Angel T. Alvarado

Prof. Dr. Angel T. Alvarado

Vicerrectorado de Investigación, Universidad San Ignacio de Loyola, Lima, Peru
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Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2012 in Journal of Medicinal Food
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Journal Article
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Fernando Ramos-EscuderoFernando Ramos-Escudero
Fernando Ramos-Escudero
AMAna María Muñoz
Ana María Muñoz
CACarlos Alvarado-Ortíz
Carlos Alvarado-Ortíz
Angel T. AlvaradoAngel T. Alvarado
Angel T. Alvarado
JYJaime A. Yáñez
Jaime A. Yáñez
This study was designed to determine the contents of total polyphenols, flavonoids, flavonols, flavanols, and anthocyanins of purple corn (Zea mays L.) extracts obtained with different methanol:water concentrations, acidified with 1% HCl (1 N). Another objective was to determine the antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and deoxyribose assay, individual phenolic compounds by high-performance liquid chromatography (HPLC), and endogenous antioxidant enzyme (superoxide dismutase [SOD], catalase [CAT], and total peroxidase [TPX]) activity and lipid peroxidation activity (thiobarbituric acid–reactive substances [TBARS] assay) in isolated mouse organs. Overall, the highest total content of polyphenols, anthocyanins, flavonoids, flavonols, and flavanols was obtained with the 80:20 methanol:water extract, acidified with 1% HCl (1 N). The 50% inhibitory concentration values obtained by the DPPH and ABTS assays with this extract were 66.3 μg/mL and 250 μg/mL, respectively. The antioxidant activity by the FRAP assay was 26.1 μM Trolox equivalents/g, whereas the deoxyribose assay presented 93.6% inhibition. Because of these results, the 80:20 methanol:water extract, acidified with 1% HCl (1 N), was used for the remaining tests. Eight phenolic compounds were identified by HPLC: chlorogenic acid, caffeic acid, rutin, ferulic acid, morin, quercetin, naringenin, and kaempferol. Furthermore, it was observed that the purple corn extract was capable of significantly reducing lipid peroxidation (lower malondialdehyde [MDA] concentrations by the TBARS assay) and at the same time increasing endogenous antioxidant enzyme (CAT, TPX, and SOD) activities in isolated mouse kidney, liver, and brain. On the basis of the results, it was concluded that the purple corn extract contained various bioactive phenolic compounds that exhibited considerable in vitro antioxidant activity, which correlated well with the decreased MDA formation and increase in activity of endogenous antioxidant enzymes observed in the isolated mouse organs. This warrants further in vivo studies with purple corn extracts to assess its antioxidant activity and other bioactivities.

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Andrés López-CortésAndrés López-Cortés
Andrés López-Cortés
SGSantiago Guerrero
Santiago Guerrero
MRMaria Ana Redal
Maria Ana Redal
Angel T. AlvaradoAngel T. Alvarado
Angel T. Alvarado
Luis A. QuiñonesLuis A. Quiñones
Luis A. Quiñones
Over the past decades, several studies have shown that tumor-related somatic and germline alterations predicts tumor prognosis, drug response and toxicity. Latin American populations present a vast geno-phenotypic diversity due to the great interethnic and interracial mixing. This genetic flow leads to the appearance of complex characteristics that allow individuals to adapt to endemic environments, such as high altitude or extreme tropical weather. These genetic changes, most of them subtle and unexplored, could establish a mutational profile to develop new pharmacogenomic therapies specific for Latin American populations. In this review, we present the current status of research on somatic and germline alterations in Latin America compared to those found in Caucasian and Asian populations.

1 September 2019 in Biomédica
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Journal Article
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Angel T. AlvaradoAngel T. Alvarado
Angel T. Alvarado
Naysha Rojas-VillaNaysha Rojas-Villa
Naysha Rojas-Villa
BLBerta Loja
Berta Loja
JMJessica Michiko Miyasato
Jessica Michiko Miyasato
JGJorge Antonio García
Jorge Antonio García
NVNelson Varela
Nelson Varela
Introducción. El citocromo CYP2C9 metaboliza, aproximadamente, el 15 % de los fármacos prescritos. Su gen presenta alelos cuyas frecuencias difieren entre grupos étnicos y poblaciones. Los alelos CYP2C9*2 y CYP2C9*3 dan cuenta de una enzima con actividad disminuida cuya frecuencia no ha sido determinada en la población mestiza peruana.Objetivo. Caracterizar la frecuencia de las variantes *2 (rs1799853) y *3 (rs1057910) del gen CYP2C9 en muestras de población mestiza peruana provenientes de Lima, Tacna y Junín.Materiales y métodos. Se hizo un estudio descriptivo, observacional y prospectivo, con muestreo no probabilístico, por conveniencia e incidental. Se incluyeron 218 sujetos según los criterios de inclusión y exclusión; todos los participantes otorgaron su consentimiento informado. El ADN genómico se obtuvo mediante hisopado de mucosa oral, y la detección de los genotipos para los alelos CYP2C9*2 y CYP2C9*3 se hizo mediante reacción en cadena de la polimerasa (PCR) en tiempo real, utilizando sondas TaqMan™.Resultados. Las variantes de CYP2C9*2 y CYP2C9*3 están presentes en la población mestiza peruana con frecuencias de 0,046 y 0,062, respectivamente. El análisis de las frecuencias genotípicas observadas permitió predecir que la frecuencia de fenotipos metabolismo intermedio sería del 15,13 % (CYP2C9*1/*2: 5,96 %; CYP2C9*1/*3: 9,17 %), y la de fenotipos de metabolismo lento, del 3,22 % (CYP2C9*2/*2: 1,38 %; CYP2C9*3/*3: 1,38 %; CYP2C9*2/*3: 0,46 %).Conclusiones. Se lograron determinar las frecuencias genotípicas y alélicas para las variantes *2 y *3 del gen CYP2C9 en una muestra no probabilística de población mestiza peruana.

