Monoterpenoid compounds in Gentianae Radix et Rhizoma have been relatively less reported. Nevertheless, recent studies have gradually unveiled some monoterpenoid compounds within it. For instance, three monoterpenoid compounds were isolated from the flowers of Gentiana rhodantha, among which compound 1 is a novel compound, while compounds 2 and 3 are new natural products. These findings suggest that there may be more undiscovered monoterpenoid compounds in Gentianae Radix et Rhizoma, warranting further investigation. The ¹H NMR and ¹³C NMR data for these compounds have been assigned (Zhou et al., 2023). Monoterpenoid compounds from Gentianae Radix et Rhizoma are presented in Table 1, and their chemical structures are illustrated in Figure 1.

The majority of iridoid components in Gentianae Radix et Rhizoma are secoiridoids, which are commonly glycosylated at the C-1 position. The isolated iridoids are primarily classified into regular iridoids, 4-demethylated iridoids, and secoiridoids (Ye et al., 2023). The regular iridoids include loganic acid (4), 6′-O-β-D-glucopyranosyl loganic acid (5), and loganin (7); the 4-demethylated iridoids include Scrophulariadioside A (22), Rehmannioside B (23), Rehmannioside C (24); and the secoiridoids include gentiopicroside (25), Gentiotrifloroside (36), and Swertiamarin (51). For detailed information on the iridoid components in Gentianae Radix et Rhizoma, refer to Table 2 and Figure 2.

Sesterterpenoid compounds found in gentians are similar in scarcity to monoterpenoids. Liu et al. identified the sesterterpenoid pranferin from a methanol extract of G. scabra Bunge. (Liu, 2004). Specific information on sesterterpenoid constituents from Gentiana can be found in Table 3 and Figure 3.

Triterpenoids isolated from Gentiana plants mainly include dammarane-type compounds, characterized by a β-configured angular methyl group at the C-8 position, such as gentirigenic acid (76), gentirigeoside A (77), and gentirigeoside B (78); ursane-type compounds, with A/B, B/C, and C/D rings in a trans configuration and D/E rings mostly in a cis configuration, such as α-amyrin (84), α-amyrin palmitate (85), and ursolic acid (86); and lupane-type compounds, featuring a five-membered E ring with isopropyl substitution, such as 17β,21β-epoxyhopan-3-one (90), hop-17 (21)-en-3-one (91), and hop-17 (21)-en-3β-ol (92). Specific information on triterpenoid constituents from Gentianae Radix et Rhizoma can be found in Table 4 and Figure 4. Additionally, purified dammarane-type triterpenoids from Gentiana rigescens exhibited in vitro antifungal activity against Glomerella cingulata (inhibition zones: 0.8–2.0 cm) in a disk diffusion assay at 1 mg/mL, with Carbendazim as a positive control after 72 h of incubation (Xu et al., 2007).

The anti-inflammatory effects of Gentianae Radix et Rhizoma primarily target the NF-κB (Nuclear Factor κB) signaling axis. Experimental evidence confirms that its active component, gentiopicroside, inhibits IκB kinase β (IKKβ) phosphorylation, blocks NF-κB nuclear translocation, and subsequently downregulates key inflammatory mediators such as COX-2 (Cyclooxygenase-2) and TNF-α (Tumor Necrosis Factor-α). Gentiopicroside directly inhibits the phosphorylation of IKKβ, which prevents the degradation of IκB and subsequent nuclear translocation of the NF-κB p65 subunit. This blockade leads to the downregulation of key inflammatory mediators, including COX-2, TNF-α, and IL-6. Concurrently, gentiopicroside suppresses the activation of JNK and p38 within the MAPK pathway, further reducing the production of pro-inflammatory cytokines. In rheumatoid arthritis models, this mechanism significantly alleviates synovial inflammation and joint destruction. Concurrently, it suppresses JNK (c-Jun N-terminal Kinase)/p38 activation in the MAPK (Mitogen-Activated Protein Kinase) pathway, reducing macrophage secretion of IL-6 (Interleukin-6) and IL-1β (Interleukin-1β), thereby mitigating inflammatory infiltration in alcoholic liver injury. An in vivo study demonstrated that the ethyl acetate crude extract of Gentiana striata Maxim alleviated paw edema in a rat model of rheumatoid arthritis after 28 days of oral administration at doses of 100 and 200 mg/kg. This protective effect was associated with decreased levels of PGE₂ and NO and was superior to that achieved with 100 mg/kg prednisone, a common anti-inflammatory drug (Cao et al., 2012). Notably, Gentianae Radix et Rhizomacomponents also remodel the inflammatory microenvironment via epigenetic regulation: in ulcerative colitis models, they promote macrophage polarization toward the M2 anti-inflammatory phenotype and inhibit histone deacetylase activity, enhancing chromatin accessibility of anti-inflammatory genes (Xie et al., 2021).

