Development of a Capillary Electrophoretic Method for the Determination of Huperzine A Concentration in Vietnamese Huperzia serrata

Huperzine A, isolated from Huperzia serrata, is a potent, specific, and reversible inhibitor of acetylcholinesterase with high efficiency and low toxicity. To evaluate the presence of huperzine A in Vietnamese H serrata, a reliable capillary zone electrophoresis method was developed. The analytical conditions were established using 80 mM ammonium acetate buffer, pH 6.0, hydrodynamic injection at 50 mbar for 5 s, applied voltage of 20 kV, temperature at 25 °C, uncoated fused-silica capillary, 56 cm (50 cm effective length) × 70 µm inner diameter, and ultraviolet detection at 310 nm. The recovery rates ranged from 98.05% to 100.64%, with a relative standard deviation <2%. Good linear regression was observed in the concentration range of 1 to 500 µg/mL, with a correlation coefficient of 0.9994. The limit of detection and limit of quantification were 0.33 and 1.0 µg/mL, respectively. These results demonstrate that this method is simple, selective, and suitable for performing quality control for huperzine A derived from Vietnamese H serrata.

Huperzia serrata Extract ‘NSP01’ With Neuroprotective Effects-Potential Synergies of Huperzine A and Polyphenols

Huperzia serrata (Thunb.) Trevis is widely used in traditional asiatic medicine to treat many central disorders including, schizophrenia, cognitive dysfunction, and dementia. The major alkaloid, Huperzine A (HA), of H. serrata is a well-known competitive reversible inhibitor of acetylcholinesterase (AChE) with neuroprotective effects. Inspired by the tradition, we developed a green one-step method using microwave assisted extraction to generate an extract of H. serrata, called NSP01. This green extract conserves original neuropharmacological activity and chemical profile of traditional extract. The neuroprotective activity of NSP01 is based on a precise combination of three major constituents: HA and two phenolic acids, caffeic acid (CA) and ferulic acid (FA). We show that CA and FA potentiate HA-mediated neuroprotective activity. Importantly, the combination of HA with CA and FA does not potentiate the AChE inhibitory property of HA which is responsible for its adverse side effects. Collectively, these experimental findings demonstrated that NSP01, is a very promising plant extract for the prevention of Alzheimer’s disease and memory deficits.

Reference Gene Selection for RT-qPCR Assays in Different Tissues of Huperzia Serrata Based on Full-Length Transcriptome Sequencing

Background Huperzia serrata (H. serrata) produces various types of effectively lycopodium alkaloids, especially Huperzine A (HupA), which is a promising drug for the treatment of Alzheimer’s disease. Numerous studies focused on the chemistry, bioactivities, toxicology, and clinical trials of HupA, however, the public genomic and transcriptomic resources are very limited for H. serrata research, especially for the selection of optimum reference genes. Results Based on the full-length transcriptome datasets and previous studies, thirteen candidate reference genes were selected in different tissue of H. serrata. Then, two optimal reference genes GAPDHB and HisH2A were confirmed by various analysis softwares. In order to further verify the accuracy of the two reference genes, they were used to analyze the expression patterns of four HupA-biosynthetic related genes (lysine decarboxylas, RS-norcoclaurine 6-O-methyltransferase, cytochrome P45072A1 and copper amine oxidase). The data suggested that the expression trends of HupA-biosynthetic related genes were consistent with them in transcriptome sequencing in different tissue of H. serrata. Conclusions This study screened the best reference genes GAPDHB and HisH2A in different tissues of H. serrata, which provides suitable normalization for analyzing the expression of HupA-biosynthetic gene in transcriptional level in H. serrata.

In Vitro Propagation, Huperzine A Content and Antioxidant Activity of Three Genotypic Huperzia serrata

Huperzia serrata is a traditional herb and endangered Chinese medicinal material, which has attracted much attention due to its production of Huperzine A (HupA). In vitro propagation of H. serrata is considered a new way to relieve the resource pressure of H. serrata. In this study, three different genotypic wild H. serrata were used for in vitro propagation. Then, the antioxidant activity and the content of HupA in the regenerated H. serrata were investigated. The results showed the survival rate of the explant was increased to 25.37% when using multiple sterilization processes. The best induction medium for H. serrata was the Schenk and Hildebrandt (SH) medium supplemented with 0.5 mg·L−1 Naphthalene acetic acid (NAA) and 0.1 mg·L−1 2,4-Dichlorophenoxyacetic acid (2,4-D), where the regeneration rate of the explant was to 57.04%. The best proliferation medium was the SH medium with NAA (1.0 mg·L−1), as the biomass of in vitro tissue increased 164.17 ± 0.41 times. High-performance liquid chromatography analysis showed that the in vitro culture of three genotypes could produce HupA and the content of HupA was 53.90–87.17 µg·g−1. The antioxidant experiment showed that the methanol extract of in vitro H. serrata had higher antioxidant activity than that of wild H. serrata. This study provides a reliable in vitro H. serrata culture protocol and laid an important foundation for the antioxidant capacity of the thallus and the content of HupA.

Endophytic Fungal Community of Huperzia serrata: Diversity and Relevance to the Production of Huperzine A by the Plant Host

As the population ages globally, there seem to be more people with Alzheimer’s disease. Unfortunately, there is currently no specific treatment for the disease. At present, Huperzine A (HupA) is one of the best drugs used for the treatment of Alzheimer’s disease and has been used in clinical trials for several years in China. HupA was first separated from Huperzia serrata, a traditional medicinal herb that is used to cure fever, contusions, strains, hematuria, schizophrenia, and snakebite for several hundreds of years in China, and has been confirmed to have acetylcholinesterase inhibitory activity. With the very slow growth of H. serrata, resources are becoming too scarce to meet the need for clinical treatment. Some endophytic fungal strains that produce HupA were isolated from H. serrate in previous studies. In this article, the diversity of the endophytic fungal community within H. serrata was observed and the relevance to the production of HupA by the host plant was further analyzed. A total of 1167 strains were obtained from the leaves of H. serrata followed by the stems (1045) and roots (824). The richness as well as diversity of endophytic fungi within the leaf and stem were higher than in the root. The endophytic fungal community was similar within stems as well as in leaves at all taxonomic levels. The 11 genera (Derxomyces, Lophiostoma, Cyphellophora, Devriesia, Serendipita, Kurtzmanomyces, Mycosphaerella, Conoideocrella, Brevicellicium, Piskurozyma, and Trichomerium) were positively correlated with HupA content. The correlation index of Derxomyces with HupA contents displayed the highest value (CI = 0.92), whereas Trichomerium showed the lowest value (CI = 0.02). Through electrospray ionization mass spectrometry (ESI-MS), it was confirmed that the HS7-1 strain could produce HupA and the total alkaloid concentration was 3.7 ug/g. This study will enable us to screen and isolate the strain that can produce HupA and to figure out the correlation between endophytic fungal diversity with HupA content in different plant organs. This can provide new insights into the screening of strains that can produce HupA more effectively.