Steroidal Saponins from the Rhizomes of Aspidistra typica

Aspidiatas C and D, two new spirostanol saponins from Aspidistra triradiata and their cytotoxic activities

Aspidiatas C and D (1 and 2), two new spirostanol saponins, were isolated along with two known compounds, (25 R*)-spirost-5-en-3β-yl α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside (3), (25 R*)-spirost-5-en-3β-yl α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside (4) from the whole plant of Aspidistra triradiata collected in Vietnam. The chemical structures were determined by HRESIMS, 1D- and 2D-NMR analysis, and comparison with published data. Compound 3 exhibited potent cytotoxicity against MCF7, HepG2, SK-LU-1, and HT-29 human cancer cell lines with IC50 values ranging from 0.19 to 0.65 µM. Compounds 1, 2, and 4 displayed moderate cytotoxic effects with IC50 values ranging from 12.32 to 82.27 µM. Compounds 1-4 were isolated from the genus Aspidistra for the first time.

A new spirostanol steroid and a new spirostanol steroidal saponin from Aspidistra triradiata and their cytotoxic activities

A new spirostanol steroid, aspidiata A (1), and a new spirostanol steroidal saponin, aspidiata B (2), along with three known compounds, paris saponin VII (3), daucosterol (4), and (25R)-spirostane-1β,2β,3β,4β,5β,6β-hexol (5), were isolated from whole plants of Aspidistra triradiata collected in Vietnam. Their chemical structures were established by spectroscopic analysis and comparison with previously published data. Compound 3 showed strong cytotoxicity against LU-1, Hep-G2, MCF-7, and KB human cancer cell lines with half maximal inhibitory concentration (IC50) values ranging from 0.57 to 1.23 µM. Compound 5 exhibited weak cytotoxic activity against the LU-1 cell line, with an IC50 value of 95.81 µM.

A comprehensive overview on the role of phytocompounds in human immunodeficiency virus treatment

Acquired immune deficiency syndrome (AIDS) is a worldwide epidemic caused by human immunodeficiency virus (HIV) infection. Newer medicines for eliminating the viral reservoir and eradicating the virus are urgently needed. Attempts to locate relatively safe and non-toxic medications from natural resources are ongoing now. Natural-product-based antiviral candidates have been exploited to a limited extent. However, antiviral research is inadequate to counteract for the resistant patterns. Plant-derived bioactive compounds hold promise as powerful pharmacophore scaffolds, which have shown anti-HIV potential. This review focuses on a consideration of the virus, various possible HIV-controlling methods and the recent progress in alternative natural compounds with anti-HIV activity, with a particular emphasis on recent results from natural sources of anti-HIV agents. Please cite this article as: Mandhata CP, Sahoo CR, Padhy RN. A comprehensive overview on the role of phytocompounds in human immunodeficiency virus treatment. J Integr Med. 2023; Epub ahead of print.

Steriodal saponins from the rhizomes of Tupistra chinensis Baker

Chemical constituent investigation on the n-BuOH extract of the rhizomes of Tupistra chinensis Baker leads to the isolation of ten compounds including eight undescribed furostanol saponins, tupischinosides A - H, and two known ones. The structures of isolated compounds were determined by extensive spectral analysis and chemical evidences. Interestingly, tupischinosides A and B, C and D, E and F, G and H were identified as four pairs of epimers. The cytotoxicity of tupischinosides A - H against human cancer cell lines U87, SHG44, U251, LN229 and HepG-2 was evaluated by CCK-8 method. As a result, tupischinosides A and C exhibited significant proliferation inhibitory effect on the tested cancer cells. On the contrary, the corresponding epimers, tupischinosides B and D, which only differ in the configuration of C-23 didn't exhibit any cytotoxicity to cancer cells. These results indicated that the stereochemistry of C-23 was crucial to the activity of the compounds.

Three New Steriodal Saponins from the Rhizomes of Tupistra chinensis Baker

The phytochemical constituent investigation on the 70 % ethanol extract of the rhizomes of Tupistra chinensis Baker resulted in the isolation of three new steroidal saponins which were named tuchinosides A-C (1-3). Their structures were determined by extensive spectrum analysis and chemical evidence, especially 2D NMR and HR-ESI-MS techniques. In addition, the cytotoxicity of compounds 1-3 against several human cancer cell lines was evaluated.

