Evaluation of indigenous plants' extracts for mosquitocidal activity against different stages of Culex quinquefasciatus say (Diptera: Culicidae) / Avaliação de extratos de plantas indígenas quanto à atividade mosquitocida contra diferentes estágios de culex quinquefasciatus say (Diptera: Culicidae)

Being vector of West Nile Virus and falariasis the control of Culex quinquefasciatus is likely to be essential. Synthetic insecticide treatment is looking most effective for vectors mosquito control. However, these products are toxic to the environment and non-target organisms. Consequently, ecofriendly control of vectors mosquito is needed. In this regard botanical insecticide is looking more fruitful. Therefore, the present research aimed to investigate the effectiveness of methanolic extract and various fractions, including, n-hexane, ethyl-acetate, chloroform, and aqueous fraction, obtained from methanolic extract of Ailanthus altissima, Artemisia scoparia, and Justicia adhatoda using separating funnel against larval, pupal, and adult stages of Culex quinquefasciatus. The larvae and pupae of Culex quinquefasciatus were exposed to various concentrations (31.25-1000 ppm) of methanolic extract and its fractions for 24 hours of exposure period. For knock-down bioassay (filter paper impregnation bioassay) different concentration of the methanolic extract and its various fractions (i.e. 0.0625, 0.125, 0.25, 0.5 and 1mg/mL) were applied for 1 hour exposure period. The results were statistically analysed using standard deviation, probit analysis, and linear regression. The R2 values of larvae, pupae, and adult range from 0.4 to 0.99. The values of LC50 (concentration causing 50% mortality) for late 3rd instar larvae after 24 hours exposure period range from 93-1856.7 ppm, while LC90 values range from 424 -7635.5ppm. The values of LC50for pupae range form 1326.7-6818.4ppm and and values of LC90 range from 3667.3-17427.9ppm, respectively. The KDT50 range from 0.30 to 2.8% and KDT90 values range from1.2 to 110.8%, respectively. In conclusion, Justicia adhatoda may be effective for controlling populations of vector mosquito.

Por ser o vetor do vírus do Nilo Ocidental e da falaríase, o controle de Culex quinquefasciatus Say é provavelmente essencial. O tratamento com inseticida sintético parece ser mais eficaz para o controle dos mosquitos vetores. No entanto, esses produtos são tóxicos para o meio ambiente e organismos não visados. Consequentemente, o controle ecológico dos mosquitos vetores é necessário. Nesse sentido, o inseticida botânico parece mais produtivo. Portanto, a presente pesquisa teve como objetivo investigar a eficácia do extrato metanólico e de várias frações, incluindo n-hexano, acetato de etila, clorofórmio e fração aquosa, obtidos do extrato metanólico de Ailanthus altissima (Mill.) Swingle, Artemisia scoparia Waldst. & Kit. e Justicia adhatoda L. usando funil de separação contra os estágios larval, pupal e adulto de C. quinquefasciatus. As larvas e pupas de C. quinquefasciatus foram expostas a várias concentrações (31,25-1000 ppm) de extrato metanólico, e suas frações por 24 horas de período de exposição. Para o bioensaio knock-down (bioensaio de impregnação de papel de filtro), diferentes concentrações do extrato metanólico e suas várias frações (ou seja, 0,0625, 0,125, 0,25, 0,5 e 1 mg / mL) foram aplicadas por um período de exposição de 1 hora. Os resultados foram analisados estatisticamente usando desvio padrão, análise Probit e regressão linear. Os valores de R2 de larvas, pupas e adultos variaram de 0,4 a 0,99. Os valores de LC50 (concentração que causa 50% de mortalidade) para larvas de terceiro estádio tardio após 24 horas de período de exposição variaram de 93-1856,7 ppm, enquanto os valores de LC90 variaram de 424-7635,5ppm. Os valores de LC50 para pupas variaram de 1326,7-6818,4 ppm e os valores de LC90 variaram de 3667,3-17427,9 ppm, respectivamente. O KDT50 variou de 0,30 a 2,8% e os valores de KDT90 variaram de 1,2 a 110,8%, respectivamente. Por fim, a espécie J. adhatoda pôde ser eficaz para controlar populações de mosquitos vetores.

