Ononin: A candidate anti-parasitic drug isolated from Spatholobi caulis against infections of Dactylogyrus intermedius (Monogenea)

Antiparasitic effect of (+)-catechin derived from Pseudolarix amabilis against Dactylogyrus intermedius in goldfish

Medicinal plants are considered promising candidates for controlling parasitic pathogen in aquaculture. Our previous study demonstrated that the crude extracts of Pseudolarix amabilis exhibit promising anti-Dactylogyrus intermedius activity. However, the specific compounds responsible for the antiparasitic effects of these crude extracts remain elusive. In this study, the bioactive compounds from the ethyl acetate extract of P. amabilis were isolated by the multi-column chromatography and in vivo bioassay-guided methods. Two crystalline compounds were identified as (+)-catechin through the nuclear magnetic resonance spectroscopy and specific rotation analysis. (+)-Catechin showed 98.1 % antiparasitic activity at 20 mg/L with the median effective concentration (EC50) of 4.3 mg/L. The 96 h median lethal concentration (LC50) of (+)-catechin for zebrafish larvae and goldfish was determined to be 32.9 and 152.8 mg/L, respectively. The therapeutic index (TI) of (+)-catechin was 6.8 and 35.5, indicating a potential for safe application in aquaculture. These findings suggest that (+)-catechin could be further developed as a viable therapeutic agent against D. intermedius.

Predicting Pharmacokinetics of Active Constituents in Spatholobi caulis by Using Physiologically Based Pharmacokinetic Models

BACKGROUND/OBJECTIVES

Spatholobi Caulis (SPC) is a medicinal plant that mainly grows in China and Southeast Asian countries and commonly used in clinics; the pharmacokinetic characteristics in humans need to be determined. This study was to establish the physiologically based pharmacokinetic (PBPK) models of multiple active constituents from SPC in rats, and predict the pharmacokinetic properties of rats with different dosages and extrapolated to humans.

METHODS

The parameters were collected based on our previous study and by prediction using ADMET Predictor software predict. The PBPK models for 3'-methoxydadizein (1), 8-O-methylretusin (2), daidzin (3), and isolariciresinol (4) administered orally to rats were established using GastroPlus software. These models were employed to simulate the pharmacokinetic properties in rats across various dosages, and subsequently extrapolated to humans. The calculated parameters including Cmax, Tmax, and AUC were compared with observed values. The accuracy of the PBPK models was assessed using fold-error (FE) values.

RESULT

The FE values ranged from 1.03 to 1.52, meeting the PBPK model regulations where FE should be less than 2. The sensitivity analysis focusing on the absorption amount and AUC0→t of these four constituents in humans was also conducted. These results confirm the successful establishment of PBPK models of these four constituents from SPC in this study, and these models were applicable to predict pharmacokinetics across various doses and extrapolate across species.

CONCLUSIONS

The PBPK models of four constituents can be used to predict the pharmacokinetic characteristics in humans after oral administration of SPC and provide useful data for safe and rational medication in clinical practice.

Ethnopharmacology, Phytochemistry, and Pharmacological Activities of Spatholobus suberectus Vine Stem

Spatholobus suberectus vine stem is an important medicinal material in Chinese, Vietnamese, and Korean traditional medicines. Its decoction has long been used to treat blood disorders, such as anemia and menstrual irregularity, as well as rheumatoid diseases. Previous phytochemical investigations characterized 88 compounds from S suberectus, which mainly belonged to the phenolic class, especially of the flavonoid type. Pharmacological studies showed the beneficial effects of extracts of the plant on the cardiovascular tract, which is ethnopharmacologically relevant to the plant's use in traditional medicine. Besides that, the extracts and isolated compounds also exhibited antimicrobial, anticancer, antiinflammatory, and antioxidant activities. The past study results support the use of S suberectus vine stem in traditional medicine and also revealed new directions of pharmacological effects of this medicinal plant.

Pressurized natural deep eutectic solvents: An alternative approach to agro-soy by-products

Soybeans are mainly used for food and biodiesel production. It is estimated that soy crops worldwide will leave about 651 million metric tons of branches, leaves, pods, and roots on the ground post-harvesting in 2022/23. These by-products might serve as largely available and cheap source of high added-value metabolites, such as flavonoids, isoflavonoids, and other phenolic compounds. This work aimed to explore green approaches based on the use of pressurized and gas expanded-liquid extraction combined with natural deep eutectic solvents (NADESs) to achieve phenolic-rich extracts from soy by-products. The total phenolic and flavonoid contents of the generated extracts were quantified and compared with conventional solvents and techniques. Pressurized liquid extraction (PLE) with choline chloride/citric acid/water (1:1:11 – molar ratio) at 120°C, 100 bar, and 20 min, resulted in an optimized condition to generate phenolic and flavonoid-rich fractions of soy by-products. The individual parts of soy were extracted under these conditions, with their metabolic profile obtained by UHPLC-ESI-QToF-MS/MS and potential antioxidant properties by ROS scavenging capacity. Extracts of soy roots presented the highest antioxidant capacity (207.48 ± 40.23 mg AA/g), three times higher than soybean extracts (68.96 ± 12.30). Furthermore, Hansen solubility parameters (HSPs) were applied to select natural hydrophobic deep eutectic solvents (NaHDES) as substituents for n-heptane to defat soybeans. Extractions applying NaHDES candidates achieved a similar yield and chromatography profile (GC-QToF-MS) to n-heptane extracts.