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20 result(s) for "Sotelo-Leyva, Cesar"
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Cytotoxic and Antimicrobial Activity of the Ageratina Genus
Medicinal plants have long been used for therapeutic purposes in many cultures. They represent sources of important bioactive compounds, often of pharmacological significance. Spach is the largest genus in Mexico and is characterised by its traditional use in the treatment of cancer and infections of the skin, blood, and intestines. Different species of have been biologically evaluated at the extract and compound levels, and their chemical contents have been purified and characterised. Following a PRISMA meta-analysis, 29 scientific reports were selected and analysed. Tables of different species were integrated to compare their cytotoxic and antimicrobial activity at the extract and compound levels. Twelve pure and isolated natural compounds were tested for cytotoxic activity against several cell lines from lung, colon, and breast cancer, cervical carcinoma, hepatocarcinoma, promyelocytic leukaemia, and histiocytic lymphoma. Forty-one pure and isolated natural compounds were evaluated for antimicrobial activity against a wide spectrum of microorganisms, including Gram-positive and Gram-negative bacteria, yeast, fungi, parasites and viruses. Spach contains cytotoxic and antimicrobial substances with broad chemical profiles. In addition to being a plant with active compounds, it could be useful for future rational drug design.
In Vitro Insecticidal Effect of Commercial Fatty Acids, β-Sitosterol, and Rutin against the Sugarcane Aphid, Melanaphis sacchari Zehntner (Hemiptera: Aphididae)
The sugarcane aphid, Melanaphis sacchari Zehntner (Hemiptera: Aphididae), is the main pest of sorghum, Sorghum bicolor L. Moench (Poaceae), in Mexico. To control this insect, farmers currently use synthetic chemical insecticides, which are toxic to humans and biodiversity. However, natural products are a promising potential source of safer alternative means to control different agricultural pests. The main objective of this study was to evaluate the insecticidal effect of contact by fumigation of pure molecules of four commercial fatty acids (palmitic, stearic, pentadecanoic, and linoleic acids), the phytosterol β-sitosterol, and the flavonoid rutin. The results showed that fatty acids were the most effective against M. sacchari; the highest mortality rate (85%) was produced by linoleic acid and the mean lethal concentration was 1,181 ppm, followed by stearic and palmitic acids with 74 and 63% mortality, respectively, at a concentration of 2,500 ppm at 72 h. The positive control, imidacloprid, had 100% mortality in 24 h and the Tween 20, negative control, exhibited 4% mortality in 72 h. Our results show that commercial fatty acids are effective against adults of M. sacchari and can be considered an environmentally friendly alternative to the frequent use of synthetic chemical insecticides.
Bioactivity of a Linoleic Acid–Rich Fraction of Ricinus communis L. (Euphorbiaceae) Leaves against the Yellow Sugarcane Aphid, Sipha flava (Hemiptera: Aphididae)
The insecticidal activity of a Ricinus communis leaf hexane extract and its fractions against adult yellow sugarcane aphids (Sipha flava) was evaluated using a contact bioassay after fumigation. The n-hexane extract at 10,000 ppm achieved the highest mortality (80%); the positive control had 100% mortality and the negative control had only 4% mortality over the 72-h experiment time. Chemical fractionation of the hexane extract of R. communis leaves produced multiple fractions, and 10,000 ppm of the F4 fraction resulted in 92% aphid mortality at 72 h. Gas chromatography-mass spectrometry of the F4 fraction revealed linoleic acid as the major compound (84.5%). The R. communis n-hexane extract and linoleic acid could be used for integrated pest control as an ecologically friendly alternative to synthetic chemical insecticides.
Anthelmintic Activity of Protocatechuic Acid Against Ivermectin-Susceptible and Resistant Haemonchus contortus Strains
The frequent and indiscriminate use of all classes of synthetic anthelmintics to deworm small ruminants has decreased their effectiveness in a worldwide problem of anthelmintic resistance. Using active plant metabolites with anthelmintic properties has become a suggested alternative to control parasitic helminths. The present study investigated the ovicidal and larvicidal activity of a fraction (CnF4) containing protocatechuic acid (3,4-dihydroxybenzoic acid) from Chamaecrista nictitans (Fabaceae) and a commercial standard of protocatechuic acid against strains of the parasitic nematode Haemonchus contortus susceptible (HcIVM-S) and resistant (HcIVM-R) to ivermectin, using egg hatch inhibition (EHI) and L3 larval mortality assays. The CnF4 fraction showed an EHI greater than 90% at 0.8 mg/mL against HcIVM-S and an EHI = 88.39% at 1.6 mg/mL against HcIVM-R. The commercial standard of protocatechuic acid displayed an EHI of 97.49% at 0.25 mg/mL against HcIVM-S and an EHI greater than 98% at 0.5 mg/mL. In the larval mortality assays, protocatechuic acid caused 72.4% larval mortality of HcIVM-S at 8 mg/mL and 53.2% mortality of HcIVM-R at 16 mg/mL. These results indicate that protocatechuic acid was more effective in inhibiting egg hatching and causing larval mortality against HcIVM-S compared to HcIVM-R.
