Anti-inflammatory Properties of Ethanolic Extract and 2″-O-β-D-Glucopyranosyl-vitexin Obtained from Alternanthera tenella Colla Whole Plant

Anti-inflammatory and antiophidic effects of extract of Hymenaea eriogyne benth and structure-activity relationship prediction of the major markers in silico

ETHNOPHARMACOLOGICAL RELEVANCE

Hymenaea eriogyne Benth (Fabaceae) is popularly known as "Jatobá". Despite its use in folk medicine to treat inflammatory disorders, there are no descriptions that show its anti-inflammatory potential.

AIM OF THE STUDY

In this sense, this study aimed to evaluate the anti-inflammatory and antivenom action of bark and leaves extract of H. eriogyne.

MATERIALS AND METHODS

The in vivo anti-inflammatory activity was conducted by carrageenan-induced paw edema and zymosan-induced air pouch models, evaluating the edematogenic effect, leukocyte migration, protein concentration, levels of pro-inflammatory cytokines, malondialdehyde (MDA) and myeloperoxidase (MPO) activity. The antivenom potential was investigated in vitro on the enzymatic action (proteolytic, phospholipase and hyaluronidase) of Bothrops brazili and B. leucurus venom, as well as in vivo on the paw edema model induced by B. leucurus. Furthermore, the influence of its markers (astilbin and rutin) on MPO activity was investigated in silico. For molecular docking, AutodockVina, Biovia Discovery Studio, and Chimera 1.16 software were used.

RESULTS

The extracts and bark and leaves of H. eriogyne revealed a high anti-inflammatory effect, with a reduction in all inflammatory parameters evaluated. The bark extract showed superior results when compared to the leaf extract, suggesting the influence of the astilbin concentration, higher in the bark, on the anti-inflammatory action. In addition, only the H. eriogyne bark extract was able to reduce MDA, indicating an associated antioxidant effect. Regarding the in vitro antivenom action, the extracts (bark and leaves) revealed the ability to inhibit the proteolytic, phospholipase and hyaluronidase action of both bothropic venom, with a greater effect against B. leucurus venom. In vivo, extracts from the bark and leaves of H. eriogyne (50-200 mg/kg) showed antiedematogenic activity, reducing the release of MPO and pro-inflammatory cytokines, indicating the presence of bioactive components useful in controlling the inflammatory process induced by the venom. In the in silico assays, astilbin and rutin showed reversible interactions of 9 possible positions and orientations towards MPO, with affinities of -9.5 and -10.4 kcal/mol and interactions with Phe407, Gln91, His95 and Arg239, important active pockets of MPO. Rutin demonstrated more effective types of interactions with MPO.

CONCLUSION

This approach reveals for the first time the anti-inflammatory action of H. eriogyne bark and leaf extracts in vivo, as well as its antiophidic potential. Moreover, the distinct effect of pharmacogens as antioxidant agents and distinct effect of astilbin and rutin under MPO sheds light on the different anti-inflammatory mechanisms of bioactive compounds present in H. eriogyne extracts, with high potential for the prospection of new pharmacological agents.

Phytochemical analysis and investigation of analgesic, anti-inflammatory, and antispasmodic activities of hydroethanolic extracts of Alternanthera dentata, Ocimum carnosum, and Plectranthus barbatus, three species with vernacular names derived from analgesic drugs

ETHNOPHARMACOLOGICAL RELEVANCE

Plant vernacular names can provide clues about the popular use of a species in different regions and are valuable sources of information about the culture or vocabulary of a population. Several medicinal plants in Brazil have received names of medicines and brand-name products.

AIM OF THE STUDY

The present work aimed to evaluate the chemical composition and pharmacological activity in the central nervous system of three species known popularly by brand names of analgesic, anti-inflammatory, antispasmodic, and digestive drugs.

MATERIALS AND METHODS

Hydroethanolic extracts of Alternanthera dentata (AD), Ocimum carnosum (OC), and Plectranthus barbatus (PB) aerial parts were submitted to phytochemical analysis by HPLC-PAD-ESI-MS/MS and evaluated in animal models at doses of 500 and 1000 mg/kg. Mice were tested on hot plate, acetic acid-induced writing, formalin-induced licking, and intestinal transit tests. Aspirin and morphine were employed as standard drugs.

