Screening of herbal extracts for rapid effect on activity-induced knee joint discomfort: a randomized, placebo-controlled pilot study

Background: A feasibility study was conducted to investigate the effect of different proprietary extracts on joint discomfort associated with repeated episodes of physical activity. Methods: A single-dose randomized, double-blind, placebo-controlled cross-over study was conducted in three phases with different extract combinations. Seventeen individuals aged 40-60 years with a history of knee joint pain aggravation on physical stress were randomized to receive the investigational product or the placebo in a 1:1 ratio. The primary outcome was the time taken to achieve meaningful pain relief (MPR) from baseline using a pain visual analog scale (VAS) compared to the placebo. The secondary outcomes were the pain intensity difference (PID) and joint discomfort at 1-, 2-, 3-, and 4-hours post-product administration and the time-weighted sum of pain intensity difference (SPID) over 4 hours compared to placebo. Results: Participants in two out of eight investigational product groups achieved MPR successfully. The proprietary combination ZV-E (consisting of Z. officinale and V. negundo) showed the fastest pain reduction with more than 50% of the participants achieving meaningful relief. The BS-ZP (consisting of B. serrata + Z. officinale + P. lanceolata) group also had more than 50% of participants reporting MPR at 4 hours post-IP administration. Subsequently, the SPID was found to be lowest in the participants of above stated groups. Conclusions: The proprietary combination of Z. officinale and V. negundo extracts, 200 mg could be a promising lead to conduct a further trial to investigate its effect on joint pain.