1 March 2023 in Journal of Pharmacy & Pharmacognosy Research
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Open access
FSFelipe Surco-Laos
Felipe Surco-Laos
JGJorge A. Garcia
Jorge A. Garcia
MBMaría R. Dolores Bendezú
María R. Dolores Bendezú
Angel T. AlvaradoAngel T. Alvarado
Angel T. Alvarado
DLDoris Laos-Anchante
Doris Laos-Anchante
BLBerta Loja
Berta Loja
Context: In the Valley of Ica-Peru, the seeds of the fruit of Vitis vinifera L. (grape) are residues from the Pisco Industry, and due to their bioactive compounds, they can represent a new economic and sustainable activity for the population of the mentioned Valley. Aims: To characterize polyunsaturated fatty acids from the seeds of the fruit of Vitis vinifera L. (grape) from the Ica Valley, Peru and determine the antioxidant activity in vitro. Methods: The oil from five grape varieties (Quebranta, Moscatel, Torontel, Mollar, and Italia) was obtained by ethereal extraction with ultrasound. The profile of fatty acids was characterized by gas chromatography with a flame ionization detector (GC-FID). The total polyphenolic content was determined by the Folin-Ciocalteu method and antioxidant activity by two in vitro methods. Results: The values obtained from the 5 grape varieties are presented in a range: total polyphenolic content (TPC: 0.59-154 mg GAE/g); linoleic acid content (69.90-71.87%), oleic acid (18.35-19.90%) and others in a lower percentage (p>0.05). Antioxidant activity: DPPH IC50 38.30-48.43 µL; FRAP 0.49-0.77 μg TEAC/g. TPC/DPPH and TPC/FRAP were significantly different (p0.05). Conclusions: The oils from the seeds of the Vitis vinifera fruit (grapes) that are residues from the production of Pisco present physicochemical characteristics of oils of high nutritional value with a predominance of polyunsaturated fatty acids and potential antioxidant activity.

1 November 2021 in Journal of Pharmacy & Pharmacognosy Research
Verified
Journal Article
Open access
HCHaydee Chávez
Haydee Chávez
FPFreddy Palomino
Freddy Palomino
JAJackeline Angelino
Jackeline Angelino
ETErnesto Torres
Ernesto Torres
MBMaría R. Bendezú
María R. Bendezú
Angel T. AlvaradoAngel T. Alvarado
Angel T. Alvarado
Context: Asthma is characterized by hyperresponsiveness and bronchoconstriction, induced by histamine and other noxes, with a prevalence in Peru of 20.7-28.2%, which is why, in traditional medicine, Jatropha macrantha Müll.Arg is used. Aims: To evaluate the in vivo bronchodilator activity of the ethanolic extract of the stems of J. macrantha. Methods: The powdered material of the stem of J. macrantha was extracted with ethanol 96° by maceration; then, the phytochemical screening was carried out. The doses of 200, 400 and 800 mg/kg of the extracts were subjected to in vivo evaluation in guinea pigs (Cavia porcellus) with 1% histamine-induced bronchoconstriction, determining the latency period and the intensity of the effect. Results: Phytochemical sieving showed alkaloids, catechins, flavonoids, tannins and terpenes. The activity was observed at the three doses of the J. macrantha extract, being higher at a single dose of 400 mg/kg, with a latency period of 33.0 ± 1.02 s, asphyxia 84.5 ± 1.08 s and anaphylaxis 105.6 ± 0.59 s. The analysis of variance and Dunnett’s test resulted with p<0.05 as statistically significant. Conclusions: The results showed bronchodilator activity of the ethanolic extract of J. macrantha at an average dose of 400 mg/kg, orally, in Cavia porcellus.

15 August 2023 in Pharmacia
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Angel T. AlvaradoAngel T. Alvarado
Angel T. Alvarado
AMAna María Muñoz
Ana María Muñoz
NVNelson Varela
Nelson Varela
LSLuis Sullón-Dextre
Luis Sullón-Dextre
MPMario Pineda
Mario Pineda
JAJosé Almeida-Galindo
José Almeida-Galindo
Epilepsy is the most common neurological disorder with a worldwide incidence of 20% and a treatment failure rate of 25–30%. The fluctuation in serum levels, efficacy and safety of antiepileptic drugs can be attributed to single nucleotide polymorphisms of genes encoding their respective proteins involved in drug metabolism. The present study attempted to evaluate the pharmacogenetic variants of CYP2C9 and CYP2C19 associated with adverse reactions induced by antiepileptic drugs used in Peru. Few studies were found to significantly associate the CYP2C9*2, CYP2C9*3, CYP2C19*2, and CYP2C19*3 single nucleotide polymorphisms with elevated serum levels of valproic acid and carbamazepine, and valproic acid induction of hyperammonemia, and adverse reactions cutaneous for carbamazepine. There is further evidence of a significant association of CYP2C9*2/CYP2C9*3 with severe cutaneous adverse reactions (SCARs) such as Stevens-Johnson syndrome (SJS) and epidermal necrolysis (TEN) phenytoin-induced. CYP2C9*3 may be a pharmacogenetic biomarker for such a drug. It is proposed to reduce the dose of drugs for intermediate and poor metabolizers. No pharmacogenetic studies were found in patients with epilepsy in Peruvian populations. It is concluded that this review could help physicians in the prediction and prevention of adverse reactions induced by antiepileptic drugs, as well as to improve their pharmacotherapeutic results. It could also be used as scientific evidence to carry out pharmacogenetic and precision medicine studies in Peruvian patients with epilepsy, due to their tricontinental and Latin American ancestry.