Bowdenol, a new 2,3-dihydrobenzofuran constituent from Bowdichia virgilioides

Using the plants of Brazilian Cerrado for wound healing: From traditional use to scientific approach

ETHNOPHARMACOLOGICAL RELEVANCE

The Brazilian Cerrado is a biome with a remarkable diversity of plant species, many of which are used mainly by local communities as a source of treatment to several pathologic processes, especially for the treatment of wounds. However, no systematic review exists focusing on the plants used in this respect and on the appropriate pharmacological investigations that substantiate the actions that are reported. This study revisits the traditional use of medicinal plants from the Brazilian Cerrado in the treatment of wounds and the pharmacological characteristics of the reported plant species.

METHOD

ology: For the present article, previous studies on plants of the Brazilian Cerrado used for wound healing carried out between 1996 and 2018 were researched on various academic databases (PubMed, Elsevier, Springer, Lilacs, Google Escolar, and Scielo).

RESULTS

A total of 33 studies were carried out on 29 plant species distributed into 18 families, mainly Fabaceae or Leguminosae (9), Bignoniaceae (2), Asteraceae (2), Euphorbiaceae (2). Considering the great diversity of Cerrado plants, only a small number of wound healing studies were carried out between 1996 and 2018. It was observed that there is a large gap between experimentation assay and traditional use. There are only few connections between the form of use by the population and the experiments conducted in the laboratory. We found that only about 12% of these studies considered to use the methodologies, or at least in parts, to obtain extracts such as those used in folk medicine. Approximately 37% of the experiments were performed using the bark as well as the same ratio for leaves, 6% using the fruits, and 9% using the seeds, roots or flowers. In several studies, there are reports of chemical constituents such as flavonoids and tannins, followed by steroid terpenes, saponins, and fatty acids, and alkaloids. However, approximately 35% of the studies did not supply information about compounds present in the preparation or the effect which could be attributed to these agents in respect to wound healing. Regarding treatment, most of the studies employed a topical treatment, though intraperitoneal and oral treatment were also described using either topical, oil-based formulations, but also gel- or saline-based formulations.

CONCLUSIONS

Although, there has been an increase in knowledge about the biological actions of plants from Cerrado biome, the scientific basis for the traditional use of these local medicinal plants in wound healing does not provide sufficient information on the efficacy of the treatment, the molecular mechanisms, or, in particular, the effective doses used and the drug interactions. Thus, focused research investigating these hypotheses from traditional knowledge is necessary to prove the evidence of the potential pharmacological action.

Lupeol, a Pentacyclic Triterpene, Promotes Migration, Wound Closure, and Contractile Effect In Vitro: Possible Involvement of PI3K/Akt and p38/ERK/MAPK Pathways

Skin wound healing is a dynamic and complex process involving several mediators at the cellular and molecular levels. Lupeol, a phytoconstituent belonging to the triterpenes class, is found in several fruit plants and medicinal plants that have been the object of study in the treatment of various diseases, including skin wounds. Various medicinal properties of lupeol have been reported in the literature, including anti-inflammatory, antioxidant, anti-diabetic, and anti-mutagenic effects. We investigated the effects of lupeol (0.1, 1, 10, and 20 μg/mL) on in vitro wound healing assays and signaling mechanisms in human neonatal foreskin keratinocytes and fibroblasts. Results showed that, at high concentrations, Lupeol reduced cell proliferation of both keratinocytes and fibroblasts, but increased in vitro wound healing in keratinocytes and promoted the contraction of dermal fibroblasts in the collagen gel matrix. This triterpene positively regulated matrix metalloproteinase (MMP)-2 and inhibited the NF-κB expression in keratinocytes, suggesting an anti-inflammatory effect. Lupeol also modulated the expression of keratin 16 according to the concentration tested. Additionally, in keratinocytes, lupeol treatment resulted in the activation of Akt, p38, and Tie-2, which are signaling proteins involved in cell proliferation and migration, angiogenesis, and tissue repair. These findings suggest that lupeol has therapeutic potential for accelerating wound healing.

Sucupiranins A-L, Furanocassane Diterpenoids from the Seeds of Bowdichia virgilioides

Twelve new furanocassane diterpenoids, sucupiranins A-L (1-12), and three known compounds (13-15) were isolated from the seeds of Bowdichia virgilioides. The structures of the compounds were elucidated via ¹H and ¹³C NMR analysis, including 2D NMR (¹H-¹H COSY, HSQC, HMBC, and NOESY); HRMS data; and X-ray crystallographic analysis. The absolute configurations were defined using their electronic circular dichroism (ECD) spectra by applying the exciton chirality method to the bis-p-bromobenzoate of compound 13. Sucupiranin J (10) inhibited lipopolysaccharide-induced nitric oxide production (IC₅₀ 30.6 μM), whereas sucupiranins J (10), K (11), and 13 exhibited weak antimalarial activity against Plasmodium falciparum K1 with IC₅₀ values of 32.2, 23.5, and 22.9 μM and selectivity indices of 4.3, 1.9, and >12.0 (MRC-5/K1), respectively.

