Chemical constituents and biological applications of the genus Symplocos

Anti-inflammatory Effect of Symplocos prunifolia Extract in an In Vitro Model of Acute Pneumonia

Acute pneumonia is a respiratory disease characterized by inflammation within the lung tissue, exhibiting higher morbidity rates and mortality rates among immunocompromised children and older adults. Symplocos species have been traditionally used as herbal remedies for conditions like dysentery, skin ulcers, diarrhea, and dyspepsia. Contemporary research has employed various Symplocos species in the study of diverse diseases. However, the exact efficacy and mechanisms of action of Symplocos Prunifolia remain unknown. Therefore, this study investigated the anti-inflammatory mechanism of S. prunifolia extract (SPE) in A549 and RAW264.7 cells stimulated by lipopolysaccharide (LPS). SPE significantly reduced nitric oxide (NO) production and the protein expression levels of like inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW 264.7 cells. Furthermore, it reduced the protein expression levels of iNOS, COX-2 and the levels of pro-inflammatory cytokines in LPS-stimulated A549 cells. The mechanism underlying the anti-inflammatory effect of SPE was associated with the inhibition of LPS stimulated the phosphoinositide-3-kinase/protein kinase B (PI3K/Akt) and Mitogen-activated protein kinase (MAPK) phosphorylation. Moreover, we confirmed that SPE decreased the nuclear translocation of nuclear factor-κB (NF-κB)/p65 stimulated by LPS. In conclusion, these results demonstrate that SPE alleviates inflammatory responses by deactivating the PI3K/Akt, MAPK, and NF-κB signaling pathways. Our findings suggest that SPE is a potential candidate for acute pneumonia prevention.

Climate-Affected Australian Tropical Montane Cloud Forest Plants: Metabolomic Profiles, Isolated Phytochemicals, and Bioactivities

The Australian Wet Tropics World Heritage Area (WTWHA) in northeast Queensland is home to approximately 18 percent of the nation's total vascular plant species. Over the past century, human activity and industrial development have caused global climate changes, posing a severe and irreversible danger to the entire land-based ecosystem, and the WTWHA is no exception. The current average annual temperature of WTWHA in northeast Queensland is 24 °C. However, in the coming years (by 2030), the average annual temperature increase is estimated to be between 0.5 and 1.4 °C compared to the climate observed between 1986 and 2005. Looking further ahead to 2070, the anticipated temperature rise is projected to be between 1.0 and 3.2 °C, with the exact range depending on future emissions. We identified 84 plant species, endemic to tropical montane cloud forests (TMCF) within the WTWHA, which are already experiencing climate change threats. Some of these plants are used in herbal medicines. This study comprehensively reviewed the metabolomics studies conducted on these 84 plant species until now toward understanding their physiological and metabolomics responses to global climate change. This review also discusses the following: (i) recent developments in plant metabolomics studies that can be applied to study and better understand the interactions of wet tropics plants with climatic stress, (ii) medicinal plants and isolated phytochemicals with structural diversity, and (iii) reported biological activities of crude extracts and isolated compounds.

Phytochemical profiling of Symplocos tanakana Nakai and S. sawafutagi Nagam. leaf and identification of their antioxidant and anti-diabetic potential

Symplocos sp. contains various phytochemicals and is used as a folk remedy for treatment of diseases such as enteritis, malaria, and leprosy. In this study, we discovered that 70% ethanol extracts of Symplocos sawafutagi Nagam. and S. tanakana Nakai leaves have antioxidant and anti-diabetic effects. The components in the extracts were profiled using high-performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry; quercetin-3-O-(6''-O-galloyl)-β-d-galactopyranoside (6) and tellimagrandin II (7) were the main phenolic compounds. They acted as strong antioxidants with excellent radical scavenging activity and as inhibitors of non-enzymatic advanced glycation end-products (AGEs) formation. Mass fragmentation analysis demonstrated that compounds 6 and 7 could form mono- or di-methylglyoxal adducts via reaction with methylglyoxal, which is a reactive carbonyl intermediate and an important precursor of AGEs. In addition, compound 7 effectively inhibited the binding between AGE2 and receptor for AGEs as well as the activity of α-glucosidase. Enzyme kinetic study revealed that compound 7 acts as a competitive inhibitor of α-glucosidase, through interaction with the active site of the enzyme. Therefore, compounds 6 and 7, the major constituents of S. sawafutagi and S. tanakana leaves, are promising for developing drugs for preventing or treating diseases caused by aging and excessive sugar consumption.

