A Comprehensive Review on Phytochemistry and Pharmacological Activities of Clinacanthus nutans (Burm.f.) Lindau

Bioactive compound schaftoside from Clinacanthus nutans attenuates acute liver injury by inhibiting ferroptosis through activation the Nrf2/GPX4 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Clinacanthus nutans (Burm. f.) Lindau, a traditional herb renowned for its anti-tumor, antioxidant, and anti-inflammatory properties, has garnered considerable attention. Although its hepatoprotective effects have been described, there is still limited knowledge of its treatment of acute liver injury (ALI), and its mechanisms remain unclear.

AIM OF THE STUDY

To assess the efficacy of Clinacanthus nutans in ALI and to identify the most effective fractions and their underlying mechanism of action.

METHODS

Bioinformatics was employed to explore the underlying anti-hepatic injury mechanisms and active compounds of Clinacanthus nutans. The binding ability of schaftoside, a potential active ingredient in Clinacanthus nutans, to the core target nuclear factor E2-related factor 2 (Nrf2) was further determined by molecular docking. The role of schaftoside in improving histological abnormalities in the liver was observed by H&E and Masson's staining in an ALI model induced by CCl4. Serum and liver biochemical parameters were measured using AST, ALT and hydroxyproline kits. An Fe2+ kit, transmission electron microscopy, western blotting, RT-qPCR, and DCFH-DA were used to measure whether schaftoside reduces ferroptosis-induced ALI. Subsequently, specific siRNA knockdown of Nrf2 in AML12 cells was performed to further elucidate the mechanism by which schaftoside attenuates ferroptosis-induced ALI.

RESULTS

Bioinformatics analysis and molecular docking showed that schaftoside is the principal compound from Clinacanthus nutans. Schaftoside was shown to diminish oxidative stress levels, attenuate liver fibrosis, and forestall ferroptosis. Deeper investigations revealed that schaftoside amplified Nrf2 expression and triggered the Nrf2/GPX4 pathway, thereby reversing mitochondrial aberrations triggered by lipid peroxidation, GPX4 depletion, and ferroptosis.

CONCLUSION

The lead compound schaftoside counters ferroptosis through the Nrf2/GPX4 axis, providing insights into a novel molecular mechanism for treating ALI, thereby presenting an innovative therapeutic strategy for ferroptosis-induced ALI.

Phytochemical composition of Clinacanthus nutans based on factors of environment, genetics and postharvest processes: A review

Herpes simplex, varicella-zoster lesions, skin rashes, diabetes, snake bites and insect bites have all been treated by using Clinacanthus nutans (C. nutans). The pharmacological effects of C. nutans are influenced by the presence of terpenoids, flavonoids, alkaloids, phenolic acids, saponins, glycosides, steroids and tannins. This review focused on the phytochemical makeup, which varies geographically and is a subject of scarcely existing knowledge. C. nutans served as the primary search term, while the keywords "phytochemicals", "chemical component" and "phytochemistry" were used to search the literature in the Google Scholar, PubMed, Scopus and Web of Science databases. The articles pertinent to the subject were found and reviewed. The phytochemical composition of C. nutans varied depending on the region it was cultivated in, and was influenced by the environmental conditions, genetics, air temperature and postharvest practices.

Schaftoside reduces inflammation in Aspergillus fumigatus keratitis through the inhibition of the TLR4/MyD88 pathway

PURPOSE

The purpose of this research study was to investigate the impact of schaftoside on Aspergillus fumigatus (A. fumigatus) keratitis and elucidate its underlying mechanisms.

METHODS

In order to establish safe experimental concentrations of schaftoside in human corneal epithelial cells (HCECs), RAW264.7 cells, and mouse models, various techniques were employed including cytotoxicity assay (CCK-8) assay, cell scratch assay, and Draize test. The therapeutic effect of schaftoside was assessed using slit-lamp biomicroscopy, clinical scores, as well as determination of neutrophil infiltration through hematoxylin and eosin (HE) staining, immunofluorescence (IF) staining, and myeloperoxidase (MPO) assay. The levels of Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), pro-inflammatory mediators interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6 were determined using quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and IF techniques.

RESULTS

Schaftoside at a concentration of 160 μM displayed no harmful side effects on HCECs, RAW cells, and mouse corneas, rendering it suitable for further experiments. In a murine fungal keratitis model, schaftoside mitigated the severity of fungal keratitis by inhibiting neutrophil infiltration and reducing MPO activity. Both in vitro and in vivo experiments demonstrated that schaftoside treatment suppressed the upregulation of IL-1β, TNF-α, and IL-6 expression, while also downregulating the expressions of TLR4 as well as MyD88 at both mRNA and protein levels.

CONCLUSIONS

Schaftoside demonstrated a protective effect against A. fumigatus keratitis by reducing corneal damage through inhibition of neutrophil recruitment and downstream inflammatory cytokines. The anti-inflammatory properties of schaftoside in A. fumigatus keratitis may involve modulation of the TLR4/MyD88 pathway.

Clinacanthus nutans leaf extract reduces pancreatic β-cell apoptosis by inhibiting JNK activation and modulating oxidative stress and inflammation in streptozotocin-induced diabetic rats

Background

Controlling apoptosis induced by oxidative stress in pancreatic β-cells provides promising strategies for preventing and treating diabetes. Clinacanthus nutans leaves possess bioactive constituents with potential antioxidant and anti-diabetic properties.

Aim

This study aimed to investigate the molecular mechanisms by which C. nutans extract protects pancreatic β-cells from apoptotic damage in streptozotocin (STZ)-induced diabetic rats.

