A standardized chamuangone enriched extract from Garcinia cowa roxb. leaves shows acute and sub-acute safety.

ETHNOPHARMACOLOGICAL RELEVANCE: The safety assessment of herbal products is critical for their appropriate pharmacological applications. Garcinia cowa Roxb., commonly known as Cha-muang in Thai, has ethnopharmacological relevance for inflammation, infectious diseases, and diabetes. The leaf extracts of G. cowa have been extensively reported for their anticancer, anti-inflammatory, antimicrobial, and antioxidant effects. Notably, chamuangone is their major active constituent that contributes to various pharmacological properties. AIM OF THE STUDY: The current study aims to establish a standardized chamuangone enriched extract (CEE) and assess its acute and sub-acute toxicities in animal models. METHODOLOGY: CEE was established from G. cowa leaves using a microwave-assisted extraction (MAE), followed by fractionation and enrichment through silica gel vacuum and column chromatography. The concentration of chamuangone in the extract was quantified using a validated quantitative high-performance liquid chromatography (HPLC) method. The safety profiles of CEE were thoroughly evaluated in rodents according to the Organization for Economic Cooperation and Development (OECD) 425 and 407 guidelines. The effects on oxidative stress markers such as superoxide dismutase (SOD), reduced glutathione (GSH), catalase (CAT), and malondialdehyde (MDA) levels were also evaluated in various organs. RESULTS: Based on the quantitative HPLC analysis, the CEE contained 73.0 ± 2.0% w/w of chamuangone. In the acute toxicity study, following up and down procedure the female rats were dosed with CEE at 1750 and 550 mg/kg body weight (b.w.), with CEE 1750 mg/kg b.w. was toxic, causing mortality, while CEE 550 mg/kg b.w. was deemed safe. An LD50 value was calculated according to the standard protocols, resulting in 970 mg/kg b.w. In histopathological examination, 550 mg/kg b.w. of CEE was safe in all the selected organs, while the 1750 mg/kg b.w. CEE treated rats exhibited toxic effects in histological tissues sections in the form of necrosis in the brain, cardiac muscle hypertrophy, liver inflammation, mild untoward effect in the spleen, fibrosis in the lungs, pancreatitis, pyelonephritis, and ovarian cyst. Administration of CEE at doses of 550 mg/kg b.w. (single dose) in the acute and 100 mg/kg b.w. (regularly 28-days) in the sub-acute toxicity studies significantly (p < 0.05) decreased levels of uric acid, triglycerides, and cholesterol. Importantly, the CEE (550 and 100 mg/kg b.w.) also significantly increased the levels of antioxidant enzymes (SOD, GSH, and CAT) and decreased MDA levels. Normal histopathology was observed in the sub-acute toxicity study in all treated groups. CONCLUSION: This study successfully concludes that CEE at a dose of 100 mg/kg b.w. is safe for therapeutic application or use as a chemopreventive functional food utilizing green extraction methods. However, chronic toxicity studies are further recommended to validate safety concerns over an extended period.

Novel human STING activation by hydrated-prenylated xanthones from Garcinia cowa.

OBJECTIVES: We investigate the anticancer activity and human stimulator of interferon genes pathway activation by a new hydrated-prenylated tetraoxygenated xanthone, garcicowanone I (1) and two known xanthones (2 and 3) that were isolated from the root bark of Garcinia cowa Roxb. ex Choisy. METHODS: The anticancer activity of each compound was evaluated by sulforhodamine B assay in immortalized cancer cell lines. Stimulator of interferon genes pathway activation was assessed by western blot analysis using human THP-1-derived macrophages. The production of pro-inflammatory cytokines from these macrophages was also evaluated via enzyme-linked immunosorbent assay. KEY FINDINGS: Both compounds 1 and 3 displayed moderate inhibitory effects on the cancer cells, including a cisplatin-resistant cell line, with IC50 values in the range of 10-20 µM. All three xanthones activated the stimulator of interferon genes, as evidenced by phosphorylation of tank-binding kinase 1, the stimulator of interferon genes protein and interferon regulatory factor 3. Furthermore, treatment of these macrophages with compounds 1-3 led to the production of pro-inflammatory cytokines, including interleukin 6, tumour necrosis factor α and interleukin 1ß. CONCLUSIONS: In conclusion, the isolated xanthones, including the novel garcicowanone I, displayed promising anticancer and immunomodulatory activity that warrants further research.

