Optimization of extraction method and HPLC analysis of six caffeoylquinic acids in Pluchea indica leaves from different provenances in Thailand

Insights into the anti-infective effects of Pluchea indica (L.) Less and its bioactive metabolites against various bacteria, fungi, viruses, and parasites

ETHNOPHARMACOLOGICAL RELEVANCE

Pluchea indica (L.) Less (family Asteraceae) is popularly consumed as a medicinal vegetable and used in ethnomedicine to treat various diseases including gastrointestinal problems such as dysentery and leucorrhoea, which are due to bacterial, fungal or parasitic infections. There have been numerous studies on the antimicrobial effects of the plant due to these ethnomedicine use.

AIM OF THIS REVIEW

This review is comprehensively discussed the information on the anti-infective properties of P. indica and its secondary metabolites, and highlight the potential of the plant as a new source of anti-infective agents.

MATERIALS AND METHODS

Scientific databases such as Scopus, Google Scholar, ScienceDirect, PubMed, Wiley Online Library, and ACS Publications were used to gather the relevant information on the ability of P. indica to fight infections, with the leaves and roots receiving most of the attention.

RESULTS

Anti-bacterial, anti-mycobacterial, anti-malarial, and anti-viral activities have been the most exploited. Most studies were carried out on the crude extracts of the plant and in most studies the bioactive extracts were not standardized or chemically characterized. Several studies have reported the anti-infective activity of several bioactive components of P. indica including caffeoylquinic acids, terpenoid glycosides, thiophenes, and kaempferol.

CONCLUSIONS

The strong anti-infective effect and underlying mechanisms of the compounds provide insights into the potential of P. indica as a source of new leads for the development of anti-infective agents for use in food and pharmaceutical industries.

Toxicity, physiological, and morphological alterations of Indian camphorweed (Pluchea indica) in response to excess copper

Indian camphorweed (Pluchea indica (L.) Less.) is used as herbal tea due to the presence of volatile aromatic oils and several phytochemical compounds. The aim of this study was to assess the impact of copper (Cu) contamination on the physiology and morphology of P. indica, and the health risks associated with its consumption as tea. The cuttings of P. indica were subjected to 0 mM (control), 5 mM (low Cu), and 20 mM (excess Cu) of CuSO4 treatments for 1, 2, and 4 weeks. Thereafter, Cu contamination as well as physiological and morphological parameters were assessed. Cu accumulation was higher in the root tissues of plants (25.8 folds higher as compared to the leaves) grown under 20 mM CuSO4 for 4 weeks. This increased Cu accumulation resulted in the inhibition of root length, root fresh weight, and root dry weight. Cu concentration was found maximum (1.36 μg g-1 DW) in the leaf tissues under 20 mM Cu exposure for 4 weeks, with the highest target hazard quotient (THQ = 1.85), whereas Cu was not detected in control. Under exposure to 20 mM Cu treatment for 4 weeks, leaf greenness, maximum quantum yield of photosystem II, and photon yield of photosystem II diminished by 21.4%, 16.1%, and 22.4%, respectively, as compared to the control. Leaf temperature was increased by 2.5 °C, and the crop stress index (CSI) exceeded 0.6 when exposed to 20 mM Cu treatment for 2 and 4 weeks; however, the control had a CSI below 0.5. This led to a reduced transpiration rate and stomatal conductance. In addition, the net photosynthetic rate was also found sensitive to Cu treatment, which resulted in decreased shoot and root growth. Based on the key results, it can be suggested that P. indica herbal tea derived from the foliage of plants grown under a 5 mM Cu level (0.75 μg g-1 DW) with a target hazard quotient below one aligns with the recommended dietary intake of Cu in leafy vegetables. The study recommends choosing cuttings from plants with a small canopy as plant material in the greenhouse microclimates to validate the growth performance in the Cu-contaminated soil and simulate the natural shrub architecture and life cycle.