Chemical composition of Ricinus communis and Momordica charantia seeds extracts and its bioactivity against the sugarcane aphid, Melanaphis sacchari (Zehntner)
Melanaphis sacchari Zehntner (Hemiptera: Aphididae) is currently the most destructive pest insect of the sorghum crop (Sorghum bicolor L. Moench) and has caused economic losses worldwide. Strategies using natural products such as plant extracts can offer alternatives for the control of this pest. In this investigation, we evaluated the insecticidal effect of the hexane extract of Ricinus communis L. and Momordica charantia L. seeds on M. sacchari in contact bioassays. The results showed that the extract of R. communis presented a mortality rate of 100% in 48 h at 10,000 ppm, while M. charantia presented 80% in 72 h, at 10,000 ppm. Gas chromatography—mass spectrometry (GC–MS) identified the major compounds as squalene in R. communis (51.57%) and linalool oxide in M. charantia (30.45%). The hexanic extracts of these plant species could be considered an ecologically friendly alternative to control this pest, given the use of synthetic chemical insecticides.
Entomopathogenic Bacteria Species and Toxins Targeting Aphids (Hemiptera: Aphididae): A Review
Aphids (Hemiptera: Aphididae) are cosmopolitan generalist pests of many agricultural crops. Their ability to reproduce rapidly through parthenogenesis allows them to quickly reach population sizes that are difficult to control. Their damage potential is further exacerbated when they act as vectors for plant pathogens, causing diseases in plants. Aphids are typically managed through the widespread use of insecticides, increasing the likelihood of short-term insecticide resistance. However, for the past few decades, entomopathogenic bacteria have been used as an alternative management strategy. Entomopathogenic bacteria have demonstrated their effectiveness for biologically suppressing insect pests, including aphids. In addition to identifying bacterial species that are pathogenic to aphids, research has been conducted on toxins such as Cry, Cyt, Vip, recombinant proteins, and other secondary metabolites with insecticidal activity. Most studies on aphids have been conducted in vitro, exposing them to an artificial diet contaminated with entomopathogenic bacteria or bacterial metabolites for periods ranging from 24 to 96 h. The discovery of new bacterial species with insecticidal potential, as well as the possibility of biotechnological applications through the genetic improvement of crops, will provide more alternatives for managing these agricultural pests in the future. This will also help address challenges related to field application.
A Review of Biological Control One Decade After the Sorghum Aphid (Melanaphis sorghi) Outbreak
Melanaphis sorghi is a pest that is native to Africa but is now distributed worldwide. In 2013, its destructive capacity was demonstrated when it devastated sorghum crops in the United States and Mexico, making it a new pest of economic importance in North America. At the time, the phytosanitary authorities of both countries recommended the use of pesticides to control the outbreak, and biological control products for the management of this pest were not known. In response to the outbreak of M. sorghi in North America, several field studies have been performed in the last decade on sorghum crops in the USA and Mexico. Works have focused on assessing resistant sorghum hybrids, pesticide use, and recruitment of associated aphid predators and entomopathogens for natural control of M. sorghi populations. The objective of this review is to compile the information that has been generated in the past decade about indigenous enemies affecting M. sorghi naturally in the field, as well as the search for biological control alternatives and evaluations of interactive effects of resistant sorghum hybrids, pesticides, and natural enemies. To date, different predators, parasitoids, fungi, and bacteria have been evaluated and in many cases found to affect M. sorghi populations in sorghum agroecosystems or laboratory bioassays, and the use of resistant sorghum varieties and pesticides did not have clear toxic effects on natural enemy populations. Many of the macroorganisms and microorganisms that have been evaluated as potential biological controls have shown potential as alternatives to synthetic pesticides for keeping M. sorghi population densities below economic damage thresholds and are compatible with integrated management of sorghum aphids. While most tests of these biological alternatives have shown that they have aphidicidal potential against sorghum aphids, it is crucial to take into account that their effectiveness in the field depends on a number of abiotic and biotic factors, including soil texture, temperature, humidity, and natural enemies.
