Background/Objectives: Curcuma longa is widely recognized for its antioxidant, antimicrobial, and wound-related biological effects. The present study aimed to compare two extracts prepared from organic turmeric powder (Curcuma longa), using distilled water (CUR-H₂O) and 96% ethanol (CUR-EtOH), in terms of extraction yield, phytochemical profile, antimicrobial activity, and in vitro biological behavior relevant to future oral-health-oriented applications. Methods: The extracts were prepared by maceration followed by ultrasound-assisted processing, concentration, and lyophilization. Their antioxidant potential (AOP) was evaluated by DPPH assay, total phenolic content (TPC) by the Folin–Ciocalteu method, and targeted polyphenolic profile by UHPLC-MS. Antimicrobial activity was assessed by broth microdilution against Streptococcus mutans, Streptococcus oralis, and Candida albicans. In vitro biological activity was investigated on HaCaT keratinocytes. Results: CUR-EtOH extract showed a higher extraction yield than CUR-H₂O (5.13% vs. 2.01%), higher AOP (69.54 ± 0.49% vs. 53.35 ± 0.30%), and a higher TPC (163.87 ± 0.32 vs. 78.05 ± 0.28 mg GAE/g dry extract). Consistent with these TPC results, UHPLC-MS revealed a richer targeted polyphenolic profile in CUR-EtOH extract, particularly in terms of p-coumaric and ferulic acid derivatives. CUR-EtOH extract was more active against the tested oral streptococci, especially S. mutans (MIC 10 µL vs. 60 µL for CUR-H₂O), whereas CUR-H₂O extract showed a slightly better antifungal effect against C. albicans (MIC 60 µL vs. 80 µL). In HaCaT cells, CUR-H₂O extract exhibited the more favorable compatibility profile, while CUR-EtOH extract showed stronger cytotoxicity, despite promoting faster wound-gap closure at 10 µg/mL. Conclusions: The extraction solvent strongly influenced both the chemical profile and biological behavior of the turmeric-powder-derived extracts. These findings suggest that solvent selection may be used to tailor the balance between antimicrobial efficacy and epithelial compatibility in future turmeric-powder-derived preparations intended for oral-health-oriented applications.

Gastric cancer remains a highly heterogeneous malignancy in which chemotherapy response is limited by intrinsic and acquired resistance, cumulative toxicity, and the restricted predictive value of conventional preclinical models. This review critically synthesizes evidence on selected medicinal plants and their bioactive phytocompounds as adjuncts to standard chemotherapy for gastric cancer, with an emphasis on mechanistic plausibility, preclinical synergy, and translational barriers. Across the reviewed literature, phytocompounds from Curcuma longa, Scutellaria baicalensis, Camellia sinensis, Syzygium aromaticum, Glycyrrhiza glabra, Allium sativum, Marsdenia tenacissima, and Rhus verniciflua showed anticancer or chemopreventive activity through multitarget effects on apoptosis, proliferation, invasion, inflammation, oxidative stress, and resistance-associated signaling. The most convincing chemosensitizing evidence involved curcumin, wogonin, baicalein, EGCG, which enhanced the activity of fluoropyrimidines, platinum agents, paclitaxel, doxorubicin, or related antitumor regimens in selected gastric cancer models. However, the evidence base remains heterogeneous and is constrained by variable extract standardization, incomplete dose reporting, poor bioavailability, insufficient pharmacokinetic/pharmacodynamic integration, and underuse of clinically relevant model systems. Overall, medicinal plant bioactives remain promising adjunct candidates in gastric cancer. Still, meaningful translation will require chemically defined interventions, rigorous synergy analysis, interaction-aware study design, and validation in advanced preclinical and clinical settings.

Background/Objectives: Oral diseases remain among the most prevalent noncommunicable conditions worldwide, with biofilm-driven dysbiosis playing a central role in dental caries, gingivitis, periodontitis, and oral candidiasis. Curcumin has attracted considerable interest because of its anti-inflammatory, antioxidant, antimicrobial, and regenerative properties. However, its clinical use remains limited by poor water solubility, chemical instability, rapid metabolism, and low bioavailability. This review aimed to provide a comprehensive analysis of curcumin-based nanoformulations for oral health applications, with emphasis on their mechanistic actions, antibiofilm activity, and translational relevance. Methods: This review examined representative nanocarrier systems developed for curcumin delivery in oral health. These included polymeric nanoparticles, nanomicelles and nanoemulsions, solid lipid nanoparticles and nanostructured lipid carriers, nanogels, hydrogels, mucoadhesive films, and metallic or hybrid nanosystems. The analysis focused on molecular mechanisms of action, antimicrobial and antibiofilm effects against major oral pathogens, and key translational challenges. Results/Findings: Across the reviewed studies, nanoformulations consistently improved curcumin solubility, stability, tissue penetration, mucosal retention, and controlled release. Mechanistically, they enhanced anti-inflammatory activity through inhibition of nuclear factor kappa B (NF-κB), strengthened antioxidant defenses via the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) axis, supported tissue repair and osteogenic responses, disrupted oral biofilms, and modulated local immune responses. Antimicrobial activity was reported against Streptococcus mutans, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Candida albicans, with reduced exopolysaccharide production, impaired adhesion, and improved biofilm penetration. Conclusions: Curcumin-based nanoformulations represent promising adjunctive platforms for oral healthcare. However, their clinical translation still requires improved stability in the oral-environment standardized manufacturing and characterization, rigorous safety evaluation, and well-designed controlled clinical studies.