Isolation, structural elucidation and cytotoxicity evaluation of a new pentahydroxy-pimarane diterpenoid along with other chemical constituents from Aerva lanata

Pimarane diterpenoids: sources, structures and biological activities

The pimarane diterpenoids, a widespread class of secondary metabolites, have been found in several dozens of plant species from various families and in organisms from other taxonomic groups. According to the different chiral centres, pimarane diterpenes can be divided into four types, including pimarane, isopimarane, ent-pimarane, and ent-isopimarane. Meanwhile, these compounds possessed many pharmacological activities, such as cytotoxic, anti-inflammatory, and antibacterial activities. Due to their notable structure and biological activities these substances have attracted interest in recent years. A comprehensive account of the structural diversity (368 structures, 117 references) and biological activities of pimarane diterpenes discovered from 2000 until 2023 is given in this review.

Novel Canthin-6-one Derivatives: Design, Synthesis, and Their Antiproliferative Activities via Inducing Apoptosis, Deoxyribonucleic Acid Damage, and Ferroptosis

A series of novel canthin-6-one (CO) derivatives (8a-l) were designed and synthesized by introducing different amide side chains at the C-2 position, and their water solubility, antiproliferative activity, and preliminary mechanism were investigated. Most compounds displayed high cytotoxicity exhibiting low-micromolar IC50 values against four human cancer cell lines, especially HT29 cells. Meanwhile, the water solubility of active CO derivatives was significantly improved. Among these compounds, compound 8h with the N-methyl piperazine group exhibiting the highest antiproliferative capability with an IC50 value of 1.0 μM against HT29 cells, which was 8.6-fold lower than that of CO. Furthermore, 8h could upregulate the levels of reactive oxygen species, leading to mitochondrial damage. In addition, 8h could promote cell apoptosis and DNA damage by regulating the expression of apoptosis-associated proteins (Bcl-2 and cleaved-caspase 3) and the DNA damage-associated protein (H2AX). Most importantly, 8h also exerted ferroptosis by reducing the GSH level and GPX4 expression as well as increasing the lipid peroxidation level. Thus, the novel CO derivative 8h with N-methylpiperazine represents a promising anticancer candidate and warrants a more intensive study.

Anti-inflammatory activity of 3-cinnamoyltribuloside and its metabolomic analysis in LPS-activated RAW 264.7 cells

BACKGROUND

Inflammation is a response to tissue injuries, which is indispensable and important for human health, but excessive inflammation can potentially cause damage to the host organisms. Camellia nitidissima Chi, one traditional medicinal and edible plant in China, was reported to exhibit anti-inflammation capability. Hence, this study was conducted to isolate the bioactive compounds from the flowers of C. nitidissima Chi and evaluate their anti-inflammatory activity.

METHODS

The phytochemicals from the flowers of C. nitidissima Chi were isolated and purified by silica gel, Sephadex LH-20 gel, C18 reversed silica gel, semi-preparative HPLC, and identified by the spectrum technologies. The anti-inflammatory activity of isolated compounds was evaluated using cultured macrophage RAW 264.7 cells. Whereafter the potential metabolic mechanism of the anti-inflammatory activity of the bioactive compound was investigated by a 1H-NMR based metabolomics approach. The metabolites in 1H-NMR spectra were identified by querying the Human Metabolome Database and Madison Metabolomics Consortium Database online. And the multivariate statistical analysis was performed to evaluate the variability of metabolites among samples and between sample classes.

RESULTS

The compound isolated from the flowers of C. nitidissima Chi was identified as 3-cinnamoyltribuloside (3-CT). 3-CT could inhibit the NO production and the mRNA expression of iNOS involved in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Moreover, 3-CT could inhibit the expression of a series of inflammatory cytokines, including TNF-α, IL-1β, and IL-6, both at the mRNA level and protein level. The 1H-NMR based metabolomics approach was applied to investigate the potential metabolic mechanism of the anti-inflammatory activity of 3-CT. Thirty-five metabolites were identified and assigned. Orthogonal signal correction partial least-squares discriminant analysis (OSC-PLS-DA) of the 1H-NMR data showed 3-CT could balance the significant changes in many endogenous metabolites (e.g., choline, glucose, phenylalanine) induced by LPS in RAW 264.7 cells, which related to cholinergic anti-inflammatory pathway, oxidative stress, energy metabolism, and amino acids metabolism.

