Methanol Extract of Dicranopteris linearis Leaves Attenuate Pain via the Modulation of Opioid/NO-Mediated Pathway

Alpha-Glucosidase and Nitric Oxide Inhibitors from Paramignya trimera Leaves and Dicranopteris linearis Spores: In Silico and In Vitro Aspects

Dicranopteris linearis and Paramignya trimera, widely utilized plants in traditional Vietnamese medicine, lack comprehensive chemical and biological data pertaining to their composition. The crude extracts of these biosources showed remarkable alpha-glucosidase and nitric oxide (NO) inhibition. Bioguided isolation based on alpha-glucosidase inhibition and anti-inflammatory activity was applied to P. trimera and D. linearis, providing 14 metabolites. Upon evaluating the alpha-glucosidase activity of compounds 1-14, it was observed that all tested compounds exhibited significant activity, with IC50 values ranging from 22.5 to 157.7 µM. Notably, compound 14 was identified as a new compound. Compounds 6-8 exhibited potent NO inhibitory effect in LPS-induced RAW264.7 macrophage cells, with IC50 values ranging from 26.65 to 28.79 µg/mL.

Endogenous opiates and behavior: 2020

This paper is the forty-third consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2020 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Antinociceptive Synergism of Pomegranate Peel Extract and Acetylsalicylic Acid in an Animal Pain Model

Several modern drugs, which are derived from traditional herbal medicine are used in contemporary pharmacotherapy. Currently, the study of drug-plant interactions in pain has increased in recent years, looking for greater efficacy of the drug and reduce side effects. The antinociception induced by intragastric co-administration of the combination of pomegranate peel extract (PoPEx) and acetylsalicylic acid (ASA) was assessed using the isobolographic analysis in formalin test (nociceptive and inflammatory pain). The effective dose that produced 30% of antinociception (ED30) was calculated for both drugs from the logarithmic dose-response curves, subsequently generating a curve with the combination on fixed proportions (1:1) of PoPEx and ASA. Through isobolographic analysis, this experimental ED30 was compared with the calculated theoretical additive ED30. The result was a synergistic interaction, the experimental ED30 was significantly smaller (p < 0.05) than the theoretical ED30. The antinociceptive mechanism of the PoPEx-ASA combination involves the l-Arginine/NO/cGMP pathway, antioxidant capacity, and high content of total phenols. These findings suggest that an interaction between PoPEx and ASA could be a novel treatment for inflammatory and nociceptive pain, also diminish the secondary reactions of ASA.

Hepatoprotective and antioxidant activities of Dicranopteris linearis leaf extract against paracetamol-induced liver intoxication in rats

Context: Dicranopteris linearis L. (Gleicheniaceae) leaves have been reported to exert hepatoprotective activity.Objective: The hepatoprotective and antioxidant effects of ethyl acetate partition of D. linearis (EADL) are investigated.Materials and methods: EADL was subjected to antioxidant and anti-inflammatory studies, and phytochemical analyses. In vivo study involved six groups (n = 6) of overnight fasted Sprague Dawley rats. The test solutions [10% DMSO (normal), 10% DMSO (negative), 200 mg/kg silymarin (positive) or EADL (50, 250 or 500 mg/kg)] were administered orally once daily for 7 consecutive days followed by oral vehicle (only for normal) or hepatotoxic induction using 3 g/kg paracetamol (PCM).Results: EADL exerted ≈ 90% radical scavenging effects based on the DPPH and superoxide anion radical scavenging assays, high antioxidant capacity in the oxygen radical absorbance capacity assay (≈ 555,000 units), high total phenolic content (≈ 350 mg GAE/100 g extract) (p < 0.05), but low anti-inflammatory effect. EADL also attenuated PCM-induced liver intoxication as indicated by reduced level of serum liver enzymes; increased activity of endogenous enzymatic antioxidant (superoxide dismutase - 8.3 vs. 4.0 U/g tissue; catalase - 119 vs. 52 U/g tissue) and; reduced level of lipid peroxidation marker (2.7 vs. 5.0 µM). Preliminary screening of EADL revealed the presence of saponins, tannins and flavonoids with further HPLC analysis demonstrating the presence of rutin and quercetin.Discussion and conclusion: EADL exerted hepatoprotective and antioxidant activities; thus, these data support the potential use of D. linearis as a new source for future hepatoprotective drug development.