Antioxidant and cytoprotective properties of loganic acid isolated from seeds of Strychnos potatorum L. against heavy metal induced toxicity in PBMC model

A simple and sensitive LC-MS/MS method for the determination of loganic acid in rat plasma and its pharmacokinetic analysis

Loganic acid is an iridoid compound extracted from Gentianaceae plant Gentiana macrophylla Pall. It can effectively inhibit inflammation and tumor migration and has antioxidant activity. In this paper, we establish a simple, fast, sensitive and validated LC-MS method with the purpose of quantification of loganic acid in rat plasma with gliclazide as an internal standard (IS). Methanol was used to precipitate the protein in the plasma sample, and a C18 column (2.1 × 50 mm, 1.7 μm) was used for the separation of the target compound. Meanwhile, 0.1% formic acid water-methanol was employed as the mobile phase. Multiple reaction monitoring detection mode was adopted in detection with m/z 375.1 > 213.2 for loganic acid and m/z 322.1 > 169.9 for the IS, respectively, in negative ion scan mode. The linear range of calibration curve was 5.77-11,540.00 ng/ml, and the lower limit of detedtion was 2.89 ng/ml. The inter-day and intra-day precision and accuracy were <15% for lower limit of quantitation, low, middle and high quality control samples. This method was successfully used for the pharmacokinetic study of loganic acid in rat plasma at a dose range of 50-150 mg/kg for oral administration and 2 mg/kg for intravenous administration. The pharmacokinetic results showed that the oral bioavailability of loganic acid was low (2.71-5.58%).

Comparative polyphenolic profiling of five ethnomedicinal plants and their applicative potential in the treatment of type 2 diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

The medicinal plants Salvia officinalis, Trifolium pratense, Agrimonia eupatoria, Cichorium intybus and Vinca minor are traditionally used for the prevention and treatment of numerous diseases, including diabetes.

AIM OF THE STUDY

Type 2 diabetes (T2D) is one of the most common diseases nowadays, often accompanied by oxidative stress and microbial infections. The aim of our work was to examine the antidiabetic, antioxidant, and antimicrobial properties of ethanol extracts of five medicinal plants for the purpose of their possible use in the treatment of T2D.

MATERIALS AND METHODS

The polyphenolic profile of the plant extracts was analyzed by Ultra-High Performance Liquid Chromatography with a diode array detector configured with a triple quadrupole mass spectrometer (UHPLC/DAD/(-)HESI-MS2). In vitro antidiabetic activity of extracts was determined by measuring the percentage of α-amylase and α-glucosidase inhibition. The antioxidant activity of the extract was determined by different spectrophotometric methods, while the antimicrobial activity was determined by agar dilution and disc diffusion methods.

RESULTS

A. eupatoria extract contains the highest percentage of flavonoids (94%, with isoquercetin, vitexin, and rutin as the most abundant) in relation to the concentration of total phenolic compounds and exhibits excellent antidiabetic, antioxidant, and antimicrobial activity. S. officinalis extract contains 60% flavonoids (predominately cirsimaritin and epigallocatechin gallate) and 40% phenolic acids (with rosmarinic acid being the most abundant from this group) and exhibits weak antidiabetic activity, significant antioxidant activity, and excellent antibacterial activity. A 45% percentage of flavonoids (with isoquercetin as the most abundant one) and 55% of phenolic acids (with ferulic acid as the most abundant) were measured in the extract of T. pratense, which had excellent antidiabetic activity but weaker antioxidant and antimicrobial activity. A similar percentage of flavonoids (52%, with epigallocatechin gallate in the highest concentration) and phenolic acids (48%, with chlorogenic acid as the most abundant) was measured in the extract of C. intybus which showed moderate antidiabetic, antioxidant, and antimicrobial properties. The extract of V. minor was the richest in phenolic acids (80%, with the most abundant chlorogenic acid), which resulted in weaker antidiabetic and antioxidant activities (except for Fe2+ chelating ability) and antimicrobial activity.

CONCLUSION

The results indicate that specific phenolic compounds are responsible for the different biological activities of the plant extracts. Among the investigated plants, the extract of A. eupatoria has the greatest potential for applications in the treatment of T2D.

In Vitro and In Vivo Anti-Psoriasis Activity of Ficus carica Fruit Extracts via JAK-STAT Modulation

Psoriasis, a chronic and autoimmune inflammatory disorder of the skin, has been often underdiagnosed and underestimated despite its prevalence and considerable negative effects on the quality of life. In this study, the anti-inflammatory activity of Ficus carica fruit extract (FFE) was investigated against LPS-stimulated RAW 264.7 cells. The in vitro results showed that FFE reduced the production of nitric oxide (NO) and iNOS expression. Moreover, FFE reduced the level of β-hexosaminidase released with histamine in allergic reactions. However, the MAPK and NFκB signaling molecules associated with the inflammatory response were not significantly regulated by FFE. In contrast, the phosphorylation of JAK1 and STAT3 in the JAK-STAT signaling pathway was dramatically reduced by FFE treatment. Psoriasis-like skin lesions were induced in BALB/c mice using imiquimod (IMQ) to test the feasibility of FFE as a treatment for psoriasis. The efficacy of FFE was evaluated based on phenotypic and histological features. FFE was effective in relieving the symptoms of psoriasis-like skin lesions, such as erythema, dryness, scales, and thick epidermis. Notably, STAT3 modulation was also contributable to the in vivo ameliorative activity of FFE. Taken together, FFE with anti-psoriasis activity in vitro and in vivo through the JAK-STAT modulation could be developed as a therapeutic agent against psoriasis.

