Phytochemical and biological activities of some Iranian medicinal plants

Adaptive evolution of Salmonella Typhimurium LT2 exposed to carvacrol lacks a uniform pattern

Emergence of genetic variants with increased resistance/tolerance to natural antimicrobials, such as essential oils, has been previously evidenced; however, it is unknown whether mutagenesis follows a general or a specific pattern. For this purpose, we carried out four adaptive laboratory evolutions (ALE) in parallel of Salmonella enterica Typhimurium with carvacrol. After 10 evolution steps, we selected and characterized one colony from each lineage (SeCarA, SeCarB, SeCarC, and SeCarD). Phenotypic characterization of the four evolved strains revealed enhanced survival to lethal treatments; two of them (SeCarA and SeCarB) showed an increase of minimum inhibitory concentration of carvacrol and a better growth fitness in the presence of carvacrol compared to wild-type strain. Whole genome sequencing revealed 10 mutations, of which four (rrsH, sseG, wbaV, and flhA) were present in more than one strain, whereas six (nirC, fliH, lon, rob, upstream yfhP, and upstream argR) were unique to individual strains. Single-mutation genetic constructs in SeWT confirmed lon and rob as responsible for the increased resistance to carvacrol as well as to antibiotics (ampicillin, ciprofloxacin, chloramphenicol, nalidixic acid, rifampicin, tetracycline, and trimethoprim). wbaV played an important role in increased tolerance against carvacrol and chloramphenicol, and flhA in cross-tolerance to heat treatments. As a conclusion, no common phenotypical or genotypical pattern was observed in the isolated resistant variants of Salmonella Typhimurium emerged under carvacrol stress. Furthermore, the demonstration of cross-resistance against heat and antibiotics exhibited by resistant variants raises concerns regarding food safety. KEY POINTS: • Stable resistant variants of Salmonella Typhimurium emerged under carvacrol stress • No common pattern of mutagenesis after cyclic exposures to carvacrol was observed • Resistant variants to carvacrol showed cross-resistance to heat and to antibiotics.

Natural Polymers as Carriers for Encapsulation of Volatile Oils: Applications and Perspectives in Food Products

The technique of encapsulating different materials into matrices that can both protect and release their contents under specific circumstances is known as encapsulation. It serves the primary function of shielding delicate components from outside influences, including heat, light, and humidity. This can be accomplished by a variety of procedures that, depending on the method and materials selected, result in the creation of particles with various structures. The materials used for encapsulation in food applications must be of high quality, acceptable for human consumption, and stable during processing and storage. The most suitable natural polymers for food applications are carbohydrates, proteins, or mixtures thereof. Volatile oils are end products of plant metabolism, accumulated and stored in various plant organs, cells, or secretory tissues. These are natural and are characterized by the scent of the aromatic plants they come from. Because of their antibacterial and antioxidant qualities, they are being utilized more and more in the food and pharmaceutical industries. Since volatile oils are highly sensitive to environmental changes, they must be stored under specific conditions after being extracted from a variety of plant sources. A promising method for increasing the applicability of volatile oils is their encapsulation into colloidal particles by natural polymers such as carbohydrates and proteins. Encapsulation hides the unfavorable taste of nutrients while shielding delicate dietary ingredients from the effects of heat, moisture, oxygen, and pH. This technique results in improved stability for volatile oils that are often sensitive to environmental factors and offers the possibility of using them in an aqueous system even if they are insoluble in water. This paper aims to provide an overview of the current advances in volatile oil encapsulation technologies and presents a variety of natural polymers used in the food industry for encapsulation. Also, a distinct section is created to highlight the current advances in dairy products enriched with encapsulated volatile oils.

Effect of Silica Xerogel Functionalization on Intensification of Rindera graeca Transgenic Roots Proliferation and Boosting Naphthoquinone Production

Secondary metabolites derived from plants are recognized as valuable products with several successful applications in the pharmaceutical, cosmetic, and food industries. The major limitation to the broader implementation of these compounds is their low manufacturing efficiency. Current efforts to overcome unprofitability depend mainly on biotechnological methods, especially through the application of plant in vitro cultures. This concept allows unprecedented bioengineering opportunities for culture system modifications with in situ product removal. The silica-based xerogels can be used as a novel, porous biomaterial characterized by a large surface area and high affinity to lipophilic secondary metabolites produced by plant tissue. This study aimed to investigate the influence of xerogel-based biomaterials functionalized with methyl, hydroxyl, carboxylic, and amine groups on Rindera graeca transgenic root growth and the production of naphthoquinone derivatives. The application of xerogel-based scaffolds functionalized with the methyl group resulted in more than 1.5 times higher biomass proliferation than for reference untreated culture. The naphthoquinone derivatives' production was noted exclusively in culture systems supplemented with xerogel functionalized with methyl and hydroxyl groups. Applying chemically functionalized xerogels as in situ adsorbents allowed for the enhanced growth and productivity of in vitro cultured R. graeca transgenic roots, facilitating product isolation due to their selective and efficient accumulation.

Effects of Chaerophyllum macropodum Boiss. leaves essential oil in inflammatory and neuropathic pain: uncovering the possible mechanism of action

BACKGROUND

Chaerophyllum macropodum Boiss. (popularly known as "Jafari farangi kohestani") is a predominant medicinal plant traditionally utilized in the treatments of peritoneal inflammation and headache in Persian folk medicine. Here, we have revealed the anti-neuropathic and anti-nociceptive activities of C. macropodum leaves essential oil (CMEO) in addition to uncovering the possible mechanisms of action.

