Composition of essential oil from the bark and leaves of two morphotypes of Salmea scandens (Asteraceae), a medicinal plant in Oaxaca, Mexico.

The chemical composition of the essential oils (EOs) from leaves and bark of two morphotypes, white (WM) and black (BM) of Salmea scandens obtained by microwave-assisted extraction (MAE) were analyzed by GC-MS. The major components of the bark EOs were aliphatic hydrocarbons (38.0% in WM, 48.6% in BM) and oxygenated sesquiterpenes (27.6% in WM, 11.3% in BM); in leaves EOs major components were oxygenated sesquiterpenes (43.9% in WM, 45.7% in BM) and oxygenated aliphatics (13.7% in WM, 1.1% in BM) stood out. Nine components have been reported to have antimicrobial and anti-inflammatory potential. The agglomerative hierarchical clustering and principal component analysis confirmed the variability of the EOs. These results suggest that WM may have a better therapeutic effect for treating infectious and inflammatory processes in traditional medicine.

Role of LTB4 and nitric oxide in the gastroprotective effect of Prosthechea karwinskii leaves extract in the indomethacin-induced gastric injury in the rat.

Gastric injury is mainly described by inflammation of the gastric epithelium. Recently, our group of work demonstrated that Prosthechea karwinskii leaves extract induces both an in vitro antioxidative action and an in vivo gastroprotective effect in a rat. However, the molecules involved in the gastroprotective action by Prosthechea karwinskii are not known. Thus, the aim of this study is to determine whether Prosthechea karwinskii extract modifies anti-inflammatory and antioxidative biomarkers in an in vivo rat model of indomethacin-induced gastric injury. Rats were orally administered with indomethacin and Prosthechea karwinskii leaf extract. Our results suggest that the gastroprotective effect of Prosthechea karwinskii leaf extract is related to the reduction in leukocyte infiltration and antioxidative action in a model of indomethacin-induced gastric injury. Further studies are warranted to investigate the role of the compounds identified in the gastroprotective action of Prosthechea karwinskii leaves extract.

Validation of the traditional medicinal use of a Mexican endemic orchid (Prosthechea karwinskii) through UPLC-ESI-qTOF-MS/MS characterization of its bioactive compounds.

Ethnopharmacological relevance: The orchid Prosthechea karwinskii is a medicinal orchid in Oaxaca, Mexico, used to treat diabetes, cough, wounds, and burns, prevent miscarriage and assist in labor. Each part of the plant (leaves, pseudobulbs, or flowers) is used by healers for certain treatment conditions, indicating that each part has different biocompounds with specific pharmacological activity. Aim of the study: To characterize the biocompounds in extracts from leaves, pseudobulbs, and flowers of P. karwinskii and evaluate their ROS inhibition capacity to associate it with medicinal uses. Materials and methods: The compounds present in extracts from leaves, pseudobulbs, and flowers of P. karwinskii were identified by UPLC-ESI-qTOF-MS/MS. The chemical differentiation of each extract was tested by principal component analysis (PCA) using compound intensity values. For each extract, total phenol and flavonoid contents were quantified. Their antioxidant capacity was evaluated ex vivo by inhibition of ROS with DCFH-DA and in vitro with DPPH radical. Results: Based on the PCA, it was observed that some compounds were completely separated from others according to the correlation that they presented. The compounds common to all three plant parts were quinic, malic, succinic, azelaic, and pinellic acids. Among the compounds identified, two were exclusive to leaves, four to pseudobulbs, and ten to flowers. Some of the identified compounds have well-known antioxidant activity. The leaves had the highest content of total phenols and flavonoids, and the highest in vitro and ex vivo antioxidant capacity. A strong correlation was observed between phenol and flavonoid contents, and antioxidant capacity ex vivo and in vitro. Conclusions: It was found that the bioactive compounds and antioxidant capacity of each part of the plant were associated with its traditional medicinal use. A pharmacological potential was also found in P. karwinskii for further biological studies because of the type of compounds it contained.

Bioactive compounds from Prosthechea karwinskii decrease obesity, insulin resistance, pro-inflammatory status, and cardiovascular risk in Wistar rats with metabolic syndrome.

