Naturally occurring steroidal saponins as potential anticancer agents: Current developments and mechanisms of action

New steroidal saponins from Physochlainae Radix: Structures and anti-inflammatory efficacy

Physochlainae Radix (PR), a crucial herbal medicine, has been widely utilized in the treatment of pulmonary disorders, such as asthma and bronchitis. In the present study, nine previously undescribed steroidal saponins, designated as infundilides A-I (1-9), were isolated from PR. These compounds exhibit unique structural features characterized by the presence of unusual hydroxymethyl or carboxyl substituents at the C-20 position. Additionally, five new analogues, infundilides J-N (10-14), were also obtained. Their planar structures were elucidated based on analysis of MS and NMR spectroscopy data, and the absolute configurations were determined by single-crystal X-ray diffraction and comparisons of spectroscopic data. In vitro anti-inflammatory activity assays revealed that infundilide A (1), infundilide E (5), and infundilide K (11) exhibited pronounced inhibitory effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW264.7 macrophages. Subsequently, to further explore the anti-inflammatory efficacy of steroidal saponins in PR, the therapeutic potential of infundilide A (1) was evaluated in a mouse model of acute lung injury (ALI). The results demonstrated that infundilide A effectively alleviated ALI-associated pathological changes, reduced inflammatory cytokines levels (IL-1β, TNF-α, IL-6, and COX-2) in the lung tissues, and modulated the TLR4/MyD88/NF-κB signaling pathway. To sum up, infundilide A holds promise as a potential anti-inflammatory lead compound. These discoveries emphasize the prospective therapeutic uses of steroidal saponins from PR in the treatment of inflammatory disorders.

Anticancer Activities of Natural and Synthetic Steroids: A Review

Steroids have demonstrated a wide field of research on the subject of anticancer compounds, particularly antiproliferative with cell lines, with special emphasis on the historical link between steroids and cancer and the use of in silico technologies to understand the impact of natural and synthetic steroids on cancer cells focused on finding common denominators of the type of structural changes that give antiproliferative and/or cytotoxic properties, both in control and cancer cell lines. Through this review and classification by origin and/or synthesis, it is found that steroidal saponins are highly cytotoxic, although with low selectivity against control cells, while on the part of the aglycone the presence of heteroatoms such as nitrogen and oxygen increases the antiproliferative activity, mainly via cell cycle arrest and the induction of apoptosis, mechanisms that have been partially proven, using semisynthetic derivatives, as well as bioconjugates between saponins and nitrogenous steroids with now a high cytotoxicity and selectivity against control cell lines. This gives rise to the idea that steroids as a study model for the design of anticancer agents are an excellent template with a wide field of study.

Two New Isospirostanol-Type Saponins from the Bulbs of Lilium Brownii and Their Anti-Hepatocarcinogenic Activity

Bulbs of Lilium brownii, commonly known as "Bai-he" in China, serve both edible and medicinal purposes in clinical practice. In this study, two new isospirostanol-type saponins were isolated from L. brownii, and their structures were identified by spectroscopic method, and absolute configurations were elucidated by comprehensive analysis of spectral data obtained from combined acid hydrolysis. Two compounds were finally identified as 3-O-[α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside]-(22R,25R)-5α-spirosolane-3β-ol (1) and 3-O-{α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)]-β-D-glucopyranoside}-(22R,25R)-5α-spirosolane-3β-ol (2), respectively. Further, we found that compound 2 significantly suppressed the proliferation of SMMC-7721 and HepG2 cells with IC50 values of 26.3±1.08 μM and 30.9±1.59 μM, whereas compound 1 didn't inhibit both of the two hepatocellular carcinoma. Subsequently, compound 2 effectively decreased the levels of interleukin-1β and tumor necrosis factor-α and the expression of Bcl-2, and increased the expression of Bax and Caspase-3 proteins. Which indicated that the anti-hepatocellular carcinoma effect of compound 2 involves reducing the level of inflammation and inducing apoptosis.

