Recently, the exploration of traditional botanicals for therapeutic applications has highlighted the importance of understanding the molecular mechanisms underlying their anti-inflammatory properties [20]. The critical signaling pathways modulated by these botanicals include the NF-κB, iNOS, and MAPK pathways, which play pivotal roles in the regulation of inflammation, cellular stress responses, and immune functions [21]. This study provides a detailed analysis of how 13 selected botanicals, including Lonicera japonica Thunb., Platycodon grandiflorus, and Arctium lappa L., interact with these pathways to exert their anti-inflammatory effects.
We investigated the anti-inflammatory potential of VAH on NF-κB, iNOS, and MAPK pathways using an LPS-induced inflammation model comprising RAW264.7 cells. Establishing this model was crucial for comprehensively evaluating VAH's ability to modulate inflammatory responses. Our results demonstrate that VAH effectively suppresses the LPS-induced upregulation of key inflammatory markers, including pNF-κB, iNOS, pp38, and pERK, mediated by DE and EE. Additionally, VAH treatment significantly reduces NO production and expression of the inflammatory cytokines TNF-α, IL-6, and IL-1β, underscoring VAH's anti-inflammatory properties and highlighting its multifaceted regulatory effects on inflammatory pathways (Fig. 7).
The 13 components of VAH influence various anti-inflammatory pathways, thus presenting a holistic approach to reducing inflammation [22]. Modulation of the NF-κB pathway, which is central to the regulation of immune and inflammatory responses, by plant-derived compounds, has been a significant focus of research. In Lonicera japonica Thunb., chlorogenic acid and luteolin play critical roles in inhibiting NF-κB activation, thereby reducing the expression of inflammatory mediators [23]. Platycodon grandiflorus uses saponins, particularly platycodin D, to suppress NF-κB activation [24]. Arctium lappa L. utilizes arctiin and arctigenin to inhibit this pathway, demonstrating the diverse molecular structures that can impact NF-κB signaling [25]. The NF-κB pathway is a common target of several botanicals, indicating its pivotal role in regulating inflammation.
The iNOS pathway, responsible for producing NO during inflammatory responses, is another target of botanical compounds. Arctium lappa L. and Zingiber officinale Roscoe directly inhibit iNOS expression via the compounds arctigenin and gingerol, respectively [26, 27]. Reducing NO production is critical for mitigating the cellular effects of inflammation. The ability of these compounds to influence iNOS expression underscores the potential of botanicals to modulate inflammation at the biochemical level and provides a foundation for their therapeutic applications.
The MAPK pathway is involved in the cellular responses to various stress signals and plays a crucial role in regulating inflammation. Schisandra chinensis contains schisandrin, which has been shown to affect this pathway, potentially inhibiting the activation of MAPK, and thus modulating inflammatory responses [28]. Camellia sinensis L., rich in epigallocatechin gallate, targets the MAPK pathway to exert anti-inflammatory effects [29], illustrating the potential of polyphenolic compounds in managing inflammation. The modulation of MAPK by these botanicals indicates their ability to influence cellular responses to inflammation at multiple levels.
Additionally, the Nrf2 pathway, which is key in the defense against oxidative stress-induced inflammation, is positively influenced by Ginseng and Green tea, which boost the body's antioxidant defense and reduce inflammation [30, 31]. The JAK-STAT pathway, another target for anti-inflammatory action, although not specifically mentioned for all VAH ingredients, may be influenced by Ginseng, aiding its anti-inflammatory effects [32]. Furthermore, Ginseng has been shown to affect Toll-like receptor signaling, which is crucial for initiating innate immune responses and potentially leads to inflammation when overactivated [33]. By addressing distinct but interconnected pathways, this ensemble of ingredients in VAH suggests a synergistic approach for reducing inflammation, which could prove beneficial in treating chronic inflammatory conditions. The cooperative effects of these components highlight the importance of understanding their collective impact on various signaling pathways to fully understand the anti-inflammatory potential of VAH.
The differential anti-inflammatory effects of the DE and EE of VAH can be attributed to the distinct phytochemical profiles obtained through different solvent extractions [34]. Water, as a polar solvent, extracts more polar substances, leading to DE being rich in hydrophilic compounds such as glycosides and polar flavonoids, which are potent in modulating the NF-κB pathway, resulting in a significant reduction in inflammation markers [35]. In contrast, ethanol, a less polar solvent than water, facilitates the extraction of both polar and nonpolar compounds, yielding a diverse range of phytochemicals [36]. However, the EE may not be as efficient in targeting specific anti-inflammatory pathways because of the lower concentration of polar anti-inflammatory agents, resulting in a less pronounced effect on the NF-κB pathway [37]. This highlights the importance of solvent selection in the extraction process, which directly affects the therapeutic efficacy of botanical extracts for the treatment of inflammatory conditions.
The development of a natural anti-inflammatory agent from VAH ingredients has potential applications in a range of inflammatory and autoimmune diseases [38]. Capable of targeting NF-κB, MAPK, Nrf2, JAK-STAT, and Toll-like receptor pathways, this agent could provide a multidimensional approach to alleviating inflammation [39]. The agent could benefit conditions such as rheumatoid arthritis and osteoarthritis by reducing joint inflammation [40, 41], asthma [42], and chronic obstructive pulmonary disease [43] by alleviating airway inflammation; inflammatory bowel diseases such as Crohn’s disease [44] and ulcerative colitis through the reduction of gut inflammation [45]; and autoimmune conditions such as lupus [46] and psoriasis [47] by modulating the immune response. Neurodegenerative diseases such as Alzheimer’s disease could also benefit from its anti-inflammatory and antioxidant actions [48]. Moreover, the agent could aid in managing metabolic syndrome and obesity-related inflammation, which are risk factors for type 2 diabetes and cardiovascular diseases [49]. This broad applicability of the potential agent, rooted in VAH’s diverse ingredient profile, underscores its potential as a comprehensive natural solution for inflammation-driven health issues, necessitating further research to confirm its efficacy and safety across these varied conditions.