A New Pimarane-type Diterpenoid from the Seeds of Bowdichia virgilioides

A new pimarane-type diterpenoid, sucupiol (1), and nine known furanocassane-type diterpenoids, vouacapane (2), 7β-hydroxyvouacapane (3), 7β-acetoxyvouacapane (4), 6α-hydroxyvouacapane (5), 6α-acetoxyvouacapane (6), sucutinirane F (7), sucutinirane E (8), 6α, 7β-diacetoxyvouacapane (9), and 6α, 7β-diacetoxyvouacapane-14β-al (10), were isolated from the seeds of Bowdichia virgilioides and their structures were elucidated by using 2D NMR data. The isolation of 1 provides evidence to support the presence of intermediate A in the course of biosynthesis of furanocassane-type diterpenoids.

Acute and subchronic antihyperglycemic activities of Bowdichia virgilioides roots in non-diabetic and diabetic rats

Aim:

The present study was undertaken to evaluate the acute and subchronic antihyperglycemic effects of methanolic extract of Bowdichia virgilioides root bark of B. virgilioides in streptozotocin (STZ)-induced diabetic rats.

Materials and Methods:

The extract (100, 250 or 500 mg/kg) was orally administered to male Wistar diabetic (STZ, 42 mg/kg i.v.) and non-diabetic rats into two main protocols: (i) subchronic experiments, where animals were treated for 21 days with B. virgilioides extract and the following parameters were evaluated: Body weight, fluid and food intake (determined daily), urinary glucose and urea (every 3 days) and glycemia (every 5 days). At the end of the experimental period, skeletal muscles (extensor digitorum longus [EDL] and soleus), retroperitoneal and epididymal white adipose tissues were collected and weighed; liver samples were used for the determination of the lipid and glycogen contents; (ii) acute experiments, which evaluated the alterations on fasting and post-prandial glycemia and on glucose tolerance using the oral glucose tolerance test (OGTT).

Results:

In subchronic experiments, the treatment with B. virgilioides extract did not change any parameter evaluated in diabetic and non-diabetic animals. On fasting and post-prandial glycemia, the extract treatment did not promote changes in the glycemia values in diabetic or non-diabetic animals. In OGTT, the treatment with 500 mg/kg B. virgilioides extract reduced the hyperglycemia peak after a glucose overload, when compared with non-treated diabetic animals, resulting in a lower area under curve.

Conclusion:

The results of our work indicate that B. virgilioides root extract promotes an acute antihyperglycemic effect in STZ-diabetic rats; this effect probably occurs through an inhibition of the intestinal glucose absorption. The continuity of the research is necessary to elucidate these possibilities.

Evaluation of wound healing and antimicrobial properties of aqueous extract from Bowdichia virgilioides stem barks in mice

The decoction of the stem barks from Bowdichia virgilioides KUNTH is a folk remedy used to treat inflammatory disorders in Latin American and Brazil. In the present study, the wound healing activity of aqueous extract of the stem bark from B. virgilioides, called AEBv, was evaluated by the rate of healing by wound contraction and period of epithelization at different days post-wound using the wound excisional model. On day 9, the AEBv-treated animals exhibited significative reduction in the wound area when compared with controls. In wound infected with S. aureus, the AEBv significantly improved the wound contraction when compared to the saline-treated mice. The histological analysis showed that AEBv induced a collagen deposition, increase in the fibroblast count and few inflammatory cells than compared to saline-treated group. The expression of collagen type I was increased in the group treated with AEBv as indicated by immunohistochemical staining. In vitro, the AEBv was effective only against S. aureus but not against P. aeruginosa. Together, the results of this study demonstrate, for the first time, the healing and antimicrobiological effects of aqueous extract of the stem bark from B. virgilioides in the therapy of skin wounds.