Methods

Diabetes was induced in male Wistar rats by intraperitoneal injection of 45 mg/kg STZ, followed by 28 days of treatment with C. nutans leaf extract and Glibenclamide as the standard drug. At the end of the study, blood samples were collected to measure glucose levels, oxidative stress markers, and inflammation. Pancreatic tissue was stained immunohistochemically to detect c-Jun N-terminal kinase (JNK) and Caspase-3 expression.

Results

The administration of C. nutans leaf extract to diabetic rats significantly reduced fasting blood glucose, malondialdehyde, and tumor necrosis factor-α levels, while concurrently enhancing the activity of superoxide dismutase. The immunohistochemical studies revealed a decrease in the expression of JNK and caspase-3 in the pancreatic islets of diabetic rats.

Conclusion

Clinacanthus nutans exhibits the potential to protect pancreatic β-cells from apoptosis by suppressing oxidative stress and inflammation.

Synergistic effects of combined cisplatin and Clinacanthus nutans extract on triple negative breast cancer cells

Objective

Triple negative breast cancer (TNBC) is the most invasive breast cancer subtype enriched with cancer stem cells. TNBCs do not express estrogen, progesterone, or human epidermal growth factor receptor 2 (HER2) receptors, making them difficult to be targeted by existing chemotherapy treatments. In this study, we attempted to identify the effects of combined cisplatin and Clinacanthus nutans treatment on MDA-MD-231 and MDA-MB-468 breast cancer cells, which represent TNBC subtypes.

Methods

The phytochemical fingerprint of C. nutans ethanolic leaf extract was evaluated by LC-MS/MS analysis. We investigated the effects of cisplatin (0-15.23 μg/mL), C. nutans (0-50 μg/mL), and a combination of cisplatin (3.05 μg/mL) and C. nutans (0-50 μg/mL), on cell viability, proliferation, apoptosis, invasion, mRNA expression in cancer stem cells (CD49f, KLF4), and differentiation markers (TUBA1A, KRT18) in TNBC cells. In addition, we also studied the interaction between cisplatin and C. nutans.

Results

Derivatives of fatty acids, carboxylic acid ester, and glycosides, were identified as the major bioactive compounds with potential anticancer properties in C. nutans leaf extract. Reductions in cell viability (0-78%) and proliferation (2-77%), as well as a synergistic anticancer effect, were identified in TNBC cells when treated with a combination of cisplatin and C. nutans. Furthermore, apoptotic induction via increased caspase-3/7 activity (MDA-MB-231: 2.73-fold; MDA-MB-468: 3.53-fold), and a reduction in cell invasion capacity to 36%, were detected in TNBC cells when compared to single cisplatin and C. nutans treatments. At the mRNA level, cisplatin and C. nutans differentially regulated specific genes that are responsible for proliferation and differentiation.

Conclusion

Our findings demonstrate that the combination of cisplatin and C. nutans represents a potential treatment for TNBC.

Clinacanthus nutans L Extracts Reduce the Serum Tumor Necrosis Factor-α, Malondialdehyde, and Interleukin-6 Levels and Improve the Langerhans Islet Area in Diabetic Rat Models

Background

Diabetes mellitus-induced hyperglycemia increases oxidative stress and inflammatory cytokine production, which play a significant role in the damage and apoptosis of pancreatic β cells. Therefore, the administration of medications that can reduce oxidative stress and inflammation plays an important role in diabetes treatment.

Objective

To probe the Clinacanthus nutans leaf extract effect on oxidative stress and inflammatory markers and the Langerhans islet area in diabetic rat models.

Design

An experimental laboratory in the animal model.

Methods

Twenty-five diabetic rat models were randomly assigned into 5 clusters. Clusters 1, 2, and 3 were administered with C. nutans leaf extract in aqueous suspension with vehicle 1% Na-CMC at 75 mg/kg body weight (BW), 150 mg/kg BW, and 300 mg/kg BW, respectively. Cluster 4 was diabetic control rats administered with metformin at a 21 mg/rat dose. Cluster 5 was a control diabetic rat only administered with 1% Na-CMC suspension. Treatment was administered orally for 14 days. On the 15th day, the rats were sacrificed to obtain blood samples and pancreatic tissues. Serum interleukin (IL)-6, malondialdehyde (MDA), and tumor necrosis factor (TNF-α) were measured using the enzyme-linked immunosorbent assay (ELISA) method. Histopathological examination was performed by counting the Langerhans islet areas.

Results

The average IL-6, MDA, and TNF-α levels declined in the cluster receiving C. nutans extract and were significantly different from the untreated cluster (P < .05). Histopathological examination revealed a significant upsurge in the Langerhans islets area in diabetic rats receiving C. nutans extract at doses of 75 and 150 mg/kg (P < .05).

Conclusion

C. nutans leaf extract reduced the serum MDA, TNF-α, and IL-6 levels, and increased the Langerhans islets area in a diabetic rat model.

Antiviral and Immunomodulatory Activities of Clinacanthus nutans (Burm. f.) Lindau

Clinacanthus nutans (Burm. f.) Lindau has been used as a traditional herbal medicine for treating snake bites, scalds, burns, and viral and bacterial infections. It has been attracting an increasing amount of attention because of its biological activities, including its antidiabetic, antioxidant, antibacterial, anticancer, anti-inflammatory, antiviral, and immunoregulatory activities. Here, we conducted a panoramic survey of the literature regarding the immunoregulatory, anti-inflammatory, and antiviral activities of C. nutans. We discovered that C. nutans extracts have virucidal activities against herpes simplex virus types 1 and 2, varicella-zoster virus, cyprinid herpesvirus 3, porcine reproductive and respiratory syndrome virus, mosquito-borne chikungunya virus, and potentially SARS-CoV-2; such activities likely result from C. nutans interfering with the entry, penetration, infection, and replication of viruses. We also reviewed the phytochemicals in C. nutans extracts that exhibit anti-inflammatory and immunoregulatory activities. This updated review of the antiviral, anti-inflammatory, and immunoregulatory activities of C. nutans may guide future agricultural practices and reveal clinical applications of C. nutans.

