Specialized Plant Metabolism Characteristics and Impact on Target Molecule Biotechnological Production

Plant secondary metabolism evolved in the context of highly organized and differentiated cells and tissues, featuring massive chemical complexity operating under tight environmental, developmental and genetic control. Biotechnological demand for natural products has been continuously increasing because of their significant value and new applications, mainly as pharmaceuticals. Aseptic production systems of plant secondary metabolites have improved considerably, constituting an attractive tool for increased, stable and large-scale supply of valuable molecules. Surprisingly, to date, only a few examples including taxol, shikonin, berberine and artemisinin have emerged as success cases of commercial production using this strategy. The present review focuses on the main characteristics of plant specialized metabolism and their implications for current strategies used to produce secondary compounds in axenic cultivation systems. The search for consonance between plant secondary metabolism unique features and various in vitro culture systems, including cell, tissue, organ, and engineered cultures, as well as heterologous expression in microbial platforms, is discussed. Data to date strongly suggest that attaining full potential of these biotechnology production strategies requires being able to take advantage of plant specialized metabolism singularities for improved target molecule yields and for bypassing inherent difficulties in its rational manipulation.     

Effects of Irrigation Regime and Foliar Application of Salicylic Acid and Spermine on the Contents of Essential Oil and Caffeic Acid Derivatives in Echinacea purpurea L.

Journal of Plant Growth Regulation - This study investigated the effect of irrigation regimes and the foliar application of salicylic acid (SA) and spermine (SPM) on the content of essential oil...     

Oxidative stress‐induced renal telomere shortening as a mechanism of cyclosporine‐induced nephrotoxicity

Due to the association of oxidative stress and telomere shortening, it was aimed in the present study to investigate the possibility whether cyclosporine‐A exerts its nephrotoxic side effects via induction of oxidative stress‐induced renal telomere shortening and senescent phenotype in renal tissues of rats. Renal oxidative stress markers, 8‐hydroxydeoxyguanosine, malondialdehyde, and protein carbonyl groups were measured by standard methods. Telomere length and telomerase activity were also evaluated in kidney tissue samples. Results showed that cyclosporine‐A treatment significantly (P < 0.05) enhanced renal malondialdehyde, 8‐hydroxydeoxyguanosine, and protein carbonyl groups levels, decreased renal telomere length, and deteriorated renal function compared with the controls. Renal telomerase activity was not affected by cyclosporine‐A. Renal telomere length could be considered as an important parameter of both oxidative stress and kidney function. Telomere shortening and accelerated kidney aging may be caused by cyclosporine‐induced oxidative stress, indicating the potential mechanism of cyclosporine‐induced nephrotoxicity.     

Monophosphoryl Lipid A and Pam3Cys Prevent the Increase in Seizure Susceptibility and Epileptogenesis in Rats Undergoing Traumatic Brain Injury

Five percent of all epilepsy cases are attributed to traumatic brain injury (TBI), which are known as post-traumatic epilepsy (PTE). Finding preventive strategies for PTE is valuable. Remarkable feature of TBI is activation of microglia and subsequent neuroinflammation, which provokes epileptogenesis. The toll-like receptor agonists monophosphoryl lipid A (MPL) and tri-palmitoyl-S-glyceryl-cysteine (Pam3Cys) are safe, well-tolerated and effective adjuvants existing in prophylactic human vaccines. We examined the impact of early injection of MPL and Pam3Cys to rats, on the rate of kindled seizures acquisition following TBI. Rats received a single dose (1 µg/rat) of MPL or Pam3Cys through intracerebroventricular injection. 5 days later, trauma was exerted to temporo-parietal cortex of rats by controlled cortical impact device. After 24 h, traumatic rats underwent amygdala kindling. Brain level of the inflammatory cytokine tumor necrosis factor-alpha (TNF-α) was also measured in traumatic rats by immunoblotting. Compared to non-traumatic (sham-operated) rats, traumatic rats showed three times lower seizure threshold (133?±?5 µA vs. 416.3?±?16 µA, p?<?0.001); about three times less number of stimuli to become kindled (5?±?1 vs. 14?±?2, p?<?0.01); longer duration of kindled seizure parameters including entire seizure behavior, generalized seizures, and afterdischarges (p?<?0.001); and a two times increase in the TNF-α level. MPL and Pam3Cys did not change kindling rate and the seizure parameters in sham-operated rats. The MPL- and Pam3Cys-pretreated traumatic rats displayed seizure threshold, speed of kindling, and duration of kindled seizure parameters, similar to the non-traumatic rats. Pretreatment by MPL and Pam3Cys prevented the increase in TNF-α level by trauma. Given that MPL and Pam3Cys currently have clinical use as well-tolerated vaccines with reliable safety, they have the potential to be used in prevention of PTE.     

Detection of adulteration in Iranian saffron samples by <Superscript>1</Superscript>H NMR spectroscopy and multivariate data analysis techniques

Introduction

The high market value of saffron (Crocus sativus L.) has made it an attractive candidate for adulteration. Safflower (Carthamus tinctorius L.) and tartrazine are among the most common herbal and synthetic foreign materials that may be added to pure saffron for the purpose of adulteration. In spite of encouraging advances achieved in the identification of adulteration in saffron samples, the lack of a simple method with sufficient power for discrimination of pure high grade saffron from meticulously adulterated saffron samples persuaded us to perform this study.

Objectives

In this work, we show that ¹H NMR spectroscopy together with chemometric multivariate data analysis methods can be used for the detection of adulteration in saffron.

Methods

Authentic Iranian saffron samples (n?=?20) and adulterated samples that were prepared by adding either different quantities of natural plant materials such as safflower, or synthetic dyes such as tartrazine or naphthol yellow to pure saffron (n?=?22) composed the training set. This training set was used to build multivariate Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA) models. The predictive power of the PLS-DA model was validated by testing the model against an external dataset (n?=?13).

Results

PCA and PLS-DA models could both discriminate between the authentic and adulterated samples, and the external validation showed 100% sensitivity and specificity for predicting the authenticity of suspicious samples. Peaks specific to authentic and adulterated samples were also characterized. Proximity of samples with unknown adulteration status to the samples adulterated with known compounds in the PCA provided insight regarding the identity of the adulterant in the suspicious samples. Furthermore, the authentic samples could be distinguished based on their cultivation site.

Conclusion

The present study demonstrates that the application of ¹H NMR spectroscopy coupled with multivariate data analysis is a suitable approach for detection of adulteration in saffron specimens. Outstanding sensitivity and specificity of the PLS-DA model in discriminating the authentic from adulterated samples in external validation confirmed the high predictive power of the model. The advantage of the present method is its power for detecting a wide spectrum of adulterants, ranging from synthetic dyes to herbal materials, in a single assay.