Anti-inflammatory effect of the ethanolic extract from Bowdichia virgilioides H.B.K stem bark

Bowdichia virgilioides H.B.K stem bark (Fabaceae), locally known as "sucupira-preta", is a reputed folk-remedy to treat some inflammatory disorders. To validate its traditional claim, the ethanolic extract from B. virgilioides was evaluated in several animal models of inflammation and nociception. The extract at oral doses of 100 to 1000 mg/kg body weight caused a significant inhibition of carrageenan-induced hind paw oedema, suppression of exudate volume and leukocyte immigration in rat pleurisy induced by carrageenan, and reduction of granuloma weights in the model of subcutaneous granulomas promoted by cotton pellets. In addition, the plant extract significantly inhibited the vascular permeability increase induced by intraperitoneal acetic acid. It also showed marked antinociceptive effect in acetic acid-induced writhing test and in the second phase of formalin test in mice. These findings evidence the anti-inflammatory potential of Bowdichia virgilioides bark and supports its traditional use in inflammatory conditions.

Antinociceptive and anti-inflammatory activities of Bowdichia virgilioides (sucupira)

ETHNOPHARMACOLOGICAL RELEVANCE

Bowdichia virgilioides Kunth (Leguminosae Papilonoideae) is a plant with anti-inflammatory activity used in folk medicine. The importance of this plant promoted its inclusion in Brazilian Pharmacopoeia.

AIM OF THE STUDY

In order to evaluate the actions of this plant, studies were performed on antinociceptive and anti-inflammatory activities.

MATERIALS AND METHODS

The aqueous extracts (AE) of Bowdichia virgilioides inner bark and leaves were used at 100, 200, and 400mg/kg. Antinociceptive activity of plant extract was evaluated by writhing, hot-plate and formalin tests. Anti-inflammatory activity was evaluated using paw oedema and peritonitis methods.

RESULTS

Oral treatment with the AE of inner bark or leaves elicited inhibitory activity (P<0.01) on acetic acid effect at 200 and 400mg/kg, and reduced the formalin effect at the second-phase (200 and 400mg/kg, P<0.01), however it did not elicit any inhibitory effect on hot-plate test. The indomethacin inhibited the acetic acid-induced writhing and the formalin effect at the second-phase (P<0.001), and the morphine reduced the both phases of formalin test (P<0.001). Carrageenan-induced oedema formation and neutrophil migration into the peritoneal cavity were reduced with the AE of inner bark or leaves at 100, 200, and 400mg/kg (P<0.05), and by the reference compounds aspirin (P<0.001) and dexamethasone (P<0.001), respectively.

CONCLUSIONS

The AE of Bowdichia virgilioides shows antinociceptive and anti-inflammatory activities, supporting the folkloric usage of the plant to treat various inflammatory diseases.

Sucutiniranes C-F, cassane-type diterpenes from Bowdichia nitida

Four new cassane-type diterpenes, sucutiniranes C-F (3-6), have been isolated from seeds of Bowdichia nitida, and their structures were elucidated by using 2D NMR data, chemical correlations, and X-ray analysis. Sucutiniranes E (5) and F (6) were moderately cytotoxic against human blood premyelocytic leukemia (HL-60), breast adenocarcinoma (MCF-7), and colon cancer (HCT-116) cells.

Anti-tuberculosis Compounds from two Bolivian Medicinal Plants, Senecio Mathewsii and Usnea Florida

Bioassay-directed fractionation of the organic extract of Senecio mathewsii gave four compounds with anti-TB activity: werneria chromene (1), capillarol (2), werneria chromanone (3) and plicatin B (4). All of these are new to the genus Senecio and one of these, werneria chromanone (3), was isolated from a natural source for the first time. With the aid of 2D NMR, revised (1) or new (2–4) spectral assignments were made. Similarly, the major anti-TB activity of Usnea florida was shown to be solely due to usnic acid.

Two new isoflavonoids fromBowdichia virgilioides

Two new isoflavonoids 7,8,4'-trimethoxyisoflavone and 7,8,4'-trimethoxyisoflavanone and calycosin (7,3'-hydroxy-4'-methoxyisoflavone) were isolated from the wood of the leguminous tree Bowdichia virgilioides by usual chromatographic procedures. Besides these compounds the pterocarpane (-)-maackianin, isoliquiritigenin (4,2',4'-trihydroxychalcone), and the hydrobenzylfurane derivative bowdenol were also obtained. The structures of these new compounds were determinated by MS and 1D and 2D NMR spectral analysis.

Bowdichine, a new diaza-adamantane alkaloid from Bowdichia virgilioides

A novel alkaloid named bowdichine (1), only the third with a diaza-adamantane skeleton containing an unusual N-acetyl enamine moiety, and the known alkaloids acosmine (2), ormosanine (3) and podopetaline (4) have been isolated from the stem bark of Bowdichia virgilioides. The structures were elucidated on the basis of spectral data, mainly 1D and 2D NMR of the diaza-adamantane alkaloids 1 and 2.