Role of Herbal Medicines in the Management of Brain Injury

Brain is susceptible to oxidative stress due to its increased oxygen consumption and low antioxidant levels. Oxidative stress plays a crucial role in the pathogenesis of various neurological diseases. This review on the role of herbal medicines in the management of brain injury was performed by searching Web of Science, PubMed, Google Scholar, Scopus, and Iran Medex between 1976 to January 2020. The search words contained brain injury, and the total number of publications for the review study was 32. Studies with various medicinal plants such as Acanthopanax senticosus, Bacopa monnieri, carnosol, Cassia mimosoides, Centella asiatica, Crocus sativus, Cuminum cyminum, curcumin, Feronia limonia, Gardenia jasminoides, Ginkgo biloba, Kaempferia parviflora, Mentha longifolia, Nigella sativa, olive, orientin, pomegranate, quercetin, rice bran, Rosa damascena, Thymus vulgaris, Viola odorata, Withania coagulans, Zingiber officinale, and Ziziphus spina-christi show a significant improvement in brain injury. The different mechanisms for improvement in brain injury by these medicinal plants include HIF-1 (hypoxia-inducible factor 1) signaling, free-radical scavenging, reduction of nitric oxide (NO) toxicity and acetylcholine esterase (AChE) activity, decrease of pAkt and its downstream targets, downregulation of the aquaporin-4 (AQP-4) and TLR4/NF-ĸB/TNF-α signal, reduction in malondialdehyde and NO levels, increasing neuronal density in the hippocampus, and inhibition of oxidative stress. In this review, the neuroprotective actions and molecular mechanisms of herbal medicines are evaluated by reviewing available studies.