Blue light is reported to be harmful to eyes by inducing reactive oxygen species (ROS). Herein, the roles of Peucedanum japonicum Thunb. leaf extract (PJE) in corneal wound healing under blue light irradiation are investigated. Blue-light-irradiated human corneal epithelial cells (HCECs) show increased intracellular ROS levels and delayed wound healing without a change in survival, and these effects are reversed by PJE treatment. In acute toxicity tests, a single oral administration of PJE (5000 mg/kg) does not induce any signs of clinical toxicity or body weight changes for 15 days post-administration. Rats with OD (oculus dexter, right eye) corneal wounds are divided into seven treatment groups: NL (nonwounded OS (oculus sinister, left eye)), NR (wounded OD), BL (wounded OD + blue light (BL)), and PJE (BL + 25, 50, 100, 200 mg/kg). Blue-light-induced delayed wound healing is dose-dependently recovered by orally administering PJE once daily starting 5 days before wound generation. The reduced tear volume in both eyes in the BL group is also restored by PJE. Forty-eight hours after wound generation, the numbers of inflammatory and apoptotic cells and the expression levels of interleukin-6 (IL-6) largely increase in the BL group, but these values return to almost normal after PJE treatment. The key components of PJE, identified by high-performance liquid chromatography (HPLC) fractionation, are CA, neochlorogenic acid (NCA), and cryptochlorogenic acid (CCA). Each CA isomer effectively reverses the delayed wound healing and excessive ROS production, and their mixture synergistically enhances these effects. The expression of messenger RNAs (mRNAs) related to ROS, such as SOD1, CAT, GPX1, GSTM1, GSTP1, HO-1, and TRXR1, is significantly upregulated by PJE, its components, and the component mixture. Therefore, PJE protects against blue-light-induced delayed corneal wound healing via its antioxidative, anti-inflammatory, and antiapoptotic effects mechanistically related to ROS production.

We previously demonstrated that urban particulate matter (UPM) exposure decreases the migration activity and survival of human corneal epithelial cells (HCECs). Herein, we investigated the potential to improve the corneal wound-healing ability of Peucedanum japonicum Thunb. leaf extract (PJE) and its active components on UPM-induced ocular surface damage in vitro and in vivo. PJE effectively assisted wound healing without altering HCEC survival and enhanced catalase (CAT), heme oxygenase 1 (HO1) and glutathione peroxidase 1 (GPX1) antioxidant gene expression. A corneal wound was uniformly induced on the right eye in all experimental animals and divided into eight groups such as two control groups (wounded right eye group—NR and non-wounded left eye group—NL), UPM treated group and PJEs (25, 50, 100, 200, 400 mg/kg) treated groups. Corneal abrasion model rats exposed to UPM showed delayed wound healing compared to unexposed rats, but wound healing was dose-dependently enhanced by PJE oral administration. Seventy-two hours after wound generation, inflammatory cells, apoptotic cells and interleukin-6 (IL-6) expression were increased substantially after UPM exposure, but PJE treatment significantly reduced the wound to an almost normal level while enhancing re-epithelialization without changing corneal thickness. Next, we tried to identify the key molecules for enhancing wound healing through fractionation. The major compounds in the fraction, confirmed by high-performance liquid chromatography (HPLC), were chlorogenic acid (CA), neochlorogenic acid (NCA) and cryptochlorogenic acid (CCA). Each type of CA isomers showed slightly different half maximal effective (EC50) and maximal effective (ECmax) concentrations, and their mixtures synergistically enhanced HCEC migration. Thus, corneal abrasion wound recovery after UPM exposure improved after PJE treatment, and the active PJE components were identified, providing an important basis to develop therapeutics for ocular surface damage using PJE.

