Curcumin and resveratrol are polyphenolic compounds that have been shown to exhibit synergistic therapeutic properties including anti-inflammatory, anticancer, and antiulcer activities, which may be exploited for the treatment of gastric diseases. However, both compounds have poor aqueous solubility and rapid metabolism, resulting in a low oral bioavailability. In situ gelling, liquid formulations were developed to produce a gastroretentive, raft-forming delivery vehicle to improve bioavailability. Solid dispersions containing a mixture of curcumin and resveratrol with Eudragit^® EPO (Cur/Res-SD) were first prepared using solvent evaporation, to improve the solubility and dissolution of the compounds. Solid dispersions of a weight ratio of 1:10 curcumin/resveratrol to Eudragit^® EPO were subsequently incorporated into in situ gelling, liquid formulations based on the gelling polymers, sodium alginate (low viscosity and medium viscosity), pectin, and gellan gum, respectively. Calcium carbonate and sodium bicarbonate were included to produce carbon dioxide bubbles in the gel matrix, on exposure to gastric fluid, and to achieve flotation. Moreover, the calcium ions acted as a crosslinking agent for the hydrogels. Optimized formulations floated rapidly (<60 s) in simulated gastric fluid (pH = 1.2) and remained buoyant, resulting in the gradual release of more than 80% of the curcumin and resveratrol content within 8 h. The optimized formulation based on medium-viscosity sodium alginate exhibited enhanced cytotoxic activity toward human gastric adenocarcinoma cell lines (AGS), compared with unformulated curcumin and resveratrol compounds, and increased anti-inflammatory activity against RAW 264.7 macrophage cells compared with the NSAID, indomethacin. These findings demonstrate that in situ gelling, liquid formulations, loaded with a combination of curcumin and resveratrol in the form of solid dispersions, show potential as gastroretentive delivery systems for local and systemic effects.

Quercus infectoria Olivier (Fagaceae) nutgall, a traditional Asian medicine, is renowned for its efficacy in treating wounds and skin disorders. Although the gall extract has shown promising results in accelerating wound healing in diabetic animal models, its mechanisms, particularly the effects on redox balance, remain poorly understood. This study aims to investigate the effects and mechanisms of Q. infectoria gall ethanolic extract (QIG) on wound healing in fibroblasts, with a specific emphasis on its modulation of oxidative stress. Hydrogen peroxide (H₂O₂)-treated L929 cells were used as an in vitro model of oxidation-damaged fibroblasts. QIG exhibited potent antioxidant activity with 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and ferric reducing antioxidant power (FRAP) assay values of 305.43 ± 7.48, 508.94 ± 15.12, and 442.08 ± 9.41 µM Trolox equivalents (TE)/µg, respectively. Elevated H₂O₂ levels significantly reduced L929 cell viability, with a 50% lethal concentration of 1.03 mM. QIG mitigated H₂O₂-induced cytotoxicity in a dose-dependent manner, showing protective effects in pre-, post-, and co-treatment scenarios. QIG significantly reduced H₂O₂-induced intracellular reactive oxygen species production and inflammation-related gene expression (p < 0.05). Additionally, at 25 µg/mL, QIG remarkably improved wound closure in H₂O₂-treated L929 cells by approximately 9.4 times compared with the H₂O₂ treatment alone (p < 0.05). These findings suggest QIG has potential therapeutic applications in wound healing, mediated through the regulation of oxidative stress and inflammatory response.

