in treated diabetic rats. Histopathologic results of diabetic rats revealed reduction in number of pancreatic islets as well as their number of β-cells and insulitis with lymphocytes infiltration. Regeneration of pancreatic islets and β-cells, along with a reduction in the number of infiltrated lymphocytes were present in plant extract –treated diabetic rats. The roots´ hydro-alcoholic extract of P.f seems to be capable to regenerate the islets of Langerhans in the treated rats in comparison with the untreated diabetic rats. This property can be due to some components of the plant that can increase insulin secretion.

It has been shown that Silybum marianum or its extracts have hepatoprotective, antioxidant, anticancer, anti-inflammatory and anti-diabetic effects. Nitric oxide (NO) plays an important role in neurotransmission, neuroprotection, neurotoxicity and pathological pain, as a neurotransmitter or neuromodulator in the central nervous system. Therefore, this experiment was performed in order to assess the analgesic effects of single and multiple-dosed ip administration of silymarin and the probable role of nitric oxide or opioid receptors using tail flick assay. Based on our results, only silymarin 100 mg/kg showed analgesic properties. Since naloxone did not change silymarin’s analgesic effects, it is concluded that opioid receptors are not involved. Although in the presence of L-arginine, analgesic effect of silymarin remained intact, but it is not possible to strongly determine the involvement of nitric oxide pathway here. Based on our results, the difference between anti nociceptive properties of single and multiple-dosed treatment of silymarin 100 mg/kg is not significant. It is concluded that silymarin exert its analgesic effects via other mechanisms. Inhibiting 5-lipooxygenase and neutrophil chemotaxis to inflammation location could be the probable ways of silymarin’s action.

Rosa damascena mill L (R. damascena) is a medicinal plant mostly known in the world for its perfume. It also has beneficial effects on stress, tension and depression. In this experiment antidepressant effect of ethanolic extract of R. damascena by forced swimming test (FST) was evaluated. Animals received ethanolic extract (15, 60 and 90 mg/kg, i.p), imipramine (15mg/kg, i.p; positive control), or saline (negative control). Thirty min post- injection, immobility and swimming times were measured and compared in the different studied groups. Intraperitoneal injection of lower concentration of extract (15 mg/kg) did not change swimming and immobility times compared to the control group. The higher concentrations of extract (60 and 90 mg/kg) significantly increased immobility time and decreased swimming time. Therefore ethanolic extract at tested doses had no antidepressant effect in this study. Although ethanolic extract did not have antidepressant effect, we cannot rule out this effect altogether. In our opinion, antidepressant effect is masked by CNS depression effect of ethanolic extract of R. damascena.