Intravenous ibuprofen for acute treatment of migraine: A double-blind, randomized, placebo-controlled pilot study

α7nAChR-mediated astrocytic activation: A novel mechanism of Xiongzhi Dilong decoction in ameliorating chronic migraine

ETHNOPHARMACOLOGICAL RELEVANCE

Alpha 7 nicotinic acetylcholine receptor (α7nAChR)-mediated astrocytic activation is closely related to central sensitization of chronic migraine (CM). Xiongzhi Dilong decoction (XZDL), originated from Xiongzhi Shigao decoction of Yi-zong-jin-jian, has been confirmed to relieve CM in experiment and clinic. However, its underlying mechanism for treating CM has not been elucidated.

AIM OF THE STUDY

To reveal the underlying mechanisms of XZDL to alleviate CM in vivo focusing mainly on α7nAChR-mediated astrocytic activation and central sensitization in TNC.

MATERIALS AND METHODS

CM rat model was established by subcutaneous injection of nitroglycerin (NTG) recurrently, and treated with XZDL simultaneously. Migraine-like behaviors of rats (ear redness, head scratching, and cage climbing) and pain-related reactions (mechanical hind-paw withdrawal threshold) of rats were evaluated before and after NTG injection and XZDL administration at different points in time for nine days. The immunofluorescence single and double staining were applied to detect the levels of CGRP, c-Fos, GFAP and α7nAChR in NTG-induced CM rats. ELISA kits were employed to quantify levels of TNF-α, IL-1β, and IL-6 in medulla oblongata of CM rats. The expression levels of target proteins were examined using western blotting. Finally, methyllycaconitine citrate (MLA, a specific antagonist of α7nAChR) was applied to further validate the mechanisms of XZDL in vivo.

RESULTS

XZDL significantly attenuated the pain-related behaviors of the NTG-induced CM rats, manifesting as constraints of aberrant migraine-like behaviors including elongated latency of ear redness and decreased numbers of head scratching and cage climbing, and increment of mechanical withdrawal threshold. Moreover, XZDL markedly lowered levels of CGRP and c-Fos, as well as inflammatory cytokines (IL-1β, IL-6 and TNF-α) in CM rats. Furthermore, XZDL significantly enhanced α7nAChR expression and its co-localization with GFAP, while markedly inhibited the expression of GFAP and the activation of JAK2/STAT3/NF-κB pathway in the TNC of CM rats. Finally, blocking α7nAChR with MLA reversed the effects of XZDL on astrocytic activation, central sensitization, and the pain-related behaviors in vivo.

CONCLUSION

XZDL inhibited astrocytic activation and central sensitization in NTG-induced CM rats by facilitating α7nAChR expression and suppressing JAK2/STAT3/NF-κB pathway, implying that the regulation of α7nAChR-mediated astrocytic activation represents a novel mechanism of XZDL for relieving CM.

Parenteral NSAIDs for acute treatment of migraine: Adherence to the IHS guidelines for controlled trials

Background:

Parenteral non-steroidal anti-inflammatory drugs (NSAIDs) are important alternatives to oral NSAIDs, especially in patients with severe migraine who have emesis or gastroparesis. With increasing research on using parenteral NSAIDs for acute migraine, it is critical to examine the quality of these studies. Our goal was to assess the adherence of these trials to the International Headache Society (IHS) controlled trial guidelines for acute treatment of migraine.

Methods:

We queried PubMed for clinical trials investigating parenteral NSAIDs for acute treatment of migraine in adult patients. We developed a 14-point scoring system based on the essential components of the IHS guidelines. To date, four versions of the IHS’s Guidelines for controlled trials of acute treatment of migraine attacks have been published. Each trial was evaluated with the appropriate edition of the guidelines.

Results:

We identified 216 studies and assessed 27 eligible clinical trials. The mean score was 6.7 ± 2.1 (2–11). Most trials followed the IHS migraine diagnosis criteria (85.2%), but only six (22.2%) selected patients based on the recommended headache frequency. Most trials were randomized (88.8%), but fewer were double-blinded (74.1%) or placebo-controlled (11.1%). Almost every trial clearly explained the pain scale (96.3%), and three-quarters (77.8%) assessed headache-associated symptoms. However, no trial utilized the recommended primary endpoint: pain-freedom at 2-hours.

Conclusions:

Most clinical trials on parenteral NSAIDs for acute migraine did not fully adhere to the IHS recommendations. Future studies should pay special attention to the IHS guideline to improve the quality of clinical trials for the acute treatment of migraine.