Diterpenoids from the Whole Plants of Ajuga nipponensis and Their Inhibition of RANKL-Induced Osteoclastogenesis

A newly developed UPLC-MS/MS method for simultaneous quantitative analysis of ajuforrestin A, ajuforrestin B, ajugamacrin and 8-O-acetylharpagide derived from Ajuga plants in mice blood and the in vivo pharmacokinetics

OBJECTIVE

To develop a sensitive and fast detection method via ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to assess the concentration of ajuforrestin A, ajuforrestin B, ajugamacrin and 8-O-Acetylharpagide primarily derived from Ajuga plants in mice blood and their pharmacokinetics.

METHODS

Single protein precipitation with high-proportioned acetonitrile is chosen for sample clean-up. The UPLC HSS T3 (2.1 mm × 100 mm, 1.8 µm) column with a mobile phase in gradient elution mode at the flow rate of 0.4 mL/min was used for sample separation. Acetonitrile was selected as the organic phase solution and water containing 0.1% formic acid was chosen as the aqueous solution. A tandem mass spectrometer containing an electrospray ionization (ESI) source in the positive ionization mode was used to detect four compounds via multiple reaction monitoring (MRM).

RESULTS

The calibration curves (5-1000 ng/mL) of four compounds were linear with correlation coefficients > 0.997. The matrix effects, accuracy, precision, and recovery were all within permissible scope.

CONCLUSIONS

In this approach, the corresponding pharmacokinetic parameters were successfully clarified in mouse for the first time, which provided a theoretical basis for the improvement of the standard of Ajuga plants and the safety of clinical medication. Furthermore, this method may provide the UPLC-MS/MS evidence for the differentiation of the main close relative varieties of genus Ajuga according to these plants contain different mixtures of the four marker compounds.

Five previously undescribed compounds from Ajuga lupulina Maxim. and their in vitro activities

A new biflavone (philonotisflavone-3'''-methyl ether), three diterpenes (lupulin G, lupulin H, lupulin I), a new ecdysteroid (ajugasterone E), and four known compounds were isolated from the whole plant of Ajuga lupulina Maxim. Their structures were determined by spectroscopic analysis, including MS, NMR and ECD spectral data. Compounds 1-3 has DPPH radical scavenging ability, and compound 1 has stronger activity than vitamin C. Compounds 2, 3, 7 and 8 have potential cytotoxic activity against Hela, with IC50 values less than 20.0 μM. Abietane diterpenes 2, 3, 7 and 8 are also found to have NO inhibitory effects with IC50 values less than 40.0 μM.

Natural epoxyquinoids: isolation, biological activity and synthesis. An update

Epoxyquinoids are of continuing interest due to their wide natural distribution and diverse biological activities, including, but not limited to, antibacterial, antifungal, anticancer, enzyme inhibitory, and others. The last review on their total synthesis was published in 2017. Since then, almost 100 articles have been published on their isolation from nature and their biological profile. In addition, the review specifically considers synthesis, including total and enantioselective, as well as the development of shorter approaches for the construction of epoxyquinoids with complex chemical architecture. Thus, this review focuses on progress in this area in order to stimulate further research.

Ferroptosis Inhibitory Aromatic Abietane Diterpenoids from Ajuga decumbens and Structural Revision of Two 3,4-Epoxy Group-Containing Abietanes

Two new 3,4-epoxy group-containing abietane diterpenoids (1 and 2), together with five known diterpenoids (3-7), were isolated from Ajuga decumbens. Their structures were elucidated by spectroscopic data analysis, NMR calculations, and X-ray diffraction experiments. The structures of two known abietane diterpenoids were revised based on NMR calculations and X-ray diffraction data. Notably, compound 4 specifically inhibited RSL3-induced ferroptosis with an EC₅₀ of 56 nM by antioxidation. Moreover, 4 significantly decreased RSL3-induced lipid and cytosolic ROS accumulation and ferroptosis marker gene PTGS2 mRNA expression. This work reports the most potent natural inhibitor against ferroptosis found so far.

Ethnobotanical Survey on Bitter Tea in Taiwan

Ethnopharmacological evidence: In Taiwan, herbal tea is considered a traditional medicine and has been consumed for hundreds of years. In contrast to regular tea, herbal teas are prepared using plants other than the regular tea plant, Camellia sinensis (L.) Kuntze. Bitter tea (kǔ-chá), a series of herbal teas prepared in response to common diseases in Taiwan, is often made from local Taiwanese plants. However, the raw materials and formulations have been kept secret and verbally passed down by store owners across generations without a fixed recipe, and the constituent plant materials have not been disclosed.

Aim of the study: The aim was to determine the herbal composition of bitter tea sold in Taiwan, which can facilitate further studies on pharmacological applications and conserve cultural resources.

Materials and methods: Interviews were conducted through a semi-structured questionnaire. The surveyed respondents were traditional sellers of traditional herbal tea. The relevant literature was collated for a systematic analysis of the composition, characteristics, and traditional and modern applications of the plant materials used in bitter tea. We also conducted an association analysis of the composition of Taiwanese bitter tea with green herb tea (qing-cao-cha tea), another commonly consumed herbal tea in Taiwan, as well as herbal teas in neighboring areas outside Taiwan.

Results: After visiting a total of 59 stores, we identified 32 bitter tea formulations and 73 plant materials. Asteraceae was the most commonly used family, and most stores used whole plants. According to a network analysis of nine plant materials used in high frequency as drug pairs, Tithonia diversifolia and Ajuga nipponensis were found to be the core plant materials used in Taiwanese bitter tea.

Conclusion: Plant materials used in Taiwanese bitter tea were distinct, with multiple therapeutic functions. Further research is required to clarify their efficacy and mechanisms.

Medicinal Importance of Ajuga Species in Iran: Ethnobotanical and Traditional Applications, Phytochemical, and Pharmacological Studies

Context: Five species of the genus Ajuga (Lamiaceae) having the common name of "bugle" are found in Iran. In Persian medicine (PM), the genus Ajuga (Kamaphytus) is used for treating jaundice, joint pain, gout, amenorrhea, sciatica, and wound healing. This study aimed to review the ethnobotanical, phytochemical, and biological activities of Ajuga species that grow in Iran to determine their therapeutic potentials and suggest further studies on the healing properties of this genus in Iran. Evidence Acquisition: Electronic databases such as PubMed, Scopus, and Google Scholar were comprehensively searched for studies on Ajuga species in Iran, including "Ajuga austro-iranica," "Ajuga chamaecistus," "Ajuga comata" (Syn.: "Ajuga Chia," "Ajuga chamaepitys subsp. Chia"), "Ajuga orientalis," and "Ajuga reptans." The search period was from 1966 to February 2021. The related articles were selected according to the inclusion and exclusion criteria of the current study. Results: Several ethnobotanical and pharmacologic reports have verified the traditional uses of the genus Ajuga for anti-inflammatory, hypoglycemic, hypolipidemic, analgesic, anabolic, anti-arthritis, antipyretic, and hepatoprotective activities. Numerous phytochemicals have been identified from Ajuga species involving phytoecdysteroids, neo-clerodane-diterpenes, iridoids, flavonoids, withanolides, phenylethyl glycoside, and essential oils. Conclusions: Due to the beneficial therapeutic effects of Ajuga genus, it can be considered in future clinical studies as a source of natural antioxidants, dietary supplements in the pharmaceutical industry, and stabilizing food against oxidative deterioration.