ETHNOPHARMACOLOGICAL RELEVANCE: The orchid Prosthechea karwinskii is a species endemic to Mexico, which is used in traditional medicine to lower glucose levels in patients with diabetes, and to treat inflammation-related problems. Recent studies have shown that this orchids can reduce glucose, cholesterol, and triglyceride levels in Wistar rats, which were previously induced to have metabolic syndrome (MS). AIM OF THE STUDY: To evaluate the effect of P. karwinskii leaves extract on the components of metabolic syndrome: obesity, insulin resistance, pro-inflammatory status, and cardiovascular risk in a Wistar rat model, and to identify the bioactive compounds in the extract. MATERIALS AND METHODS: UPLC-ESI-qTOF-MS/MS was used to identify the compounds present in the extract. MS was induced in Wistar rats through administration of a 40% sucrose diet for 20 weeks. The rats were divided into five groups that received different treatments for 4 weeks: one group without any treatment, one group receiving metformin (200 mg/kg p.o.), and three groups receiving different doses of P. karwinskii leaves extract (100, 200, and 300 mg/kg p.o.). The animals' body weights were recorded weekly, and at the end of the experiment, they were sacrificed after fasting for 18 h to determine the levels of glucose, insulin, insulin resistance index, total cholesterol, triglycerides, and adiponectin in the serum, as well as levels of TNF-α and HS-CRP in the serum and liver homogenates. The abdominal and pericardial fat weights were also recorded. RESULTS: The main bioactive compounds of the extract were quinic acid, neochlorogenic acid, chlorogenic acid, rutin, kaempferol-3-o-ß-rutinoside, and embelin, known to exhibit MS-related bioactivity. Oral administration of P. karwinskii leaves extract at a dose of 300 mg/kg decreased weight gain, abdominal and pericardial fat deposits, and insulin resistance. At the end of the treatment, levels of triglycerides, TNF-α, HS-CRP, and adiponectin returned to levels similar to normal. CONCLUSION: P. karwinskii extract (300 mg/kg) had an anti-obesity effect, decreased insulin resistance, pro-inflammatory status, and cardiovascular risk in rats with induced MS by increasing adiponectin levels and decreasing TNF-α and HS-CRP levels. The compounds identified in the extract could be responsible for these effects, acting alone or in synergy, as several compounds in the extract are known to have MS-related bioactivity. The foliar extract of P. karwinskii has potential as an effective alternative to a cocktail of drugs used to treat problems associated with MS.

Prosthechea karwinskii, an orchid used as traditional medicine, exerts anti-inflammatory activity and inhibits ROS.

ETHNOPHARMACOLOGICAL RELEVANCE: Prosthechea karwinskii (Mart.) J.M.H. Shaw is a Mexican orchid used in traditional medicine by some indigenous communities to treat issues related to inflammation (cough, wounds, burns, and diabetes). Pharmacological research of this orchid could validate its therapeutic uses and demonstrate its potential for treating other health conditions of high prevalence in Mexico, including those associated with oxidative stress such as diabetes, cancer, atherosclerosis, and hypertension as well as inflammation. AIM OF THE STUDY: The leaf extract from P. karwinskii was examined to identify its compounds and elucidate its inhibitory effect on reactive oxygen species as well as its anti-inflammatory activity and gastroprotective effects in an animal model. MATERIALS AND METHODS: Compounds were identified via ultra-high-performance liquid chromatography coupled with electrospray ionization with quadrupole time of flight-mass spectrometry. Inhibition of reactive oxygen species was determined ex vivo in peripheral blood mononuclear cells with 2',7'-dichlorodihydrofluorescein diacetate. The anti-inflammatory activity was assessed using a carrageenan-induced paw edema model in Wistar rats; nitric oxide and tumor necrosis factor alpha levels were quantified. The gastroprotective effect was evaluated in Wistar rats with indomethacin-induced gastric injury. RESULTS: Nine compounds were identified in the P. karwinskii leaf extract. Most compounds, such as quinic acid, malic acid, neochlorogenic acid, chlorogenic acid, rutin, embelin, pinellic acid, and azelaic acid, were reported to exhibit antioxidant and/or anti-inflammatory activity. The extract was also found to inhibit reactive oxygen species in the ex vivo model. Unlike other anti-inflammatory drugs, the extract exerted a dual effect: anti-inflammatory activity and protection of the gastric mucosa. The results showed that the extract could significantly inhibit the release of nitric oxide without a dose-response relationship. CONCLUSION: P. karwinskii leaf extract inhibited reactive oxygen species and exerted an anti-inflammatory effect. Moreover, this extract did not induce gastric damage in the animals. The bioactivity of the species was found to support its use in traditional medicine. This orchid could be used to treat inflammatory diseases without causing the side effects associated with nonsteroidal anti-inflammatory drugs. It can also be employed to treat other pathological conditions associated with oxidative stress. The findings herein form the basis for the future discovery of natural products that may serve as safe alternative therapies for inflammatory disorders.

Argemone mexicana (Papaverales: Papavaraceae) as an Alternative for Mosquito Control: First Report of Larvicidal Activity of Flower Extract.

