Crocins for Ischemic Stroke: A Review of Current Evidence.

Crocins (CRs) and the related active constituents derived from Crocus sativus L. (Saffron) have demonstrated protective effects against cerebral ischemia and ischemic stroke, with various bioactivities including neuroprotection, anti-neuroinflammation, antioxidant, and cardiovascular protection. Among CRs, crocin (CR) has been shown to act on multiple mechanisms and signaling pathways involved in ischemic stroke, including mitochondrial apoptosis, nuclear factor kappa light chain enhancer of B cells pathway, S100 calcium-binding protein B, interleukin-6 and vascular endothelial growth factor-A. CR is generally safe and well-tolerated. Pharmacokinetic studies indicate that CR has poor bioavailability and needs to convert to crocetin (CC) in order to cross the blood-brain barrier. Clinical studies have shown the efficacy of saffron and CR in treating various conditions, including metabolic syndrome, depression, Alzheimer's disease, and coronary artery disease. There is evidence supporting CR as a treatment for ischemic stroke, although further studies are needed to confirm their efficacy and safety in clinical settings.

Inhibition of inducible nitric oxide production and iNOS protein expression in lipopolysaccharide-stimulated rat aorta and Raw 264.7 macrophages by ethanol extract of a Chinese herbal medicine formula (RCM-101) for allergic rhinitis.

AIM OF THE STUDY: A Chinese herbal formula (RCM-101) has shown to be effective in reducing symptoms of seasonal allergic rhinitis (SAR) in a randomised, placebo-controlled clinical trial. The aim of this study is to investigate the effects of RCM-101 on the actions and synthesis of nitric oxide (NO). l-Arginine-induced endothelium-independent relaxations were studied in rat isolated aorta which was pre-treated with lipopolysaccharide (LPS). MATERIALS AND METHODS: NO production and inducible nitric oxide synthase (iNOS) protein expression were studied in LPS and interferon gamma-stimulated murine macrophages (Raw 264.7), measured by NO sensors and Western blotting. RESULTS: In rat aortic preparations, RCM-101 significantly inhibited endothelium-independent relaxations to l-arginine, but not affected those to sodium nitroprusside (SNP). In Raw 264.7 cells, RCM-101 and some of its individual ingredients (e.g., Radix glycyrrhizae, Radix bupleuri, Radix saposhnikoviae and Atractylodis rhizome macrocephalae) significantly inhibited the NO production and iNOS protein expression. CONCLUSIONS: The findings indicate that RCM-101 may inhibit inducible NO production by suppressing iNOS. In addition, its inhibitory action of iNOS is likely to be mediated by several key herbal ingredients.