CONCLUSION

3-CT, isolated from the flowers of C. nitidissima Chi, had potent anti-inflammatory activity in LPS-activated RAW 264.7 cells. Furthermore, our results indicated that 3-CT had effects on the cholinergic anti-inflammatory pathway, oxidative stress, energy metabolism, and amino acids metabolism in LPS-activated RAW 264.7 cells.

Pharmaceutical, Ethnopharmacological, Phytochemical and Synthetic Importance of Genus Aerva: A Review

Aerva plants are known widely for their exceptional medicinal uses. They have been employed conventionally for their medicinal properties by the common folk in several regions of the world. This indicates the efficacy of these remarkable herbs. They are also known for their multiple biological activities such as antioxidant, antibacterial, antilithiatic, hepatoprotective, antidiabetic, anticancer, antihyperlipidemic and nephroprotective potential. These pharmacological actions are associated with the presence of valuable nutrients and biochemical compounds such as sterols/terpenes, flavonoids, alkaloids, phenolics and sugars. The proper utilization of the substances obtained from these plants can enhance the finesse of the capabilities of these plants. These plants are not only medicinally important but are significantly serving several other scientific purposes. In the prospect of medicinal, scientific uses and the bioavailability of precious chemicals of Aerva species, a comprehensive review is compiled, which focuses on the detailed profile of biochemical compounds, pharmacological functions and biological activities of Aerva plants. The review also discusses the synthetic importance and the toxicity of these plants. The study aims to compile comprehensively what is already done and what more is needed to be done in the future investigations related to Aerva species.

Toxicological evaluation of the aqueous whole plant extract of Aerva lanata (l.) Juss. ex Schult (Amaranthaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Aerva lanata (L.) of the family Amaranthaceae is a Nigerian medicinal plant used traditionally for the management of lithiasis, headache, renal disorder, haematemesis, bronchitis, nasal bleeding, cough, scorpion stings, fractures and spermatorrhoea. Studies that show the pharmacological basis for some of such uses have been reported. There is, however, no scientific report on its toxicity profile to the best of our knowledge.

AIM OF THE STUDY

This study was therefore aimed at investigating the toxicity profile of the aqueous extract of Aerva lanata.

MATERIALS AND METHODS

Acute toxicity tests for the extract administered orally at 1-30g/kg and intraperitoneally at 0.1-2g/kg were carried out in albino mice; while a sub-chronic toxicity test was done by daily oral administration of the extract at 40-1000mg/kg to albino rats for 90 days. Anthropometric, biochemical and haematological parameters' assessments as well as vital organs histological examinations were performed in the sub-chronic toxicity study.

RESULTS

The LD₅₀ of the extract for oral and intraperitoneal acute toxicity tests were 22.62g/kg and 0.432g/kg respectively. The extract produced apparent changes in body weights of both male and female rats and significantly (p < 0.05) increased the weights of lungs, brain and pancreas of female rats while reducing the weight of testes in male rats. Haematological parameters were also altered with total leukocytes significantly (p < 0.05) increased and platelets significantly (p < 0.05) reduced in female rats; while neutrophils significantly (p < 0.05) increased in male rats. The extract (40-1000mg/kg) produced significant (p < 0.05) reduction of serum alanine transaminase concentration in both male and female rats. Aspartate transaminases and albumin were also significantly (p < 0.05) reduced in both male (at 1000mg/kg) and female (at 200mg/kg) rats. Alkaline phosphatase was also significantly (p < 0.05) reduced in female rats at 200mg/kg of the extract. Substantial alterations of creatinine, urea and uric acid were also observed. Triglyceride and cholesterol concentrations were significantly increased in male rats but decreased in female rats. At 1000mg/kg, the extract significantly elevated catalase and superoxide dismutase levels with no effect on malondialdehyde levels. It also reduced sperm count and motility of male rats. Mild to moderate cellular changes in the brain, kidney, liver, lungs, spleen and testes of treated rats were observed on histological examinations. Significant changes in biochemical and haematological parameters were also noted in treated animals when compared to control animals 30 days after cessation of treatment.