RESULTS

The three extracts did not change the mice's response on the hot plate. Hydroethanolic extracts of AD and PB reduced the number of writhes and licking time, while OC was only effective on the licking test at dose of 1000 mg/kg. In addition, AD and OC reduced intestinal transit, while PB increased gut motility.

CONCLUSIONS

Pharmacological tests supported some popular uses, suggesting peripheral antinociceptive and anti-inflammatory effects, while the phytochemical analysis showed the presence of several flavonoids in the three hydroethanolic extracts and steroids in PB, with some barbatusterol derivatives described for the first time in the species.

Anti-arthritic potential and antioxidant properties of infusion, fractions and flavonoid glycosides from Dipteryx alata (baru) leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Dipteryx alata Vogel., popularly known as "baru", is a native species of Brazilian cerrado used by "Ribeirinhos" in the North Araguaia microregion. In the traditional medicine, maceration of barks or leaves infusion are used to treat back and muscle pain, osteoporosis and rheumatism. However, few studies have demonstrated the pharmacological effects of this species.

AIM OF THE STUDY

The goal of this study was to perform phytochemicals studies of lyophilized infusion of D. alata leaves (LI-DA), as well as obtaining ethyl acetate fraction (EAF-DA) and hydromethanolic fraction (HMF-DA), and isolated flavonoids. The antioxidant of LI-DA, EAF-DA and HMF-DA, anti-inflammatory effects of LI-DA and quercetin-3-O-β-glucoside-7-O-α-rhamnoside (DA-1) and quercetin-7-O-α-rhamnoside (DA-2) were performed while in silico tests were used for absorption, distribution, metabolism, excretion and toxicity predictions of DA-1 and DA-2.

MATERIALS AND METHODS

LI-DA, EAF-DA and HMF-DA were evaluated in antioxidant assays (2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid - ABTS; 2,2-diphenyl-1-picrylhydrazyl - DPPH; hydrogen peroxide - H2O2; reducing power and oxidation of β-carotene). The DA-1 and DA-2 were isolated from EAF-DA using chromatographic methods and characterized by Nuclear Magnetic Resonance (NMR) spectrometer. The Programs ProTox 3.0 and ADMETlab 2.0 were used for the prediction studies of DA-1 and DA-2. Mice received a single dose of LI-DA (3, 30, and 100 mg/kg), DA-1 (3 mg/kg) and DA-2 (3 mg/kg) and were subjected to inflammation induced by Complete Freund's Adjuvant (CFA) and in the zymosan-induced articular inflammation model.

RESULTS

DA-1 and DA-2 have been identified for the first time in the leaves of D. alata. LI-DA, EAF-DA and HMF-DA demonstrated a high level of antioxidant activity as measured by ABTS (IC50 ≤ 5.62 μg/mL) and DPPH (IC50 ≤ 11.45 μg/mL). Oral administration of LI-DA (3, 30 and 100 mg/kg), DA-1 (3 mg/kg) and DA-2 (3 mg/kg) showed significantly reduced edema, cold and mechanical allodynia in the CFA-induced inflammation model (24 h). LI-DA (3, 30, and 100 mg/kg) and DA-1 (3 mg/kg) reduced leukocytes migration into the joint cavity, mechanical allodynia, edema and NO production in mice (24 h) in the zymosan-induced articular inflammation model. Additionally, DA-2 (3 mg/kg) reduced leukocyte migration and LI-DA (30 mg/kg) reduced protein exudation (24 h) in zymosan model. DA-1 and DA-2 showed good oral bioavailability and low toxicity predicted by the ProTox model.

CONCLUSION

This is the first chemical and biological study performed of D. alata infusion and two quercetin glycoside derivatives. The results indicated promising potential for the treatment of inflammation, pain, and rheumatism, supporting the traditional use of the infusion obtained from the leaves of D. alata.