Anti-Inflammatory Activity of Glyceryl 1,3-Distearate Identified from Clinacanthus nutans Extract against Bovine Mastitis Pathogens

Clinacanthus nutans is widely used as a traditional medicine in Thailand and other countries in Southeast Asia. Although its effectiveness is well documented, its therapeutic use is limited to the treatment of only a few diseases; mostly it is used as an anti-viral agent against varicella-zoster and herpes simplex virus infections. Herein, we demonstrate the therapeutic activity of C. nutans extracts in lowering inflammation in a model of bovine mastitis caused by bacterial infection. Lipopolysaccharide (LPS), a gram-negative bacterial component, caused inflammation activation in bovine endothelial cells (CPAE) through the upregulation of proinflammatory cytokines (IL6 and IL1β) and chemokines (CXCL3 and CXCL8) gene expression, partially leading to cell death. Treatment with C. nutans crude extract significantly diminished these responses in a dose-dependent manner. The solvent fractionation of C. nutans extract revealed that the ethyl acetate (C4H8O2) fractions had a high potential to protect against cell death and diminished IL1β, IL6, CXCL3, and CXCL8 levels to less than 0.45 folds relative to the LPS-treated control. Glyceryl 1,3-distearate (C39H76O5) was identified as a bioactive compound responsible for the anti-inflammation activity but not the anti-cell death activity of C. nutans extract. This study highlighted the efficiency of C. nutans extracts as an alternative therapeutic option for the natural-product sustainable development of bovine mastitis treatment.

Recent Updates on Phytoconstituent Alpha-Glucosidase Inhibitors: An Approach towards the Treatment of Type Two Diabetes

Diabetes is a common metabolic disorder marked by unusually high plasma glucose levels, which can lead to serious consequences such as retinopathy, diabetic neuropathy and cardiovascular disease. One of the most efficient ways to reduce postprandial hyperglycemia (PPHG) in diabetes mellitus, especially insulin-independent diabetes mellitus, is to lower the amount of glucose that is absorbed by inhibiting carbohydrate hydrolyzing enzymes in the digestive system, such as α-glucosidase and α-amylase. α-Glucosidase is a crucial enzyme that catalyzes the final stage of carbohydrate digestion. As a result, α-glucosidase inhibitors can slow D-glucose release from complex carbohydrates and delay glucose absorption, resulting in lower postprandial plasma glucose levels and control of PPHG. Many attempts have been made in recent years to uncover efficient α-glucosidase inhibitors from natural sources to build a physiologic functional diet or lead compound for diabetes treatment. Many phytoconstituent α-glucosidase inhibitors have been identified from plants, including alkaloids, flavonoids, anthocyanins, terpenoids, phenolic compounds, glycosides and others. The current review focuses on the most recent updates on different traditional/medicinal plant extracts and isolated compounds' biological activity that can help in the development of potent therapeutic medications with greater efficacy and safety for the treatment of type 2 diabetes or to avoid PPHG. For this purpose, we provide a summary of the latest scientific literature findings on plant extracts as well as plant-derived bioactive compounds as potential α-glucosidase inhibitors with hypoglycemic effects. Moreover, the review elucidates structural insights of the key drug target, α-glucosidase enzymes, and its interaction with different inhibitors.

Antioxidant activity and antidiabetic activities of Northern Thai indigenous edible plant extracts and their phytochemical constituents

Diabetes mellitus is the most common non-infective disease characterized by hyperglycemia (high level of blood glucose). Formation of advanced glycation end products (AGEs) in long termed-hyperglycemia and oxidative stress are the key factors to accelerate diabetic complications. To screen potential candidates for treating diabetes, total phenolic content, total flavonoid content, antioxidant activity from crude extracts of some Thai edible plants were primarily assessed, and the inhibiting potential of diabetes and its complications provided from some of these plants were evaluated in terms of their inhibitory activities of α-amylase, α-glycosidase, and AGEs formation. The highest amounts of phenolic and flavonoid compounds were found in the ethanolic extract of Caesalpinia mimosoides (S20, 12.63 ± 1.70 mg GAE/g DW) and Glochidion hirsutum (S8, 3.02 ± 0.25 mg CE/g DW), respectively. The highest antioxidant activity was found in Schinus terebinthifolius Raddi (S26, 217.94 ± 32.30 μg AAE/g DW) whereas the highest inhibitory activities of α-amylase and α-glycosidase were obtained from Basella alba L. (S11, IC₅₀ = 0.21 ± 0.01 mg/ml) and S. terebinthifolius (S26, IC₅₀ = 0.05 ± 0.02 mg/ml) respectively. The inhibitory effects of AGEs formation were studied in vitro using two model systems: BSA-glucose and BSA-methylglycoxal (MGO). The extracts of Glochidion hirsutum (Roxb.) Voigt (S8, IC₅₀ = 0.20 ± 0.01 mg/ml) and Polygonum odoratum Lour. (S13, IC₅₀ = 0.03 ± 0.01 mg/ml) exhibited the inhibitory activity of AGEs formation derived from glucose (BSA-glucose system) stronger than aminoguanidine (AG) (0.26 ± 0.00 mg/ml), which is a common AGEs formation inhibitory drug. By BSA-MGO assay, the inhibition of some selected extracts in this study (G. hirsutum, G. sphaerogynum, and S. terebinthifolius with IC₅₀ = 0.11 ± 0.01, 0.11 ± 0.01, and 0.10 ± 0.00 mg/ml, respectively) were slightly less efficient than AG (the IC₅₀ = 0.06 ± 0.00 mg/ml). These results indicated that some selected Thai edible plants in this present study provided potential applications towards the prevention of diabetes and their complications via the inhibitory of α-amylase, α-glycosidase, AGEs formation, and oxidative stress. This fundamental information would be important for alternative drug discovery and nutritional recommendations for diabetic patients.