Cytotoxic steroidal glycosides from Polygonatum odoratum (Mill.) Druce

Twenty-five steroidal glycosides including eight undescribed compounds which were named as polygonatumosides H-O, were isolated from the 70 % EtOH extract of rhizomes of Polygonatum odoratum (Mill.) Druce (Asparagaceae). Their structures were elucidated by extensive spectroscopic analyses and chemical methods. The isolated compounds were evaluated cytotoxicity against three human cancer cell lines: human non-small cell lung cancer (A549), human epithelial colorectal adenocarcinoma (Caco2), and human hepatocellular carcinoma (HepG2) cells. Five compounds showed cytotoxicity against these cell lines with IC₅₀ values in the range of 1.7-30.8 μM.

Inducing regulated necrosis and shifting macrophage polarization with anti-EMMPRIN antibody (161-pAb) and complement factors

Treatment of solid tumors is often hindered by an immunosuppressive tumor microenvironment (TME) that prevents effector immune cells from eradicating tumor cells and promotes tumor progression, angiogenesis, and metastasis. Therefore, targeting components of the TME to restore the ability of immune cells to drive anti-tumoral responses has become an important goal. One option is to induce an immunogenic cell death (ICD) of tumor cells that would trigger an adaptive anti-tumoral immune response. Here we show that incubating mouse renal cell carcinoma (RENCA) and colon carcinoma cell lines with an anti-extracellular matrix metalloproteinase inducer polyclonal antibody (161-pAb) together with complement factors can induce cell death that inhibits caspase-8 activity and enhances the phosphorylation of receptor-interacting protein kinase 3 (RIPK3) and mixed-lineage kinase-like domain (MLKL). This regulated necrotic death releases high levels of dsRNA molecules to the conditioned medium (CM) relative to the necrotic death of tumor cells induced by H2 O2 or the apoptotic death induced by etoposide. RAW 264.7 macrophages incubated with the CM derived from these dying cells markedly enhanced the secretion of IFNβ, and enhanced their cytotoxicity. Furthermore, degradation of the dsRNA in the CM abolished the ability of RAW 264.7 macrophages to secrete IFNβ, IFNγ-induced protein 10 (IP-10), and TRAIL. When mice bearing RENCA tumors were immunized with the 161-pAb, their lysates displayed elevated levels of phosphorylated RIPK3 and MLKL, as well as increased concentrations of dsRNA, IFNβ, IP-10, and TRAIL. This shows that an antigen-targeted therapy using an antibody and complement factors that triggers ICD can shift the mode of macrophage activation by triggering regulated necrotic death of tumor cells.

Antitumor activities of Aspiletrein A, a steroidal saponin from Aspidistra letreae, on non-small cell lung cancer cells

BACKGROUND

Lung cancer is one of the leading causes of death worldwide due to its strong proliferative and metastatic capabilities. The suppression of these aggressive behaviors is of interest in anticancer drug research and discovery. In recent years, many plants have been explored in order to discover new bioactive secondary metabolites to treat cancers or enhance treatment efficiency. Aspiletrein A (AA) is a steroidal saponin isolated from the whole endemic species Aspidistra letreae in Vietnam. Previously, elucidation of the structure of AA and screening of its cytotoxic activity against several cancer cell lines were reported. However, the antitumor activities and mechanisms of action have not yet been elucidated. In this study, we demonstrated the anti-proliferative, anti-migrative and anti-invasive effects of AA on H460, H23 and A549 human lung cancer cells.

METHODS

MTT, wound healing and Transwell invasion assays were used to evaluate the anti-proliferation, anti-migration and anti-invasion effects of AA, respectively. Moreover, the inhibitory effect of AA on the activity of protein kinase B (Akt), a central mediator of cancer properties, and apoptotic regulators in the Bcl-2 family proteins were investigated by Western blotting.

RESULTS

AA exhibits antimetastatic effects in human lung cancer cells through the inhibition of the pAkt/Akt signaling pathway, which in turn resulted in a significant inhibitory effect of AA on the migration and invasion of the examined lung cancer cells.