A dispersive liquid-liquid microextraction followed by reverse-phase high-performance liquid chromatography for QuEChERS determination of chlorogenic acid

INTRODUCTION

The presence of chlorogenic acid (CGA) not only imparts a characteristic flavour to foods but also makes them useful against chronic diseases and metabolic syndromes, especially diabetes mellitus and asthma.

OBJECTIVES

The present study was designed to develop a quick, easy, cheap, effective, rugged, and safe (QuEChERS) and pragmatic method to analyse CGA in plant-based products by applying dispersive liquid-liquid microextraction (DLLME) followed by reverse-phase high-performance liquid chromatography under a diode array detector (RP-HPLC-DAD).

METHODOLOGY

The DLLME was carried out using Triton X-100 as a dispersant and ethanol as an extraction solvent, while method development and validation activities were performed on a Shimadzu 10-AT HPLC-DAD system equipped with C-18 columns as stationary phases.

RESULTS

The well-resolved peak for the standard CGA was observed at 2.92 min for the mobile phase comprising 0.1% aqueous formic acid-ethanol (22:78 v/v) of pH 3.0 programmed under an isocratic flow rate of 1.0 mL/min. The developed method was found to be linear (R²  = 0.9976) over 1-500 μg/mL of CGA concentration at 328 nm. Moreover, the assay was found to be repeatable with RSD ≤ 5.0, and the limit of detection (LOD) and limit of quantification (LOQ) were 0.0281 and 0.0853 μg/mL of CGA, respectively. The DLLME offered an overall recovery rate between 97.60% and 99.54% at an acceptable level of reproducibility [relative standard deviation (RSD) ≤ 5.0].

CONCLUSION

The developed assay was found to be a QuEChERS and pragmatic choice for the high-throughput analysis of CGA in plant-based products/foods. Finally, the analysis revealed the presence of an ample level of CGA in guava fruit in addition to coffee beans and black tea.

Phytoconstituents and Pharmacological Activities of Indian Camphorweed (Pluchea indica): A Multi-Potential Medicinal Plant of Nutritional and Ethnomedicinal Importance

Pluchea indica (L.) Less. (Asteraceae) commonly known as Indian camphorweed, pluchea, or marsh fleabane has gained great importance in various traditional medicines for its nutritional and medicinal benefits. It is utilized to cure several illnesses such as lumbago, kidney stones, leucorrhea, inflammation, gangrenous and atonic ulcer, hemorrhoids, dysentery, eye diseases, itchy skin, acid stomach, dysuria, abdominal pain, scabies, fever, sore muscles, dysentery, diabetes, rheumatism, etc. The plant or its leaves in the form of tea are commonly used for treating diabetes and rheumatism. The plant is a rich source of calcium, vitamin C, dietary fiber, and β-carotene. Various biomolecules have been isolated from P. indica, including thiophenes, terpenes, quinic acids, sterols, lignans, phenolics, and flavonoids. The current review reports detailed information about the phytoconstituents and pharmacological relevance of P. indica and the link to its traditional uses. The reported studies validated the efficacy and safety of P. indica, as well as supported its traditional uses for treating various ailments and promoting health and well-being. Thus, this could encourage the development of this plant into a healthy food supplement or medicine for the prevention and treatment of various diseases. However, further studies on the drug interactions, mechanism of action, pharmacokinetics, toxicology, and metabolism, as well as clinical trials, should be carried out.

Four almost unexplored species of Brazilian Connarus (Connaraceae): Chemical composition by ESI-QTof-MS/MS-GNPS and a pharmacologic potential

INTRODUCTION

Species of Connaraceae are globally used in traditional medicines. However, several of these have not been studied regarding their chemical composition, and some are even at risk of extinction without proper studies. Therefore, the chemical composition and pharmacological potential of Connarus blanchetii Planch., Connarus nodosus Baker, Connarus regnellii G. Schellenb., and Connarus suberosus Planch., which were previously unknown, were analyzed.

