Comparison of active constituents, antioxidant capacity, and α-glucosidase inhibition in Pluchea indica leaf extracts at different maturity stages

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.

Oral Glucose Tolerance Test (OGTT) Evidence for the Postprandial Anti-Hyperglycemic Property of Salacca zalacca (Gaertn.) Voss Seed Extract

Salak seed extract (Salacca zalacca) is known for its high antioxidant content and low caffeine levels, making it a promising candidate for the development of value-added health products. However, there is a lack of scientific evidence for its anti-hyperglycemic effects. To address this, we investigated the in vitro and in vivo anti-hyperglycemic and antioxidant effects of salak seed extract. The HPLC chromatogram of salak seed extract shows a prominent peak that corresponds to chlorogenic acid. In vitro studies revealed that salak seeds inhibited α-glucosidase activity and glucose uptake in Caco-2 cells in a concentration-dependent manner, while also exhibiting antioxidant properties. The extract exhibits a non-competitive inhibition on α-glucosidase activity, with an IC50 and Ki of 16.28 ± 7.22 and 24.81 μg/mL, respectively. In vivo studies utilizing streptozotocin-nicotinamide-induced diabetic mice showed that the extract significantly reduced fasting blood glucose (FBG) levels in the oral glucose tolerance test. Continuous administration of the salak seed extract resulted in lower FBG levels by 13.8% as compared with untreated diabetic mice, although this change was not statistically significant. The estimated LD50 value of salak seed extract exceeds 2000 mg/kg, and no toxicity symptoms have been detected. Our research supports that salak seed extract has the potential to serve as a functional food or supplement that may be beneficial in reducing postprandial hyperglycemia among people with type 2 diabetes. This effect was explained by the salak's inhibitory mechanisms of glucose absorption due to inhibition of both α-glucosidase activity and intestinal glucose uptake, coupled with its antioxidant effects.

How does maturity stage affect seeds metabolome via UPLC/MS based molecular networking and chemometrics and in relation to antioxidant effect? A case study in 4 major cereals and legumes

Legumes and cereals as staple food are typically consumed at mature stage, though also consumed at earlier stages. UPLC/MS based molecular networking and chemometrics were employed for the first time to address metabolome composition heterogeneity amongst seeds in the context of their maturity stages. The study included 4 major cereal and leguminous seeds of different species, and cultivars i.e., Triticum aestivum, Hordeum vulgare, Vicia faba and Cicer arietinum. 146 Metabolites from various classes were identified of which several are first time to be reported. Supervised OPLS model of all datasets revealed that sugars and oxylipids were dominant in mature and immature seeds, respectively. DPPH and FRAP assays were assessed for differential secondary metabolites' correlation. Results were attributed to flavonoids, oxylipids, and amino acids/peptides. Mature barley seeds possessed the strongest antioxidant activity among examined seeds. This study provides novel insights on seeds' maturation process in context to holistic metabolic changes.

Effect of Maturity Stage on Cereal and Leguminous Seeds' Metabolome as Analyzed Using Gas Chromatography Mass-Spectrometry (GC-MS) and Chemometric Tools

Cereal and leguminous seeds are considered as major generic dietary source of energy, carbohydrates as well as proteins in the Mediterranean diet and are frequently consumed in their immature form in several regions including the Middle East. Hence, the current study aimed to assess metabolites' heterogeneity amongst five major cereal and leguminous seeds of different species, and cultivars, i.e., Triticum aestivum L. (two cultivars), Hordeum vulgare L., Vicia faba L. and Cicer arietinum L., at different maturity stages. Gas chromatography mass-spectrometry (GC-MS) analysis using multivariate data analyses was employed for nutrient profiling and sample segregation assessed using chemometric tools, respectively. A total of 70 peaks belonging to sugars, fatty acids/esters, steroids, amino acids and organic acids were identified including sucrose, melibiose, glucose and fructose as major sugars, with butyl caprylate, hydroxybutanoic acid and malic acid contributing to the discrimination between seed species at different maturity stages. The investigation of total protein content revealed comparable protein levels amongst all examined seeds with the highest level detected at 20.1% w/w in mature fava bean. Results of this study provide a novel insight on cereal and leguminous seeds' metabolomics in the context of their maturity stages for the first time in literature.