Culex quinquefasciatus Say (Diptera: Culicidae), an arboviral and filarial vector, is one of the most widespread mosquitoes in the world. The indiscriminate use of synthetic chemical insecticides has led to the development of resistance in mosquito populations worldwide. The effect of continuous exposure to crude extracts of Argemone mexicana, the Mexican poppy, on the development and growth stages of second-instar larvae of the mosquito was studied, along with qualitative chemical analysis of the different plant parts. Inhibition, mortality, and larval and pupal duration phases were assessed. Second-instar mosquito larvae were exposed to crude ethanol extracts of flowers, stems, and seeds. Flower extract exhibited the strongest larvicidal activity with LC50 and LC90 values after 24 h of exposure of 18.61 and 39.86 ppm, respectively, and 9.47 and 21.76 ppm after 48 h. Extracts from stem and seeds were significantly less effective. The flower extract registered a Growth Inhibition Index of 0.01 at 25 ppm, with stems and seeds registering 0.05 and 0.08, respectively, at 100 ppm (control group 1.02). Qualitative chemical analysis by thin-layer chromatography showed characteristic spots indicating the presence of alkaloids and flavonoids and phytochemical screening showed the presence of alkaloids, anthraquinones, flavonoids, tannins, and terpenoids in the various crude extracts. This is the first report of the effectiveness of an ethanol flower extract of A. mexicana on Cx. quinquefasciatus; it can be considered a promising alternative control for this mosquito species.

Larvicidal effect of Clinopodium macrostemum essential oil extracted by microwave-assisted hydrodistillation against Culex quinquefasciatus (Diptera: Culicidae)

Abstract INTRODUCTION: In the present study, we determined the chemical composition of Clinopodium macrostemum essential oil obtained by microwave-assisted hydrodistillation and its effect on the growth and development of Culex quinquefasciatus mosquito larvae. METHODS: The essential oil compounds were identified by gas chromatography-mass spectrometry analysis, and bioassays were conducted to evaluate the influence on the developmental stages of early second instar larvae of Cx. quinquefasciatus until the emergence of adults, using essential oil concentrations of 50, 100, 200, 400, and 800mg/L. RESULTS: The gas chromatography-mass spectrometry analyses revealed that the leaf essential oil of C. macrostemum contained 32 compounds and the major chemical compounds identified were linalool (55.4%), nerol (6.4%), caryophyllene (6.25%), menthone (5.8%), geraniol acetate (4.1%), terpineol (3.7%), and pulegone (2.8%). The essential oil yield obtained by microwave-assisted hydrodistillation was 0.8% at 20 min. The treatments showed lethal concentrations (LC50 and LC90) of 22.49 and 833.35mg/L, respectively, after the final measurement of the total number of dead larvae (second, third, and fourth instars), and LC50 and LC90 of 6.62 and 693.35mg/L, respectively, at the end of the experimental period. The essential oil inhibited the growth and development of the mosquito larvae by 32% (relative growth index = 0.68) at 50mg/L, and up to 47% (relative growth index = 0.53) at 800mg/L. CONCLUSION: The present study demonstrated the larvicidal effect of C. macrostemum essential oil on Cx. quinquefasciatus, which can be attributed to the oxygenate compounds obtained by the extraction method.

Inhibition of the growth and development of mosquito larvae of Culex quinquefasciatus (Diptera: Culicidae) treated with extract from leaves of Pseudocalymma alliaceum (Bignonaceae).

OBJECTIVE: To determine larvicidal activity of the essential oil, hydrolat and botanical extracts derived from leaves of Pseudocalymma alliaceum on mosquito larvae of Culex quinquefasciatus. METHODS: Groups of twenty larvae were used in the larvicidal assays. The mortality, relative growth rate, the larval and pupal duration and viability was estimated. The essential oil was analyzed by solid phase microextraction using gas chromatography coupled to mass spectrometry. RESULTS: Essential oil at 800 ppm showed larvicidal activity at 24 h with lethal values of LC50 and LC90 of 267.33 and 493.63 ppm. The hydrolat at 20% and 10% on 2nd stage larvae showed 100% effectiveness after 24 h. The aqueous extract at 10% had a relative growth index of 0.58, while the ethanolic and methanolic extract obtained values of 0.76 and 0.70 and control reached 0.99. Larvae treated with 10% of methanol, ethanol and aqueous extract showed a reduction in larval duration of 5.00, 2.20 and 4.35 days; ethanol extract at 1% provoke decrease of 2.40 days in the development and exhibited an increment of 3.30 days when treated with 0.01%. Aqueous, ethanol and methanol extracts at 10% reduced in 6.15, 3.42 and 5.57 days pupal development. The main compounds were diallyl disulfide (50.05%), diallyl sulfide (11.77%) and trisulfide di-2-propenyl (10.37%). CONCLUSIONS: The study demonstrated for the first time, the larvicidal activity of the essential oil and hydrolat of Pseudocalymma alliaceum; aqueous, ethanol and methanol extracts inhibited the normal growth and development of mosquito larvae, prolonging and delaying larval and pupal duration.