In vitro immunomodulatory activity study of Garcinia cowa Roxb. fraction.

OBJECTIVES: The objective of this study is to determine the activity of Garcinia cowa Roxb. n-hexane, ethyl acetate, and butanol fractions as an immunomodulator in vitro and obtain the fraction that has the potential as an immunomodulator. METHODS: Raw 264.7 macrophages were used to asses G. cowa Roxb. immunomodulatory activity. The MTT assay was chosen to measure cell viability to evaluate the cytotoxic effect on cells. ELISA method was used to measure the concentration of Interleukin-6 (IL-6) and Tumor Necrosis Factor Alpha (TNF-α) secreted by cells after being treated with G. cowa Roxb. fraction. The neutral red uptake assay determined the effect of Garcinia cowa Roxb. on the phagocytic activity. RESULTS: After Raw 264.7 macrophages were given the Hexan fraction (Hex) at concentrations of 12.5 and 25 µg/mL, there was a decrease in the concentration of IL-6, TNF-α, and the phagocytosis index of cells. Administration of the Ethyl Acetate fraction (EtOAc) at concentrations of 12.5 and 25 µg/mL on cells caused a decrease in IL-6 and TNF-α levels but did not affect the phagocytosis index. There was an increase in the level of TNF-α and the phagocytosis index after being given the Butanol fraction (BuOH) with concentrations of 12.5 and 25 µg/mL but there was a slight decrease in the level of IL-6. CONCLUSIONS: Both Hex and EtOAc fractions could suppress immune responses through decreasing IL-6, TNF-α, and slightly decreased phagocytic activity. BuOH fraction could stimulate immunomodulatory activities through enhanced TNF-α levels and phagocytic index, but less potent in enhancing IL-6 production. The BuOH fraction could be developed as an immunostimulant.

Garcowacinols A-J, cytotoxic polyprenylated benzoylphloroglucinol derivatives from the twigs of Garcinia cowa.

Ten undescribed polyprenylated benzoylphloroglucinol derivatives named garcowacinols A‒J (1-10) and four known analogues (11-14) were isolated from the twigs of Garcinia cowa. Their structures were determined by spectroscopic data analysis (1D and 2D NMR and HRESIMS), and their absolute configurations were established based on NOESY and ECD data. All isolated compounds were evaluated for their cytotoxicity against five types of human cancer cells (KB, HeLa S3, MCF-7, Hep G2, and HT-29) as well as Vero cells by MTT colorimetric assay. Garcowacinol C was significantly active against all the five cancer cells with IC50 values in the range of 0.61-9.50 µM. Selective proliferative inhibitions were observed on garcowacinol F and 7-epiclusianone against KB cells, and guttiferone Q toward MCF-7 cells with IC50 values less than 10 µM.

A Comprehensive Review of the Phytochemical and Pharmacological Potential of an Evergreen Plant Garcinia cowa.

Garcinia cowa of the Clusiaceae family, native to South-East Asia used in traditional medicine. It has antipyretic, antimicrobial, and many other biological activities. In this review, a thorough study of this plant's chemical constituents and pharmacological and therapeutic effects was conducted from the research articles from PubMed, Science Direct, Google Scholar, and Scopus from 1977 to 2022. Reported secondary metabolites are enriched with xanthones, phloroglucinols, depsidones, steroids, etc. α-mangostin, ß-mangostin, cowaxanthone, rubraxanthone, cowanin, norcowanin, etc. represent the major xanthones. This article discusses the relationship between the different functional groups in xanthone compounds and their bioactivity against cancer, diabetes, bacteria, leishmania, malaria, and inflammation. This review is a comprehensive compendium of major bioactive molecules and its implication for human disease.