OBJECTIVE

This work aims to investigate the pharmacological potential of these four Connarus species. The chemical composition of different extracts was determined by high-resolution mass spectrometry (HRMS), with subsequent analysis by the GNPS platform and competitive fragmentation modeling (CFM).

MATERIALS AND METHODS

Leaf extracts (C. blanchetii, C. nodosus, C. regnellii, and C. suberosus) and bark extracts (C. regnellii and C. suberosus) were obtained by decoction, infusion, and maceration. LC/HRMS data were submitted to the GNPS platform and evaluated using CFM in order to confirm the structures.

RESULTS

The HRMS-GNPS/CFM analysis indicated the presence of 23 compounds that were mainly identified as phenolic derivatives from quercetin and myricetin, of which 21 are unedited in the Connarus genus. Thus, from the analyses performed, we can identify different compounds with pharmacological potential, as well as the most suitable forms of extraction.

CONCLUSION

Using HRMS-GNPS/CFM, 21 unpublished compounds were identified in the studied species. Therefore, our combination of data analysis techniques can be used to determine their chemical composition.

Phytochemical Analysis, Antioxidant, and Wound Healing Activity of Pluchea indica L. (Less) Branch Extract Nanoparticles

Proliferation and migration of keratinocytes and fibroblasts play an important role in cutaneous wound healing, while oral mucosal squamous cell proliferation and migration are crucial for oral wound healing. In this study, the phytochemical profile of Pluchea indica branch ethanolic extract was characterized. The bioactive compound of Pluchea indica branch ethanolic extract was identified and analyzed by the validated HPLC method. The nanoparticles of P. indica branch extract were formulated by solvent displacement method to increase the solubility and the colloidal stability of the extract. The stability of the nanoparticles was investigated by using the dynamic light scattering technique. Effects of P. indica crude extract and nanoparticles on cell viability, proliferation and migration of primary epidermal keratinocytes, human dermal fibroblasts, and oral mucosal keratinocyte cells were investigated by MTT assay and scratch assay, respectively. The results showed that P. indica branch extract contained a high content of total phenolic and total flavonoids. The HPLC analysis revealed that the main compound in the extract was 4,5-O-dicaffeoylquinic acid. The cell viability of the extract and nanoparticles decreased when cells were exposed to a high concentration of extract and nanoparticles. These results demonstrate that P. indica branch extract and extract nanoparticles at specific concentrations possess in vitro wound healing activity and they may be possibly used to treat different types of wounds including dermal and oral mucosal wounds.

Effect of gamma irradiation on the caffeoylquinic acid derivatives content, antioxidant activity, and microbial contamination of Pluchea indica leaves

Pluchea indica (L.) Less. leaf has a long history of being used as a food and in traditional medicines. Although gamma irradiation is an effective decontamination method, it must be performed appropriately to preserve the bioactive constituents and biological activities of the plant. This study investigated the influence of gamma irradiation on the caffeoylquinic acid derivatives content, antioxidant capacity, and microbial burden of P. indica leaf. Dried P. indica leaf powder was exposed to gamma rays from cobalt-60 at the absorbed doses of 2.5, 5.0, 7.5, and 10 kGy. After a maceration of P. indica leaf with 70% ethanol, the content of six caffeoylquinic acid derivatives (CQAs) in the extract was assayed using high-performance liquid chromatography. The antioxidant capacity of the ethanolic extract was also determined using the DPPH, ABTS, and ferric reducing antioxidant power (FRAP) methods. The total aerobic bacteria and total yeast and mold counts were investigated using the Petrifilm method at 0 and 3 months after irradiation. Doses of 5–10 kGy significantly increased the CQA level (P < 0.05). The antioxidant activity was enhanced significantly at 2.5–10 kGy (P < 0.05). Doses of 2.5–10 kGy also effectively reduced the microbial load (P < 0.05). Among the irradiation doses, 10 kGy showed the best results. Thus, gamma irradiation at 10 kGy is useful in increasing CQA content and antioxidant capacity as well as reducing the microbial load of P. indica leaf.