Novel in situ gelling liquid formulations incorporating garcinia extract were developed to achieve prolonged delivery of hydroxycitric acid (HCA), an active compound displaying anti-obesity function, following oral administration. The optimized formulation was composed of sodium alginate (1.5% w/v), hydroxypropyl methylcellulose (HPMC K100) (0.25% w/v), calcium carbonate (1% w/v) and garcinia extract (2% w/v). The formulation displayed rapid gelation in less than a minute on exposure to 0.1 N hydrochloric acid (pH 1.2) and remained afloat for more than 24 h. The formulations were capable of gradually releasing more than 80% of HCA load over 8 h, depending on the composition. The resulting gels exhibited high values of gel strength by texture analysis, suggesting they would offer resistance to breakdown under the action of stomach content movement. The optimized formulation loaded garcinia extract significantly reduced lipid accumulation in 3T3-L1 adipocyte cells and displayed moderate anti-inflammatory activity by inhibiting the production of nitric oxide (NO) in LPS-stimulated RAW 264.7 macrophage cells. These findings demonstrate that oral in situ gelling liquid formulations based on sodium alginate and HPMC K100 offer much potential for sustained delivery of HCA and other anti-obesity compounds.

Expandable films represent a promising gastroretentive drug delivery system, offering prolonged gastric retention and sustained drug release features particularly advantageous for obesity treatment. This study developed high-expansion films using konjac and various low glycemic index starches, including purple potato, brown rice, resistant, and red jasmine rice starches, in combination with chitosan and hydroxypropyl methylcellulose (HPMC) E15. Garcinia extract was incorporated into the films using the solvent casting technique. Among 27 formulations, all demonstrated rapid unfolding (within 15 min) and significant expansion (2-4 folds). Hydroxycitric acid (HCA), the active component, was encapsulated at efficiencies exceeding 80% w/w. The konjac-based films exhibited favorable mechanical properties, expansion capacity, and drug content uniformity. Notably, the CK3-H1 formulation (2% w/v chitosan, 3% w/v konjac, 1% w/v HPMC E15) provided sustained HCA release over 8 h via diffusion. Cytotoxicity tests showed no toxic effects on RAW 264.7 macrophages at concentrations up to 400 μg/mL. Furthermore, CK3-H1 achieved notable nitric oxide inhibition (35.80 ± 1.21%) and the highest reduction in lipid accumulation (31.09 ± 3.15%) in 3T3-L1 adipocytes, outperforming pure HCA and garcinia extract. These results suggest that expandable konjac-based films are a viable and effective delivery system for herbal anti-obesity agents.

Medicinal plants have long been a source of lead compounds for drug discovery. Among these, the Annonaceae family has gained recognition for its potential to yield novel compounds, particularly those that can be used in the development of drugs targeting chronic diseases like diabetes mellitus (DM). We employed various chromatographic methods to isolate bioactive compounds from the roots, leaves, and twigs of Uvaria dulcis Dunal. We used spectroscopic methods to determine the chemical structures of these compounds. We successfully identified twelve known compounds from various parts of U. dulcis: patchoulenon, polygochalcone, 2′3′-dihydroxy-4′,6′-dimethoxydihydrochalcone, 2′,3′-dihydroxy-4′,6′-dimethoxychalcone, chrysin, techochrysin, 8-hydroxy-5,7-dimethoxyflavanone, pinocembrin, 3-farnesylindole, onysilin, cinchonain la, and cinchonain lb. Interestingly, cinchonain la and cinchonain lb exhibited more potent anti-α-glucosidase activity than acarbose (standard drug), with IC₅₀ values of 11.88 ± 1.41 μg/mL and 15.18 ± 1.19 μg/mL, respectively. Cinchonain la inhibited the DPP-IV enzyme, with IC₅₀ value lower than the standard compound (diprotin A) at 81.78 ± 1.42 μg/mL. While 2′,3′-dihydroxy-4′,6′-dimethoxychalcone show more potent inhibitory effect than standard drug with IC₅₀ value of 8.62 ± 1.19 μg/mL. Additionally, at a concentration of 10 μg/mL, cinchonain lb and 2′,3′-dihydroxy-4′,6′-dimethoxychalcone promoted glucose uptake in L6 myotubes cells to the same extent as 100 nM insulin. These findings suggest that cinchonain la, cinchonain lb, and 2′,3′-dihydroxy-4′,6′-dimethoxychalcone are the U. dulcis-derived bioactive compounds that hold promise as potential structures to use in the development of anti-diabetic drugs.