The analgesic mechanisms of Gentianae Radix et Rhizoma extend beyond conventional anti-inflammatory frameworks, exerting analgesic effects through a central-peripheral synergistic network. Centrally, gentiopicroside downregulates NR2B (N-Methyl-D-aspartate receptor subunit 2B) subunit expression of NMDAR (N-Methyl-D-Aspartate Receptor) in the anterior cingulate cortex, inhibiting glutamatergic synaptic transmission and blocking pain sensitization (Chen et al., 2008). Peripherally, it reduces substance P release in the spinal dorsal horn and activates the μ-opioid receptor pathway to stimulate endogenous analgesic substances such as β-endorphin (Jia et al., 2012). In neuropathic pain models, this multi-target approach significantly alleviates mechanical allodynia and thermal hyperalgesia without inducing tolerance typically associated with traditional opioids (Xie et al., 2021). Particularly in chronic inflammatory pain, Gentianae Radix et Rhizoma synergistically enhance anti-inflammatory and analgesic outcomes by inhibiting PGE2 (Prostaglandin E2) synthesis and TRPV1 (Transient Receptor Potential Vanilloid 1) channel activation, offering novel strategies for managing inflammatory bowel disease. The specific compounds with anti-inflammatory and analgesic effects, as well as their mechanisms of action, are presented in Table 9.

Crude Gentianae Radix et Rhizomaextracts and gentiopicroside significantly reduce ALT (Alanine Aminotransferase) and AST (Aspartate Aminotransferase) levels in acute liver injury models induced by CCl₄ or D-galactosamine, while enhancing glutathione peroxidase and superoxide dismutase (SOD) activity, reducing malondialdehyde (MDA) accumulation, directly scavenging free radicals, and reinforcing hepatic antioxidant defenses (Kikuchi et al., 2005). Swertiamarin accelerates toxicant metabolism by activating cytochrome P450 family 3 subfamily A member 4 (CYP3A4) and cytochrome P450 family 2 subfamily E member 1 (CYP2E1) enzymes, thereby attenuating CCl₄-induced hepatotoxicity. Oral swertiamarin (100–200 mg/kg, 8 weeks) alleviated CCl₄-induced hepatotoxicity in rats by activating the Nrf2/HO-1 pathway, reducing oxidative stress and inflammation (Wu et al., 2017). Additionally, Gentianae Radix et Rhizomacomponents suppress NF-κB signaling, downregulating hepatic pro-inflammatory cytokines such as TNF-α and IL-6, thereby ameliorating lipopolysaccharide-and Bacillus Calmette-Guérin-induced liver injury. In ALD models, gentiopicroside targets the P2X purinoceptor 7 (P2X7) receptor/NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome axis, inhibiting inflammasome activation, reducing lipogenesis, and promoting lipid oxidation to alleviate alcoholic steatosis (Li X. et al., 2018). Swertiamarin exerts its hepatoprotective effects by activating the Nrf2 antioxidant pathway. Furthermore, gentiopicroside targets the P2X7 receptor, inhibiting NLRP3 inflammasome assembly and subsequent IL-1β maturation.

Angiotensin system modulation: Swertiamarin inhibits AngII-AT1R signaling, blocking ERK (Extracellular Signal-Regulated Kinase)/c-Jun phosphorylation, thereby attenuating N-nitrosodimethylamine-induced hepatic stellate cell activation and fibrosis. The in vitro study using primary rat hepatic stellate cells showed that purified tetramethylpyrazine (5–20 μM, 12–24 h treatment) inhibited Ang II-induced activation, with DMSO as vehicle control and imatinib/rapamycin as positive controls (Zhang et al., 2014). This in vitro and in vivo study demonstrated that purified swertiamarin (Swe, 98% purity) at doses of 2.4–15 µM (in primary rat HSCs) and 15–20 mg/kg (in DMN-induced fibrotic rats) inhibited angiotensin II–induced activation and fibrosis, with losartan as a positive control and vehicle as negative control; treatment durations were 24 h (in vitro) and 2 weeks (in vivo), but no IC₅₀/EC₅₀ values were provided (Li et al., 2016). TGF-β1/Smad pathway regulation: G. rigescens suppresses TGF-β1/Smad2/3 signaling, downregulates connective tissue growth factor expression, reduces collagen deposition, and mitigates bleomycin-induced hepatic fibrosis (Li X. et al., 2018). Lipid metabolic balance: Gentiopicroside reduces triglyceride accumulation in ALD by modulating fatty acid synthase (FASN) and carnitine palmitoyltransferase 1 (CPT1) expression, restoring lipid oxidation-synthesis equilibrium. The study used acute and chronic alcoholic hepatosteatosis mouse models (40–80 mg/kg GPS) and ethanol-exposed HepG2 cells to show that purified genitopicroside (>99%) improved lipid metabolism via LKB1/AMPK activation and P2x7R–NLRP3 inflammasome inhibition. Metformin and A438079 served as positive controls, with treatments lasting 24 h (in vitro) to 10 days (in vivo); IC₅₀/EC₅₀ values were not provided (Lian et al., 2018).