The Effect of Pluchea indica (L.) Less. Tea on Blood Glucose and Lipid Profile in People with Prediabetes: A Randomized Clinical Trial

Objective: Diabetes mellitus and dyslipidemia are currently increasing dramatically, and conventional medicine in the treatment of them has limited efficacies and serious adverse effects. Pluchea indica (L.) Less. tea (PIT) is widely consumed as a health-promoting drink in Southeast Asia. This study aimed to investigate whether P. indica tea has antidyslipidemic and antihyperglycemic effects and toxicity in humans. Design: A randomized clinical trial. Setting/Location: Nakhonratchasima, Thailand. Participants: Forty-five participants with prediabetes. Interventions: Participants were randomized to receive placebo tea, 1.5 g of PIT, and 1.5 g Camellia sinensis tea (green tea, CST) once daily for 12 weeks. Outcome Measurements: The oral glucose tolerance test (OGTT), total cholesterol, triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), blood urea nitrogen (BUN), creatinine, alanine transaminase (ALT), alkaline phosphatase (ALP), and complete blood count (CBC) before and after treatment were investigated. Results: The results showed that PIT significantly ameliorated hyperglycemia and significantly lower serum TG (109.22 ± 5.21 mg/dL) and LDL-C (122.20 ± 3.67 mg/dL) than placebo (145.56 ± 8.18 and 142.07 ± 8.58 mg/dL, respectively) (p < 0.05). Moreover, PIT exhibited serum TG (109.22 ± 5.21 mg/dL) significantly lower than CST (124.38 ± 4.70 mg/dL) (p < 0.05). In addition, the serum HDL-C of PIT (57.56 ± 3.05 mg/dL) was significantly higher than the placebo (46.44 ± 2.47 mg/dL) (p < 0.05). Furthermore, the toxicity testing showed that no significant difference in BUN, creatinine, ALT, ALP, and CBC of PIT-treated group compared with the placebo (p > 0.05). Conclusions: These results suggest that PIT may ameliorate hyperglycemia and dyslipidemia in prediabetes people. It may not be toxic to the kidney, liver, and blood. So, PIT has the potential to develop to be a health-promoting tea or herbal medicine for hyperglycemia and dyslipidemia prevention.

The Free Radical Scavenging and Anti-Isolated Human LDL Oxidation Activities of Pluchea indica (L.) Less. Tea Compared to Green Tea (Camellia sinensis)

Tea is one of the most popular beverages in the world. Camellia sinensis tea (CST) or green tea is widely regarded as a potent antioxidant. In Thailand, Pluchea indica (L.) Less. tea (PIT) has been commercially available as a health-promoting drink. This study focused on free radical scavenging activities of PIT, and its ability to protect isolated human low-density lipoproteins (LDL) from oxidation by chemical agents. A preliminary study to investigate the antioxidant nature of PIT was undertaken. These included common antioxidant assays involving 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS), hypochlorous acid (HOCl), and its potential to scavenge peroxynitrite. In separated experiments, isolated human LDL was challenged with either 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH), copper (Cu²⁺), or 3-Morpholinosydnonimine hydrochloride (SIN-1) to induce LDL oxidation. PIT exhibited antioxidant activity in all test systems and performed significantly better than CST in both DPPH (P < 0.05; IC₅₀PIT = 245.85 ± 15.83 and CST = 315.41 ± 24.18 μg/ml) and peroxynitrite scavenging assays. PIT at 75 μg/ml almost fully prevented the peroxynitrite over a 5 h period. Moreover, it displayed similar properties to CST during the antioxidation of isolated human LDL using AAPH, Cu²⁺, SIN-1, and hypochlorous acid scavenging assays. However, it revealed a significantly lower ABTS scavenging activity than CST (P < 0.05; IC₅₀PIT = 30.47 ± 2.20 and CST = 21.59 ± 0.67 μg/ml). The main constituents of the PIT were identified using LC-MS/MS. It contained 4-O-caffeoylquinic acid (4-CQ), 5-O-caffeoylquinic acid (5-CQ), 3,4-O-dicaffeoylquinic acid (3,4-CQ), 3,5-O-dicaffeoylquinic acid (3,5-CQ), and 4,5-O-dicaffeoylquinic acid (4,5-CQ). In conclusion, caffeoyl derivatives in PIT could play an important role in potent antioxidant properties. So, it may be further developed to be antioxidant beverages for preventing atherosclerosis and cardiovascular diseases associated with oxidative stress.