CONCLUSION

The overall findings of this study suggest that the aqueous extract of A. lanata is relatively safe on acute oral exposure, moderately toxic on acute intraperitoneal administration and is relatively safe with antioxidant actions on prolonged exposure. It however shows potentials for toxic effects such as cellular damage to organs, dyslipidaemia and reduction in male reproductive capacity. Caution must therefore be applied in its use on a long term basis.

Fruitful Decades for Canthin-6-ones from 1952 to 2015: Biosynthesis, Chemistry, and Biological Activities

In this review, more than 60 natural canthin-6-one alkaloids and their structures are considered. The biosynthesis, efficient and classic synthetic approaches, and biological activities of canthin-6-one alkaloids, from 1952 to 2015, are discussed. From an analysis of their structural properties and an investigation of the literature, possible future trends for canthin-6-one alkaloids are proposed. The information reported will be helpful in future research on canthin-6-one alkaloids.

Synthesis and Evaluation of Ester Derivatives of 10-Hydroxycanthin-6-one as Potential Antimicrobial Agents

As part of our continuing research on canthin-6-one antimicrobial agents, a new series of ester derivatives of 10-hydroxycanthin-6-one were synthesized using a simple and effective synthetic route. The structure of each compound was characterized by NMR, ESI-MS, FT-IR, UV, and elemental analysis. The antimicrobial activity of these compounds against three phytopathogenic fungi (Alternaria solani, Fusarium graminearum, and Fusarium solani) and four bacteria (Bacillus cereus, Bacillus subtilis, Ralstonia solanacearum, and Pseudomonas syringae) were evaluated using the mycelium linear growth rate method and micro-broth dilution method, respectively. The structure-activity relationship is discussed. Of the tested compounds, 4 and 7s displayed significant antifungal activity against F. graminearum, with inhibition rates of 100% at a concentration of 50 μg/mL. Compounds 5, 7s, and 7t showed the best inhibitory activity against all the tested bacteria, with minimum inhibitory concentrations (MICs) between 3.91 and 31.25 μg/mL. Thus, 7s emerged as a promising lead compound for the development of novel canthine-6-one antimicrobial agents.

Diterpenoids of terrestrial origin

This review covers the isolation and chemistry of diterpenoids from terrestrial as opposed to marine sources and includes labdanes, clerodanes, pimaranes, abietanes, kauranes, cembranes and their cyclization products. The literature from January to December, 2015 is reviewed.

Impact of Nutrition on Non-Coding RNA Epigenetics in Breast and Gynecological Cancer

Cancer is the second leading cause of death in females. According to the American Cancer Society, there are 327,660 new cases in breast and gynecological cancers estimated in 2014, placing emphasis on the need for cancer prevention and new cancer treatment strategies. One important approach to cancer prevention involves phytochemicals, biologically active compounds derived from plants. A variety of studies on the impact of dietary compounds found in cruciferous vegetables, green tea, and spices like curry and black pepper have revealed epigenetic changes in female cancers. Thus, an important emerging topic comprises epigenetic changes due to the modulation of non-coding RNA levels. Since it has been shown that non-coding RNAs such as microRNAs and long non-coding RNAs are aberrantly expressed in cancer, and furthermore are linked to distinct cancer phenotypes, understanding the effects of dietary compounds and supplements on the epigenetic modulator non-coding RNA is of great interest. This article reviews the current findings on nutrition-induced changes in breast and gynecological cancers at the non-coding RNA level.