A Review with Updated Perspectives on the Antiviral Potentials of Traditional Medicinal Plants and Their Prospects in Antiviral Therapy

Exploration of the traditional medicinal plants is essential for drug discovery and development for various pharmacological targets. Various phytochemicals derived from medicinal plants were extensively studied for antiviral activity. This review aims to highlight the role of medicinal plants against viral infections that remains to be the leading cause of human death globally. Antiviral properties of phytoconstituents isolated from 45 plants were discussed for five different types of viral infections. The ability of the plants’ active compounds with antiviral effects was highlighted as well as their mechanism of action, pharmacological studies, and toxicological data on a variety of cell lines. The experimental values, such as IC₅₀, EC₅₀, CC₅₀, ED₅₀, TD₅₀, MIC₁₀₀, and SI of the active compounds, were compiled and discussed to determine their potential. Among the plants mentioned, 11 plants showed the most promising medicinal plants against viral infections. Sambucus nigra and Clinacanthus nutans manifested antiviral activity against three different types of viral infections. Echinacea purpurea, Echinacea augustofolia, Echinacea pallida, Plantago major, Glycyrrhiza uralensis, Phyllanthus emblica, Camellia sinensis, and Cistus incanus exhibited antiviral activity against two different types of viral infections. Interestingly, Nicotiana benthamiana showed antiviral effects against mosquito-borne infections. The importance of phenolic acids, alkamides, alkylamides, glycyrrhizin, epicatechin gallate (ECG), epigallocatechin gallate (EGCG), epigallocatechin (EGC), protein-based plant-produced ZIKV Envelope (PzE), and anti-CHIKV monoclonal antibody was also reviewed. An exploratory approach to the published literature was conducted using a variety of books and online databases, including Scopus, Google Scholar, ScienceDirect, Web of Science, and PubMed Central, with the goal of obtaining, compiling, and reconstructing information on a variety of fundamental aspects, especially regarding medicinal plants. This evaluation gathered important information from all available library databases and Internet searches from 1992 to 2022.

Efficacy and Safety of Clinacanthus nutans Lindau Cream vs. Podophyllin for the Treatment of Adults with Condyloma Acuminata

Human papillomavirus (HPV) infection causes condyloma acuminata (CA). Podophyllin is the standard treatment. Clinacanthus nutans Lindau (C. nutans), a medicinal plant, has potent anti-inflammatory and antiviral effects. C. nutans cream is widely used in Thailand to treat the herpes simplex virus. We proposed that C. nutans might also induce CA clearance. There are no studies of C. nutans treatment of CA. This randomized controlled trial at Siriraj Hospital, Thailand, was conducted between January 2018 and December 2019. CA samples were obtained from 10 men with at least two CAs 1 centimeter apart. Each wart was randomized to a 4-week treatment with either C. nutans or podophyllin. The participants were 24 to 72 years old. Most HPV types were low-risk HPVs (HPV 11, HPV 6). Median CA clearance with podophyllin was a 97% CA clearance with podophyllin and 82% with C. nutans. C. nutans may be an alternative treatment for CA.

Metabolomic Approach for Rapid Identification of Antioxidants in Clinacanthus nutans Leaves with Liver Protective Potential

Antioxidants are currently utilized to prevent the occurrence of liver cancer in non-alcoholic fatty liver disease (NAFLD) patients. Clinacanthus nutans possesses anti-oxidative and anti-inflammatory properties that could be an ideal therapy for liver problems. The objective of this study is to determine the potential antioxidative compounds from the C. nutans leaves (CNL) and stems (CNS). Chemical- and cell-based antioxidative assays were utilized to evaluate the bioactivities of CNS and CNL. The NMR metabolomics approach assisted in the identification of contributing phytocompounds. Based on DPPH and ABTS radical scavenging activities, CNL demonstrated stronger radical scavenging potential as compared to CNS. The leaf extract also recorded slightly higher reducing power properties. A HepG2 cell model system was used to investigate the ROS reduction potential of these extracts. It was shown that cells treated with CNL and CNS reduced innate ROS levels as compared to untreated controls. Interestingly, cells pre-treated with both extracts were also able to decrease ROS levels in cells induced with oxidative stress. CNL was again the better antioxidant. According to multivariate data analysis of the 1H NMR results, the main metabolites postulated to contribute to the antioxidant and hepatoprotective abilities of leaves were clinacoside B, clinacoside C and isoschaftoside, which warrants further investigation.