Pluchea indica (L.) Less. Tea Ameliorates Hyperglycemia, Dyslipidemia, and Obesity in High Fat Diet-Fed Mice

Pluchea indica (L.) Less. (P. indica) tea has been used for a health-promoting drink, especially in Southeast Asia. The effect of P. indica tea (PIT) on amelioration of hyperglycemia; dyslipidemia that was total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), and triglyceride (TG); and obesity in high fat diet-induced (HFD) mice was investigated. Oral glucose tolerance test (OGTT) displayed that PIT at 400 and 600 mg/kg orally ameliorated hyperglycemia with a dose-dependent manner compared to the untreated group. Moreover, PIT at these dosages exhibited significantly lower TC, LDL-C, TG, and perigonadal fat weight in HFD treated mice compared to HFD mice (P < 0.05) with a dose-dependent manner. In contrast, HDL-C was higher than in the HFD group, but not a significant difference (P > 0.05). The PIT chemical analysis results demonstrated that PIT contained total phenolic content (TPC), total flavonoid content (TFC), 4-O-caffeoylquinic acid (4-CQ), 5-O-caffeoylquinic acid (5-CQ), 3,4-O-dicaffeoylquinic acid (3,4-CQ), 3,5-O-dicaffeoylquinic acid (3,5-CQ), 4,5-O-dicaffeoylquinic acid (4,5-CQ), beta-caryophyllene, and gamma-gurjunene that may play an important role in inhibiting hyperlipidemia and hyperglycemia. Also, histological analysis expressed that the mean area and amount of perigonadal fat adipocytes of PIT treated groups were significantly lower and higher than the HFD group (P < 0.05), respectively. The toxicity test of PIT at 600 mg/kg/day in mice showed that serum creatinine, alanine transaminase (ALT), alkaline phosphatase (ALP), and complete blood count (CBC) levels of HFD and PIT treated groups were not significantly different compared to the normal control diet group (NCD) (P > 0.05). These results suggest that PIT does not become toxic to the kidney, liver, and blood. In conclusion, PIT has the potential to develop into healthy food supplement or medicine for the prevention and treatment of hyperglycemic, hyperlipidemic, and obese patients.

In vitro and in vivo evidence of hypouricemic and anti-inflammatory activities of Maclura cochinchinensis (Lour.) Corner heartwood extract