Evaluación fitoquímica preliminar y actividad hipoglicemiante aguda del extracto acuoso de la raíz de Ruellia tuberosa L. en ratas con diabetes experimental / Preliminary phytochemical screening and acute hypoglycemic effects of the aqueous extract of Ruellia tuberosa L. root in experimental diabetes in rats

La diabetes es uno de los principales problemas de la salud pública mundial. En Venezuela se utilizan varias plantas para el tratamiento de la diabetes, sin embargo, los estudios farmacológicos de estas especies han sido insuficientes. Ruellia tuberosa L. (Acanthaceae) es una de estas plantas de uso en la medicina tradicional. En los últimos años, he mos estudiado la farmacología del extracto acuoso de la raíz de la R. tuberosa (RT) demostrando su actividad an ti - inflamatoria, antioxidante y protectora frente al daño renal inducido por la diabetes. El tratamiento subcrónico con este extracto fue capaz de inhibir el aumento de la glucosa sanguínea en ratas con diabetes inducida por la es - treptozotocina (ETZ). En este trabajo se evaluó el perfil fitoquímico preliminar y el contenido de polifenoles totales del extracto de RT, así como también sus efectos agudos sobre la glicemia en ratas diabéticas. Los resultados muestran que el RT produjo un efecto hipoglicemiante tanto en los animales controles como en las ratas con diabetes inducida por la ETZ, con porcentajes de variación de la glicemia comparables con el hipoglicemiante oral de referencia, la glibenclamida. Este extracto mostró la presencia de un alto contenido de polifenoles, lo que posiblemente se encuentre asociado con su actividad antidiabética y antioxidante, reflejada a través de la reacción del RT con el radical 2,2- difenil-1-picrilhidrazil (DPPH). Todos estos hallazgos contribuyen con la validación del RT como un extracto antidiabético, el cual involucran la disminución de la glicemia y el decremento del estrés oxidativo. Asimismo, sienta las bases para el aislamiento y caracterización de los componentes responsables de su actividad farmacológica.

Estudio fitoquímico de plantas utilizadas en el control de la diabetes mellitus y evaluación de la actividad biológica sobre glucosa-6-fosfatasa de los metabolitos aislados y productos sintetizados / Phytochemical study of plants used in the control of diabetes mellitus and evaluation of the biological activity on glucose-6-phosphatase of isolated metabolites and synthesized products