CONCLUSIONS

Aspiletrein A may be a potent inhibitor of protein kinase B (Akt). Hence, AA could be further explored as a potential antimetastatic lead compound.

Antioxidant Activity of a New Xanthone Derivative from Aspidistra Letreae: In Vitro and In Silico Studies

A new xanthone derivative, aspidxanthone A (1), and three known compounds ((2S)-1-(β-D-galactopyranosyloxy)-3-(hexadecanoyloxy)propan-2-yl (9Z,12Z)-octadeca-9,12-dienoate (2), (25S)-spirostane-1β,3α,5β-triol (3), and asparenyldiol (4)) were isolated from the whole of the endemic species Aspidistra letreae in Vietnam. Their structures were elucidated by means of extensive spectroscopic analyses and comparison with published data. In this study, we report the isolation and structure elucidation of a new compound aspidxanthone A, antioxidant activities of the extract and isolates 1-4, and in silico molecular docking of aspidxanthone A. The ethyl acetate extract had good antioxidant activity with an IC₅₀ value of 26.3 μg mL^-1 . Among the isolates, aspidxanthone A exhibited DPPH reduction activity with an IC₅₀ value of 11.2 μM, which is in the same range as that of the positive control, ascorbic acid. The mechanism of action of aspidxanthone A on the tyrosinase and xanthine oxidase proteins have been clarified by in silico studies.

New steroidal glycosides from the roots of Asparagus cochinchinensis

Steroidal saponins were the main active constituents of the traditional medicinal herb Asparagus cochinchinensis. A phytochemical investigation of A. cochinchinensis roots led to the isolation of nine new steroidal glycosides (1-9) and seven known analogues (10-16). Their structures were established by spectroscopic analyses as well as necessary chemical evidence.

Steroidal glycosides, homoisoflavanones and cinnamic acid derivatives from Polygonatum odoratum and their inhibitory effects against influenza A virus

A phytochemical investigation of Polygonatum odoratum roots led to the isolation of fifteen steroidal glycosides (1-15), three homoisoflavanones (16-18) and four cinnamic acid derivatives (19-22). The structures of all isolated compounds were established mainly by spectroscopic analyses as well as necessary chemical evidence, of which 1-8 (polygodorasides A-G) were identified as new steroidal glycosides. Among the isolates, compounds 7 and 17 showed remarkable in vitro inhibitory effects against influenza A virus with IC₅₀ values of 14.30 and 49.70 μM (positive control ribavirin 28.4 μM).

Three new steroidal saponins from Aspidistra letreae plants and their cytotoxic activities

Three new steroidal saponins, aspiletreins A-C (1-3), together with 2H-chromen-2-one (4), and α-tocopherol (5), were isolated from whole Aspidistra letreae plants collected in Vietnam. Their structures were elucidated by a combination of spectroscopic analyses, including 1D- and 2D-NMR, IR, and HRESIMS, and by comparison with the reported data in the literature. Compounds 1-3 exhibited moderate cytotoxicities against the LU-1, HeLa, MDA-MB-231, HepG2, and MKN-7 human cancer cell lines, with IC50 values ranging from 7.69 ± 0.40 to 20.46 ± 3.11 µM.

Mediterranean herb extracts inhibit microbial growth of representative oral microorganisms and biofilm formation of Streptococcus mutans