Garcicowanones C-E, three new hydrated-geranylated xanthones from the roots of Garcinia cowa Roxb. ex Choisy, and their α-glucosidase inhibition activities.

Three new xanthones, garcicowanones C-E (1 - 3), and six known xanthones (4 - 9) were isolated from the roots of Garcinia cowa Roxb. ex Choisy. Their chemical structures were determined using spectroscopic technics, including HR-ESI-MS and 2 D NMR. All isolated compounds were evaluated for in vitro α-glucosidase inhibition. Cowanol (6) and norcowanin (8) had the most potent α-glucosidase inhibitory activity, with respective IC50 values of 33.5 ± 0.8 and 17.2 ± 0.3 µM, compared with the positive control, acarbose (IC50 257.3 ± 4.8 µM).

Development and validation of TLC-densitometry method for quantification of tetraprenyltoluquinone in the stem bark hexane extract of Garcinia cowa roxb.

A thin layer chromatography (TLC) method coupled with densitometry was optimized and established to quantify tetraprenyltoloquinon (TPTQ) in the hexane extract of Garcinia cowa roxb stem bark. The stationary phase was TLC plates of silica gel 60 F254, with a thickness of 250 µm, while a mobile phase was the mixture of hexane: chloroform: ethyl acetate: formic acid in the ratio of 20:70:9:1 was selected for the chromatographic system. TLC separation of the components was followed by densitometric analysis at 230 nm. The chromatogram revealed a tight spot for TPTQ at the Rf = 0.41 ± 0.03). The value of the regression equation (r2 = 0.992) demonstrated an excellent linear association between peak area and TPTQ amount in the 250-750 µg.spot-1 range. The precision, specificity, and accuracy of the approach were all validated. The 72.65 and 242.15 µg.spot-1 were found as the limit of detection and quantification, respectively. The proposed TLC method can be considered for identifying and quantifying TPTQ in Garcinia cowa Roxb bark hexane extracts.

Six New Polyoxygenated Xanthones from Garcinia cowa and Their Neuroprotective Effects on Glutamate-Mediated Hippocampal Neuronal HT22 Cell Death.

Six new polyoxygenated xanthones, garcicowanones F-H (1-3), norcowanol A-B (4-5), and garcinone F (6) along with twelve known compounds 7-18 were obtained from the latex of Garcinia cowa Roxb. ex Choisy. All new compounds have a 1,3,7-trioxygenated or 1,3,6,7-tetraoxygenated xanthone nucleus and differ from majority of xanthones from G. cowa by hydrated side chains. Compounds 1, 7, 8 and 18 exhibited significant neuroprotective effects on glutamate-mediated hippocampal neuronal HT22 cell death. In particular, compound 1 exhibited the most potent neuroprotective effect with >80 % cell viability in the concentration range of 2.9-115 µM. Further studies on compound 1 showed that it decreased cellular Ca2+ influx and inhibits cellular reactive oxygen species generation in HT22 cells. A Western blot analysis showed that MAPK phosphorylation, Bax, and AIF translocation dramatically increased upon treatment with 5 mM glutamate and decreased upon a co-treatment with compound 1.

Protective effect of standardised fruit extract of Garcinia cowa Roxb. ex Choisy against ethanol induced gastric mucosal lesions in Wistar rats.

