Francisca Renata Lopes da Silva

Tephrosia toxicaria Pers. reduces temporomandibular joint inflammatory hypernociception: The involvement of the HO‐1 pathway

We investigated both the efficacy and the sub‐chronic toxicity of Tephrosia toxicaria Pers. in the zymosan‐induced temporomandibular joint (TMJ) inflammatory hypernociception in rats evaluating the possible role of heme oxygenase‐1 (HO‐1).

Rotenoids from Tephrosia toxicaria with larvicidal activity against Aedes aegypti, the main vector of dengue fever

In the search for new larvicides from plants, we have investigated the potential activity of the rotenoids deguelin (1), 12a-hydroxy-α-toxicarol (2) and tephrosin (3), isolated from the bioactive ethanol extract of roots of Tephrosia toxicaria Pers., against Aedes aegypti, the main vector of dengue. The absolute configuration of these compounds was determined by circular dichroism (CD) spectra. The LC50 values of the compounds evaluated justify the potential of T. toxicaria as a new natural larvicide.

Potentiation of in vitro antibiotic activity by Ocimum gratissimum L.

Escherichia coli is known to produce enterotoxins, whose properties and its role in diseases causing diarrhea has been investigated. Some species of Staphylococcus are often recognized as etiological agents of many animal and human infections opportunistic. This study is the first test of antibiotics sensitivity against multi resistant strains of E. coli and Staphylococcus aureus using Ocimum gratissimum L. In this study, the dichloromethane fraction of O. gratissimum L. was tested for antibacterial activity alone and in combination with aminoglycosides against strains bacterianas. A synergy of dichloromethane was verified by the method described by Matos. A synergistic effect of the fraction alone and in combination with aminoglycosides has been demonstrated. Therefore, we suggested that the fractions of O. gratissimum L. could be used as a source of natural products derived from this plant, as it has the ability to change antibacterial activity, providing a new weapon against the problem of bacterial resistance to antibiotics.

Stemodia maritima L. Extract Decreases Inflammation, Oxidative Stress, and Alveolar Bone Loss in an Experimental Periodontitis Rat Model

Periodontitis is very prevalent worldwide and is one of the major causes of tooth loss in adults. About 80% of the worldwide population use medicinal plants for their health care. Stemodia maritima L. (S. maritima) antioxidant and antimicrobial effects in vitro as well as anti-inflammatory properties. Herein, the potential therapeutic effect of S. maritima was assessed in rats subjected to experimental periodontitis (EP). EP was induced in female Wistar rats by nylon thread ligature around 2nd upper left molars for 11 days. Animals received (per os) S. maritima (0.2; 1 or 5 mg/kg) or vehicle (saline + DMSO) 1 h before ligature and then once daily for 11 days. The naive group had no manipulation. After this time-point, the animals were terminally anesthetized, and the maxillae were removed for morphometric and histological analyzes (HE). Gingival tissues were dissected to cytokine levels detection (TNF-α, IL1-β, CINC-1, and IL-10), enzymes superoxide dismutase (SOD), and catalase (CAT) analysis, as well as gene expression (TNF-α, IL-1β, RANK, and iNOS) by qRT-PCR. Systemic parameters (weight variation, plasma levels of hepatic enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT), creatinine, total alkaline phosphatase (TALP), and bone alkaline phosphatase (BALP) were performed. Histological analysis of the stomach, liver, kidney, and heart was also performed. S. maritima (5 mg/kg) decreased alveolar bone loss, TNF-α and CINC-1 gingival levels, oxidative stress, and transcription of TNF-α, IL1-β, RANK, and iNOS genes. It elevated both BALP activity and IL-10 gingival levels. The animals showed no any signs of toxicity. In conclusion, S. maritima reduced pro-inflammatory cytokine production, oxidative stress, and alveolar bone loss in a pre-clinical trial of periodontitis. S. maritima is a potential tool for controlling the development of periodontitis.

Phytochemical study, antioxidant and antibacterial activities of Stemodia maritima

Stemodinol, a new natural compound, together with known compounds including jaceidin, stemodin, stemodinoside B, isocrenatoside, verbascoside, crenatoside, and isoverbascoside, were isolated from Stemodia maritima Linn. The antioxidant (DPPH method) and antimicrobial activities of stemodin, stemodinoside B, and crenatoside were investigated. Among the components tested, only crenatoside isolated from the roots showed a high antioxidant power. Stemodin and stemodinoside B exhibited antibacterial activities.