In light of the growing antibiotic resistance, the usage of plant-derived antimicrobial agents could serve as an effective alternative treatment against oral infections. The aim of this study was to investigate the antimicrobial and antibiofilm activity of Mediterranean herb extracts against representative oral microorganisms. The extraction procedures and the analysis of the obtained extracts were performed under established experimental conditions. The minimum inhibitory (MIC) and bactericidal (MBC) concentrations of the methanol extracts of Cistus creticus ssp. creticus, Cistus monspeliensis, Origanum vulgare, Rosmarinus officinalis, Salvia sclarea and Thymus longicaulis against eight typical oral bacteria and the fungus Candida albicans were determined. The antibiofilm activity against Streptococcus mutans was also quantified using the microtiter plate test. Overall, all tested extracts inhibited effectively the screened obligate anaerobic microorganisms and in concentrations ≥0.3 mg ml-1 had moderate to high antibiofilm activity comparable to that of chlorhexidine (CHX) against S. mutans. In particular, R. officinalis (MIC: 0.08-5.00 mg ml-1) and S. sclarea (MIC: 0.08-2.50 mg ml-1) showed the highest antibacterial activity, while Cistus spp., R. officinalis and S. sclarea significantly inhibited S. mutans biofilm formation at 0.60, 1.25 and 2.50 mg ml-1, respectively. Porphyromonas gingivalis and Parvimonas micra were high susceptible to O. vulgare (MIC = 0.30 mg ml-1), whereas T. longicaulis eradicated all oral bacteria (MBC: 0.15-2.50 mg ml-1). Nevertheless, C. albicans showed no sensitivity to the tested extracts. In conclusion, the tested plant extracts could serve as alternative natural antibacterial and antibiofilm components against oral infections.

Recent advances in steroidal saponins biosynthesis and in vitro production

Steroidal saponins exhibited numerous pharmacological activities due to the modification of their backbone by different cytochrome P450s (P450) and UDP glycosyltransferases (UGTs). Plant-derived steroidal saponins are not sufficient for utilizing them for commercial purpose so in vitro production of saponin by tissue culture, root culture, embryo culture, etc, is necessary for its large-scale production. Saponin glycosides are the important class of plant secondary metabolites, which consists of either steroidal or terpenoidal backbone. Due to the existence of a wide range of medicinal properties, saponin glycosides are pharmacologically very important. This review is focused on important medicinal properties of steroidal saponin, its occurrence, and biosynthesis. In addition to this, some recently identified plants containing steroidal saponins in different parts were summarized. The high throughput transcriptome sequencing approach elaborates our understanding related to the secondary metabolic pathway and its regulation even in the absence of adequate genomic information of non-model plants. The aim of this review is to encapsulate the information related to applications of steroidal saponin and its biosynthetic enzymes specially P450s and UGTs that are involved at later stage modifications of saponin backbone. Lastly, we discussed the in vitro production of steroidal saponin as the plant-based production of saponin is time-consuming and yield a limited amount of saponins. A large amount of plant material has been used to increase the production of steroidal saponin by employing in vitro culture technique, which has received a lot of attention in past two decades and provides a way to conserve medicinal plants as well as to escape them for being endangered.

Spirostane-Type Saponins Obtained from Yucca schidigera

It is well known that spirostane-type saponins show various bioactivities. In our on-going program of screening these kinds of constituents from natural products, Yucca schidigera was found to be rich in them, and nine new spirostanol saponins, Yucca spirostanosides A₁ (1), A₂ (2), B₁ (3), B₂ (4), B₃ (5), C₁ (6), C₂ (7), C₃ (8), and D₁ (9), together with five known ones (10–14) were isolated from the plant. Their structures were elucidated by extensive spectroscopic methods, including 1D and 2D NMR and MS spectra, and comparing with published data.

Rapid Characterization of Constituents in Tribulus terrestris from Different Habitats by UHPLC/Q-TOF MS

A strategy for rapid identification of the chemical constituents from crude extracts of Tribulus terrestris was proposed using an informatics platform for the UHPLC/Q-TOF MS^E data analyses. This strategy mainly utilizes neutral losses, characteristic fragments, and in-house library to rapidly identify the structure of the compounds. With this strategy, rapid characterization of the chemical components of T. terrestris from Beijing, China was successfully achieved. A total of 82 steroidal saponins and nine flavonoids were identified or tentatively identified from T. terrestris. Among them, 15 new components were deduced based on retention times and characteristic MS fragmentation patterns. Furthermore, the chemical components of T. terrestris, including the other two samples from Xinjiang Uygur Autonomous region, China, and Rome, Italy, were also identified with this strategy. Altogether, 141 chemical components were identified from these three samples, of which 39 components were identified or tentatively identified as new compounds, including 35 groups of isomers. It demonstrated that this strategy provided an efficient protocol for the rapid identification of chemical constituents in complex samples such as traditional Chinese medicines (TCMs) by UHPLC/Q-TOF MS^E with informatics platform. Graphical Abstract ᅟ.