Plant-based products play an increasingly vital role in the pharmaceutical industry, including Pogostemon cablin (Blanco) Benth. (patchouli), which is notable for its rich history and extensive use in traditional medicine. Patchouli has a longstanding historical use as a remedy for a wide range of health conditions, including colds, fevers, headaches, inflammation, digestive disorders, and insect and snake bites. Comprehensive phytochemical studies have revealed that patchouli leaves contain diverse valuable bioactive compounds, notably patchouli alcohol, β-patchoulene, pogostone, α-bulnesene, and β-caryophyllene. Recent studies have demonstrated that patchouli leaves exhibit various pharmacological properties, including anti-oxidant, anti-inflammatory, antimicrobial, antidepressant, and anticancer effects. Despite robust traditional knowledge, specific therapeutic applications of patchouli leaves require scientific validation and standardization of their bioactive compounds. This review provides a comprehensive overview of the existing literature on the phytochemical composition, pharmacological properties, and underlying mechanisms of action of patchouli essential oil (PEO) and plant extracts obtained from patchouli leaves. It offers detailed insights into potential therapeutic applications, aiming to inform and guide future research across multiple medical disciplines. Ultimately, this review underscores the need for further research to validate and develop the medicinal applications of patchouli leaves, providing a foundation for future healthcare advancements.

In this study, we investigated the mechanism of conversion of active components as well as the color change of forest ginseng (FG) during the drying process with the self-developed negative-pressure circulating airflow-assisted desiccator (PCAD) drying method, using a widely targeted metabolomics analytical method based on ultraperformance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). During the drying process, a total of 1862 metabolites were identified in FG, along with 748 differential abundant metabolites (DAMs). Further analysis of the types and metabolic pathways of the DAMs revealed that both primary and secondary metabolites changed by 50–70% moisture content (MC); secondary metabolites dominated with a 30–50% MC, and primary metabolites dominated with a 10–30% MC, which revealed the differences in the transformation of the active ingredients in the drying process. In addition, the results showed the browning characteristics during the drying process. MC-50 and MC-10 showed the smallest and largest color changes, as well as enzyme activities, compared to the other MCs, respectively. As drying proceeded, browning reactions were mainly related to lipid and nucleotide metabolism and phenylpropane and flavonoid biosynthesis. In conclusion, the present study provides theoretical support for the mechanisms of active ingredient transformation as well as the color change of FG during PCAD drying.

Forest ginseng (FG) is a rare medicinal and culinary plant in China, and its drying quality is heavily dependent on the drying method. This study investigated the effects of traditional hot air drying (HAD) and the self-developed negative-pressure circulating airflow-assisted desiccator drying (PCAD) method on the quality of FG using metabolomics and enzyme activity. The results revealed that the enzyme activities of dried FG were reduced considerably. PCAD preserved higher enzyme activity than HAD. Metabolomics data demonstrate that HAD promotes the formation of primary metabolites (amino acids, lipids, nucleotides, etc.), whereas PCAD promotes the formation of secondary metabolites (terpenoids, phenolic acids, etc.). A change-transformation network was built by combining the metabolites listed above and their biosynthetic pathways, and it was discovered that these biosynthetic pathways were primarily associated with the mevalonate (MVA) pathway, lipid metabolism, phenylpropane biosynthesis, and nucleotide metabolism. It is also believed that these findings are related to the chemical stimulation induced by thermal degradation and the ongoing catalysis of enzyme responses to drought stress. The facts presented above will give a scientific basis for the selection of FG drying processes, as well as helpful references for increasing the nutritional quality of processed FG.