8-Methoxypsoralen (8-MOP) Isolated from Ficus petiolaris (Moraceae) Has Insecticidal Activity against Spodoptera frugiperda
In this study, we tested the insectistatic and insecticidal effects of the ethanolic extract of stems and bark of Ficus petiolaris Kunth (Moraceae) in laboratory bioassays with an artificial diet against newly hatched larvae of the fall armyworm, Spodoptera frugiperda Smith (Lepidoptera: Noctuidae). The extract was evaluated at five different concentrations (500, 1000, 1500, 2000, and 2500 ppm). The 2500 ppm extract had the strongest inhibitory effects on larval (89%) and pupal (20%) weight as well as the highest mortality (80%). The positive control, methyl parathion (Methyl Parathion®) at 1%, eliminated 100% of the fall armyworm, and the negative control (artificial diet) had a mortality of only 5%. Chemical fractionation of F. petiolaris stem and bark extract produced five fractions of FpR1-5, each of which was evaluated at 250, 500, 750, 1000, and 1250 ppm. FpR4 presented the strongest inhibitory effect, reducing the weight of the larva and pupa by 35% and 18%, while FpR2 had the strongest insecticidal effect, with 90% mortality at 1250 ppm. The pure 8-Methoxypsoralen compound extracted from this fraction was even more effective, with 100% S. frugiperda mortality at 100 ppm. The 50% lethal concentration (LC50) of 8-Methoxypsoralen was 67.68 ppm. Our results indicate that the F. petiolaris extract showed toxic activity against the fall armyworm, and its compound 8-Methoxypsoralen showed strong insecticidal activity at low concentrations.
Neuropharmacological Activity of the Acetonic Extract of Malpighia mexicana A. Juss. and Its Phytochemical Profile
Mental and neurological disorders are conditions that affect thoughts, emotions, behavior, and relationships. Malpighia mexicana A. Juss. is a plant used in Mexican traditional medicine for the treatment of such disorders. This work aimed to investigate the antidepressant, anxiolytic, sedative, hypnotic, and anticonvulsant effects of the acetonic extract (MmAE) of M. mexicana and its fractions (F3, F4-10, F14) using the forced swimming test (FST), elevated plus maze (EPM), open field test (OFT), pentobarbital-induced sleep test (PBTt), and pentylenetetrazol-induced seizure test (PTZt). MmAE, F3, F4-10, F14, and vehicle were administrated orally 24, 18, and 1 h prior to the evaluations. Imipramine (15 mg/kg, p.o.) was administrated 1 h prior to the evaluations as a positive control for the FST, while diazepam (1 mg/kg, p.o.) was administrated 1 h prior to the evaluations as a positive control for the EPM, OFT, PBTt, and PTZt. MmAE had an anxiolytic effect; MmAE and F3, F4-10, and F14 showed an antidepressant effect, sedative effect, hypnotic effect, and anticonvulsant effect. Using HPLC, we identified the compounds quercetin 3-O-rutinoside (1), kaempferol 3-O-glucoside (2), luteolin 7-O-glucoside (3), quercetin (4), and kaempferol (5) in MmAE and compounds (1), (2), and (3) in F14. Using GC-MS, we identified α-tocopherol, phytol, and β-amyrin in F3; β-tocopherol, phytol, β-sitosterol, and β-amyrin in F4-10; and α- tocopherol, phytol, β-sitosterol, and β-amyrin in F4-10. The neuropharmacological effects found in this work may be due to the presence of vitamins, phytosterols, terpenes, and flavonoids. This research requires further study to clarify the mechanisms of action of the identified compounds.
Chemical Compounds, Pharmacological and Toxicological Activity of Brugmansia suaveolens: A Review
This study investigates updated information in different search engines on the distribution, phytochemistry, pharmacology, and toxicology of Brugmansia suaveolens (Solanaceae) using the extracts or chemical compounds at present. This plant has been used in traditional medicine in different cultures as a hallucinatory, analgesic, aphrodisiac, nematicide, sleep inducer, and muscle relaxant, as well as a treatment for rheumatism, asthma, and inflammation. The flowers, fruits, stems, and roots of the plant are used, and different chemical compounds have been identified, such as alkaloids, volatile compounds (mainly terpenes), coumarins, flavonoids, steroids, and hydrocarbons. The concentration of the different compounds varies according to the biotic and abiotic factors to which the plant is exposed. The toxic effect of the plant is mainly attributed to atropine and scopolamine, their averages in the flowers are 0.79 ± 0.03 and 0.72 ± 0.05 mg/g of dry plant, respectively. Pharmacological studies have shown that an aqueous extract exhibits the antinociceptive effect, at doses of 100 and 300 mg/kg i.p. in mice. On the other hand, the ethanolic extract at 1000 mg/L, showed a nematocidal activity in vitro of 64% against Meloidogyne incognita in 72 h. Likewise, it showed a 100% larvicidal activity at 12.5 mg/L against Ancylostoma spp. In another study, the lethal activity of shrimp in brine from an ethanolic extract showed an LC50 of 106 µg/mL at double serial concentrations of 1000–0 (µg/mL). Although there are pharmacological and phytochemical studies in the plant, they are still scarce, which has potential for the examination of the biological activity of the more than one hundred compounds that have been reported, many of which have not been evaluated.