Background and Objectives: This study aimed at investigating the laxative effects of a standardized aqueous extract of Dendropanax morbiferus H. Lév. on two different constipation rat models. Materials and Methods: Animal studies were conducted with low-fiber diet-induced and loperamide-induced constipation animal models, and isolated colons were used in ex vivo analysis to determine the changes in colonic motility caused by D. morbiferus H. Lév. leaf extract (DPL). Results: The results showed that DPL administration significantly improved certain reduced fecal parameters (number, weight, and water content of the stools) in a both low-fiber diet and loperamide-induced constipation models without adverse effects of diarrhea. The laxative effect of DPL was confirmed to improve the charcoal excretion time upon DPL treatment in a low-fiber diet or loperamide-induced constipation model through gastrointestinal (GI) motility evaluation using the charcoal meal test. In addition, when DPL was administered to RAW264.7 cells and loperamide-induced constipation model rats, the production of prostaglandin E₂ (PGE₂) increased significantly in cells and tissue. Furthermore, DPL dose-dependently stimulated the spontaneous contractile amplitude and frequency of the isolated rat colon. Conclusion: Although our study did not provide information on the acute or chronic toxicity of DPL, our results demonstrated that DPL can effectively promote defecation frequency and rat colon contraction, providing scientific evidence to support the use of DPL as a therapeutic application. However, further toxicity studies of DPL are needed prior to the initiation of clinical trials and clinical applications.

In this study, we focused on reducing the molecular weight of purified red okra pectin using various hydrolytic enzymes and evaluating its physicochemical properties or characterization. The enzyme treatments targeted both the main pectin chain and the side-chain sugars, resulting in a reduction in the molecular weight by approximately 10% (from 647 kDa) to 60% (down to 252 kDa). Both the purified red okra pectin and enzyme-treated pectins exhibited a homogalacturonan (HG)-type backbone. Fourier transform infrared (FT-IR) spectroscopy revealed a decrease in the absorbance peak for the pectin backbone (1200–1000 cm⁻¹) in the low-molecular-weight (LMW) pectin. The most significant decrease was observed at 3300 cm⁻¹ in pectin treated with both RGH+RGAE enzymes, indicating reduced sugar bonds. These results demonstrate the physicochemical changes in LMW red okra pectin following enzyme treatment and confirm its potential applications due to its unique characteristics.

Recently, many studies have reported the properties and functionality of okra pectin. However, these studies are about green okra pods, and pectin in red okra pods, stems, and roots has not been reported. Therefore, this study aimed to optimize the red okra extraction method using response surface methodology (RSM) analysis and evaluate the effects of extraction time, temperature, solvent ratio, and pH on the extract yield and crude pectin content. Based on RSM analysis, 4.35 h, 98.04 °C, 23.34 solvent ratio, and pH 3.36 are the optimal parameters for extracting crude pectin from red okra, and the crude pectin content was predicted to be 40.83%. When red okra was extracted under these extraction conditions (4 h, 100 °C, 23 solvent ratio, and pH 3), the extraction yield was 45.26%, and the crude pectin content was 38.42%, which was similar to the yield obtained under the conditions derived from the RSM analysis. In addition, the pH control using hydrochloric acid was replaced with citric acid, and the changes in extract yield and crude pectin content were compared. When citric acid was used, the extract yield was 49.15% (8.6% increase), and the crude pectin content was 42.76 ± 2.56% (11.3% increase); compared to when hydrochloric acid was used, the yield increased. Finally, the standardization of red okra raw materials was determined by analyzing the extraction yield and crude pectin content by part, harvest time, and size of red okra using the established extraction method using citric acid. As a result, it was confirmed that the extraction yield obtained from the established extraction method was reached from the extraction of red okra fruits up to 12 cm in size that were harvested between July and November. Additionally, compared to the non-pectin fraction, the crude pectin fraction isolated from red okra pod extract showed significantly higher total phenolic content (TPC) and total flavonoid content (TFC). These findings, reported for the first time, may contribute to the development of processes to purify red okra pectin, functional evaluation studies of pectin, and potential applications of red okra extract in various industries and research.