Anti-Inflammatory Effects of Phytochemical Components of Clinacanthus nutans

Recent studies on the ethnomedicinal use of Clinacanthus nutans suggest promising anti-inflammatory, anti-tumorigenic, and antiviral properties for this plant. Extraction of the leaves with polar and nonpolar solvents has yielded many C-glycosyl flavones, including schaftoside, isoorientin, orientin, isovitexin, and vitexin. Aside from studies with different extracts, there is increasing interest to understand the properties of these components, especially regarding their ability to exert anti-inflammatory effects on cells and tissues. A major focus for this review is to obtain information on the effects of C. nutans extracts and its phytochemical components on inflammatory signaling pathways in the peripheral and central nervous system. Particular emphasis is placed on their role to target the Toll-like receptor 4 (TLR4)-NF-kB pathway and pro-inflammatory cytokines, the antioxidant defense pathway involving nuclear factor erythroid-2-related factor 2 (NRF2) and heme oxygenase 1 (HO-1); and the phospholipase A₂ (PLA₂) pathway linking to cyclooxygenase-2 (COX-2) and production of eicosanoids. The ability to provide a better understanding of the molecular targets and mechanism of action of C. nutans extracts and their phytochemical components should encourage future studies to develop new therapeutic strategies for better use of this herb to combat inflammatory diseases.

A Narrative Review on the Phytochemistry, Pharmacology and Therapeutic Potentials of Clinacanthus nutans (Burm. f.) Lindau Leaves as an Alternative Source of Future Medicine

The application of natural products and supplements has expanded tremendously over the past few decades. Clinacanthus nutans (C. nutans), which is affiliated to the Acanthaceae family, has recently caught the interest of researchers from the countries of subtropical Asia due to its medicinal uses in alternative treatment for skin infection conditions due to insect bites, microorganism infections and cancer, as well as for health well-being. A number of bioactive compounds from this plant's extract, namely phenolic compounds, sulphur containing compounds, sulphur containing glycosides compounds, terpens-tripenoids, terpens-phytosterols and chlorophyll-related compounds possess high antioxidant activities. This literature search yielded about one hundred articles which were then further documented, including the valuable data and findings obtained from all accessible electronic searches and library databases. The promising pharmacological activities from C. nutans leaves extract, including antioxidant, anti-cancer, anti-viral, anti-bacterial, anti-fungal, anti-venom, analgesic and anti-nociceptive properties were meticulously dissected. Moreover, the authors also discuss a few of the pharmacological aspect of C. nutans leaves extracts against anti-hyperlipidemia, vasorelaxation and renoprotective activities, which are seldom available from the previously discussed review papers. From the aspect of toxicological studies, controversial findings have been reported in both in-vitro and in-vivo experiments. Thus, further investigations on their phytochemical compounds and their mode of action showing pharmacological activities are required to fully grasp both traditional usage and their suitability for future drugs development. Data related to therapeutic activity and the constituents of C. nutans leaves were searched by using the search engines Google scholar, PubMed, Scopus and Science Direct, and accepting literature reported between 2010 to present. On the whole, this review paper compiles all the available contemporary data from this subtropical herb on its phytochemistry and pharmacological activities with a view towards garnering further interest in exploring its use in cardiovascular and renal diseases.

Chemical characterization, antiproliferative and antifungal activities of Clinacanthus nutans

Clinacanthus nutans Lindau (Family: Acanthaceae) is a medicinal herb widely distributed in the tropic and subtropic areas of Asia. C. nutans is traditionally consumed as vegetable or herbal tea, as well as a folk medicine for anticancer and antifungal activities. However, to date, chemical constituent responsible for observed health beneficial effects of this medicinal plant is not clear. In the current study, 32 compounds (1-32), including three new megastigmanes (1-3) were isolated from the aerial parts of C. nutans. Their structures were elucidated on the basis of comprehensive NMR, MS, and CD spectroscopic data analysis, as well as chemical hydrolysis. Among the isolates, cycloartane triterpenoids (9, 10, and 12) displayed moderate anti-proliferative effects against HepG2 cell growth with IC₅₀ values ranging from 9.12 to 19.89 μM. Data obtained from flow cytometry analysis and western blotting assays revealed that compounds 9 and 12 induced apoptosis of HepG2 cells by modulating the expression of proteins associated to mitochondrial-mediated apoptotic pathway. Furthermore, megastigmanes 1, 2, 7, and 8 enhanced the anti-Candida albicans activity of amphotericin B (AmB), supporting the synergistic effects between megastigmanes and AmB. This is the first report of anticancer and antifungal potential of cycloartane triterpenoids and megastigmanes in C. nutans, which shed useful insights on the relationship between C. nutans's chemical constituent and its beneficial effects to health. Findings from this study support further development of this medicinal plant for potential pharmaceutical applications.

Immunomodulatory potential of Clinacanthus nutans extracts in the co-culture of triple-negative breast cancer cells, MDA-MB-231, and THP-1 macrophages

Triple-negative breast cancer is the main type of breast carcinoma that causes mortality among women because of the limited treatment options and high recurrence. Chronic inflammation has been linked with the tumor microenvironment (TME) in breast cancer progression. Clinacanthus nutans (CN) has gained much attention because of its anticancer properties, but its mechanism remains unclear. We aimed to study the qualitative phytochemical content and elucidate the cytotoxicity effects of CN on human triple-negative breast cancer (TNBC), MDA-MB-231 and human macrophage-like cells such as THP-1 by using sulforhodamine B (SRB) assay. As highly metastatic cells, MDA-MB-231 cells can migrate to the distal position, the effect of CN on migration were also elucidated using the scratch assay. The CN effects on ameliorating chronic inflammation in TME were studied following the co-culture of MDA-MB-231/THP-1 macrophages. The cytokine expression levels of IL-6, IL-1β and tumor necrosis factor-alpha (TNF-α) were determined using ELISA assays. The results showed that both ethanolic and aqueous CN extracts contained alkaloid, phenol and tannin, flavonoid, terpenoid, glycoside and steroid. However, saponin was only found in the aqueous extract of CN. CN was not cytotoxic to both MDA-MB-231 and THP-1 cells. The ability of MDA-MB-231 to migrate was also not halted by CN treatment. However, CN ethanol extract decreased IL-6 at 25 μg/mL (p = 0.02) and 100 μg/mL (p = 0.03) but CN aqueous extract increased IL-6 expression at 50 μg/mL (p = 0.08) and 100 μg/mL (p = 0.02). IL-1β showed decreased expression after treated with CN ethanol and CN aqueous both at 25 μg/mL (p = 0.03). TNF-α were significantly decreased after CN ethanol treatment at concentration 25- (p = 0.001), 50- (p = 0.000) and 100 μg/mL (p = 0.000). CN aqueous extract slightly inhibited TNF-α at all 25–50- and 100 μg/mL (p = 0.001, p = 0.000, p = 0.000, respectively). Overall, CN acts by ameliorating the pro-inflammatory condition in the TME and may be a potential strategy for its anticancer mechanism on highly metastatic breast cancer condition. The major pathways that link both cancer and inflammation were NF-κB and STATs thus further study on the upstream and downstream pathways is needed to fully understand the mechanism of CN extracts in cooling the inflamed TME in breast cancer.