Loganic acid regulates the transition between epithelial and mesenchymal-like phenotypes by alleviating MnSOD expression in hepatocellular carcinoma cells

AIMS

Cancer metastasis is the major cause of cancer-related deaths. There are few prior studies reported on molecules targeting C-X-C chemokine receptor (CXCR) family and manganese superoxide dismutase (MnSOD). CXCRs are known to involve in angiogenesis, metastasis, cell survival and MnSOD is reported to be related in Epithelial-mesenchymal transition (EMT).

MAIN METHODS

Cell viability and cell proliferation were measured by MTT and BrdU assay. Protein expression level of CXCR4/7, MMP-2/9, MnSOD, and EMT markers were evaluated by Western blot analysis. mRNA levels of Snail and Occludin were analyzed by Real-time RT-qPCR. Expression of EMT markers in cells was observed by immunocytochemistry. Cell invasion and migrations were evaluated by wound healing assay and boyden chamber assay.

KEY FINDINGS

We noticed that LGA abolished proliferation, invasive ability, and cellular migration. LGA down-regulated the protein levels of mesenchymal markers such as Twist, Snail, Fibronectin, and Vimentin in CXCL12-treated HCC cells. It also suppressed the gelatinolytic activity of MMP-9/2. The amplification of MnSOD increased EMT-like phenotypes but with LGA treatment, these phenotypes were markedly attenuated. The overexpression of MnSOD increased the ROS levels significantly but ROS levels were decreased upon exposure to LGA and deletion of MnSOD suppressed the levels of various mesenchymal proteins.

SIGNIFICANCE

LGA could function as a novel anti-metastatic agent by suppressing metastasis and EMT process via attenuation of MnSOD expression in hepatocellular carcinoma cells.

Biological Activity of Extracts of Red and Yellow Fruits of Cornus mas L.-An In Vitro Evaluation of Antioxidant Activity, Inhibitory Activity against α-Glucosidase, Acetylcholinesterase, and Binding Capacity to Human Serum Albumin

Although extracts are broadly used in order to support the treatment of numerous diseases, only in a limited number of cases is the process of applying and establishing their mechanisms of action scientifically analyzed. Fruits of Cornelian cherry are an abundant source of iridoids, anthocyanins, flavonols and phenolic acids. The aim of the present study was to evaluate the in vitro bioactivity of red and yellow Cornelian cherry fruits’ extracts. The biological potential of extracts, in a broad sense, involved antioxidant activity in relation to phosphatidylcholine liposomes, inhibitory ability against α-glucosidase and acetylcholinesterase enzymes, as well as interactions with human serum albumin. Studies showed that both extracts were more effective in protecting liposome membranes against free radicals produced by AAPH in an aqueous environment due to the fact that they can be better eliminated by the hydrophilic components of the extracts than those produced by UVB radiation. Extracts exhibited inhibitory activity against acetylcholinesterase and α-glucosidase, wherein loganic acid extract showed noncompetitive inhibition of the enzyme. Moreover, extracts binded to albumin mainly through hydrogen bonds and van der Waals forces. Taken together, red and yellow cherry fruits’ extracts exhibit diverse biological properties and can be exploited as a source of natural therapeutic agents.

Loganic Acid, an Iridoid Glycoside Extracted from Cornus mas L. Fruits, Reduces of Carbonyl/Oxidative Stress Biomarkers in Plasma and Restores Antioxidant Balance in Leukocytes of Rats with Streptozotocin-Induced Diabetes Mellitus

The various complications related to diabetes are due to the alteration in plasma components and functional activity of blood cells, hence the search for preventive remedies that would ameliorate the clinical condition of patients is a relevant problem today. The main aim of the present study was to examine the antidiabetic potency and antioxidant effects of loganic acid (LA) in blood of diabetic rats. LA showed a restoration of balance between functioning of antioxidant defense system and oxidative stress in leukocytes without notable effects on blood glucose levels when administered orally to rats (20 mg/kg b.w./day) for 14 days. LA ameliorated antioxidant status in leukocytes, as indicated by increasing the content of reduced glutathione and activities of catalase, glutathione peroxidase and glutathione reductase along with decreasing levels of intracellular reactive oxygen species. In addition, we observed the ability of LA to protect against formation and accumulation of glycation and oxidation protein products and malondialdehyde derivates in plasma. Therefore, LA showed antioxidant properties that may have beneficial effects under diabetes. Such results may represent LA as one of the plant components in the development of new drugs that will correct metabolic and functional disorders in leukocytes under diabetes.