METHODS

Formalin-induced paw licking model was used to assess the anti-nociceptive activity of CMEO and its major constituent, terpinolene (TP). The anti-nociceptive activity of these compounds was determined by investigating the roles of various non-opioid and NO-cGMP-K+ channels. Additionally, the anti-neuropathic potential of CMEO and TP was determined using cervical spinal cord contusion/CCS technique.

RESULTS

The CMEO exerted significant anti-nociceptive activity with a remarkable activity seen in the second phase of formalin-induced paw licking model and this activity were remarkably reversed by pre-treatment of naloxone (an opioid antagonist). Pretreatment with several types of NO-cGMP-potassium channel pathway meaningfully reversed the anti-nociceptive potential of CMEO in phase II of formalin model. Moreover, pre-treatment with several antagonists of non-opioid receptors revealed that only the antagonist of TRPV-1, serotonin type 3, 5-HT2, α2 adrenergic, and CB1 receptors (capsaicin, ondansetron, ketanserin, yohimbine, and SR141716A, respectively) reversed CMEO anti-nociception. CMEO and TP also remarkably reversed hyperalgesia and mechanical allodynia in the CCS technique.

CONCLUSION

The CMEO exerts anti-nociceptive and anti-neuropathic activities via the modulation of NO-cGMP potassium channel pathway, opioid as well as several non-opioid receptor activity. TP might partly contribute to the observed activities of CMEO.

Study of the Chemical Composition of Rosa beggeriana Schrenk's Fruits and Leaves

Rosa species are widely used in folk medicine in different countries of Asia and Europe, but not all species are studied in-depth. For instance, Rosa beggeriana Schrenk, a plant which grows in Central Asia, Iran, and some parts of China, is little described in articles. Column and thin-layer chromatography methods were used to isolate biologically active substances. From a study of fruits and leaves of Rosa beggeriana Schrenk, a large number of compounds were identified, seven of which were isolated: 3β,23-dihydroxyurs-12-ene (1), β-sitosterol (2), betulin (3), (+)-catechin (4), lupeol (5), ethyl linoleate (6), and ethyl linolenoate (7). Their structures were elucidated by 1H, DEPT and 13C NMR spectroscopy, mass spectrometry, and GC-MS (gas chromatography-mass spectrometry). The study also identified the structures of organic compounds, including volatile esters and acids. Consequently, comprehensive data were acquired concerning the chemical constitution of said botanical specimen.

A new anti-neuroinflammation labdane diterpenoid from Salvia tricuspis

One new labdane diterpenoid, tricuspion A (1), as well as five known triterpenoids (2-6) were isolated from Salvia tricuspis Franch (family Labiatae). The structure of tricuspion A was identified by extensive spectroscopic analysis and by comparison with previously reported data. Compounds 1-6 were evaluated for their inhibitory effects on the NO production in LPS-stimulated BV-2 microglia cells, and 1 exhibited potent inhibitory activity with IC50 value of 14.92 ± 0.51 μM. Compound 1 might exert anti-neuroinflammatory activity through inhibiting the excessive production of NO and down-regulating the protein expression of iNOS and COX-2. As such, labdane diterpenoid (tricuspion A) could provide promising anti-neuroinflammatory lead compound for further structural modification.

Citronellal Attenuates Oxidative Stress-Induced Mitochondrial Damage through TRPM2/NHE1 Pathway and Effectively Inhibits Endothelial Dysfunction in Type 2 Diabetes Mellitus

In type 2 diabetes mellitus (T2DM), oxidative stress induces endothelial dysfunction (ED), which is closely related to the formation of atherosclerosis. However, there are few effective drugs to prevent and cure it. Citronellal (CT) is an aromatic active substance extracted from citronella plants. Recently, CT has been shown to prevent ED, but the underlying mechanism remains unclear. The purpose of this study was to investigate whether CT ameliorated T2DM-induced ED by inhibiting the TRPM2/NHE1 signal pathway. Transient receptor potential channel M2 (TRPM2) is a Ca²⁺-permeable cation channel activated by oxidative stress, which damages endothelial cell barrier function and further leads to ED or atherosclerosis in T2DM. The Na⁺/H⁺ exchanger 1 (NHE1), a transmembrane protein, also plays an important role in ED. Whether TRPM2 and NHE1 are involved in the mechanism of CT improving ED in T2DM still needs further study. Through the evaluations of ophthalmoscope, HE and Oil red staining, vascular function, oxidative stress level, and mitochondrial membrane potential evaluation, we observed that CT not only reduced the formation of lipid deposition but also inhibited ED and suppressed oxidative stress-induced mitochondrial damage in vasculature of T2DM rats. The expressions of NHE1 and TRPM2 was up-regulated in the carotid vessels of T2DM rats; NHE1 expression was also upregulated in endothelial cells with overexpression of TRPM2, but CT reversed the up-regulation of NHE1 in vivo and in vitro. In contrast, CT had no inhibitory effect on the expression of NHE1 in TRPM2 knockout mice. Our study show that CT suppressed the expression of NHE1 and TPRM2, alleviated oxidative stress-induced mitochondrial damage, and imposed a protective effect on ED in T2DM rats.