Recent Advancement in Anticancer Activity of Clinacanthus nutans (Burm. f.) Lindau

Clinacanthus nutans is a traditional medicinal herb that is applied for the therapy of snake bites, skin infection, herpes infection, burns, scalds, dysentery, and diabetes. Clinacanthus nutans is also used to treat several cancers, including breast, cervical, colon, gastric, head and neck, liver, lung, pancreatic, and skin cancers, as well as lymphoma and leukemia; however, the underlying mechanisms of its anticancer activity remained undetermined. We searched PubMed and Google with key words “Clinacanthus nutans and cancer” and collected recent papers of Clinacanthus nutans with anticancer activity. We focused on the preparation, effects, and action mechanisms of Clinacanthus nutans extracts on various types of cancers. We hope that this mini review can help update our knowledge about active components, effects, and molecular mechanisms of extracts from this promising herb Clinacanthus nutans for ongoing studies and speed up its clinical application in the future.

Enhanced cytotoxic effects of Clinacanthus nutans and doxorubicin in combination toward breast cancer cell lines

Breast cancer is one of the most common cancers with a relatively high mortality rate. Despite the advancement of its medical treatments, many patients are still seeking complementary alternative medicines, namely Clinacanthus nutans which is found mainly in South-East Asian countries. We aim to find the antioxidant properties and cytotoxic activity of the plant extract toward breast cancer cell lines Michigan Cancer Foundation-7 (MCF7) and T47D individually and in combination with doxorubicin. Extractions of C. nutans with ethanol, n-hexane, and ethyl acetate were done using rotatory vacuum evaporators with the reflux method. Screening of biochemical properties was conducted. Antioxidant activity was measured toward α, α-diphenyl-β-picrylhydrazyl (DPPH) with IC₅₀ scores were shown to be highest in ethyl acetate extract. Cytotoxic effects of all three extracts were shown to be low in both MCF7 and T47D cells. However, combinations of 125 μg/ml n-hexane extract of C. nutans, and 0.1 μg/ml doxorubicin in T47D cancer cells showed further proliferation reduction compared to the single administration. The results suggested possible synergisms of the treatment combination.

Comparison of diclofenac with apigenin-glycosides rich Clinacanthus nutans extract for amending inflammation and catabolic protease regulations in osteoporotic-osteoarthritis rat model

BACKGROUND

Osteoporotic-osteoarthritis is an incapacitating musculoskeletal illness of the aged.

OBJECTIVES

The anti-inflammatory and anti-catabolic actions of Diclofenac were compared with apigenin-C-glycosides rich Clinacanthus nutans (CN) leaf extract in osteoporotic-osteoarthritis rats.

METHODS

Female Sprague Dawley rats were randomized into five groups (n = 6). Four groups were bilateral ovariectomised for osteoporosis development, and osteoarthritis were induced by intra-articular injection of monosodium iodoacetate (MIA) into the right knee joints. The Sham group was sham-operated, received saline injection and deionized drinking water. The treatment groups were orally given 200 or 400 mg extract/kg body weight or 5 mg diclofenac /kg body weight daily for 28 days. Articular cartilage and bone changes were monitored by gross and histological structures, micro-CT analysis, serum protein biomarkers, and mRNA expressions for inflammation and catabolic protease genes.

RESULTS

HPLC analysis confirmed that apigenin-C-glycosides (shaftoside, vitexin, and isovitexin) were the major compounds in the extract. The extract significantly and dose-dependently reduced cartilage erosion, bone loss, cartilage catabolic changes, serum osteoporotic-osteoarthritis biomarkers (procollagen-type-II-N-terminal-propeptide PIINP; procollagen-type-I-N-terminal-propeptide PINP; osteocalcin), inflammation (IL-1β) and mRNA expressions for nuclear-factor-kappa-beta NF-κβ, interleukin-1-beta IL-1β, cyclooxygenase-2; and matrix-metalloproteinase-13 MMP13 activities, in osteoporotic-osteoarthritis rats comparable to Diclofenac.

CONCLUSION

This study demonstrates that apigenin-C-glycosides at 400 mg CN extract/kg (about 0.2 mg apigenin-equivalent/kg) is comparable to diclofenac in suppressing inflammation and catabolic proteases for osteoporotic-osteoarthritis prevention. Graphical abstract.

