Kombucha is a traditional beverage of Manchurian origin, typically made by fermenting sugared black or green tea with the symbiotic consortium of bacteria and yeast (SCOBY). The beverage has gained increasing popularity in recent years, mainly due to its heralded health benefits. The fermentation process of kombucha also results in the production of various bioactive compounds with antimicrobial potential, making it a promising candidate in the exploration of alternative sources of antimicrobial agents, and may be helpful in combating the rising threat of antibiotic resistance. Literature survey performed on Web of Science, Scopus, and PubMed revealed the extensive research that has firmly established the antimicrobial activity of kombucha against a broad spectrum of bacteria and fungi. This activity could be attributed to the synergistic activities of the microbial species in the kombucha microbiota that led to the synthesis of compounds with antimicrobial properties such as acetic acid and various polyphenols. However, research thus far only involved screening for the antimicrobial activity of kombucha. Therefore, there is still a research gap about the molecular mechanism of the kombucha reaction against specific pathogens and its influence on human health upon consumption. Future research may focus on investigating this aspect. Further characterization of the biological activity of the microbial community in kombucha may also facilitate the discovery of novel antimicrobial compounds, such as bacteriocins produced by the microorganisms.
Despite the progressive advances, current standards of treatments for peripheral nerve injury do not guarantee complete recovery. Thus, alternative therapeutic interventions should be considered. Complementary and alternative medicines (CAMs) are widely explored for their therapeutic value, but their potential use in peripheral nerve regeneration is underappreciated. The present systematic review, designed according to guidelines of Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols, aims to present and discuss the current literature on the neuroregenerative potential of CAMs, focusing on plants or herbs, mushrooms, decoctions, and their respective natural products. The available literature on CAMs associated with peripheral nerve regeneration published up to 2020 were retrieved from PubMed, Scopus, and Web of Science. According to current literature, the neuroregenerative potential of Achyranthes bidentata, Astragalus membranaceus, Curcuma longa, Panax ginseng, and Hericium erinaceus are the most widely studied. Various CAMs enhanced proliferation and migration of Schwann cells in vitro, primarily through activation of MAPK pathway and FGF-2 signaling, respectively. Animal studies demonstrated the ability of CAMs to promote peripheral nerve regeneration and functional recovery, which are partially associated with modulations of neurotrophic factors, pro-inflammatory cytokines, and anti-apoptotic signaling. This systematic review provides evidence for the potential use of CAMs in the management of peripheral nerve injury.