Tephrosia purpurea: A Source of Larvicidal Compounds Against Aedes Aegypti

Tephrosia purpurea (L.) Pers., a member of the Fabaceae family, is a shrub popularly known in northeastern Brazil as “anil-bravo.” The species is reported to have various biological properties, such as hepatoprotective, laxative, deobstruent, and diuretic activities. The plant is useful for treating bronchitis, bilious febrile attacks, and obstructions of the liver, spleen, and kidneys, and a decoction of its roots is used as a nematicide 1–3 . In addition to its wound-healing, antileishmanial, anticarcinogenic, antimicrobial, and anti-lipid peroxidative effects, the potential use of T. purpurea for the treatment of polycystic ovary syndrome has been recently reported 4–6]. The genus Tephrosia, which is distributed in tropical and subtropical regions of the world, is noted for the presence of flavonoids, especially rotenoids. The latter group is an interesting class of compounds showing primarily fish-poisoning, insecticidal, and antimicrobial activities [7–10]. The aim of the present study was to evaluate the activities of essential oil from T. purpurea stems, extracts from its leaves, roots, pods, and stems, and isolated compounds lanceolatin B, pongamol, and rotenone against third-instar Aedes aegypti larvae. Aedes aegypti is one of the mosquito species responsible for transmission of dengue fever and dengue hemorrhagic fever. These diseases emerged in the second half of the twentieth century as a major public health concern in many of the world’s tropical and sub-tropical regions. In addition to their association with high mortality levels, these diseases cause great economic losses and social disruption, both in Brazil and elsewhere [11]. Because no effective drug or vaccine currently exists against dengue, the only method of prevention is control of its host [12]. The synthetic insecticides applied for vector eradication are hazardous to handle and are harmful to humans, other mammals, and the environment. Several plants from different families have been reported to exert mosquitocidal activity, and their extracts and essential oils have been evaluated as biological agents against A. aegypti [13]. In this manner, alternatives to chemical pesticides can be discovered. In the study reported here, we investigated the chemical composition and larvicidal activity of T. purpurea from northeastern Brazil [8, 10] as part of an attempt to find ecological and economically feasible alternative insecticides for controlling dengue. Essential oil was obtained from T. purpurea fresh stems (450 g) by hydrodistillation using a modified Clevenger-type apparatus. GC/FID and GC/MS analyses of the essential oil allowed the identification of 90.1% of its constituents (Table 1). The quantitative analysis was performed on a Shimadzu GC-17A model gas chromatograph equipped with a flame ionization detector (FID) and a non-polar DB-5 fused silica capillary column (30 m 0.25 mm i.d.; 0.25 m film thickness). Hydrogen was used as the carrier gas at a flow rate of 1 mL/min, with a split ratio of 1:30 and an injection volume of 1 L.

The semi-synthetic molecule [4″,5″] dihydro-obovatin isolated from Tephrosia Toxicaria pers reduces zymosan-induced temporomandibular joint inflammatory hypernociception in rats

Arthritis possesses inflammatory components and flavonoids of well-known structures exert anti-inflammatory activity. Here, we aim to evaluate the effects of [4″,5″] dihydro-obovatin and three structurally-defined flavonoids from Tephrosia toxicaria Pers roots on the zymosan-induced temporomandibular joint inflammatory hypernociception in rats as well as their toxicity. Rats were pretreated with the flavonoids (1 and 10 mg/kg) and [4″,5″] dihydro-obovatin (0.1 and 1.0 mg/kg) 1 h before intra-articular zymosan injection (2 mg, 40 μL). Von Frey test was used to evaluate the nociceptive threshold at the 4th hour after zymosan injection. Six hours after zymosan injection, synovial lavage was collected for total cell counting. Acute toxicity assay for [4″,5″] dihydro-obovatin (1, 10, and 100 mg/kg) were performed along with the subchronic toxicity assay by administering [4″,5″] dihydro-obovatin (0.01 mg/kg) or saline solution for 14 consecutive days and the rota-rod test was carried out to determine whether [4″,5″] dihydro-obovatin would impair motor functions. The tested flavonoids and [4″,5″] dihydro-obovatin increased nociceptive threshold and reduced the cell counting in the synovial lavage in the temporomandibular joint compared with the zymosan group. [4″,5”] dihydro-obovatin did not induce toxic effects as well as did not alter the motor function in the rota-rod test. The flavonoids and [4″,5″] dihydro-obovatin exerted antinociceptive and anti-inflammatory effects on the zymosan-induced temporomandibular joint inflammatory hypernociception in rats and the latter did not show significant toxic effects. Therefore, [4″,5″] dihydro-obovatin would be a promising anti-inflammatory and antinociceptive agent.