The anti-inflammatory properties of Acanthus Ebracteatus, Barleria Lupulina and Clinacanthus Nutans: a systematic review

This appraisal is comprised of the inflammatory studies that have been conducted on Clinacanthus nutans, Acanthus ebracteatus, and Barleria lupulina. The review aims to provide a comprehensive evaluation of the supporting and contradictory evidence on each plants' anti-inflammatory properties, whilst addressing the gaps in the current literature. The databases used to obtain relevant studies were Google Scholar, ResearchGate, PubMed and Nusearch (University of Nottingham). A total of 13 articles were selected for this review. A. ebracteatus was found to suppress neutrophil migration and weakly inhibits chronic inflammatory cytokines. Furthermore, B. lupulina and C. nutans were shown to possess very similar anti-inflammatory properties. The studies on C. nutans indicated that its anti-inflammatory effect is strongly related to the inhibition of toll-like receptor 4 (TLR4). Moreover, several phytoconstituents isolated from B. lupulina were shown to activate the anti-inflammatory Nrf2 pathway. Overall, all the studies have provided evidence to support the use of these plants as anti-inflammatory herbal remedies. However, their exact mechanism of action and the responsible phytoconstituents are yet to be established.

Anti-inflammatory and Cytoprotective Effect of Clinacanthus nutans Leaf But Not Stem Extracts on 7-Ketocholesterol Induced Brain Endothelial Cell Injury

Clinacanthus nutans (Lindau) (C. nutans) has diverse uses in traditional herbal medicine for treating skin rashes, insect and snake bites, lesions caused by herpes simplex virus, diabetes mellitus and gout in Singapore, Malaysia, Indonesia, Thailand and China. We previously showed that C. nutans has the ability to modulate the induction of cytosolic phospholipase A₂ (cPLA₂) expression in SH-SY5Y cells through the inhibition of histone deacetylases (HDACs). In the current study, we elucidated the effect of C. nutans on the hCMEC/D3 human brain endothelial cell line. Endothelial cells are exposed to high levels of the cholesterol oxidation product, 7-ketocholesterol (7KC), in patients with cardiovascular disease and diabetes, and this process is thought to mediate pathological inflammation. 7KC induced a dose-dependent loss of hCMEC/D3 cell viability, and such damage was significantly inhibited by C. nutans leaf extracts but not stem extracts. 7KC also induced a marked increase in mRNA expression of pro-inflammatory cytokines, IL-1β IL-6, IL-8, TNF-α and cyclooxygenase-2 (COX-2) in brain endothelial cells, and these increases were significantly inhibited by C. nutans leaf but not stem extracts. HPLC analyses showed that leaf extracts have a markedly different chemical profile compared to stem extracts, which might explain their different effects in counteracting 7KC-induced inflammation. Further study is necessary to identify the putative phytochemicals in C. nutans leaves that have anti-inflammatory properties.

Clinacanthus nutans Mitigates Neuronal Death and Reduces Ischemic Brain Injury: Role of NF-κB-driven IL-1β Transcription

Neuroinflammation has been shown to exacerbate ischemic brain injury, and is considered as a prime target for the development of stroke therapies. Clinacanthus nutans Lindau (C. nutans) is widely used in traditional medicine for treating insect bites, viral infection and cancer, due largely to its anti-oxidative and anti-inflammatory properties. Recently, we reported that an ethanol extract from the leaf of C. nutans could protect the brain against ischemia-triggered neuronal death and infarction. In order to further understand the molecular mechanism(s) for its beneficial effects, two experimental paradigms, namely, in vitro primary cortical neurons subjected to oxygen-glucose deprivation (OGD) and in vivo rat middle cerebral artery (MCA) occlusion, were used to dissect the anti-inflammatory effects of C. nutans extract. Using promoter assays, immunofluorescence staining, and loss-of-function (siRNA) approaches, we demonstrated that transient OGD led to marked induction of IL-1β, IL-6 and TNFα, while pretreatment with C. nutans suppressed production of inflammatory cytokines in primary neurons. C. nutans inhibited IL-1β transcription via preventing NF-κB/p65 nuclear translocation, and siRNA knockdown of either p65 or IL-1β mitigated OGD-mediated neuronal death. Correspondingly, post-ischemic treatment of C. nutans attenuated IκBα degradation and decreased IL-1β, IL-6 and TNFα production in the ischemic brain. Furthermore, IL-1β siRNA post-ischemic treatment reduced cerebral infarct, thus mimicking the beneficial effects of C. nutans. In summary, our findings demonstrated the ability for C. nutans to suppress NF-κB nuclear translocation and inhibit IL-1β transcription in ischemic models. Results further suggest the possibility for using C. nutans to prevent and treat stroke patients.

Antibiotic-Antiapoptotic Dual Function of Clinacanthus nutans (Burm. f.) Lindau Leaf Extracts against Bovine Mastitis

Mastitis caused by bacterial infection has negative impacts on milk quality and animal health, and ultimately causes economic losses to the dairy industry worldwide. Gram-negative bacteria and their component lipopolysaccharide (LPS) can trigger the inflammatory response of endothelial cells (ECs) and subsequently promote EC dysfunction or injury, which is a critical pathogenesis of mastitis-causing sepsis shock. To control the bacterial infection and to minimise the LPS negative effects on ECs, we thus aimed to identify the potential herb extracts that comprised antibacterial activity and protective ability to inhibit LPS-induced cell death. Extracts from seven types of herbs derived from antibacterial screening were investigated for their protective effects on LPS-stimulated bovine endothelial cell line. Clinacanthus nutans (Burm. f.) Lindau (C. nutans) extract appeared to be the most effective antiapoptotic extract against LPS stimulation. Treatment of C. nutans extract in LPS-stimulated cells significantly lowered apoptotic cell death through modulating pro-survival Bcl-2 and pro-apoptotic Bax expression. The investigation of bioactive compounds using solvent fractionation, HPLC, and LC-MS/MS analysis revealed glyceryl 1,3-disterate (C₃₉H₇₆O₅), kaempferol 3-O-feruloyl-sophoroside 7-O-glucoside (C₄₃H₄₈O₂₄), and hydroxypthioceranic acid (C₄₆H₉₂O₃) as the candidate components. Our findings indicated that C. nutans extract has great potential to be further developed as an alternative therapeutic agent for mastitis treatment.