Detoxification of comfrey (Symphytum officinale L.) extract using natural deep eutectic solvent (NADES) and evaluation of its anti-inflammatory, antioxidant, and hepatoprotective properties

Comfrey (Symphytum officinale L.) contains rosmarinic acid which has different pharmacological activities, such as antioxidant and anti-inflammatory activities. However, the medicinal use of comfrey is limited by the hepatotoxic effect of lycopsamine in comfrey, which overshadows the health benefits of rosmarinic acid. Natural deep eutectic solvents (NADES) have a wide range of extraction properties, that provides a new approach to the detoxification of comfrey. In the present study, betaine-based and choline chloride-based NADES were screened for selective extraction of rosmarinic acid over lycopsamine. Ultrasonication was used in conjunction with NADES extraction. The chemical profile of the NADES extracts on antioxidant, anti-inflammatory and hepatotoxic activities were investigated using some chemical reagents. Betaine-urea (1:2 molar ratio, 50% water) obtained the highest content of rosmarinic acid and a low level of lycopsamine (1.934 and 0.018 mg/g, respectively). Betaine-urea was also shown to be more effective to extract rosmarinic acid compared to methanol-UAE under the same conditions, which gave lower rosmarinic acid and higher lycopsamine levels (0.007 and 0.031 mg/g, respectively). Betaine-urea extracts showed higher antioxidant and anti-inflammatory properties as compared with other NADES extracts, however, had lower hepatotoxic profile. This study recommends the use of betaine-urea to detroxify comfrey to open wider opportunities for the development of comfrey for medicinal use.

Kaempferol: Antimicrobial Properties, Sources, Clinical, and Traditional Applications

Flavonoids are a category of plant-derived compounds which exhibit a large number of health-related effects. One of the most well-known and studied flavonoids is kaempferol, which can be found in a wide variety of herbs and plant families. Apart from their anticarcinogenic and anti-inflammatory effects, kaempferol and its associated compounds also exhibit antibacterial, antifungal, and antiprotozoal activities. The development of drugs and treatment schemes based on these compounds is becoming increasingly important in the face of emerging resistance of numerous pathogens as well as complex molecular interactions between various drug therapies. In addition, many of the kaempferol-containing plants are used in traditional systems all over the world for centuries to treat numerous conditions. Due to its variety of sources and associated compounds, some molecular mechanisms of kaempferol antimicrobial activity are well known while others are still under analysis. This paper thoroughly documents the vegetal and food sources of kaempferol as well as the most recent and significant studies regarding its antimicrobial applications.

The Effect of κ-Carrageenan Proportion and Hot Water Extract of the Pluchea indica Less Leaf Tea on the Quality and Sensory Properties of Stink Lily (Amorphophallus muelleri) Wet Noodles

The study aims to determine the effect of the proportion of κ-carrageenan and the hot water extract of pluchea leaf tea on the quality and sensory properties of stink lily wet noodles. The research design is a randomized block design with two factors, i.e., the difference in the proportion of κ-carrageenan (K) (0, 1, 2, and 3% w/w) and the addition of the hot water extract of the Pluchea indica Less leaf tea (L) (0, 15, and 30% w/v), with 12 treatment levels (K0L0, K0L1, K0L2, K1L0, K1L1, K1L2, K2L0, K2L1, K2L2, K3L0, K3L1, K3L2). The data are analyzed by the ANOVA at p < 5% and continued with the Duncan’s multiple range test at p < 5%, and the best treatment was determined by the spider web method based on sensory assay by a hedonic method. The proportions of κ-carrageenan and the concentration of pluchea tea extract had a significant effect on the cooking quality and sensory properties. However, the interaction of the two factors affected the swelling index, yellowness (b*), chroma (C), hue (h), total phenol content (TPC), total flavonoid content (TFC), and DPPH free radical scavenging assay (DPPH). The best treatment of wet noodles was K2L0, with a preference score of 15.8. The binding of κ-carrageenan and phenolic compounds to make a networking structure by intra- and inter-disulfide bind between glucomannan and gluten was thought to affect the cooking quality, sensory properties, bioactive compounds (TPC and TFC), and DPPH.

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.

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.

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.

Phytochemical content and antioxidant activity in aqueous extracts of Cyclocarya paliurus leaves collected from different populations

Cyclocarya paliurus (Batal) Iljinskaja is a multiple function tree species, but its main utilization is for the harvesting of its leaves as materials for tea production and recently as ingredients for the food industry. In this study aqueous extracts of C. paliurus leaves collected from 21 natural populations were evaluated for their phytochemical content and antioxidant activity. The content of water-soluble polysaccharide, total flavonoid and total polyphenol varied from 66.05 to 153.32 mg/g, 9.01 to 19.65 mg/g and 20.80 to 52.69 mg/g, respectively. Quercetin-3-O-glucuronide, aemferol-3-O-glucuronide and 3-O-caffeoylquinic acid were the major phenolic components in aqueous extracts of C. paliurus leaves. Both redundancy analysis and Pearson's correlation analysis indicated that water-soluble polysaccharide, total polyphenol, total flavonoid, quercetin-3-O-glucuronide, 3-O-caffeoylquinic acid and 4-O-caffeoylquinic acid were significantly correlated with antioxidant activity, but total polyphenol showed the greatest contribution to antioxidant capacity. The antioxidant activity of the 21 populations was classified into six distinct groups based on the squared Euclidean distance. These results would provide a theoretical basis for obtaining the greatest yield of targeted antioxidant phytochemicals of C. paliurus leaves for tea and food ingredient production.