BACKGROUND AND AIM: The fruit of Garcinia is a rich and valuable source of bioactive compounds and is traditionally used for treating wounds and ulcers. The present study was carried out to investigate the protective effect of chromatographically standardized fruit extract of Garcinia cowa (GCE) on ethanol-induced gastric lesions in rats and its possible mechanisms. METHODS: The effect of GCE (200 and 400 mg/kg body weight) was evaluated by determining various gastric ulcer parameters like gastric wall mucus, non-protein sulfhydryls (NP-SH) content, microvascular permeability, endogenous antioxidant enzyme, and gastric histopathological study. RESULTS AND CONCLUSIONS: Oral administration of GCE at doses of 200 and 400 mg/kg exhibited significant (p < .01) dose-dependent inhibition of ulcer index by 18.94-44.02%, respectively. Pre-treatment of rats with GCE (400 mg/kg) significantly restored the depleted gastric wall mucus level by 34.09% and NP-SH content by 33.35% induced by ethanol administration. In addition, GCE (400 mg/kg) showed a significant decrease in microvascular permeability of Evans Blue by 47.43%, rationalizing its protective effect. Furthermore, a significant increase in oxidative enzyme levels with reduction in malondialdehyde level and elevation of superoxide dismutase (SOD) activity was observed in the GCE treated group as compared to the ulcer control group. The histopathological assessment also confirmed the protective nature of GCE. HPTLC analysis showed the presence of 0.27%, 0.11% w/w gallic acid, and amentoflavone, respectively in GCE. The content of α-mangostin and xanthochymol in the G. cowa extract sample quantified by HPLC-PDA method was 0.72 and 8.46%, respectively. The results obtained indicate that the protective effect of GCE against gastric ulcers in rats through multiple actions confirmed by the reduction of oxidative stress and restoration of adhered gastric mucus, NP-SH content, and histological architecture.KEY MESSAGESEthanol is the most typical ulcerogenic agent and has been shown to extend the risk of ulcer in humans.Natural products are promising alternative medication for the development of new drugs to regulate gastrointestinal diseases.Garcinia cowa protects the gastric mucosa through multiple actions that include restoration of adhered gastric mucus and inhibition of lipid peroxidation.

DNA Repair Biosensor-Identified DNA Damage Activities of Endophyte Extracts from Garcinia cowa.

Recent developments in chemotherapy focus on target-specific mechanisms, which occur only in cancer cells and minimize the effects on normal cells. DNA damage and repair pathways are a promising target in the treatment of cancer. In order to identify novel compounds targeting DNA repair pathways, two key proteins, 53BP1 and RAD54L, were tagged with fluorescent proteins as indicators for two major double strand break (DSB) repair pathways: non-homologous end-joining (NHEJ) and homologous recombination (HR). The engineered biosensor cells exhibited the same DNA repair properties as the wild type. The biosensor cells were further used to investigate the DNA repair activities of natural biological compounds. An extract from Phyllosticta sp., the endophyte isolated from the medicinal plant Garcinia cowa Roxb. ex Choisy, was tested. The results showed that the crude extract induced DSB, as demonstrated by the increase in the DNA DSB marker γH2AX. The damaged DNA appeared to be repaired through NHEJ, as the 53BP1 focus formation in the treated fraction was higher than in the control group. In conclusion, DNA repair-based biosensors are useful for the preliminary screening of crude extracts and biological compounds for the identification of potential targeted therapeutic drugs.

Bioassay-guided isolation and identification of antidiabetic compounds from Garcinia cowa leaf extract.

Garcinia cowa Roxb. ex Choisy (Clusiaceae) is a Thai local edible plant, which has been used for the treatment of diabetes. The aim of this study is to discover and identify bioactive compounds related to antidiabetic properties from the leaf extract of G. cowa. α-Glucosidase inhibitory bioassay-guided isolation of the ethyl acetate extract of the leaves of G.cowa resulted in the isolation and identification of 11 compounds. Of these, a decahydro-1H-xanthene derivative, garciniacowone K (1), was identified as a novel compound. Their structures were characterized by spectroscopic data and by comparison of their NMR spectroscopic data with those previously reported. All compounds were evaluated for their α-glucosidase inhibitory and glucose consumption activities. Compound 2 showed the highest efficacy in inhibiting α-glucosidase enzyme and promoting glucose consumption activity by 3T3-L1 cells, with IC50 values of 0.5 µM and 13.1 µM, respectively, without causing toxicity to cells.