Subacute Oral Administration of Clinacanthus nutans Ethanolic Leaf Extract Induced Liver and Kidney Toxicities in ICR Mice

This study investigated the leaves of Clinacanthus nutans for its bioactive compounds and acute and subacute toxicity effects of C. nutans ethanolic leaf extract (CELE) on blood, liver and kidneys of ICR mice. A total of 10 8-week-old female mice were divided into groups A (control) and B (2000 mg/kg) for the acute toxicity study. A single dose of 2000 mg/kg was administered to group B through oral gavage and mice were monitored for 14 days. In the subacute toxicity study, mice were divided into five groups: A (control), B (125 mg/kg), C (250 mg/kg), D (500 mg/kg) and E (1000 mg/kg). The extract was administered daily for 28 days via oral gavage. The mice were sacrificed, and samples were collected for analyses. Myricetin, orientin, isoorientin, vitexin, isovitexin, isookanin, apigenin and ferulic acid were identified in the extract. Twenty-eight days of continuous oral administration revealed significant increases (p < 0.05) in creatinine, ALT and moderate hepatic and renal necrosis in groups D and E. The study concluded that the lethal dose (LD₅₀) of CELE in mice is greater than 2000 mg/kg and that repeated oral administrations of CELE for 28 days induced hepatic and renal toxicities at 1000 mg/kg in female ICR mice.

The efficacy of honey and a Thai Herbal Oil preparation in the treatment of pressure ulcers based on Thai traditional medicine wound diagnosis versus standard practice: An open-label randomized controlled trial

Background

Scientific support for Thai traditional medicine (TTM) practice is warranted for reintroduction into modern healthcare systems. A promising TTM practice for treatment of pressure ulcers was selected to conduct a clinical trial. This study aimed to evaluate the efficacy of the TTM practice for the treatment of pressure ulcers using honey or a Thai Herbal Oil preparation (THO) based on the TTM wound diagnosis comparing with the standard practice.

Methods

The study design was an open-label randomized controlled trial. Sixty-six participants, with pressure ulcers at least stage II-IV or unstageable, were allocated to two groups via minimization. A TTM practice group received honey or THO depending on the TTM diagnosis via the Thai Traditional Medicine Pressure Ulcer Assessment Tool (TTM-PUAT). A standard practice group received advanced dressings, including hydrogel, alginate, silver-impregnated, or hydrocolloid dressings. The primary outcome was the Pressure Ulcer Scale for Healing (PUSH).

Results

Both TTM practice and standard practice showed a significant reduction in PUSH scores after treatments. However, there was no significant difference in PUSH score reduction between the groups. The mean PUSH score reduction over the 6-week period was 2.58 ± 3.38 (95% CI 1.34-3.82) in the TTM practice group and 3.24 ± 3.49 (95% CI 1.91-4.57) in the standard practice group (p = 0.284). The TTM practice and standard practice accelerated pressure ulcer healing without statistically significant difference between the practices, during 6 weeks in a home-based care setting. This finding supported the TTM practice as an alternative treatment for pressure ulcer.

The synergism of Clinacanthus nutans Lindau extracts with gemcitabine: downregulation of anti-apoptotic markers in squamous pancreatic ductal adenocarcinoma

BACKGROUND

Clinacanthus nutans extracts have been consumed by the cancer patients with the hope that the extracts can kill cancers more effectively than conventional chemotherapies. Our previous study reported its anti-inflammatory effects were caused by inhibiting Toll-like Receptor-4 (TLR-4) activation. However, we are unsure of its anticancer effect, and its interaction with existing chemotherapy.

METHODS

We investigated the anti-proliferative efficacy of polar leaf extracts (LP), non-polar leaf extracts (LN), polar stem extract (SP) and non-polar stem extracts (SN) in human breast, colorectal, lung, endometrial, nasopharyngeal, and pancreatic cancer cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT assay. The most potent extracts was tested along with gemcitabine using our established drug combination analysis. The effect of the combinatory treatment in apoptosis were quantified using enzyme-linked immunosorbent assay (ELISA), Annexin V assay, antibody array and immunoblotting. Statistical significance was analysed using one-way analysis of variance (ANOVA) and post hoc Dunnett's test. A p-value of less than 0.05 (p < 0.05) was considered statistical significance.

RESULTS

All extracts tested were not able to induce potent anti-proliferative effects. However, it was found that pancreatic ductal adenocarcinoma, PDAC (AsPC1, BxPC3 and SW1990) were the cell lines most sensitive cell lines to SN extracts. This is the first report of C. nutans SN extracts acting in synergy with gemcitabine, the first line chemotherapy for pancreatic cancer, as compared to conventional monotherapy. In the presence of SN extracts, we can reduce the dose of gemcitabine 2.38-5.28 folds but still maintain the effects of gemcitabine in PDAC. SN extracts potentiated the killing of gemcitabine in PDAC by apoptosis. Bax was upregulated while bcl-2, cIAP-2, and XIAP levels were downregulated in SW1990 and BxPC3 cells treated with gemcitabine and SN extracts. The synergism was independent of TLR-4 expression in pancreatic cancer cells.

CONCLUSION

These results provide strong evidence of C. nutans extracts being inefficacious as monotherapy for cancer. Hence, it should not be used as a total substitution for any chemotherapy agents. However, SN extracts may synergise with gemcitabine in the anti-tumor mechanism.