Journal of Medicinal Plants
Volume:13 Issue: 49, 2014

Evidence based medicine is very important for success of modern medicine. It is the ongoing process of using the most reliable evidence from clinical studies، scientific understanding and medical practice to make the best possible medical choice for patients. Evidence based medicine is how medicine advances and how we get improvements in life expectancy and quality of life. It not only identifies which treatments are effective but also those which are ineffective and may do more harm than good، and identifies areas where more investigation is needed and where there may be gaps in knowledge. In this review we focus on clinical trials.

Nanosilver particles are among the potentially candidates for modulating the redox status and changing the growth، performance and quality of plants because of their physicochemical characteristics. This study was carried out to elucidate the potential effects of nanosilver particles application on variations of photosynthetic pigments (chlorophyll and carotenoids) and essential oil content and composition of Pelargonium graveolens. Four nanosilver particles (5 - 20 nm) concentration (0، 20، 40، and 80 mg. L-1) were used as foliar application. The essential oils were isolated from aerial flowering parts of the plants by hydro-distillation method and then subjected to GC and GC-MS apparatus to determine the oil constituents. Chlorophyll and carotenoids content increased in leaves of nanosilver treated plants in compare with the control. Nanosilver application at 40 mg. L-1 was the most effective treatments in pigments and essential oil content. Also، results showed that 26 components were identified in essential oil and citronellol was the major component under all employed treatments. Maximum citronellol/geraniol ratio was obtained at 80 mg. L-1 nanosilver treatment، indicating the positive influence of nanosilver particles on essential oil quality of Pelargonium plants. The nanosilver particles application could maintain and enhanced the photosynthetic pigments and essential oil content of P. graveolens plants. Our findings suggested that nanosilver application improved quality and quantity of essential oil.

Echinophora platyloba DC (Apiaceae) is one of the two endemic species of Echinophora genus in Iran. It has many folkloric uses and several biological activities but there is no information about its phytoconstituents. In this work some of the secondary metabolites were isolated، purified and identified from n-hexane، ethyl acetate and methanol extracts from the aerial parts and root of this plant for the first time. Resulting extracts were subjected to column chromatography using EtOAc/n-hexane as eluent. Further purifications were carried out using preparative TLC and recrystallization techniques. Characterization of compounds were established using spectroscopic data (1H-NMR، 13C-NMR، MS and FT-IR)، and by comparing with the literature. Stigmasterol، Sitosterol، Stigmasterol-β-D-glycoside and Saccharose were purified from these extracts and their chemical structures were characterized. Several phytosterols were isolated from various extracts of aerial parts and great amount of saccharose was purified from the sweet root of the plant.

The antioxidant components have been identified in some pine species. Antioxidant properties of proantocyanidins reduce free radicals induced by DNA fragmentation and lipid proxidation and also proanthocyanidines could curb lipid peroxidation. In this study، we analyzed different parts of Pinus eldarica (bark، seed and needle) and assessed their antioxidant contents. Pine specimens were collected from four different geographic locations in Tehran. The HPLC method (UV detector، C18 reverse phase column، 4. 6 mm (25 cm، and water/ H3PO4/ methanol/ acetonitril as eluant) were employed for evaluating total polyphenols. The wavelength for detection of polyphenolic compounds was 280 nm in this study. The highest range of total polyphenols was detected in the bark of this pine، specially reported a considerable amount of tyrosol in Pinus eldarica. Tyrosol stimulated resistance to oxidative stress and also has anti aging effect. The high amount of total phenolic compounds in P. eldarica bark might be attractive for future research considering its health benefits.

Nepeta menthoides Boiss & Buhse is a species from Lamiaceae family. It is used as a herbal medicine with common name “Ostokhodus” in Iranian traditional and folk medicine but there is not enough information about its quality and quantity control methods. In this study we use micromorphological and phytochemical evaluations for qualitative and quantitative control of N. menthoides powder. Macroscopic and microscopic characteristics، phytochemical screening and flavonol quantification were done on N. menthoides powder. Results showed that all of these assessments can use as quality control parameters for authentication of N. menthoides، particularly micromorphological specifications. Our study shows the importance of micromorphological evaluation in authentication of this herbal medicine but further investigations are needed to complete these data.