High Performance Thin layer Chromatography: Densitometry Method for Determination of Rubraxanthone in the Stem Bark Extract of Garcinia cowa Roxb.

CONTEXT: Garcinia cowa is a medicinal plant widely grown in Southeast Asia and tropical countries. Various parts of this plant have been used in traditional folk medicine. The bark, latex, and root have been used as an antipyretic agent, while fruit and leaves have been used as an expectorant, for indigestion and improvement of blood circulation. AIMS: This study aims to determine the concentration of rubraxanthone found in ethyl acetate extract of the stem bark of G. cowa by the high-performance thin-layer chromatography (HPTLC). MATERIALS AND METHODS: HPTLC method was performed on precoated silica gel G 60 F254 plates using an HPTLC system with a developed mobile-phase system of chloroform: ethyl acetate: methanol: formic acid (86:6:3:5). A volume of 5 µL of standard and sample solutions was applied to the chromatographic plates. The plates were developed in saturated mode of twin trough chamber at room temperature. The method was validated based on linearity, accuracy, precision, limit of detection (LOD), limit of quantification (LOQ), and specificity. The spots were observed at ultraviolet 243 nm. RESULTS: The linearity of rubraxanthone was obtained between 52.5 and 157.5 ppm/spot. The LOD and LOQ were found to be 4.03 and 13.42 ppm/spot, respectively. CONCLUSION: The proposed method showed good linearity, precision, accuracy, and high sensitivity. Therefore, it may be applied for the quantification of rubraxanthone in ethyl acetate extract of the stem bark of G. cowa. SUMMARY: High performance thin layer chromatography (HPTLC) method provides rapid qualitative and quantitative estimation of rubraxanthone as a marker com¬pound in G. cowa extract used for commercial productRubraxanthone found in ethyl acetate extracts of G. cowa was successfully quantified using HPTLC method. Abbreviations Used: TLC: Thin-layer chromatography, HPTLC: High-performance thin-layer chromatography, LOD: Limit of detection, LOQ: Limit of quantification, ICH: International Conference on Harmonization.

Cytotoxic Properties and Complete Nuclear Magnetic Resonance Assignment of Isolated Xanthones from the Root of Garcinia cowa Roxb.

OBJECTIVE: To isolate compounds from the roots of Garcinia cowa and to evaluated their cytotoxic activity against breast (MCF-7), prostate (DU-145), and lung (H-460) cell lines. MATERIALS AND METHODS: The ground air-dried root was sequentially macerated with hexane, dichloromethane (DCM), ethyl acetate (EtOAc), and methanol. The DCM soluble extract was fractionated by vacuum liquid chromatography, column chromatography, and radial chromatography over silica gel with hexane, EtOAc and methanol as eluent in progressively increasing polarity manner; to yield three compounds. Their structures were elucidated based on their spectroscopic data and their comparison with those of the literature. The cytotoxicity of isolated compounds was carried out against human cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay. The extract was added at various concentrations (0.1, 1, 10 and 100 mg/ml). The level of cytotoxicity was determined by calculating the level of IC50 that was based on the percentage of the cell death following the 24 h incubation with the extract. RESULTS: Phytochemical study on the roots of G. cowa yielded rubraxanthone (3), cowanine (4) and 1,5-dihydroxyxanthone (5). Compound 4 with an IC50 value of 4.1 ± 1.0 µM, 5.4 ± 2.3 µM and 11.3 ± 10.0 µM against MCF-7, H-460, and DU-145, respectively while compound 3 was found to be in active. CONCLUSION: The results indicate that G. cowa roots could be important sources of natural cytotoxic compounds. SUMMARY: Isolation of cytotoxic compounds from Garcinia cowaCowanine is the active constituent from the roots of Garcinia cowaComplete nuclear magnetic resonance assignment of isolated compoundsMS fragmentation of rubraxanthone.

Xanthones from the Leaves of Garcinia cowa Induce Cell Cycle Arrest, Apoptosis, and Autophagy in Cancer Cells.

