Protective and therapeutic effects of Scutellaria baicalensis and its main active ingredients baicalin and baicalein against natural toxicities and physical hazards: a review of mechanisms

Abstract

Objectives: Scutellaria baicalensis (SB) has been traditionally used to combat a variety of conditions ranging from ischemic heart disease to cancer. The protective effects of SB are due to the action of two main flavonoids baicalin (BA) and baicalein (BE). This paper aimed to provide a narrative review of the protective and antidotal effects of SB and its main constituents against natural toxicities and physical hazards.

Evidence acquisition: Scientific databases Medline, Scopus, and Web of Science were thoroughly searched, based on different keywords for in vivo, in vitro and clinical studies which reported protective or therapeutic effects of SB or its constituents in natural and physical toxicities.

Results: Numerous studies have reported that treatment with BE, BA, or total SB extract prevents or counteracts the detrimental toxic effects of various natural compounds and physical hazards. The toxic agents include mycotoxins, lipopolysaccharide, multiple plants and animal-derived substances as well as physical factors which negatively affected vital organs such as CNS, liver, kidneys, lung and heart. Increasing the expression of radical scavenging enzymes and glutathione content as well as inhibition of pro-inflammatory cytokines and pro-apoptotic mediators were important mechanisms of action.

Conclusion: Different studies on the Chinese skullcap have exhibited that its total root extract, BA or BE can act as potential antidotes or protective agents against the damage induced by natural toxins and physical factors by alleviating oxidative stress and inflammation. However, the scarcity of high-quality clinical evidence means that further clinical studies are required to reach a more definitive conclusion.

Keywords: Antidote; Baicalein; Baicalin; Natural toxin; Physical hazards; Scutellaria baicalensis.

Fig. 1

Chemical structure of baicalein and baicalin

Fig. 2

A summary of main pharmacological effects of Scutellaria baicalensis and its active constituents and some of the mechanisms involved (graphics courtesy of freepik.com)

Fig. 3

Protective effects of Scutellaria baicalensis and its constituents, baicalin and baicalein against LPS toxicity on various organ systems (graphics courtesy of freepik.com). Abbreviations: Akt, protein kinase B; ALT, alanine transaminase; AST, aspartate transaminase; BALF, bronchoalveolar lavage fluid; casp-3, caspase-3; CAT, catalase; CINC-3, cytokine-induced neutrophil chemoattractant-3; COX-2, cylooxygenase-2; CX3CL1, CX3C chemokine ligand 1; CX3CR1, CX3C chemokine receptor 1; cyt c, cytochrome c; ERK, extracellular signal-regulated kinase; ET-1, endothelin-1; HMGB1, high mobility group box 1; HO-1, heme oxygenase-1; IL, interleukin; iNOS, induced nitric oxide synthase; JNK, c-jun N-terminal kinase; MAPK, mitogen-activated protein kinase; MD-2, myeloid differentiation factor-2; MDA, malondialdehyde; MMP, matrix metalloproteinase; MPO, myeloperoxidase; NF-κB, nuclear factor kappa-light-chain-enhancer of activated B cells; NLRP3, nod-like receptor family pyrin domain containing 3; NO, nitric oxide; Nrf2, nuclear factor erythroid 2-related factor 2; PDCD4, programmed cell death 4; PGE2, prostaglandin E2; ROS, radical oxygen species; Scr, serum creatinine; SOD, superoxide dismutase; STIM1, stromal interaction molecule 1; TLR, toll-like receptor; TNF-α, tumor necrosis factor-α; TUG1, taurine upregulated gene 1; TXA₂, thromboxane A2; TXNIP, Thioredoxin-Interacting Protein; ZO-1, zonula occludens-1

Fig. 4

A summary of natural toxicities and physical hazards which Scutellaria baicalensis, baicalin or baicalein can prevent or counter