Immunomodulatory properties of Alternanthera tenella Colla aqueous extracts in mice

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.

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

Six flavonoids were identified and isolated from the ethanolic extract of Alternanthera tenella Colla (Amaranthaceae) whole plant (EEAT) including 2″-O-β-D-glucopyranosyl-vitexin (A19). Flavonoids have anti-inflammatory activity; however, the 2″-O-β-D-glucopyranosyl-vitexin anti-inflammatory property was not totally explored. The aim of the present study was to investigate the anti-inflammatory effects of ethanolic extract from A. tenella whole plant and isolated flavone C-glycoside A19 in models of inflammation. The oral administration (p.o.) of EEAT (30, 100, and 300 mg/kg), A19 (0.1, 1, and 10 mg/kg), and prednisolone (3 mg/kg) were tested against the carrageenan-induced paw edema in Swiss mice. The EEAT (100 mg/kg, p.o.), A19 (1 mg/kg, p.o.), and prednisolone (3 mg/kg, p.o.) were tested in the zymosan-articular inflammation, carrageenan-pleurisy, and complete Freund's adjuvant (CFA) models in Swiss mice. In silico analysis and search for structural relationships between vitexin derivatives flavones present in the EEAT and TNF-α inhibitors were performed. EEAT, A19, and prednisolone significantly inhibited (i) edema, mechanical hyperalgesia in carrageenan-induced paw inflammation; (ii) leukocyte migration and protein extravasation in carrageenan-induced pleurisy; (iii) knee edema, mechanical hyperalgesia, and leukocyte migration in articular inflammation induced by zymosan. Still the CFA induced the increase in myeloperoxidase and N-acetylglucosaminidase activities, EEAT, A19, and prednisolone significantly inhibited these enzymes. The in silico analysis showed that molecules with similar structure to apigenin and vitexin have a potential inhibition on the TNF system. This study confirms the anti-inflammatory properties of EEAT and A19. The C-glycosylated flavone A19 could be responsible for the EEAT anti-edematogenic and anti-hyperalgesic effects and a potential TNF-α inhibitor.

Betalains in Some Species of the Amaranthaceae Family: A Review

Natural pigments are largely distributed in the plant kingdom. They belong to diverse groups, with distinct biochemical pathways. Betalains with colours that range from yellow to red-violet can de divided into two main subgroups: betaxanthins and betacyanins. These types of pigments are confined into 13 families of the order Caryophyllales and in some genera of higher fungi (Amanita muscaria, Hygrocybe and Hygrophorus). The Amaranthaceae family includes diverse genera in which betalains are present: Alternanthera, Amaranthus, Beta, Chenopodium, Celosia and Gomphrena. The biosynthesis of betalains and their general biological properties were reviwed in the present work. In addition, the types of betalains present in some species of the aforementioned genera, their stability and production, as well as biological attributes, were reviewed.

Antiprotozoal and antioxidant alkaloids from Alternanthera littoralis

Five alkaloids, in addition to hydroxytyrosol and uridine, were isolated from aerial parts of Alternanthera littoralis P. Beauv. Among the isolated compounds, alternamide A was an unusual tricyclic alkaloid with a bridged benzoazepine core. All isolated alkaloids have a catechol moiety, indicating a possible common biosynthetic route. Their structures were established by 1D and 2D NMR spectroscopy in combination with extensive tandem MS experiments by collisional induced dissociation (CID). The antiprotozoal activity of the isolated compounds was assayed against trypomastigote forms of Trypanosoma cruzi and amastigotes of Leishmania amazonensis. Alternamine A was the most active compound, reducing markedly the viability of both parasites. Antioxidant capacities evaluated by ORAC_FL assay showed that the isolated alkaloids (mainly alternamide B) contributed to the high activity recorded for the ethanolic crude extract; possibly, the catechol moiety present in all structures plays a central role in this result.

Chromium Accumulation in Medicinal Plants Growing Naturally on Tannery Contaminated and Non-contaminated Soils

Herbal preparations used to treat human ailments globally can be contaminated with various heavy metals (HMs) originating from the raw materials or from the manufacturing processes. Therefore, we assessed 22 medicinal plants growing naturally on tannery pollutant contaminated (Site-C) and non-contaminated (Site-NC) sites for their ability to accumulate chromium (Cr). The Cr contents in soil and various plant parts were estimated using an atomic absorption spectrophotometer. Translocation and bioconcentration factors were calculated. The soil at Site-C had 27-fold higher concentration of total Cr than at Site-NC. Chromium accumulation is reported for the first time in 50 % of the medicinal plants examined and varied significantly among the sites. Shoots of Ricinus communis and Amaranthus viridis had maximum concentrations of Cr at Site-C, whereas in Site-NC, none of the plants had Cr accumulation >30 ppm. Ricinus communis, Amaranthus viridis, and Amaranthus spinosus had translocation factor (TF) greater than the one in the Site-C and Lantana camara had TF >1 in Site-NC. The bioconcentration factor (BCF) was >1 only for Ricinus communis at both the sites. The majority of the medicinal plants at Site-NC had Cr content exceeding the permissible limit of 2 ppm suggested for herbal raw material. The results of the study clearly emphasize the need for screening plants of therapeutic value for the presence of HMs even when collected from non-contaminated soils. Moreover, proportional allocation of Cr in different plant parts provided an insight on the safety of these parts when specifically used in herbal preparations.