La diabetes mellitus afecta a muchas personas alrededor del mundo, por lo que la comunidad científica está interesada en la búsqueda de nuevas drogas de origen sintético o natural para el tratamiento de la misma. En el presente trabajo se utilizaron cuatro plantas empleadas tradicionalmente en el tratamiento empírico de la diabetes y se realizó la síntesis total de los productos naturales α- yß- pentagaloilglucosa, ácido elágico y sus análogos. Las plantas estudiadas provienen de los géneros: Ouratea polyantha Engl. (Ochnaceae), Capraria biflora L. (Schrophulariaceae), Cassia fruticosa Mill. (Fabaceae) y Ruellia tuberosa L. (Acanthaceae). De la planta O. polyantha Engl., se aisló por HSCCC, e identificó por técnicas espectroscópicas el flavonoide rutina (OpC-4), la biflavona agathisflavona (OpD-5, OpB-M1), el ácido 4-hidroxibenzóico (OpD-10) y un nuevo megastigmano identificado como (6R,9S)-6'-(4''-hidroxibenzoil)-roseósido (OpD-9). Adicionalmente, se obtuvieron fracciones enriquecidas en lupeol y ß-sitosterol (OpBHex-FrCHCl3), agathisflavona (OpA, OpG) y rutina (OpA, OpC, OpG, OpH) las cuales fueron identificadas por CCF y HPLC comparando con muestras auténticas. Se evaluó el contenido de flavonoides totales como % de rutina en las fracciones OpC, OpG y OpH, por ensayos colorimétricos con AlCl3, obteniendo valores de: 7,08 ± 0,04; 31,9 ± 1,0; y 12,4 ± 0,3 %, respectivamente. De la planta C. fruticosa Mill., se aisló e identificó, por cromatografía flash y técnicas espectroscópicas el ester esteriodal ß-sitosterol palmitato•1/2•H2O (CfRS-3) y los flavonoides glicosilados kaempferol 3-O-rutinósido (nicotiflorin, CfH-1) y kaempferol 3-O-(2''-ramnosil)rutinósido (clitorin, CfH-2). Adicionalmente, se obtuvieron fracciones enriquecidas ß-sitosterol (CfB), y en los flavonoides nicotiflorin y clitorin (CfF, CfYY). De la planta C. biflora L., se aisló e identificó el glicosido manitol (CbE), el cual fue purificado por múltiples procesos de recristalización (CbM-2) y caracterizado por sus propiedades físicas y por la obtención de su derivado semisintético hexaacetilmanitol (CbM-2Ac). Adicionalmente, se obtuvieron fracciones enriquecidas en ß-sitosterol (CbI-FrCHCl3), azúcares (CbG, CbO), porfirinas tipo feoforbido-a (CbK y CbL) y terpenos aromáticos (CbK, CbF, CbN, CbP). De la planta R. tuberosa L., se obtuvieron fracciones enriquecidas en lupeol, betulina y ß-sitosterol (RtB, RtR-1, RtR-K), azúcares (RtI, RtR-G) polifenoles (RtJ, RtQac, RtSac, RtR-Mac, RtR-Nac) y terpenos aromáticos (RtQorg, RtSorg, RtR-Morg, RtR-Norg). En RtR-K se cuantificó por densitometría óptica el contenido porcentual de: lupeol 37,3 ± 0,8; ß-sitosterol 15,6 ± 0,6 y betulina (4,3 ± 0,3) % respectivamente. Los flavonoides aislados agathisflavona, nicotiflorin y clitorin mostraron inhibición significativa sobre el sistema enzimático G-6-Pasa microsomal cuyos valores fueron 63, 60 y 46 % respectivamente. Por otra parte, las fracciones terpenoidal (RtR-K) y porfirínicas (CbK y CbL) presentaron una inhibición moderada sobre la G-6-Pasa con 45, 25 y 27% respectivamente. Entre los productos sintetizados, los anómeros α- y ß-pentaacilglucosa (PAG, PBG y PGG-Bn) no presentaron actividad biológica significativa (<10%), lo cual indica claramente que el grupo galoilo es fundamental para la actividad biológica asociada a los taninos hidrolizables α-PGG y ß-PGG. A concentraciones finales de 50 µM, estos compuestos presentaron un porcentaje de inhibición de 77 y 79 % respectivamente con una significancia estadística importante (p<0,00006). Por otra parte, el ácido elágico (AE) sintetizado presentó un porcentaje de inhibición de 63% cuyo IC50 fue 76,50 µM, su derivado acetilado (AAcE) mostro un IC50 73,5 µM, mientras que, el derivado alquilico (AMeE) fue inactivo frente a la G-6-Pasa. Adicionalmente, AE y AAcE no mostraron actividad inhibitoria de la absorción intestinal de glucosa.

Formulation of tablets from the crude extract of Rhinacanthus nasutus (Thai local plant) against Aedes aegypti and Culex quinquefasciatus larvae: a preliminary study.

Dried root powder of Rhinacanthus nasutus, Thong Phan Chang (Thai name) were extracted with methanol (MeOH) in a Soxhlet apparatus and made into 2 formulations of tablet containing the extract at 5% and 10% concentration. Due to the viscous and poor flow properties of the crude MeOH extract obtained, a wet granulation method was conducted in developing the tablets. Lactose was used as a filler. Polyvinyl pyrrolidone (PVP) K30 (15% w/w solution in alcohol) was used as the binding agent, while stearic acid (2% w/w) was used as a lubricant. Both formulas of prepared tablets had a smooth shiny surface with a round shape. Other physical properties of the tablets, such as weight variation, friability and disintegration time, met the requirements of the USP XX standard. The mosquito larvicidal activity of prepared tablets containing 5% and 10% R. nasutus extract against Aedes aegypti were not significantly different from each other (p > 0.05), with 48-hour LC50 values of 13.6 and 14.2 mg/I for the 5% and 10% tablets, respectively, while their activities against Culex quinquefasciatus were similar (p > 0.05) with LC50 values of 18.7 and 17.3, respectively. The larvicidal activity levels against Ae. aegypti and Cx. quinquefasciatus were also not significantly different from each other (p > 0.05). No larval mortality was observed in the two control groups: lactose solution and dechlorinated water. Toxicity to female and male fish (Poecilia reticulata) was tested with the prepared tablets. The toxicity of tablets containing 5% and 10% extracts were not significantly different from each other for the P. reticulata females with 48-hour LC50 values of 105.2 and 110.8 mg/I, respectively, and for P. reticulata males with LC50 values of 99.1 and 103.4 mg/I, respectively. Female and male P. reticulata were sensitive to the same dose of the extract. No fish died in the two control groups, with lactose solution and dechlorinated water. Acute-toxicity bioassay with fish showed that with an exposure of 48 hours the LC50 values of the tablets containing 5% and 10% were 5- to 10-fold higher than the LC50 of R. nasutus against mosquito larvae. These prepared tablets could possibly used to control mosquito vectors and be introduced into the mosquito control program.

