Both Chuanxiong (Ligusticum chuanxiong Hort) and Tianma (Gastrodia elata Blume) have the effects of vasorelaxation and antihypertension. However, the effects of Tianshu Capsule (TSC, composed of Chuanxiong and Tianma in the mass ratio of 4:1) on antihypertensive activity have not been explored. This study aimed to investigate the eff ;ects of TSC on vascular tension and blood pressure in rats and to explore the underlying mechanisms. The vasorelaxant effect of TSC was explored on thoracic aortic rings (both intact endothelium and denuded) preincubated with phenylephrine (Phe) or potassium chloride (KCL). The mechanism was investigated in the presence of antagonists or blockers on aorta isolated from normotensive rats. The in vivo antihypertensive effect was assessed using a tail-cuff method on spontaneously hypertensive rats (SHRs). TSC (0.125-4 mg/mL) produced a concentration-dependent vasorelaxation on aortic rings preincubated with Phe (1 μM) or KCL (60 mM). Removal of aorta endothelium markedly attenuated the TSC activity. Pretreatment of aortic rings with β-adrenoceptor blocker propranolol (1 μM), muscarinic receptor antagonist atropine (1 μM), cyclooxygenase inhibitor indomethacin (IDO, 1 μM), adenylyl cyclase inhibitor 9-(tetrahydro-2-furanyl)-9H-purine-6-amine (SQ22536, 100 μM), K+ channel blockers 4-aminopyridine(4-AP, 1 mM) or barium chloride(BaCl2, 1 mM) followed by addition of Phe (1 μM) prior to TSC did not influence the TSC-induced relaxation. In contrast, the vasorelaxant effects of TSC were markedly inhibited by the NO synthase inhibitor L-NG-nitroarginine methyl ester (L-NAME, 10 μM), guanylyl cyclase inhibitor 1H- [1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ, 10 μM), K+ channel blockers, glibenclamide (100 μM) and clotrimazole (5 mM). Moreover, TSC (2 mg/mL, 4 mg/mL) inhibited CaCl2-induced contractions and caused a concentration-dependent rightward shift of the response curves. Additionally, TSC (2 mg/mL, 4 mg/mL) depressed the constriction caused by Phe (1 μM) in the absence of extracellular Ca2+. Furthermore, TSC (2.15 g/kg) lowered the systolic blood pressure (SBP), with no alteration in heart rate (HR) in SHRs. These findings demonstrated that TSC induced vasorelaxant effects via both endothelium-dependent and endothelium-independent pathways. The NO/sGC/cGMP pathway, ATP-sensitive K+ channels, Ca2+-activated K+ channels, inhibition of extracellular Ca2+ influx and intracellular Ca2+ release were probably involved in this relaxation. The vasorelaxant effects of TSC may make the greatest contribution to the reduction in high blood pressure.

Migraine is a major cause of disability worldwide, particularly in young adults and middle-aged women. Xiongshao Zhitong Recipe (XZR) is a traditional Chinese medicine prescription used for treating migraine, but its bioactive components and therapeutic mechanisms remain unclear. We aimed to confirm the therapeutic effect of XZR on migraine and to determine the possible mechanism and bioactive components of XZR. Here, a sensitive UHPLC-LTQ-Orbitrap MS assay was carried out to analyze the ingredients of XZR, and a total of 62 components were identified, including coumarins, phenolic acids, phthalides, flavonoids, and terpenoids; among them, 15 components were identified in the serum samples after XZR treatment. We established a rat model of migraine via nitroglycerin (NTG) injection. The in vivo experiments demonstrated that XZR attenuated allodynia and photophobia in rats with NTG-induced migraine, and XZR also demonstrated analgesic effects. XZR reversed the abnormal levels of nitric oxide, 5-hydroxytryptamine (5-HT), calcitonin gene-related peptide (CGRP), and substance P (SP) to normal levels. XZR also downregulated inflammatory reactions, including mast cell degranulation and serum IL-1β, IL-6, and TNF-α levels. In terms of mechanism, we revealed that XZR treated NTG-induced migraine through the inhibition of neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) expression in both the trigeminal nucleus caudalis (TNC) and periaqueductal gray matter (PAG), as well as the total NOS enzyme activity, which regulated the NF-κB signaling pathway. Additionally, imperatorin and xanthotoxin, two major ingredients of XZR, showed a high binding affinity to nNOS (Gly468-Leu616). In vitro, XZR, imperatorin, and xanthotoxin inhibited the nNOS expression and the NF-κB signaling pathway in lipopolysaccharide (LPS)-stimulated PC12 cells. In conclusion, we demonstrated the therapeutic effects of XZR and provided evidence that XZR played a critical anti-inflammatory role by suppressing NOS and NF-κB signaling pathway activation. Imperatorin and xanthotoxin were potential bioactive components of XZR. The findings from this study supported that XZR was a candidate herbal drug for migraine therapy.

Ischemic stroke (IS) elicits intertwined metabolic derangements and neuroinflammatory responses that propagate pathogenic cascades. Rhubarb (RR) is widely applied to treat IS in the clinic. However, its underlying pharmacological mechanisms remain incompletely elucidated. To dissect the mechanism and pharmacological basis of RR's ability to ameliorate IS from the side of modulating tryptophan-kynurenine (TRP-KYN) metabolism and neuroinflammation. An embolic middle cerebral artery occlusion (MCAO) model was employed in rats to simulate human IS. Neurological deficit scores, hematoxylin-eosin, 2,3,5-triphenyltetrazolium chloride, alcian blue-periodic acid-Schiff staining, Western blotting, targeted metabolomics, immunofluorescence, and enzyme-linked immunosorbent assay were utilized to evaluate the efficacy of RR against cerebral ischemic injury, gut permeability, TRP-KYN metabolism levels, and neuroinflammation. Surface plasmon resonance and cell-based assays were further utilized to screen and validate potential bioactive ingredients of RR for the treatment of IS. In addition to mitigating cerebral ischemic damage, RR treatment substantially restored intestinal barrier function in IS rats by reducing leaky gut biomarkers, ameliorating histopathological alterations, and upregulating colonic tight junction proteins. Moreover, RR modulated TRP-KYN metabolism, concomitant with regulated expression and enzymatic activity of indoleamine 2,3-dioxygenase 1 (IDO-1) and the triggering receptor expressed on myeloid cells-1 (TREM-1) levels in both colon tissue and serum. Within the central nervous system, RR attenuated neuroinflammation triggered by MCAO through orchestrating microglial polarization and cytokine levels, accompanied by suppression of the TREM-1-mediated inflammatory signaling cascade. Chrysophanol 8-O-β-d-glucoside, rutinum, lindleyin, and (-)-catechin gallate from RR were identified as potential IDO-1 inhibitors, while rhein, lindleyin, methyl gallate, and chrysophanol 8-O-β-d-glucoside were identified as potential TREM-1 inhibitors, capable of attenuating the overexpression of IDO-1 and TREM-1 or TREM-1 and NOD-like receptor protein 3 (NLRP3). This study demonstrates that RR exerts therapeutic effects in IS by improving the intestinal barrier function, reprogramming the IDO-1-dependent TRP-KYN pathway, and attenuating neuroinflammation. These effects are attributed to its bioactive components, including rutinum, chrysophanol 8-O-β-d-glucoside, lindleyin, (-)-catechin gallate, rhein, and methyl gallate.