Salviatalin A and salvitrijudin A, two diterpenes with novel skeletons from roots of Salvia digitaloides and anti-inflammatory evaluation

Ethnobotanical, Phytochemical, and Pharmacological Properties of the Subfamily Nepetoideae (Lamiaceae) in Inflammatory Diseases

Nepetoideae is the most diverse subfamily of Lamiaceae, and some species are well known for their culinary and medicinal uses. In recent years, there has been growing interest in the therapeutic properties of the species of this group regarding inflammatory illnesses. This study aims to collect information on traditional uses through ethnobotanical, pharmacological, and phytochemical information of the subfamily Nepetoideae related to inflammatory diseases. UNAM electronic resources were used to obtain the information. The analysis of the most relevant literature was compiled and organised in tables. From this, about 106 species of the subfamily are traditionally recognised to alleviate chronic pain associated with inflammation. Pharmacological studies have been carried out in vitro and in vivo on approximately 308 species belonging to the genera Salvia, Ocimum, Thymus, Mentha, Origanum, Lavandula, and Melissa. Phytochemical and pharmacological evaluations have been performed and mostly prepared as essential oil or high polarity extracts, whose secondary metabolites are mainly of a phenolic nature. Other interesting and explored metabolites are diterpenes from the abietane, clerodane, and kaurane type; however, they have only been described in some species of the genera Salvia and Isodon. This review reveals that the Nepetoideae subfamily is an important source for therapeutics of the inflammatory process.

Bioactive diterpenoids and sesquiterpenoids with different skeletons from Salvia digitaloides Diels

Salvia has been regarded as a beneficial healing herb in ancient Egypt, Rome and Greece, and is listed as an official medicine in the pharmacopoeias of many countries worldwide. Currently, Salvia is widely used to flavor and preserve food. Here, two undescribed norabietane-type diterpenoids, sadigitaloides A and B, two undescribed germacrane-type sesquiterpenoids, sadigitaloides C and D, five undescribed guaiane-type sesquiterpenoid lactones, sadigitaloides E-I, two undescribed noreudesmane-type sesquiterpenoids, sadigitaloides J and K, one known diterpenoid, three known sesquiterpenoids, and three other types of known compounds were isolated from the 95% ethanol extract of the whole plants of Salvia digitaloides. Their structures and absolute configurations were characterized using 1D and 2D NMR spectroscopic techniques, electronic circular dichroism (ECD) calculations, HRESIMS experiments, and single-crystal X-ray diffraction analysis. Some compounds were evaluated for their anti-inflammatory activities against lipopolysaccharide (LPS)-induced TNF-α production in rat macrophage NR8383 cells. Sadigitaloide A showed noticeable anti-inflammatory activity at a concentration of 100.0 μM. At a concentration of 60 μM, sadigitaloide B exhibited better protection of dopaminergic neurons than the positive control n-butylidenephthalide in the Caenorhabditis elegans model injured by 6-OHDA. The phytotoxic activities of some compounds were attributed to considerable inhibitory effects on the growth of the roots and hypocotyls of Raphanus sativus L seedlings, especially cis, trans-abscisic acid, whose inhibition rates were much higher than those of glyphosate at concentrations ranging from 50 to 400 ppm. These results indicated that abietane-type diterpenoids possessed excellent anti-inflammatory and neuroprotective activities and further suggested that the low-molecular-weight compounds exhibited outstanding phytotoxic activities.

Ethnopharmacology, phytochemistry, and pharmacology of Chinese Salvia species: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Salvia is one of the largest genera of the Lamiaceae family. In China, about 40 Salvia species have been used as medicinal plants for treatment of various diseases, specifically hepatic and renal diseases and those of the cardiovascular and immune systems.

AIM OF THIS REVIEW

This review aims to provide systematically organized information on the ethnopharmacology, phytochemistry, pharmacology, and toxicology of medicinal Salvia species in China to support their therapeutic potential in the treatment of human diseases.

MATERIALS AND METHODS

Relevant information on the Chinese Salvia species was obtained from scientific online databases such as Google Scholar, PubMed, and SciFinder. Additional information was derived from other literature sources (e.g. Chinese Pharmacopoeia 2015 edition, Chinese herbal classic books, PhD and MSc thesis, etc).

RESULTS

Our comprehensive analysis of the scientific literature indicates that many Chinese Salvia species are valuable and popular herbal medicines with therapeutic potentials to cure various ailments. Phytochemical analyses identified diterpenoids and phenolic acids as the major bioactive substances in Chinese Salvia species. Crude extracts and pure compounds isolated from the Chinese Salvia species exhibited various pharmacological activities, typically targeting the cardiovascular and immune systems and hepatic and renal diseases.

CONCLUSION

This review summarizes the results from current studies about basic properties of medicinal Salvia species in China, such as active constituents and their mechanism of action, pharmacokinetics, underlying molecular mechanisms, toxicology, and efficacy, which are still being studied and explored to achieve integration into medical practice.

