Two new sesquiterpenoids from the rhizomes of Nardostachys jatamansi

Terpenoids from Nardostachys jatamansi and their cytotoxic activity against human pancreatic cancer cell lines

Five previously unreported terpenoids, together with fifteen known analogs, were isolated from a methanol extract of the roots and rhizomes of Nardostachys jatamansi. Their structures, including absolute configurations, were elucidated by spectroscopic data and electronic circular dichroism (ECD) spectra analyses, as well as single-crystal X-ray diffraction for crystalline compounds. Structurally, (4R,5S,6S,7R)-1(10)-aristolane-8,9-diacid is a novel 8,9-dicarboxylic acid derivative of aristolane-type sesquiterpenoid. (4R,6S,7R,10S)-10-Hydroxyguaia-1(5)-6,7-epoxy-2-one is an undescribed analogue of nardoguaianone K, with a rare 6,7-epoxide group. (4R,5R,6R,8R)-1(10)-Isonardosinone-8-ol-9-one-7,11-lactone is an isonardosinane-type sesquiterpene bearing a γ-lactone ring. Dinardokanshone F is a rare example of a sesquiterpene dimer from N. jatamansi connected by an oxo bridge. The isolates were evaluated for their cytotoxic activity against four human pancreatic cancer cell lines (CFPAC-1, PANC-1, CAPAN-2 and SW1990). Compound epoxynardosinone exhibited significant cytotoxicity against CAPAN-2 cell lines with IC₅₀ value of 2.60 ± 1.85 μM. 1-Hydroxylaristolone displayed comparable cytotoxicity on CFPAC-1 cell lines (IC₅₀ 1.12 ± 1.19 μM), compared to Taxol (IC₅₀ 0.32 ± 0.13 μM). 1-Hydroxylaristolone, 1(10)-aristolane-9β-ol, 1(10)-aristolen-2-one, alpinenone, valtrate isovaleroyloxyhydrine and nardostachin displayed stronger cytotoxicity against PANC-1 cell lines with IC₅₀ values ranging from 0.01 ± 0.01 to 6.50 ± 1.10 μM. 1(10)-Aristolane-9β-ol, 10-hydroxyguaia-1(5)-6,7-epoxy-2-one, nardoguaianone K, nardonoxide, epoxynardosinone, 1(10)-isonardosinone-8-ol-9-one-7,11-lactone, valtrate isovaleroyloxyhydrine and nardostachin showed remarkable cytotoxicity against SW1990 cell lines with IC₅₀ values ranging from 0.07 ± 0.05 to 4.82 ± 6.96 μM. Furthermore, the primary mechanistic study of nardostachin demonstrated that it induced cell apoptosis via the mitochondria-dependent pathway, and induced SW1900 cell arrest at G2/M phase.

A review on traditional uses, phytochemistry, pharmacology, toxicology and the analytical methods of the genus Nardostachys

ETHNOPHARMACOLOGICAL RELEVANCE

The plants of the genus Nardostachys (Caprifoliaceae) have been used for a long history in different cultural systems of medicine, including Chinese, Ayurvedic, Korean folk medicine and Islamic, for treatments of disorders in nervous, digestive, cardiovascular and integumentary systems.

AIM OF THE REVIEW

This review aims to provide comprehensive information on Nardostachys plants including botany update, traditional uses, data mining of uses in traditional Chinese medicine (TCM) and current Chinese medicinal patents, chemical constituents, pharmacological effects, toxicity and analytical method studies.

MATERIALS AND METHODS

Studies of the genus Nardostachys were collected via Google Scholar and Baidu Scholar, ScienceDirect, SciFinder, Wiley Online Library, ACS Publications, NLM/NCBI, Web of Science, CNKI, WANFANG DATA, EMBASE, Huabeing database and Traditional Chinese Medicine Resource Network and libraries. Some local books, PhD or MS's dissertations were also included. The literatures cited in this review covered the period from 1962 to March 2021. The Plant List and Kew Herbarium Catalogue databases were used to authenticate the scientific name.

