Protective effects of aqueous extract of silybum marianum in 6-hydroxydopamine-induced model of parkinsonism in male rat: a behavioral, biochemic and histological study

Introduction : Parkinson,s disease (PD) is a common neurological disorder due to degeneration of substantia nigra pars compacta degeneration. With regard to protective effect of silybum marianum, this study was conducted to evaluate the protective effect of aqueous extract of this plant in an experimental model of PD . Materials and Methods: Forty male rats were randomly divided into 4 groups; sham-operated(SH), extract-treated sham-operated (E+SH), lesion (L) and extract-treated lesion(E+L) groups. The hemi-PD model was induced by unilateral intrastriatal injection of 6-hydroxydopamine (6-OHDA, 12.5 g/ l of saline-ascorbate).The E+SH and E+L groups received intra-peritoneal pretreatment of aqueous extract of silybummarianum (200mg/kg/daily) for one week before surgery. Two weeks after surgery, the animals were tested for rotational behavior by apomorphine hydrochloride and the number of nissle-stained neurons in the substantia nigra pars compacta (SNC). Results: Two weeks after surgery, apomorphine caused a significant contralateral turning (P<0.0001) and reduction in the number of neurons on the left side of the SNC in the L group in comparison with SH group (P<0.05). Administration of aqueous extract of silybum marianum decreased the rotational behavior in lesioned rats and attenuated the reduction of number of SNC neurons (P<0.05). On the other hand, treatment of SH group with extract of silybum marianum had no significant effect on the number of apomophine-induced rotation and neurons of SNC . Conclusion: Our finding shows in experimental model of PD, intra-peritoneal administration of aqueous extract of silybum marianum has protective effects against 6-OHDA toxicity

The impact of environmental and climatic variables on genetic diversity and plant functional traits of the endangered tuberous orchid (Orchis mascula L.)

Understanding how environmental factors shape patterns of genetic and phenotypic variations in a species is necessary for conservation and plant breeding. However, these factors have not yet been completely understood in tuberous orchid species used to make 'Salep', an important ingredient in traditional medicine and beverages in middle eastern countries and India. In many areas, increasing demand has pushed species to the brink of extinction. In this study, 198 genotypes from 18 populations of the endangered species Orchis mascula L. spanning a large-scale climatic gradient in northern Iran were used to investigate patterns of genetic diversity and plant functional traits. Populations were sampled from three land cover types (woodland, shrubland, and pastureland/grassland). Plant height, stem length, number of flowers, bulb fresh and dry weight, glucomannan, and starch concentrations showed high variation among populations and were significantly related to land cover type. In general, genetic diversity was high, particularly in those from eastern Hyrcanian; additionally, populations showed a high level of genetic differentiation (G'st = 0.35) with low gene flow (Nm = 0.46). The majority of genetic differentiation occurred within populations (49%) and land cover types (20%). The population structural analysis using the AFLP marker data in K = 4 showed a high geographical affinity for 198 O. mascula genotypes, with some genotypes having mixed ancestry. Temperature and precipitation were found to shape genetic and phenotypic variation profoundly. Significant isolation by the environment was observed, confirming the strong effect of environmental variables on phenotypic and genetic variation. Marker-trait association studies based on MLM1 and MLM2 models revealed significant associations of P-TGG + M-CTT-33 and E-AGG + M-CGT-22 markers with plant height and glucomannan content. Overall, a combination of large-scale climatic variables and land cover types significantly shaped genetic diversity and functional trait variation in O. mascula populations