Five new iridoids from roots of Salvia digitaloides

Five new iridoids, salvialosides A-E (compounds 1-5), together with fifty known compounds were isolated from the roots of Salvia digitaloides. The structures of the new compounds were completely elucidated using a combination of 2D NMR techniques (COSY, NOESY, HMQC and HMBC) and HR-ESI-MS analyses. The known compounds were identified by comparison of their spectroscopic and physical data with those reported in the literature.

Two diterpenoids and a cyclopenta[c]pyridine derivative from roots of Salvia digitaloids

Two new glucosides, salviadigitoside A (1) and salviatalin A-19-O-β-glucoside (2), belonging to the salviatalin type diterpenoids, and a new cyclopenta[c]pyridine, salviadiginine A (3), were isolated from the roots of Salvia digitaloids. Structures of these compounds were determined on the basis of spectroscopic analysis. In addition, compounds 1–3 were evaluated for their anti-inflammatory activity, but the results showed a weak anti-inflammatory activity.

Hydroxyclerodanes from Salvia shannoni

Six new hydroxyclerodanes (1-6), named sepulturins A-F, and four known diterpenes were isolated from the leaves of Salvia shannoni. The structures of these compounds were established by extensive analysis of their NMR and MS spectroscopic data. The relative configurations of compounds 1 and 2 were determined by NOESY experiments and were confirmed by single-crystal X-ray diffraction studies. All of the isolated diterpenes possess tertiary OH groups. The structure of infuscatin (7), a clerodane previously isolated from S. infuscata, was revised. Cytotoxic, antiprotozoal, and anti-inflammatory activities of these compounds were evaluated.

Neo-clerodane diterpenes from Salvia herbacea

Chemical investigation of the aerial parts of Salvia herbacea led to the isolation of eight new neo-clerodane diterpenes (1-8), named tehuanins A-H, and three known compounds. The structures of these compounds were determined by analysis of their spectroscopic data. Three of the new diterpenes possess a 1,8-epoxy group (1-3). This unusual structural feature was confirmed by X-ray diffraction of 1. The structure of the previously isolated 1α,10α-epoxysalviarin was revised. The absolute configuration of 6 was established by X-ray diffraction analysis of its bromo derivative 6a. Cytotoxic and anti-inflammatory activities of these diterpenes were examined. None of the compounds were considered to be cytotoxic; however, compound 7 exhibited anti-inflammatory activity comparable to that of indomethacin.

Search for novel remedies to augment radiation resistance of inhabitants of Fukushima and Chernobyl disasters: identifying DNA repair protein XRCC4 inhibitors

Two nuclear plant disasters occurring within a span of 25 years threaten health and genome integrity both in Fukushima and Chernobyl. Search for remedies capable of enhancing DNA repair efficiency and radiation resistance in humans appears to be a urgent problem for now. XRCC4 is an important enhancer in promoting repair pathway triggered by DNA double-strand break (DSB). In the context of radiation therapy, active XRCC4 could reduce DSB-mediated apoptotic effect on cancer cells. Hence, developing XRCC4 inhibitors could possibly enhance radiotherapy outcomes. In this study, we screened traditional Chinese medicine (TCM) database, TCM Database@Taiwan, and have identified three potent inhibitor agents against XRCC4. Through molecular dynamics simulation, we have determined that the protein-ligand interactions were focused at Lys188 on chain A and Lys187 on chain B. Intriguingly, the hydrogen bonds for all three ligands fluctuated frequently but were held at close approximation. The pi-cation interactions and ionic interactions mediated by o-hydroxyphenyl and carboxyl functional groups respectively have been demonstrated to play critical roles in stabilizing binding conformations. Based on these results, we reported the identification of potential radiotherapy enhancers from TCM. We further characterized the key binding elements for inhibiting the XRCC4 activities.

Diterpenoid constituents of the roots of Salvia digitaloides

Salvia digitaloides, belonging to the economically and medicinally important genus Salvia, is distributed in the northwest of Yunnan Province, People's Republic of China. The roots of this plant were soaked in alcohol by local Tibetans to make a special traditional "red wine", and many local people like to drink this traditional "red wine" to strengthen physical health. To investigate the bioactive diterpenoid constituents of the roots, a detailed phytochemical study was carried out, and 13 diterpenoids including two new norditerpenoids, dihydroneotanshinlactone (1) and 16,17-dinorpisferal A (2), were isolated. Their structures were established on the basis of detailed spectroscopic analysis. In addition, computational methods were applied to validate the stereochemistry of compound 1. For the bioassay to inhibit the growth of five tumor cell lines, neotanshinlactone (3) exhibited selective cytotoxic activity toward the human breast cancer cell line SK-BR-3, while the other four tanshinones (4-7) showed significant toxicity effects against all of the tested five cell lines.