Anti-Inflammatory Activities of Baobab Fruit Extracts in TNF-α/IFN-γ-Stimulated HaCaT Keratinocytes with LC–MS/MS and HPLC Profiling

Background/Objectives: Atopic dermatitis (AD)-related skin inflammation involves the release of cytokines and chemokines from keratinocytes; therefore, keratinocyte-based models are widely used to evaluate the anti-inflammatory potential of botanical extracts. This study examined the relationship between phytochemical profiles and anti-inflammatory potential of baobab fruit 30% and 70% ethanol extracts (BE-30 and BE-70, respectively) in a TNF-α/IFN-γ (TI)-stimulated HaCaT keratinocyte model. Methods: The anti-inflammatory effects of both extracts were evaluated by measuring cytokine and chemokine secretion in TI-stimulated HaCaT cells. Phytochemical characterization was performed using liquid chromatography–tandem mass spectrometry (LC–MS/MS) and targeted high-performance liquid chromatography (HPLC). Results: Both extracts were non-cytotoxic. TI-stimulation markedly increased interleukin (IL)-6, IL-8 and monocyte chemotactic protein (MCP)-1 secretion, while BE-30 and BE-70 significantly reduced all three mediators in a dose-dependent manner. At comparable doses, BE-70 exhibited greater inhibition than BE-30. BE-30 showed a non-monotonic IL-8 response at low concentrations, whereas BE-70 consistently reduced IL-8 in a dose-dependent manner. LC–MS/MS profiling revealed a polyphenol-rich composition, including flavonol glycosides and related phenolic compounds. HPLC confirmed the presence of four marker analytes (procyanidin B2, epicatechin, rutin and tiliroside), which were enriched in BE-70. The content of these four polyphenols was 1.94-fold higher in BE-70. Conclusions: Baobab fruit extracts exhibit anti-inflammatory activity associated with polyphenols. These findings suggest that they could be used as analytical standards and in dermatological applications.