Natural product HTP screening for attenuation of cytokine-induced neutrophil chemo attractants (CINCs) and NO2− in LPS/IFNγ activated glioma cells

Chronic and acute central nervous system (CNS) inflammation are contributors toward neurological injury associated with head trauma, stroke, infection, Parkinsons or Alzheimers disease. CNS inflammatory illnesses can also contribute toward risk of developing glioblastoma multiforme (GBM). With growing public interest in complementary and alternative medicines (CAMs), we conduct a high throughput (HTP) screening of >1400 natural herbs, plants and over the counter (OTC) products for anti-inflammatory effects on lipopolysaccharide (LPS)/interferon gamma (IFNγ) activated C6 glioma cells. Validation studies were performed showing a pro-inflammatory profile of [LPS 3 µg/ml/ IFNγ 3 ng/ml] consistent with greater release [>8.5 fold] of MCP-1, NO2−, cytokine-induced neutrophil chemo-attractants (CINC) 1, CINC 2a and CINC3. The data show no changes to the following, IL-13, TNF-a, fracktaline, leptin, LIX, GM-CSF, ICAM1, L-Selectin, activin A, agrin, IL-1α, MIP-3a, B72/CD86, NGF, IL-1b, MMP-8, IL-1 R6, PDGF-AA, IL-2, IL-4, prolactin R, RAGE, IL-6, Thymus Chemokine-1, CNTF,IL-10 or TIMP-1. A HTP screening was conducted, where we employ an in vitro efficacy index (iEI) defined as the ratio of toxicity (LC50)/anti-inflammatory potency (IC50). The iEI was precautionary to ensure biological effects were occurring in fully viable cells (ratio > 3.8) independent of toxicity. Using NO2− as a guideline molecule, the data show that 1.77% (25 of 1410 tested) had anti-inflammatory effects with iEI ratios >3.8 and IC50s 1750.0μg/ml, and the compound with the greatest iEI was quercetin where the IC50/LC50 was 10.0/>363.6μg/ml. These substances also downregulate the production of iNOS expression and attenuate CINC-3 release. In summary, this HTP screening provides guideline informatio