RESULTS

Botany description of Nardostachys genus is updated. Analysis of the literatures indicates that Nardostachys species are valuable herbs with therapeutic potentials for various disorders. Data mining on ancient TCM prescriptions and current Chinese medicinal patents containing Nardostachys revealed its common compatibility with other herbs in China. Phytochemical studies identified terpenoids and phenolic compounds as the main constituents in the genus Nardostachys and sesquiterpenoids as the major bioactive components. Experimental studies demonstrated that crude extracts, major fractions and the main constituents from Nardostachys species mainly exhibited pharmacological activities on nervous, digestive, cardiovascular and skin systems. Further, in vivo and in vitro toxicological studies demonstrated that Nardostachys plants showed either no or low toxicities, except at high doses. Finally, methods of qualitative and quantitative analyses on chemical constituents of genus Nardostachys were summarized, including TLC/HPTLC, GC and HPLC/UPLC methods, combined with common detectors including PDA, DAD and MS.

CONCLUSIONS

This review summarizes the progress on phytochemistry, pharmacology, toxicology and analytical methods of the genus Nardostachys. Studies demonstrate traditional uses of the genus Nardostachys, and reveal novel bioactive effects for clinical uses. These achievements expand our knowledge on the genus Nardostachys and its clinical value.

Plant Species of Sub-Family Valerianaceae-A Review on Its Effect on the Central Nervous System

Valerianaceae, the sub-family of Caprifoliaceae, contains more than 300 species of annual and perennial herbs, worldwide distributed. Several species are used for their biological properties while some are used as food. Species from the genus Valeriana have been used for their antispasmodic, relaxing, and sedative properties, which have been mainly attributed to the presence of valepotriates, borneol derivatives, and isovalerenic acid. Among this genus, the most common and employed species is Valerianaofficinalis. Although valerian has been traditionally used as a mild sedative, research results are still controversial regarding the role of the different active compounds, the herbal preparations, and the dosage used. The present review is designed to summarize and critically describe the current knowledge on the different plant species belonging to Valerianaceae, their phytochemicals, their uses in the treatment of different diseases with particular emphasis on the effects on the central nervous system. The available information on this sub-family was collected from scientific databases up until year 2020. The following electronic databases were used: PubMed, Scopus, Sci Finder, Web of Science, Science Direct, NCBI, and Google Scholar. The search terms used for this review included Valerianaceae, Valeriana, Centranthus, Fedia, Patrinia, Nardostachys, Plectritis, and Valerianella, phytochemical composition, in vivo studies, Central Nervous System, neuroprotective, antidepressant, antinociceptive, anxiolytic, anxiety, preclinical and clinical studies.

BET Inhibitors Synergize with Carfilzomib to Induce Cell Death in Cancer Cells via Impairing Nrf1 Transcriptional Activity and Exacerbating the Unfolded Protein Response

Currently, proteasome inhibitors bortezomib, carfilzomib, and ixazomib are successfully used in clinics to treat multiple myeloma. However, these agents show limited efficacy against solid tumors. Identification of drugs that can potentiate the action of proteasome inhibitors could help expand the use of this therapeutic modality to solid tumors. Here, we found that bromodomain extra-terminal (BET) family protein inhibitors such as JQ1, I-BET762, and I-BET151 synergize with carfilzomib in multiple solid tumor cell lines. Mechanistically, BET inhibitors attenuated the ability of the transcription factor Nrf1 to induce proteasome genes in response to proteasome inhibition, thus, impeding the bounce-back response of proteasome activity, a critical pathway by which cells cope with proteotoxic stress. Moreover, we found that treatment with BET inhibitors or depletion of Nrf1 exacerbated the unfolded protein response (UPR), signaling that was initiated by proteasome inhibition. Taken together, our work provides a mechanistic explanation behind the synergy between proteasome and BET inhibitors in cancer cell lines and could prompt future preclinical and clinical studies aimed at further investigating this combination.

