Arnica has traditionally been used in treating numerous medical conditions, including inflammation and pain. This review aims to summarize the results of studies testing Arnica products for pain management under different conditions, including post-operation, arthritis, low back pain, and other types of musculoskeletal pain. Based on data from clinical trials, Arnica extract or gel/cream containing Arnica extract shows promising effects for pain relief. These medical benefits of Arnica may be attributed to its chemical components, with demonstrated anti-inflammatory, antioxidant, anti-microbial, and other biological activities. In conclusion, Arnica could be an adjunct therapeutical approach for acute and chronic pain management.

Background and objectives: Heat shock protein 90 (Hsp90) is a molecular chaperone that plays an essential role in tumor growth. Numerous Hsp90 inhibitors have been discovered and tested in preclinical and clinical trials. Recently, several preclinical studies have demonstrated that Hsp90 inhibitors could modulate pain sensitization. However, no studies have evaluated the impact of Hsp90 inhibitors on pain in the patients. This study aims to summarize the pain events reported in clinical trials assessing Hsp90 inhibitors and to determine the effect of Hsp90 inhibitors on pain in patients. Materials and Methods: We searched PubMed, EBSCOhost, and clinicaltrials.gov for Hsp90 inhibitor clinical trials. The pain-related adverse events were summarized. Meta-analysis was performed using the data reported in randomized controlled trials. Results: We identified 90 clinical trials that reported pain as an adverse effect, including 5 randomized controlled trials. The most common types of pain reported in all trials included headache, abdominal pain, and back pain. The meta-analysis showed that Hsp90 inhibitors increased the risk of abdominal pain significantly and appeared to increase the risk for back pain. Conclusions: In conclusion, Hsp90 inhibitor treatment could potentially increase the risk of pain. However, the meta-analysis demonstrated only moderate evidence for the connection between Hsp90 inhibitor and pain.