Anti-hyperalgesic and Anti-inflammatory Activity of Alternanthera Maritima Extract and 2″-O-α-L-rhamnopyranosylvitexin in Mice

Alternanthera maritima are used in Brazilian popular medicine for the treatment of inflammatory and infectious diseases. Species of Alternanthera have demonstrated biological activities in previous scientific studies. The aim of this study was to determine whether the ethanol extract of the aerial parts of A. maritima (EEAM) and the isolated compound 2″-O-α-L-rhamnopyranosyl-vitexin inhibit mechanical hyperalgesia and parameters of inflammation in mice. The oral administration of EEAM significantly inhibited carrageenan (Cg)-induced paw edema and reduced leukocyte migration into the pleural cavity. 2″-O-α-L-rhamnopyranosylvitexin significantly inhibited paw edema and reduced both leukocyte migration and the leakage of protein into the pleural cavity. Both EEAM and 2″-O-α-L-rhamnopyranosylvitexin significantly prevented the Cg-induced hyperalgesia. Local administration of 2″-O-α-L-rhamnopyranosylvitexin significantly prevented the Cg- and tumor necrosis factor (TNF)-induced hyperalgesia. In conclusion, this study demonstrated that EEAM is an anti-inflammatory and anti-hyperalgesic agent, and the results suggested that 2″-O-α-L-rhamnopyranosylvitexin is responsible for the effects of EEAM and the mechanism involves the TNF pathway.

Immunomodulatory effects of Potentilla indica and Dendrophthoe pentandra on mice splenocytes and thymocytes

Immunomodulators are agents that are able to stimulate or inhibit the immune response. The leaf extracts from Potentilla indica and Dendrophthoe pentandra were analyzed in vitro for immunomodulatory activity and an MTT colorimetric assay was conducted to determine the proliferation of mice splenocytes and thymocytes. A bromodeoxyuridine assay was performed to analyze DNA synthesis and the Trypan blue exclusion method was conducted to evaluate the changes in total cell population. The results indicated that treatment with P. indica and D. pentandra produced a time- and dose-dependent increase in cell viability and proliferation. Following 72 h of treatment with P. indica and D. pentandra, thymocyte proliferation was augmented by 18 and 41%, respectively and splenocyte proliferation increased by 35 and 42%, respectively, when compared with untreated cells. The present study demonstrated that these extracts may act as potential immunostimulants and, thus, represent an alternative source of immunomodulatory compounds for the treatment of human immune-mediated diseases.

The globalization of traditional medicine in northern peru: from shamanism to molecules

Northern Peru represents the center of the Andean "health axis," with roots going back to traditional practices of Cupisnique culture (1000 BC). For more than a decade of research, semistructured interviews were conducted with healers, collectors, and sellers of medicinal plants. In addition, bioassays were carried out to evaluate the efficacy and toxicity of plants found. Most of the 510 species encountered were native to Peru (83%). Fifty percent of the plants used in colonial times have disappeared from the pharmacopoeia. Market vendors specialized either on common and exotic plants, plants for common ailments, and plants only used by healers or on plants with magical purposes. Over 974 preparations with up to 29 different ingredients were used to treat 164 health conditions. Almost 65% of the medicinal plants were applied in these mixtures. Antibacterial activity was confirmed in most plants used for infections. Twenty-four percent of the aqueous extracts and 76% of the ethanolic extracts showed toxicity. Traditional preparation methods take this into account when choosing the appropriate solvent for the preparation of a remedy. The increasing demand for medicinal species did not increase the cultivation of medicinal plants. Most species are wild collected, causing doubts about the sustainability of trade.

Immunomodulatory activity of Zingiber officinale Roscoe, Salvia officinalis L. and Syzygium aromaticum L. essential oils: evidence for humor- and cell-mediated responses

OBJECTIVES

The immunomodulatory effect of ginger, Zingiber officinale (Zingiberaceae), sage, Salvia officinalis (Lamiaceae) and clove, Syzygium aromaticum (Myrtaceae), essential oils were evaluated by studying humor- and cell-mediated immune responses.

METHODS

Essential oils were administered to mice (once a day, orally, for a week) previously immunized with sheep red blood cells (SRBCs).

KEY FINDINGS

Clove essential oil increased the total white blood cell (WBC) count and enhanced the delayed-type hypersensitivity (DTH) response in mice. Moreover, it restored cellular and humoral immune responses in cyclophosphamide-immunosuppressed mice in a dose-dependent manner. Ginger essential oil recovered the humoral immune response in immunosuppressed mice. Contrary to the ginger essential oil response, sage essential oil did not show any immunomodulatory activity.

CONCLUSIONS

Our findings establish that the immunostimulatory activity found in mice treated with clove essential oil is due to improvement in humor- and cell-mediated immune response mechanisms.

Characterising vancomycin's immunotoxic profile using Swiss and CFW mice as an experimental model

Immunotoxicology can lead to determining the adverse effects of different compounds on the immune system. Sometimes, many drugs (especially antibiotics) induce immune alterations, mainly auto-immunity. This study was aimed at determining vancomycin's immunotoxic effect by comparing the original molecule to two of the most used copies. Thirty-two mice from two murine strains (Swiss and CFW) were treated with three antibiotic formulations for studying its effect on splenic lymphoid and peripheral blood cell populations by using haemograms, flow cytometry and blastogenesis assays. The results indicated that vancomycin produces neutropenia and lymphocytosis in peripheral populations and that it induces a selective immunomodulatory effect on splenocyte sub-populations, depending on formulation and the strain so treated.