Despite the discovery of numerous antibiotics، drug resistance still remains as a major problem. Therefore، it is important to introduce and replace new sources of drug such as medicinal plants with antimicrobial properties. The genus Clematis (Ranunculaceae family) has six species in Iran. Aerial parts of Clematis have been used to cure fever and chronic diseases such as Rheumatism in traditional medicine. In this research، antibacterial activity of ethanolic and methanolic extracts of aerial part in two major species of the genus in Iran (contains C. orientalis and C. ispahanica) were studied. Aerial plant parts were dried in shade، powderized and then ethanolic and methanolic extracts were prepared. Antibacterial activity of the two extracts was measured against six laboratory standard strains including gram positive and gram negative bacteria by disc diffusion. Minimum inhibitory concentrations were also determined using broth microdilution. Results showed that antibacterial activity of methanolic extracts is stronger than the ethanolic one. Also، C. ispahanica has stronger antibacterial activity in comparison to C. orientalis. Gram positive test bacteria showed the most susceptibility to both extracts compared to gram negative organisms. According to antibacterial effects of alcoholic extracts، it seems necessary to diagnose effective antibacterial components to compare results with existed finding and introduce a new trapeutic source.

Linum album، a herbaceous and medicinal plant، has been shown to accumulate anti-tumor podophyllotoxin (PTOX) and related lignans. In this study، we have verified the time-course of cell growth، lignan production in cells treated with chitosan and chitin oligomers. To study mechanism of chitosan and chitin oligomers action، expression of phenylalanine ammonio-lyase (PAL)، cinnamoyl-CoA reductase (CCR)، cinnamyl alcohol dehydrogenase (CAD) and pinoresinol lariciresinol reductase (PLR) genes were investigated. The cells were treated with 100 mg l-1 chitin and chitosan oligomers. Cells were harvested for 5 days after elicitation. lignans quantified by reverse-phase high-performance liquid chromatography (HPLC). Cell samples frozen with liquid N2 were used to elucidate the expression level of genes by quantitative PCR (qPCR). Cells elicited with chitosan hexamer for 5 days yielded the highest amount of PTOX (73. 5 µg/g dry weight) and lariciresinol (96 µg/g DW) which were about 3-fold and 2-fold higher than control، respectively. The expression of genes by oligomers was increased، reaching a peak at 3 day after treatment. Chitosan and chitin oligomers up-regulate the production of PTOX، by effecting on gene expression of PTOX biosynthesis pathway.

Lemon verbena (Lippia citriodora H. B. K.) is an aromatic and medicinal plant of family Verbenaceae، which cultivated in North region of Iran. Evaluation of phytochemical characters in Lippia citriodora H. B. K. plantlets affected by propagation methods (micro-propagation and stem cutting) cultivated in different soil type (peat moss and mixture soil). This study was done on the base of factorial experiment in randomized complete block design with three replications and four treatments. The treatments were propagation methods (micro-propagation and stem cutting) and soil type (peat moss and mixture soil). The volatile oil was extracted by hydro-distillation using clevenger-type apparatus and analyzed by GC and GC/MS. The results indicated that the interaction effects of different soils and plantlets types had significant effect (p<0. 05) on all studied parameters. The highest content of essential oil (0. 79%)، geranial (53. 52%)، neral (31. 82%)، limonene (11. 29%)، leaf dry weight (1. 43 g) and SPAD value (20. 85) were observed in treatment of MPP (micro-propagation plantlets cultivated in peat moss) and the lowest of that was obtained in treatment of SCM (stem cutting plantlets cultivated in mixture soil). The peat moss was the best bed in respect of phytochemicals and morpho-physiological traits in both types of in vitro and stem cutting propagation. The highest essential oil content was observed in treatment of micro-propagation cultivated in peat moss.