Absence of maternal-fetal adverse effects of Alternanthera littoralis P. Beauv. following treatment during pregnancy in mice

Alternanthera littoralis P. Beauv is a plant native to Brazil that exhibits various beneficial activities including antioxidant, antibacterial, antifungal, antiprotozoal, anti-hyperalgesic, and anti-inflammatory properties. The aim of this study was to assess the impact of the ethanol extract of Alternanthera littoralis (EEAl) on reproductive outcomes, embryofetal development, and DNA integrity of pregnant female mice. Pregnant Swiss female mice were randomly assigned to three experimental groups (n = 10): controls were administered either 1% Tween 80 (vehicle), EEAl 100 mg/kg or EEAl 1000 mg/kg. Treatment was administered through gavage during the gestational period until day 18. On gestational days 16, 17, and 18, a peripheral blood sample from the tail vein was obtained for DNA integrity analysis (micronucleus test). After the last collection, animals were euthanized by cervical dislocation. Maternal organs and fetuses were collected, weighed, and subsequently analyzed. Reproductive outcome parameters were assessed by measurement of number of implants, live fetuses, and resorptions. Embryonic development was determined by adequacy of weight for gestational age as well as determination of external, visceral, and skeletal malformations. Data demonstrated that EEAl did not produce maternal toxicity at either dose associated with no marked alterations in any of the reproductive outcome parameters including implantation sites, live/dead fetuses ratio, fetal viability, post-implantation losses, resorptions, and resorption rate. However, EEAl 1000 group reduced embryofetal development by lowering placental weight. In addition, there was an increase in the frequency of external and skeletal malformations in the EEAl 1000 group, which could not be attributed to extract exposure as these values were within control levels. Based upon our findings, evidence indicates that the EEAl at the concentrations employed in our study may be considered safe for use during pregnancy and extracts of this plant show potential for development of phytomedicines to be used in pregnancy.

Microfluidic Generation of Near-Infrared Photothermal Vitexin/ICG Liposome with Amplified Photodynamic Therapy

Glioma, in which a malignant tumor cell occurs in neural mesenchymal cells, has a rapid progression and poor prognosis, which is still far from desirable in clinical treatments. We developed a lab-on-a-chip (LOC) device for the rapid and efficient preparation of vitexin/indocyanine green (ICG) liposomes. Vitexin could be released from liposome to kill cancer cell, which can potentially improve the glioma therapeutic effect and reduce the treatment time through synergistic photodynamic/photothermal therapies (PDT/PTT). The vitexin/ICG liposome was fabricated via LOC and its physicochemical property and release in vitro were evaluated. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method and live/dead staining were used to examine the enhanced antitumor effect of vitexin/ICG liposome in cooperation with PDT/PTT, while the related mechanism was explored by flow cytometry and western blot. The results were as follows: (1) The prepared vitexin/ICG liposome was smaller in size, homogenous in particle size distribution with significant low polydispersity index (PDI), and enhanced cumulative release in vitro. (2) We found that the formulated liposome presented strong cancer cell inhibition and suppression of its migration in a dose-dependent manner. (3) Further mechanistic studies showed that liposome combined with near-infrared irradiation could significantly upregulate levels of B cell lymphoma 2-associated X (Bax) protein and decrease B cell lymphoma 2 (Bcl-2) at protein levels. The vitexin/ICG liposomes prepared based on a simple LOC platform can effectively enhance the solubility of insoluble drugs, and the combined effect of PTT/PDT can effectively increase their antitumor effect, which provides a simple and valid method for the clinical translation of liposomes.

Exploration of essential oil from Psychotria poeppigiana as an anti-hyperalgesic and anti-acetylcholinesterase agent: Chemical composition, biological activity and molecular docking

ETHNOPHARMACOLOGICAL RELEVANCE

Leaves from Psychotria poeppigiana Müll. Arg. (accepted as Palicourea tomentosa (Aubl.) Borhidi), Rubiaceae, has traditionally been used in medicine for treatments of inflammation and pain; Synonymously, Cephaelis elata for the treatment of dementia; However, few scientific studies have been evidence demonstrating this activity.

AIM OF THE STUDY

The aim of this study was to investigate the chemical composition of P. poeppigiana essential oil obtained from leaves (EOPP) and its antioxidant, anti-inflammatory and acetylcholinesterase (AChE) activities. Molecular docking simulations were carried out with the main constituents.

MATERIALS AND METHODS

EOPP (hydrodistillation) was analysed by gas chromatography-mass spectrometry (GC-MS). The fractionation of EOPP afforded germacrene D and bicyclogermacrene. The antioxidant activity of EOPP was determined by MDA assay. The inflammatory parameters were evaluated using CFA model (with paw edema, mechanical, thermal hyperalgesia, MPO and NAG) in EOPP (30, 100 and 300 mg/kg), germacrene D and bicyclogermacrene (30 mg/kg). The AChE inhibition was evaluated in rat brain structures and molecular docking simulations were carried out using Autodock v.4.3.2.