Maclura cochinchinensis (Lour.) Corner (MC) heartwood extracts have been used for the treatment of gout, hyperuricemia, and inflammation in Thai traditional medicine. Despite their traditional use, their mechanisms of action remain unknown. The aim of this study was to determine the mechanisms of MC heartwood extract activity using both in vitro and in vivo models . The extraction methods were optimized to yield the highest contents of biochemical compounds and antioxidant activities. The effects of MC heartwood extract on xanthine oxidase and its enzyme kinetics were determined in vitro and the antihyperuricemic effect was evaluated in potassium oxonate (PO)-induced hyperuricemic mice. The anti-inflammatory effect of MC heartwood extract was also tested against lipopolysaccharide-induced proinflammatory mRNA upregulation in RAW 264.7 mouse macrophage cells. Soxhlet extraction of MC heartwood with 70% ethanol produced stronger antioxidant activity, and higher total phenolic and flavonoid contents than conventional methods did (maceration or decoction). By using HPLC, we found that MC contains morin as a major constituent, which may account for its pharmacological activities. Moreover, administration of MC heartwood extract (500 mg/kg) markedly decreased uric acid levels in PO-induced hyperuricemic mice (p < 0.05). MC heartwood extract inhibited the hepatic activity of xanthine oxidase ex vivo by approximately 53%. In addition, MC heartwood extract markedly downregulated mRNA expression of inflammatory mediators (TNF-α, TGF-β, iNOS, and COX-2) and this inhibition was comparable with that of dexamethasone. Therefore, MC heartwood extract is a promising candidate as a natural treatment for inflammation and the hyperuricemia that causes gout.

Ethanolic extracts of Pluchea indica (L.) leaf pretreatment attenuates cytokine-induced β-cell apoptosis in multiple low-dose streptozotocin-induced diabetic mice

Loss of β-cell mass and function is a fundamental feature of pathogenesis for type 1 and type 2 diabetes. Increasing evidence indicates that apoptosis is one of the main mechanisms of β-cell death in both types. Ethanolic extracts of Pluchea indica leaf (PILE) have been reported to possess blood glucose lowering actions in vivo. Nevertheless, further study is required to determine the underlying mechanisms. In this report, we have investigated the preventive effects of PILE on multiple low doses of streptozotocin (MLDS)-induced β-cell apoptosis. Mice were pre-treated with PILE at 50 mg/kg (PILE 50) or 100 mg/kg (PILE 100) for 2 weeks before streptozotocin (STZ) stimulation, and the treatment continued for 4 or 8 weeks. Results revealed that PILE 100 mice exhibited improved blood biochemistry, maintained a higher body weight, had decreased hyperglycemia, and restored islet architectures compared to non-treated STZ mice. Significantly, PILE 100 decreased levels of inflammatory response markers interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and interlukin1-β (IL-1β), concomitant with the inhibition of caspase-3, caspase-8, capsepase-9, phosphorylation of signal transducer and activator of transcription 1 (pSTAT1), nuclear factor-κBp65 (NF-κBp65), and inducible nitric oxide synthase (iNOS). Additionally, survival and proliferative ability of β-cells was mediated by up-regulated Bcl-2 and Ki67, respectively. These results provide strong evidence that pretreatment with PILE 100 effectively attenuated STZ-induced diabetes-related symptoms and these effects could be associated with the inhibition of cytokine-induced β-cell apoptosis.

The Effect of Pluchea indica (L.) Less. Tea on Adipogenesis in 3T3-L1 Adipocytes and Lipase Activity

Obesity and hyperlipidemia are a major problem in the world. Pluchea indica (L.) Less. tea (PIT) is a beverage that has various indications. This study focused on the effect of the PIT on inhibiting adipogenesis of 3T3-L1 cells and pancreatic lipase enzyme activity. The viability of 3T3-L1 cells was not significantly decreased after exposure to 200 to 1000 μg mL-1 PIT compared to controls (p > 0.05). The PIT at 750 to 1000 μg mL-1 exhibited a significantly reduced lipid accumulation compared to the control (p < 0.05). The inhibitory effects of the PIT at 250 to 1000 μg mL-1 on lipase activity were significantly increased compared to control (p < 0.05). The FTIR results showed that the integrated areas of lipids, proteins, nucleic acids, glycogen, and carbohydrates of the PIT-treated 3T3-L1 adipocytes were significantly lower than the untreated 3T3-L1 adipocytes (p < 0.05). These findings may indicate that the PIT is not only capable of inhibiting lipids and carbohydrate accumulation in adipocytes but also has a potential to inhibit pancreatic lipase activity. So, the PIT may be further developed to the novel lipid-lowering herbal supplement for the management of overweight or obesity.