Cornus sanguinea L subsp australis (C. A. Mey.) Jáv. (Cornaceae) is a native species in north and northwest of Iran. It is locally named Siah-al. The genus Cornus is rich source of anthocyanins. In this study the antioxidant activity، total phenol and total anthocyanin contents of different extracts of C. sanguinea L subsp australis. were investigated for the first time. The fruits were extracted with ethyl acetate، methanol (1% HCl) and water. DPPH and FRAP assay were performed for investigation of antioxidant activity of each extract. The total phenols were measured by Folin-Ciocalteu method while total anthocyanins were detected by spectroscopic method modified by Peksel. The results showed that C. sanguinea L subsp australis methanol (1% HCl) extract (CME) had the highest amount of anthocyanins (12. 56 ± 0. 01 µmol/g extract) as well as the highest amount of total phenolics (88. 56 ± 0. 04 mg GAE/ g dry extract). The CME were found to have the highest antioxidant activity in DPPH assay (IC50=90. 43 µg/ml) and in FRAP method (1419. 167± 0. 025mmol FeII / g dry extract). Radical scavenger activity of CME at 100 μg/ml was comparable with α-tocopherol (20 μg/ml) and with BHA (200 μg/ml)، p>0. 05. There was a significant correlation between the total phenolic content an antioxidant activity of CME as well as total anthocyanin and antioxidant activity in DPPH assay (R2 = 0. 99). The results suggest that C. sanguinea L subsp australis is a natural sources of anthocyanin and have considerable antioxidant activity.

Since alkaloids are nitrogenous compounds، the availability of nitrogen (N) is expected to play an important role in the biosynthesis and accumulation of alkaloids in plants. This study intended to investigate the nitrogen (N) fertilization and water deficit stress (WDS) effects on seed tropane alkaloids elicitation including hyoscyamine (HYO) and scopolamine (SCO)، and also antioxidant enzymes activities variations including superoxide dismutase (SOD)، peroxidase (POX) and catalase (CAT) in black henbane. Plants were treated with different nitrogen (0، 0. 14، 0. 28 and 0. 56 g N pot-1 as ammonium nitrate، N0-N3، respectively) and WDS treatments (30، 60 and 90% depletion of water from field capacity، W1-W3). Alkaloids extracted were identified by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis. Results showed that the highest alkaloid content values in seeds (HYO: 0. 145% dw; and SCO: 0. 271% dw) achieved in plants grown under sever (W3) and moderate (W2) WDS accompanied with nitrogen supply of 0. 28 g N pot-1 (N2)، respectively. The maximum and minimum (2. 112 and 0. 114 g. plant-1) total alkaloids yield were obtained in N3W1 and N3W3 treatments، respectively. Furthermore، SOD activity increased with increasing N fertilization in all WDS treatments. CAT activity increased with WDS up to 60% FC، and then decreased with WDS increase. The POX activity was the opposite to that of CAT activity with N application under WDS levels. Our results suggest that N in appropriate level may act as a modifier for seed physiological responses and as an elicitor for tropane alkaloids biosynthesis pathway in black henbane (hyoscyamus niger) plants.

Moringa peregrina (Forssk.) Fiori. is a small tree، which grows in south east of Iran. The shoot and root of M. peregrina contain volatile oil which has several isothiocyanates. To study the effect of salinity on volatile constituents of root and shoot of M. peregrina. The experiment was conducted on randomized complete blocks design (RCBD) with 8 treatments and 3 replications. The treatments were consist of control، 2، 4، 6، 8، 10، 12 and 14 dS/m. The volatile constituents were determined by GC and GC/MS. The results showed that the main constituent of volatile oil in control treatment was 1،2–benzendicarboxylic acid، bis (2-methyl propyl) (29. 02%) which decreased with increasing salinity. In salinity treatments، the isothiocyanates compounds such as isobutylisothiocyanate and 2-isothiocyanatepropan were increased. In control level of salinity، the main compound of root volatile oil was thiocyanic acid phenylmethyl ester (29. 6%) but was not found in the salinity treatment. The content of isothiocyanates in the shoot increased with increasing salinity up to 4dS/m. The level of salinity had significant effect on volatile oil content and component of M. peregrina.