RESULTS

GC-MS analysis identified 19 compounds, and the major compounds were germacrene D (29.38%) and bicyclogermacrene (25.21%). EOPP exhibited high antioxidant capacity (IC₅₀ = 12.78 ± 1.36 μg/mL). All the tested doses of EOPP and both major constituents significantly inhibited cold and mechanical hyperalgesia and significantly blocked the increase in MPO activity 24 h after the CFA injection. There was significant AChE inhibition by EOPP and germacrene D in the cerebral cortex and hippocampus (>50%). Enzyme-ligand molecular modelling showed that the major constituents of EOPP interacted differently with AChE.

CONCLUSIONS

The chemical compounds of the essential oil from the leaves of P. poeppigiana is based mainly on terpenes, the sesquiterpenes germacrene D (29.38%) and bicyclogermacrene (25.21%) being the major compounds. EOPP presented antioxidant, anti-inflammatory and anti-acetylcholinesterase (AChE) activities. Besides, enzyme-ligand molecular modelling showed the EOPP may act as an anti-hyperalgesic and AChE inhibitory agent. Taken together, these results might be in accordance with if folk use for pain- and inflammation-related symptoms.

UPLC-Q-TOF-MS/MS Analysis of Phenolic Compounds from the Fruit of Cephalostachyum fuchsianum Gamble and Their Antioxidant and Cytoprotective Activities

Bamboo is a widely distributed graminaceous plant in China and is a potential source of bioactive substances. Incidentally, bamboo’s fruit is rich in phytochemicals such as polyphenols and flavonoids, which are significant to human health. In this study, we identified the phenolic compounds of the fruit and investigated the antioxidant activities of Cephalostachyum fuchsianum Gamble (CFG) fruit polyphenols with in vitro and in vivo tests for the first time. UPLC–Q–TOF–MS/MS analysis results showed that the fruit contained 43 phenolic compounds, including 7 hydroxybenzoic acids, 12 flavonoids, 7 coumarins, 10 hydroxycinnamic acids, 1 terpenoid, and 5 lignans. The TPC of SP extracts was higher than that of IBPs extracts in FP and FF. The SP extracts in FP showed better antioxidant activities in vitro compared to those in FF. In addition, polyphenols from CFG fruits protected against H₂O₂-induced oxidative damage in HepG2 cells, and the protective effect of polyphenols in FP was superior to that in FF. The analysis results showed that CFG fruit has great potential in exploiting natural chemical substances, which can provide valuable pieces of information for the further development and utilization of CFG.

The Genus Alternanthera: Phytochemical and Ethnopharmacological Perspectives

Ethnopharmacological relevance: The genus Alternanthera (Amaranthaceae) comprises 139 species including 14 species used traditionally for the treatment of various ailments such as hypertension, pain, inflammation, diabetes, cancer, microbial and mental disorders.

Aim of the review: To search research gaps through critical assessment of pharmacological activities not performed to validate traditional claims of various species of Alternanthera. This review will aid natural product researchers in identifying Alternanthera species with therapeutic potential for future investigation.

Materials and methods: Scattered raw data on ethnopharmacological, morphological, phytochemical, pharmacological, toxicological, and clinical studies of various species of the genus Alternanthera have been compiled utilizing search engines like SciFinder, Google Scholar, PubMed, Science Direct, and Open J-Gate for 100 years up to April 2021.

Results: Few species of Alternanthera genus have been exhaustively investigated phytochemically, and about 129 chemical constituents related to different classes such as flavonoids, steroids, saponins, alkaloids, triterpenoids, glycosides, and phenolic compounds have been isolated from 9 species. Anticancer, antioxidant, antibacterial, CNS depressive, antidiabetic, analgesic, anti-inflammatory, and immunomodulator effects have been explored in the twelve species of the genus. A toxicity study has been conducted on 3 species and a clinical study on 2 species.

Conclusions: The available literature on pharmacological studies of Alternanthera species reveals that few species have been selected based on ethnobotanical surveys for scientific validation of their traditional claims. But most of these studies have been conducted on uncharacterized and non-standardized crude extracts. A roadmap of research needs to be developed for the isolation of new bioactive compounds from Alternanthera species, which can emerge out as clinically potential medicines.