Narjatamanins A and B, a pair of novel epimers possessing a 2,3-seco-iridoid skeleton with an unusual 1,10-oxygen bridge from Nardostachys jatamansi and evaluation of their effects on worm paralysis in AD C. elegans

Narjatamanins A (1) and B (2), a pair of epimers possessing a novel 2,3-seco-iridoid skeleton with an unusual 1,10-oxygen bridge, were isolated from the whole plants of Nardostachys jatamansi. Their structures were elucidated by a combination of various spectroscopic methods, including HRESIMS, IR and 1D and 2D NMR techniques. The absolute configurations of 1 and 2 were established by electronic circular dichroism (ECD) calculations. The pharmacological activities of 1 and 2 to alleviate AD-like symptoms were also evaluated using the Caenorhabditis elegans Alzheimer's disease (AD) pathological model, and narjatamanins A (1) and B (2) showed statistically significant delay in the worm paralysis phenotype of AD-like symptoms.

Narjatamanins A (1) and B (2), a pair of epimers possessing a novel 2,3-seco-iridoid skeleton with an unusual 1,10-oxygen bridge, were isolated from the whole plants of Nardostachys jatamansi.

Divergent synthetic route to new cyclopenta[c]pyran iridoids: syntheses of jatamanin A, F, G and J, gastrolactone and nepetalactone

Six natural iridoids including jatamanin A, F, G and J, gastrolactone and nepetalactone have been synthesized via the efficient transformation of a core cyclopenta[c]pyran intermediate. Key features of the syntheses include the stereoselective construction of the core cyclopenta[c]pyran skeleton of the iridoid lactones via a Pd(0)-catalyzed intramolecular allylic alkylation, and the facile transformation of the common intermediate into natural iridoids.

Evaluation of antioxidant and anticancer activity of extract and fractions of Nardostachys jatamansi DC in breast carcinoma

Background

Nardostachys jatamansi DC is a Himalayan medicinal herb that has been described in various traditional systems of medicine for its use in cancer. In view of its traditional claims, and chemical constituents, antioxidant and anticancer activities were evaluated in breast carcinoma.

Methods

Petroleum ether (NJPE), methanol extract (NJM) and subsequent diethyl ether (NJDE), ethyl acetate (NJEA) and aqueous (NJAQ) fractions of roots and rhizomes of N. jatamansi were prepared. Total phenolic, flavonoid content, and antioxidant activities were determined using suitable methods. Antiproliferative activity was assessed in estrogen receptor (ER)-positive (MCF-7) and ER-negative breast carcinoma (MDA-MB-231) cells by MTT and SRB assay. Cell cycle analysis, Hoechst staining, and clonogenic assay were employed to determine the mode of antiproliferative and pro-apoptotic activity in MDA-MB-231 cells.

Results

NJM/fractions exhibited prominent antioxidant activity with significant correlation between phenolic content and ABTS (IC₅₀) scavenging (R = −0.9680, P < 0.05), and total antioxidant capacity (R = 0.8396, P > 0.05). In MTT assay, NJM exhibited the highest antiproliferative activity (IC₅₀: 58.01 ± 6.13 and 23.83 ± 0.69 μg/mL in MCF-7 and MDA-MB-231 respectively). Among the fractions, NJPE and NJDE were found to be most potent in MCF-7 (IC₅₀: 60.59 ± 4.78 μg/mL) and MDA-MB-231 (IC₅₀: 25.04 ± 0.90 μg/mL) cells respectively. Statistical analyses revealed NJM and NJDE exhibited significantly higher (P < 0.05) cytotoxicity in MDA-MB-231 cells. Cell cycle analysis demonstrated that NJM, NJPE and NJEA caused G₂/M arrest while NJDE caused G₀/G₁ phase arrest in MDA-MB-231 cells. Further, NJM/fractions induced significant (P < 0.001) cell death by apoptosis characterized by apoptotic morphological changes in Hoechst staining and inhibited long-term proliferation (P < 0.001) of MDA-MB-231 cells in clonogenic assay. Lupeol and β-sitosterol were identified as anticancer principles in NJM/fractions by HPTLC.

Conclusion

Our results suggest that NJM/fractions possess significant antiproliferative potential which is mediated through cell cycle perturbation and pro-apoptotic effects in MDA-MB-231 cells. Moreover, this study highlights the antioxidant potential of NJM/fractions which can be attributed to the presence of phenols. NJDE emerged as the most potent fraction and further mechanistic and phytochemical investigations are under way to identify the active principles.