Swertiamarin enhances bile acid efflux by upregulating bile salt export pump (BSEP) and multidrug resistance-associated protein (MRP) expression, improving cholestasis. Crude Gentianae Radix et Rhizoma extracts increase hepatocyte membrane fluidity, enhance hepatic microcirculation, and alleviate biliary dysfunction in thioacetamide-induced models. In cecal ligation and puncture (CLP)-induced septic liver injury, gentiopicroside protects hepatocyte mitochondrial function by inhibiting inducible nitric oxide synthase activity and reducing excessive nitric oxide production (Zhang et al., 2022). The hepatoprotective and choleretic compounds in Gentianae Radix et Rhizoma, along with their bioactive components and mechanisms of action, are displayed in Table 10.

Gentiopicroside activates the p38/MAPK signaling pathway, upregulates pro-apoptotic B-cell lymphoma-2-associated X protein (Bax), downregulates anti-apoptotic B-cell lymphoma-2 (Bcl-2), and suppresses proliferation in human ovarian cancer HO8910 cells. It induces S-phase and G2/M-phase arrest in hepatocellular carcinoma HepG2 cells while increasing the G0/G1-phase population, effectively inhibiting proliferation. This compound also significantly reduces viability in human liver cancer SMMC-7721 and lung cancer A549 cells. Gentianae Radix et Rhizoma polysaccharides enhance thymic and splenic indices in tumor-bearing mice post-chemotherapy, boosting immune responses. Additionally, compounds such as gentiakochianin and gentiacaulein induce apoptosis in glioma U251 cells by reducing mitochondrial membrane potential and promoting reactive oxygen species (ROS) generation. Luteolin inhibits non-small cell lung cancer (NSCLC) proliferation and induces autophagy via suppression of the PI3K/Akt/mTOR/p70S6K signaling axis. Furthermore, the study demonstrated through in vitro assays that certain triterpenoids isolated from Gentiana scabra exhibit potent inhibitory activity against human indoleamine 2,3-dioxygenase (IDO), with the most active compounds showing IC₅₀ values below 10 μM (Li et al., 2015).

Crude Gentianae Radix et Rhizomaextracts inhibit proliferation in diverse cancer cell lines in vitro, including lung A549, colon HCT-116, prostate PC-3, and breast MCF-7 cells. In vivo, these extracts significantly suppress growth of mouse sarcoma S180 solid tumors, with medium- and high-dose groups showing tumor inhibition rates exceeding 30%. Specific compounds, such as chirat-16-en-3-one and chiratenol, demonstrate antiproliferative effects against cervical cancer HeLa cells. Globuloside A, cornusoside A, cornolactone A, 6,9-epi-8-O-acetylshanziside methyl ester, and polar extracts (petroleum ether, ethyl acetate) from Gentiana manshurica exhibit potent inhibition of HepG2 cell viability (Isakovic et al., 2008). The antitumor components in Gentianae Radix et Rhizoma, including their bioactive components and mechanisms of action, are presented in Table 11.

Gentiopicroside ameliorates stress-induced gastrointestinal dysmotility in rat models by upregulating motilin receptor expression and downregulating vasoactive intestinal peptide receptor 2 (VIPR2) levels, thereby enhancing gastric emptying and intestinal peristalsis (Ruan et al., 2015).

In ethanol-induced gastric mucosal injury models, gentiopicroside upregulates heat shock protein-70 (HSP70), restores epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) levels, and promotes mucosal repair (Yang et al., 2018). The gastrointestinal-regulating bioactive compounds in Gentianae Radix et Rhizoma and their mechanisms of action are presented in Table 12.

