Beta-sitosterol belongs to the group of phytosterols, which are active trace components existing in natural plants, known as the “key of life”, and have a steroid nucleus structure similar to cholesterol. Due to the insolubility issue of beta-sitosterol, most pharmacological studies and clinical applications are limited. Therefore, the modification of beta-sitosterol into its derivatives to enhance its pharmacologic activity is viable. In this study, 4 kinds of new beta-sitosterol derivative were obtained by an esterification reaction with beta-sitosterol, organic acids, EDCI and DMAP in dichloromethane. The chemical structures were defined by IR and NMR. Beta-sitosterol and its derivatives were used to carry out antidepressant research in the tail suspension test (TST) and the forced swimming test (FST) in mice. Additionally, the roles of different parts of the central nervous system (CNS) in the antidepressant-like effect of Sit-S, which is one of the beta-sitosterol derivatives, were also investigated. The results showed that the derivatives exhibited a stronger antidepressant activity than beta-sitosterol. Among the derivatives, administration of Sit-S (4 mg kg⁻¹) gave the lowest immobility time in the TST, demonstrating that Sit-S exhibited the strongest antidepressant-like activity. The study into the roles of different parts of the CNS in the antidepressant-like effect of Sit-S showed that agomelatine (40 mg kg⁻¹), haloperidol (0.2 mg kg⁻¹) and bicuculline (4 mg kg⁻¹) reversed the antidepressant effect of Sit-S (4 mg kg⁻¹). This study confirmed the conclusions that beta-sitosterol derivatives broaden the pharmacological effects of beta-sitosterol, Sit-S (4 mg kg⁻¹) exhibits antidepressant-like effects, and this antidepressant-like effect on male adult mice is mediated by the 5-HT, DA and GABA-ergic systems.

4-Hydroxybenzyl alcohol (HBA), one of the characteristic active components of Gastrodia elata, exhibits obvious effects on the human central nervous system. In order to acquire compounds with superior bioactivity, 10 derivatives of HBA were synthesized from HBA and carboxylic acids. The sedative effects of the 10 HBA derivatives were evaluated using a spontaneous locomotor activity test (SLT) in mice, and their hypnotic effects were determined to be synergistic with pentobarbital-induced sleep. The results showed that 4-hydroxybenzyl alcohol 3-furancarboxylic acid diester (2FHBA, 10 mg kg⁻¹) exhibited the strongest sedative–hypnotic activity among HBA and its derivatives, and 2FHBA could reverse the insomnia caused by p-chlorophenylalanine (pCPA), flumazenil (FLU) and thiosemicarbazide (TSC). Meanwhile, 2FHBA and 5-hydroxytryptophan (5-HTP) showed a synergistic effect. The results suggested that 2FHBA might be a potential agent against insomnia, which might be mediated by the serotonergic and GABAergic systems.

Background: The ginseng endophyte Paenibacillus polymyxa Pp-7250 (Pp-7250) has multifaceted roles such as preventing ginseng diseases, promoting growth, increasing ginsenoside accumulation, and degrading pesticide residues, however, these effects still have room for improvements. Composite fungicides are an effective means to improve the biocontrol effect of fungicides, but the effect of Pp-7250 in combination with its symbiotic bacteria on ginseng needs to be further investigated, and its mechanism of action has not been elucidated. In this study, a series of experiments was conducted to elucidate the effect of Paenibacillus polymyxa and Bacillus cereus co-bacterial agent on the yield and quality of understory ginseng, and to investigate their mechanism of action. Results: The results indicated that P. polymyxa and B. cereus co-bacterial agent (PB) treatment improved ginseng yield, ginsenoside accumulation, disease prevention, and pesticide degradation. The mechanism is that PB treatment increased the abundance of beneficial microorganisms, including Rhodanobacter, Pseudolabrys, Gemmatimonas, Bacillus, Paenibacillus, Cortinarius, Russula, Paecilomyces, and Trechispora, and decreased the abundance of pathogenic microorganisms, including Ellin6067, Acidibacter, Fusarium, Tetracladium, Alternaria, and Ilyonectria in ginseng rhizosphere soil. PB co-bacterial agents enhanced the function of microbial metabolic pathways, biosynthesis of secondary metabolites, biosynthesis of antibiotics, biosynthesis of amino acids, carbon fixation pathways in prokaryotes, DNA replication, and terpenoid backbone biosynthesis, and decreased the function of microbial plant pathogens and animal pathogens. Conclusion: The combination of P. polymyxa and B. cereus may be a potential biocontrol agent to promote the resistance of ginseng to disease and improve the yield, quality, and pesticide degradation.