Exploiting autophagy-targeting natural compounds for potential antimicrobial actions.

Natural products are biologically active compounds used for therapeutic interventions for various diseases, particularly infections. Autophagy is an intracellular catabolic pathway involving lysosomal degradation and is closely associated with immunological pathways, effectively combating bacterial, viral, fungal, and parasitic infections. Accumulating evidence suggests that autophagy activation or inhibition by natural products promotes antimicrobial responses against various pathogens. Numerous natural products can modulate autophagy through diverse signaling pathways, suggesting their potential as a host-directed therapeutic strategy that may complement conventional drug regimens or help mitigate drug resistance in various infectious diseases. However, it remains largely unclear whether these effects are mediated by direct modulation of autophagy or indirectly through associated mechanisms, including enhanced immune defense, attenuation of pathological inflammation, or crosstalk with other organelle functions. Additionally, multiple pathogens can evade host responses; thus, autophagy activation may inadvertently create favorable conditions for certain pathogens. This review discusses the current knowledge of natural products in terms of their antimicrobial actions through autophagy regulation, particularly the roles of distinct natural product classes, such as polyphenols, alkaloids, terpenoids, quinones, peptides, and macrolides in modulating autophagy for potentially contributing to control various infectious diseases. Exploring the intricate molecular interplay between natural products and autophagy in limiting infections may provide valuable insights that could inform the development of innovative host-directed antimicrobial treatments based on autophagy regulation.Abbreviations: 3-MA: 3-methyladenine; AM: alveolar macrophages; AMP: antimicrobial peptides; AMPK: 5' adenosine monophosphate-activated protein kinase; ARDS: acute respiratory distress syndrome; ART: artemisinin; ASFV: African swine fever virus; ATG: autophagy related; AZM: azithromycin; BafA1: bafilomycin A1; BECN1: beclin 1; BMDM: bone marrow-derived macrophage; BNIP3: BCL2 interacting protein 3; BNIP3L: BCL2 interacting protein 3 like; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CAMKK2: calcium/calmodulin-dependent protein kinase kinase 2; CBD: cannabidiol; CF: cystic fibrosis; CGA: chlorogenic acid; CGAS: cyclic GMP-AMP synthase; CHUK/IKKα: component of inhibitor of nuclear factor kappa B kinase complex; CLP: cecal ligation and puncture; CLR: clarithromycin; CMA: chaperone-mediated autophagy; CoV: coronavirus; DHT: dihydrotanshinone I; EGCG: epigallocatechin-3-gallate; EIF2A: eukaryotic translation initiation factor 2A; EIF2AK2: eukaryotic translation initiation factor 2 alpha kinase 2; ESKAPE: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.; ESRRA: estrogen related receptor alpha; FOXO1: forkhead box O1; FUNDC1: FUN14 domain containing 1; HBV: hepatitis B virus; HCV: hepatitis C virus; HDT: host-directed therapy; HIV: human immunodeficiency virus; HMGB1: high mobility group box 1; HSV: herpes simplex virus; IAV: influenza A virus; ICT: isocryptotanshinone; IFN: interferon; IKBKB/IKKβ: inhibitor of nuclear factor kappa B kinase subunit beta; IL: interleukin; INH: isoniazid; IRF3: IFN regulatory factor 3; KEAP1: kelch like ECH associated protein 1; LAMP: lysosomal associated membrane protein; LAP: LC3-associated phagocytosis; LPS: lipopolysaccharide; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAPK: mitogen-activated protein kinase; MDM: monocyte-derived macrophage; MDR: multidrug-resistant; MON: monotropein; Mtb: Mycobacterium tuberculosis; MTOR: mechanistic target of rapamycin kinase; mtROS: mitochondrial ROS; NET: neutrophil extracellular trap; NFE2L2/Nrf2: NFE2 like bZIP transcription factor 2; NFKB/NF-κB: nuclear factor kappa B; NLRP3: NLR family pyrin domain containing 3; NLRX1: NLR family member X1; NOTCH1: notch receptor 1; NTM: nontuberculous mycobacteria; OMS: ohmyungsamycin; PAK1: p21 (RAC1) activated kinase 1; PINK1: PTEN induced kinase 1; PKM/PKM2: pyruvate kinase M1/2; PLD: phospholipase D; PM: peritoneal macrophage; PPM1A: protein phosphatase, Mg2+/Mn2+ dependent 1A; PRKN/parkin: parkin RBR E3 ubiquitin protein ligase; PtdIns3K: phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; PTEN: phosphatase and tensin homolog; RB1CC1/FIP200: RB1 inducible coiled-coil 1; RELA/p65: RELA proto-oncogene, NF-kB subunit; RIF: rifampicin; ROS: reactive oxygen species; RSV: resveratrol; RUBCN/rubicon: rubicon autophagy regulator; SAR: selective autophagy receptor; SIRT: sirtuin; STING1: stimulator of interferon response cGAMP interactor 1; STX17: syntaxin 17; Tat: trans-activator of transcription; TB: tuberculosis; TBK1: TANK binding kinase 1; TFEB: transcription factor EB; TLR: toll like receptor; TNA: tanshinone IIA; TNF: tumor necrosis factor; UA: ursolic acid; ULK1/Atg1: unc-51 like autophagy activating kinase 1; UPR: unfolded protein response; UVRAG: UV radiation resistance associated; VAMP8: vesicle associated membrane protein 8; VDR: vitamin D receptor; WIPI2: WD repeat domain, phosphoinositide interacting 2; ZFYVE1/DFCP1: zinc finger FYVE-type containing 1; ZIKV: Zika virus.