Immunomodulatory activities of Centella asiatica and Rhinacanthus nasutus extracts.

Centella asiatica (CA) and Rhinacanthus nasutus (RN )have been used for treatment of various illnesses, but the mechanisms of action remain largely unknown. This study focused on the influence of CA and RN extracts on cell-mediated and humoral immune responses. In human peripheral blood mononuclear cells (PBMCs), CA (water extract) and RN (water and ethanol extracts) significantly increased proliferation and the production of IL-2 and TNF-alpha. In contrast, an ethanol extract of CA inhibited human PBMC mitogenesis and the production of IL-2 and TNF-alpha. BALB/c mice treated with CA extracts (100 mg/kg bw) showed higher responses to both primary and secondary antibodies against BSA when compared with non-treated group. Only the secondary antibody response was increased in RN extract-treated mice. The present study revealed immunomodulating activity of CA and RN extracts with regard to both non-specific cellular and humoral immune responses. The data available to date suggest that they may have chemopreventive or anticancer potential.

Antiulcerogenic effect of Justicia prostrata Gamble.

Antiulcerogenic effect of the alcoholic (ALJP) and aqueous (AQJP) extracts of the whole plant of Justicia prostrata was studied in aspirin+pylorus ligated rat models and analysed for gastric volume, ulcer index, free and total acidity. Biochemical parameters like total proteins, total hexoses, hexosamine, fucose and sialic acid were also estimated. Both extracts (ALJP and AQJP) significantly reduced both the gastric volume and the acidity of gastric juice. It also significantly promoted gastric mucus secretion by increasing total carbohydrates and decreasing the protein concentration in aspirin+ pylorus ligated rats. The results suggest that both the extracts (ALJP and AQJP) possess antiulcer activity, whereas AQJP is more effective when compared with ALJP in aspirin+pylorus ligated rat models. The results were compared with the standard drug Rantidine, a H2 receptor antagonist.

Effect of Asteracantha longifolia Nees. against CCl4 induced liver dysfunction in rat.

Significant recovery after treatment with the whole plant slurry of A.longifolia Nees. was observed in plasma AST, ALT and cholesterol levels in CCl4 induced hepatotoxic rats. This was amply supported by electron micrographs, which indicated normalization of cytoarchitecture of mitochondria and endoplasmic reticulum. The results suggest that the slurry of the plant is useful as a liver tonic.

Phytochemical investigation and evaluation of anti-inflammatory and anti-arthritic activities of essential oil of Strobilanthus ixiocephala Benth.

Column chromatographic fractionation of essential oil obtained by hydrodistillation from the flowering tops of S. ixiocephala resulted in the isolation of beta-caryophyllene, fenchyl acetate, T-cadinol and a new sesquiterpene alcohol for which a name ixiocephol has been proposed. The beta-caryophyllene and fenchyl acetate were identified by Co-TLC with authentic samples whereas T-cadinol and ixiocephol were structurally elucidated by UV, IR, 1H NMR, 13C NMR and Mass spectral data. The GC-MS analysis of the essential oil has also revealed the presence of various monoterpenoids and sesquiterpenoids. The essential oil of S. ixiocephala demonstrated a dose dependant anti-inflammatory activity in carrageenan-induced rat paw oedema. It has also revealed good activity in cotton pellet granuloma and adjuvant induced arthritis model in rats.