ANTI-NOCICEPTIVE EFFECT OF AGRIMONIA EUPATORIA EXTRACT ON A CISPLATIN-INDUCED NEUROPATHIC MODEL

Background: Natural products including Agrimonia eupatoria are considered an incomparable source of molecular diversity that has led to the medicines, especially for pain treatment. To investigate the antinociception of Agrimonia eupatoria, we examined its activity in a rat model of cisplatin neuropathy. Materials and Methods: Male Sprague-Dawley rats received intraperitoneal (i.p.) cisplatin twice a week at a dose of 2 mg/kg (cumulative dose, 20 mg/kg) for 4 weeks. Before each injection, 2 ml of sterile saline solution was given subcutaneously to prevent renal damage via hyperhydration. The mice were treated with gabapetin as a positive control drug with a 100mg/kg intraperitoneal injection. A. eupatoria extract of 200mg/kg was solved in saline and then treated by oral administration. Results: The mice treated with A. eupatoria showed lower withdrawal duration in the pin-prick and plantar tests, and a higher withdrawal threshold in the paw-withdrawal threshold test as compared to control animals in a cisplatin-induced neuropathic model. In the case of cold-allodynia, A. eupatoria treatment increased paw-withdrawal duration in a chemical test. A. eupatoria showed a more outstanding effect than gabapentin in all used tests for preventing cisplatin-induced nerve injury for 4 weeks. Conclusions: Our results suggest that A. eupatoria extract showed an antinociceptive effect in the pin-prick test, plantar test, and paw-withdrawal threshold test using a cisplatin-induced neuropathic rat model

In silico prediction of potential chemical reactions mediated by human enzymes

Abstract Background Administered drugs are often converted into an ineffective or activated form by enzymes in our body. Conventional in silico prediction approaches focused on therapeutically important enzymes such as CYP450. However, there are more than thousands of different cellular enzymes that potentially convert administered drug into other forms. Result We developed an in silico model to predict which of human enzymes including metabolic enzymes as well as CYP450 family can catalyze a given chemical compound. The prediction is based on the chemical and physical similarity between known enzyme substrates and a query chemical compound. Our in silico model was developed using multiple linear regression and the model showed high performance (AUC = 0.896) despite of the large number of enzymes. When evaluated on a test dataset, it also showed significantly high performance (AUC = 0.746). Interestingly, evaluation with literature data showed that our model can be used to predict not only enzymatic reactions but also drug conversion and enzyme inhibition. Conclusion Our model was able to predict enzymatic reactions of a query molecule with a high accuracy. This may foster to discover new metabolic routes and to accelerate the computational development of drug candidates by enabling the prediction of the potential conversion of administered drugs into active or inactive forms

Inhibition of complement activation by recombinant Sh-CRIT-ed1 analogues

Sh-CRIT-ed1 is a potent anti-complement peptide that inhibits the classical complement-activation pathway by interfering with the formation of the C3-convertase complex, C4b2a. C2 is an essential serum glycoprotein that provides the catalytic subunit of the C3 and C5 convertases of the classical pathways of complement activation. Because only in its C4-bound state is C2a capable of cleaving its physiological protein substrates C3 and C5, the interaction of Sh-CRIT-ed1 with C2 plays a decisive role of inhibition in the classical complement-activation process. However, the role of individual Sh-CRIT-ed1 amino acid residues in C2 binding is not fully understood. We constructed nine recombinant Sh-CRIT-ed1 (rSh1) analogues, substituted at conserved residues, and evaluated their anti-complement and C2-binding activities. Results from glutathione S-transferase (GST) pull-down and haemolytic assays suggested that residues (10)K, (17)E, (19)K and (26)Y are critical for the interaction of rSh1 with C2. We then constructed an improved anti-complement peptide by duplicating Sh-CRIT-ed1 C-terminal motifs ((17)H–(26)Y). This linear homodimer (rH17d) was more potent than rSh1 with respect to binding to C2 and anti-complement activity (the 50% inhibitory concentration value was ≈1·2 µm versus ≈6·02 µm for rSh1). Furthermore, rH17d showed higher anti-complement activity in vivo, providing additional evidence that this duplication is a more effective inhibitor of complement activation than rSh1. Taken together, these results identify four key residues in rSh1 and strongly suggest that rH17d is a potent inhibitor of complement activation that may have therapeutic applications