Two new xanthones, cowaxanthones G (1) and H (2), and 23 known analogues were isolated from an acetone extract of the leaves of Garcinia cowa. The isolated compounds were evaluated for cytotoxicity against three cancer cell lines and immortalized HL7702 normal liver cells, whereby compounds 1, 5, 8, and 15-17 exhibited significant cytotoxicity. Cell cycle analysis using flow cytometry showed that 5 induced cell cycle arrest at the S phase in a dose-dependent manner, 1 and 16 at the G2/M phase, and 17 at the G1 phase, while 16 and 17 induced apoptosis. Moreover, autophagy analysis by GFP-LC3 puncta formation and western blotting suggested that 17 induced autophagy. Taken together, our results suggest that these xanthones possess anticancer activities targeting cell cycle, apoptosis, and autophagy signaling pathways.

Kaennacowanols A-C, three new xanthones and their cytotoxicity from the roots of Garcinia cowa.

Three new xanthones, named kaennacowanols A-C (1-3), along with nineteen known xanthones were isolated from the roots of Garcinia cowa Roxb. Their structures were determined by spectroscopic analysis. All isolated compounds were evaluated for their cytotoxicity against KB and HeLa cell lines. Compounds 17 and 22 showed good cytotoxicity against KB cell with IC50 values of 7.97 and 9.10µM, respectively. On the other hand, compound 15 showed good cytotoxicity against HeLa cell with IC50 value of 9.34µM.

Antioxidant and antiplatlet aggregation properties of bark extracts of Garcinia pedunculata and Garcinia cowa.

The bark extracts of Garcinia pedunculata and Garcinia cowa, which are abundant in the Northeastern regions of India, were screened for their antioxidant and in vitro antiplatelet aggregating activities. By ß-carotene linoleate model for antioxidant assay, acetone extract of G. pedunculata and hexane extracts of G. cowa exhibited higher antioxidant activity (86.47 and 66.94 % respectively, at 25 ppm) than other extracts. Similar pattern was observed for superoxide radical scavenging method for antioxidant assay. The ethyl acetate extract of G. pedunculata and hexane extract of G. cowa exhibited higher antiplatelet aggregation capacity towards ADP induced platelet aggregation (IC50 0.16 and 0.43 ug, respectively) than other extracts.

Antibacterial tetraoxygenated xanthones from the immature fruits of Garcinia cowa.

A phytochemical investigation of the acetone extract from the immature fruits of Garcinia cowa led to the isolation of two novel tetraoxygenated xanthones, garcicowanones A (1) and B (2), together with eight known tetraoxygeanted xanthones. Their structures were determined by spectroscopic analysis. All isolated compounds were evaluated for their antibacterial activity against Bacillus cereus TISTR 688, Bacillus subtilis TISTR 008, Micrococcus luteus TISTR 884, Staphylococcus aureus TISTR 1466, Escherichia coli TISTR 780, Pseudomonas aeruginosa TISTR 781, Salmonella typhimurium TISTR 292 and Staphylococcus epidermidis ATCC 12228. α-Mangostin showed potent activity (MIC 0.25-1 µg/mL) against three Gram-positive strains and garcicowanone A and ß-mangostin exhibited strong antibacterial activity against B. cereus with the same MIC values of 0.25 µg/mL.

Cowabenzophenones A and B, two new tetracyclo[7.3.3.3(3,11).0(3,7)]tetradecane-2,12,14-trione derivatives, from ripe fruits of Garcinia cowa.

Two new tetracyclo[7.3.3.3(3,11).0(3,7)]tetradecane-2,12,14-trione derivatives, cowabenzophenones A (1) and B (2), were isolated from ripe fruits of Garcinia cowa Roxb. Their structures were determined by spectroscopic methods. The tetracyclo[7.3.3.3(3,11).0(3,7)]tetradecane-2,12,14-trione skeleton from the Garcinia genus is reported for the first time.