A review on anti-nutritional factors: unraveling the natural gateways to human health

Humans are constantly facing multiple health challenges from both communicable and non-communicable diseases that significantly affect their health. Additionally, drug resistance or failure has made the situation even worse and poses serious challenges for researchers to develop new drugs. Hence, to address these problems, there is an urgent need to discover and develop timely and long-term-based therapeutic treatments from different sources. One such approach is harnessing the potential of plant secondary metabolites. Plants have been utilized for therapeutic purposes in addition to being used for nutritional benefits. In the last two decades, plant-based drug developments have been one of the effective means of treating human diseases owing to their multiple functions. More recently, anti-nutritional factors (ANFs) have emerged as one of the important targets for novel plant-based drug development due to their multifaceted and potential pharmacological properties. However, their anti-nutritional properties have been the major setback for their limited success in the pharmacological sector. In this review, we provide an overview of ANFs and their beneficial roles in preventing human diseases with multiple case studies. We also highlight the recent developments and applications of ANFs in the food industry, agriculture, and pharmaceutics with future perspectives. Furthermore, we evaluate meta-analyses on ANFs from the last 30 years in relation to their function in human health benefits. This review is an endeavor to reevaluate the merit of these natural compounds and explore their potential for both human and animal health.

Molecular docking analysis and evaluation of the antimicrobial properties of the constituents of Geranium wallichianum D. Don ex Sweet from Kashmir Himalaya

Geranium wallichianum D. Don ex Sweet is a well-known medicinal plant in Kashmir Himalya. The evidence for its modern medicinal applications remains majorly unexplored. The present study was undertaken to elucidate the detailed antimicrobial promises of different crude extracts (methanolic, ethanolic, petroleum ether, and ethyl acetate) of G. wallichainum against common human bacterial and fungal pathogens in order to scientifically validate its traditional use. The LC–MS analysis of G. wallichainum yielded 141 bioactive compounds with the vast majority of them having therapeutic applications. Determination of minimum inhibitory concentrations (MICs) by broth microdilution method of G. wallichainum was tested against bacterial and fungal pathogens with MICs ranging from 0.39 to 400 µg/mL. Furthermore, virtual ligands screening yielded elatine, kaempferol, and germacrene-A as medicinally most active constituents and the potential inhibitors of penicillin-binding protein (PBP), dihydropteroate synthase (DHPS), elongation factor-Tu (Eu-Tu), ABC transporter, 1,3 beta glycan, and beta-tubulin. The root mean square deviation (RMSD) graphs obtained through the molecular dynamic simulations (MDS) indicated the true bonding interactions which were further validated using root mean square fluctuation (RMSF) graphs which provided a better understanding of the amino acids present in the proteins responsible for the molecular motions and fluctuations. The effective binding of elatine, kaempferol, and germacrene-A with these proteins provides ground for further research to understand the underlying mechanism that ceases the growth of these microbes.

Pennogenin-3-O-α-L-Rhamnopyranosyl-(1→2)-[α-L-Rhamnopyranosyl-(1→3)]-β-D-Glucopyranoside (Spiroconazol A) Isolated from Dioscorea bulbifera L. var. sativa Induces Autophagic Cell Death by p38 MAPK Activation in NSCLC Cells

In our previous study, we reported the isolation of pennogenin-3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→3)]-β-D-glucopyranoside (spiroconazol A), a steroidal saponin, from the flowers of Dioscorea bulbifera L. var. sativa. In the present study, we aimed to investigate the effects of spiroconazol A on autophagy and its underlying mechanisms in A549 and NCI-H358 human non-small cell lung cancer (NSCLC) cells. Spiroconazol A inhibited the proliferation of NSCLC cells in a concentration- and time-dependent manner. To determine the type of programmed cell death induced by spiroconazol A, we performed a characterization of apoptosis in spiroconazol A-treated A549 cells. Our results showed that spiroconazol A significantly suppressed A549 cell viability but did not influence cell apoptosis because phosphatidylserine and caspase activation were not detected. Furthermore, spiroconazol A treatment upregulated the expression of LC3-II and autophagy-related Beclin-1 protein, suggesting that spiroconazol A induces autophagy in A549 cells. Moreover, spiroconazol A activated the phosphorylation of p38 mitogen-activated protein kinase (MAPK) but did not affect the phosphorylation of Janus kinase or ERK1/2. Notably, SB203580, a p38 MAPK inhibitor, had a significant inhibitory effect on spiroconazol A-induced autophagic cell death in A549 cells. Our results indicated that spiroconazol A-induced autophagy is dependent on p38 MAPK signaling and has potential as a therapeutic target in NSCLC.