Design, Synthesis and Evaluation of Novel Derivatives of Curcuminoids with Cytotoxicity

Curcumin and curcuminoids have been discussed frequently due to their promising functional groups (such as scaffolds of α,β-unsaturated β-diketone, α,β-unsaturated ketone and β'-hydroxy-α,β-unsaturated ketone connected with aromatic rings on both sides) that play an important role in various bioactivities, including antioxidant, anti-inflammatory, anti-proliferation and anticancer activity. A series of novel curcuminoid derivatives (a total of 55 new compounds) and three reference compounds were synthesized with good yields using three-step organic synthesis. The anti-proliferative activities of curcumin derivatives were examined for six human cancer cell lines: HeLaS3, KBvin, MCF-7, HepG2, NCI-H460 and NCI-H460/MX20. Compared to the IC50 values of all the synthesized derivatives, most α,β-unsaturated ketones displayed potent anti-proliferative effects against all six human cancer cell lines, whereas β'-hydroxy-α,β-unsaturated ketones and α,β-unsaturated β-diketones presented moderate anti-proliferative effects. Two potent curcuminoid derivatives were found among all the novel derivatives and reference compounds: (E)-5-hydroxy-7-phenyl-1-(3,4,5-trimethoxyphenyl)hept-1-en-3-one (compound 3) and (1E,4E)-1,7-bis(3,4,5-trimethoxyphenyl)hepta-1,4-dien-3-one (compound MD12a). These were selected for further analysis after the evaluation of their anti-proliferative effects against all human cancer cell lines. The results of apoptosis assays revealed that the number of dead cells was increased in early apoptosis and late apoptosis, while cell proliferation was also decreased after applying various concentrations of (E)-5-hydroxy-7-phenyl-1-(3,4,5-trimethoxyphenyl)hept-1-en-3-one (compound 3) and (1E,4E)-1,7-bis(3,4,5-trimethoxyphenyl)hepta-1,4-dien-3-one (compound MD12a) to MCF-7 and HpeG2 cancer cells. Analysis of the gene expression arrays showed that three genes (GADD45B, SESN2 and BBC3) were correlated with the p53 pathway. From the quantitative PCR analysis, it was seen that (1E,4E)-1,7-bis(3,4,5-trimethoxyphenyl)hepta-1,4-dien-3-one (compound MD12a) effectively induced the up-regulated expression of GADD45B, leading to the suppression of MCF-7 cancer cell formation and cell death. Molecular docking analysis was used to predict and sketch the interactions of the GADD45B-α,β-unsaturated ketone complex for help in drug design.

A comprehensive analysis on Symplocos racemosa Roxb.: Traditional uses, botany, phytochemistry and pharmacological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Symplocos racemosa Roxb. belongs to a unigeneric family Symplocaceae, known as lodhra in Sanskrit; is a small evergreen tree, found throughout the tropical and sub-tropical countries. Ethnobotanical literature indicates use of S. racemosa in treatment of eye disease, skin diseases, ear diseases, liver and bowel complaints, tumors, uterine disorders, spongy and bleeding gums, asthma, fever, snake-bite, gonorrhea and arthritis. The main aim of this review is to provide detailed phytopharmacological profile on S. racemosa in support with the traditional practices and ethnomedicinal uses.

MATERIALS AND METHODS

All relevant worldwide accepted databases have been searched for the name "S. racemosa" along with other literature from Indian Classical texts and Pharmacopoeias. The accessible literatures available on S. racemosa, were collected through electronic search on Pub med, Scopus, Science direct and traditional reports.

RESULTS

S. racemosa is important Indian traditional drug used in many Ayurvedic and herbal formulations for treatment of liver as well as uterine disorders and leucorrhea. Majority of phytopharmacological reports are on stem bark of the plant which include anti-cancer, hepatoprotective, anti-oxidant, anti-androgenic effect, anti-inflammatory, wound healing activity and anti-diabetic effects. Phytochemical studies indicated presence of many phenolic glycosides like symplocoside, triterpenoids like betulinic acid, acetyloleanolic acid and oleanolic acid and flavonoids like quercetin which might have contributed to the observed protective effects.

CONCLUSION

Many ethnobotanical claims have been confirmed through systematic in-vitro and in-vivo pharmacological studies on different extracts of stem bark and isolated constituents. However, systematic studies on the bio-markers are desirable to establish mode of action and to validate the traditional claim in clinical practice after proper safety assessment. The conservation data of genus Symplocos showed risk of extinction due to restricted distribution in the wild hence systematic techniques should be developed for the maintenance of this plant.

Isolation and characterisation of three new anthraquinone secondary metabolites from Symplocos racemosa

Three new anthraquinone secondary metabolites were isolated from Symplocos racemosa, a small tree of family symplocaceae. The structures of compounds (1-3) were elucidated to be 1,4-dihydroxy-6-(ethoxymethyl)-8-propylanthracene-9,10-dione (1), 1,4-dihydroxy-6-(hydroxymethyl)-8-butylanthracene-9,10-dione (2) and 1,4-dihydroxy-6-(hydroxymethyl)-8-propyl anthracene-9,10-dione (3) using their spectral data, i.e. through IR, UV, (1)H NMR, (13)C NMR and two-dimensional (2D) NMR techniques including heteronuclear multiple quantum coherence, heteronuclear multiple bond correlation and correlation spectroscopy.

Flavonoids from Symplocos racemosa

A novel isoflavone glycoside, peseudobatigenin 7-O-[β-d-apiofuranosyl-(1''''→5''')-O-β-d-apiofuranosyl-(1'''→6'')]-β-d-glucopyranoside, namely sympracemoside (1), was isolated from the aerial parts of Symplocos racemosa along with 15 known flavonoids (2–16). Their structures were characterized by Q-TOF mass, optical rotation, UV, 1D and 2D-NMR spectroscopic data. Compounds 3, 9, 16 showed moderate inhibitory activities against NO production with IC₅₀ value of 88.2, 42.1 and 74.3 μM, respectively.