Antioxidant Synergy and Cell Survival: Bellidifolin, gentisides A/B, amarogentin, and gentiopicroside enhance neuronal survival under oxidative stress (e.g., H₂O₂-induced PC12 cells) by activating insulin receptor downstream pathways, including PI3K/Akt and Ras/Raf/ERK. These compounds elevate superoxide dismutase (SOD, SOD2) activity, reduce ROS and MDA levels, and mitigate oxidative neuronal damage (Deng, 2015). Inokosterone further attenuates mitochondrial dysfunction-mediated apoptosis in oxidative stress models.

G. rigescens extracts enhance cognitive function in memory-impaired models by inhibiting acetylcholinesterase activity, thereby preserving acetylcholine levels, and by modulating the insulin-like growth factor 1 receptor and ERK signaling pathway (Ma, 2012).

Gentiopicroside alleviates pain-depression comorbidity in reserpine-induced models by downregulating glutamate NMDA receptor subunit 2B (GluN2B) subunit expression of NMDA receptors in the basolateral amygdala, reducing glutamatergic excitotoxicity. It also restores monoamine neurotransmitter balance (e.g., serotonin, dopamine), demonstrating antidepressant efficacy (Deng, 2015; Ma, 2012).

In 6-hydroxydopamine-induced Parkinson’s disease models, gentiopicroside ameliorates motor deficits and tremors by inhibiting dopaminergic neuron degeneration in the nigrostriatal pathway, suppressing α-synuclein aggregation, and attenuating neuroinflammation (Yang, 2014).

Gentiopicroside reduces morphine-induced addictive behaviors by modulating opioid receptor signaling and dopamine reward pathways, reversing drug dependence-associated neuroplasticity (Ma, 2012).

Early studies indicate that gentianine enhances central nervous system excitability in mice, potentially through γ-aminobutyric acid (GABA) ergic system modulation (Sun and Xia, 1984). The nervous system-regulating bioactive compounds in Gentianae Radix et Rhizoma and their mechanisms of action are presented in Table 13.

Longdan Xiegan Tang (Gentian Liver-Draining Decoction) (Cao, 2022; Wu and Chen, 2022; Zhang and Zhang, 2018): Combining Gentianae Radix et Rhizoma (as the sovereign herb) with Scutellaria and Gardenia, this formula alleviates herpetic pain and accelerates crust formation.

Downregulation of serum TNF-α and IL-6, upregulation of IL-12 and CD3+/CD4+ T cells to enhance Th1 immune responses. Modulation of neuropeptides (e.g., substance P, β-endorphin) to reduce neurogenic inflammation.Longdan Jiedu Tang (Gentian Toxin-Resolving Decoction) (Sun and Sun, 2007): Enhanced with Isatis root and Clerodendrum, this formula shows superior efficacy in bacterial co-infections by reducing IgE levels, suppressing mast cell degranulation, and inhibiting histamine release to alleviate pruritus.

Longdan Shenmai Zhijing Tang (Gentian-Ginseng Spasm-Relieving Decoction) (Shao et al., 2022): Targets residual damp-heat and qi-yin deficiency by inhibiting spinal dorsal horn glial cell activation, reducing IL-1β/TNF-α-mediated neuro-sensitization, and upregulating neurotrophic factors for nerve repair. Bloodletting Acupuncture Combined Therapy: Adjunctive use with modified Longdan Xiegan Tang enhances CD8⁺ T cell activity and cytotoxic T lymphocyte responses to eliminate pathogens and restore microcirculation.

Ramsay Hunt Syndrome: Longdan Dai Xie Xiao Zhen Tang (Gentian-Indigo-Scorpion Rash-Resolving Decoction) achieves an 89.3% efficacy rate by suppressing VZV reactivation in trigeminal ganglia and reducing vestibular nerve edema, improving otalgia and facial paralysis (Zhang, 2009).

Fufang Xiongdan Yigan Jiaonang (Compound Bear Bile Hepatitis Capsule) (Hu and Li, 2002): Inhibits Hepatitis B virus DNA replication and promotes HBeAg seroconversion by blocking viral transcription and enhancing interferon-γ responses. Modified Longdan Xiegan Tang: Reduces liver stiffness and fibrosis via TGF-β1/Smad3 pathway inhibition and matrix metalloproteinase activation (Liu et al., 2017; Lyu and Lin, 2018; Wang et al., 2017).

Gentiopicroside activates PPARα/CPT1 to enhance fatty acid β-oxidation and suppresses SREBP-1c-mediated lipogenesis. Combined with lifestyle intervention, Longdan Xiegan Tang reduces hepatic steatosis and serum free fatty acids (Ge et al., 2022).