Larrea divaricata a native Argentine plant with potential activity against SARS-CoV-2? / ¿Larrea divaricata una planta nativa argentina con actividad potencial sobre SARS-CoV-2?

Larrea divaricata Cav. is an autochthonous South American plant popularly used in inflammatory and infectious diseases with reported anti - inflammatory, immunomodulatory, antimicrobial and antioxidant activities. Covid - 19 is an infection ca used by the severe acute respiratory syndrome coronavirus 2 (SARS - CoV - 2). This virus can cause pneumonia and even death in about 5% of the cases. The objective of the article was to demonstrate, through a literature review, that L. divaricata has sufficie nt attributes to be assayed against SARS - CoV - 2. For this, the chemical composition, reported activities and docking studies were taken into account. This review demonstrated that the plant extracts are capable of inhibiting the proliferation of fungi, bact eria and viruses and that they exert anti - inflammatory and immunomodulatory actions in different " in vitro " and " in vivo " models. These results suggest that the plant is a good candidate to be studied for the prevention and/or treatment of SARS - CoV - 2.

Larrea divaricata Cav. es una planta autóctona Sudamericana, utilizada popularmente en enfermedades inflamatorias e infecciosas, con activida d anti - inflamatoria, inmunomoduladora, antimicrobiana y antioxidante reportada. El Covid - 19 es una infección causada por una cepa de coronavirus, SARS - CoV - 2 (coronavirus tipo 2 causante del síndrome respiratorio agudo severo). Este virus puede originar neu monía e incluso la muerte en alrededor del 5% de los casos. Nuestro objetivo fue demostrar, a través de una revisión bibliográfica, que esta planta tiene atributos suficientes para ser ensayada en estudios contra SARS - CoV - 2. Se tuvo en cuenta la composici ón química, los antecedentes científicos y los estudios de acoplamiento molecular. Esta revisión permitió demostrar que extractos de la planta son capaces de inhibir la proliferación de hongos, bacterias y virus y que presentan acción anti - inflamatoria en diferentes modelos " in vitro " e " in vivo ", lo que los hace candidatos a ser estudiados en la prevención y/o tratamiento de la infección contra SARS - CoV - 2.

Antiproliferative activity of aqueous and polyphenol-rich extracts of Larrea divaricata Cav. on a melanoma cell line.

Most of the deaths from skin cancer are caused by melanoma, a malignancy in which STAT3 plays a crucial role. The inhibition of STAT3 is considered a potential target to induce cell death, tumor regression and metastasis inhibition. The objective of this work was to evaluate the activity of the aqueous extract of Larrea divaricata (Aq), a fraction rich in polyphenols (EA),and the isolated compound quercetin-3-methyl ether (Q3ME) on B16F10 melanoma cells. The effects of Aq, EA and Q3ME were assessed on B16F10 cells by determining the proliferation, viability, apoptosis induction and the expression and phosphorylation of STAT3. The phytochemical composition of the extracts was determined by High Performance Liquid Chromatography. Aq, EA and Q3ME presented antiproliferative activity on B6F10 cells through p-STAT3 inhibition and early and late apoptosis induction (EC50 EA= ≤0.1 µg/ml; Aq= 316 ± 30 µg/ml; Q3ME= <0.1 µg/ml). L. divaricata could be considered for the development of adjuvant phytotherapies in melanoma treatment.

Larrea divaricata Cav. aqueous extract and nordihydroguariaretic acid modulate oxidative stress in submandibular glands of diabetic rats: a buccal protective in diabetes.

BACKGROUND: Oxidative stress is an imbalance between the levels of reactive oxygen species (ROS), reactive nitrogen species (RNS) and endogenous antioxidants. The aetiology and pathogenesis of several oral diseases are attributed to this process. The antioxidant enzymes secreted in the saliva by submandibular glands maintain oral health through the scavenging of ROS. The objective of this work was to study the capacity of an aqueous extract of L. divaricata (AE), and its majority compound, nordihydroguariaretic acid (NDGA), to modulate the pro-oxidant/antioxidant status in submandibular glands in a model of oxidative stress induced by streptozotocin (STZ) in rats. METHODS: To induce oxidative stress with STZ, a group of animals was treated i.p. with 1 X PBS (control group) and other group was injected i.p. once with STZ (60 mg/kg). Ten days after the treatment, blood samples were taken from the tail vain to determine the glucose levels. Animals with glucose values ≥300 mg/ml were selected. The submandibular glands of control and STZ treated animals were incubated with either the AE (500 µg/ml) or with NDGA (1.5 µg/ml), and the content of malondialdehyde (MDA), protein carbonyl groups, ROS and RNS, and the activity and expression of peroxidase (Px), superoxide dismutase (SOD) and inducible nitric oxide synthase (iNOS) were assayed. RESULTS: AE decreased the levels of MDA (##P < 0.01) and protein carbonyl groups (#P < 0.05), and modulated the levels of ROS such as hydrogen peroxide (H2O2)(##P < 0.01), superoxide anion (O2.-) (#P < 0.05) and nitric oxide (NO) (#P < 0.05) in relation to the modulation of Px and iNOS expression. NDGA was found to be involved in these effects. CONCLUSIONS: The antioxidant activity of the AE in the submandibular glands would allow the maintenance of the antioxidant pool to prevent oral oxidative diseases.

Development of pH-responsive biopolymer-silica composites loaded with Larrea divaricata Cav. extract with antioxidant activity.

A detailed study of biomaterials is mandatory to comprehend their feasible biomedical applications in terms of drug delivery and tissue regeneration. Particularly, mucoadhesive biopolymers such as chitosan (chi) and carboxymethylcellulose (CMC) have become interesting biomaterials regards to their biocompatibility and non-toxicity for oral mucosal drug delivery. In this work, pH-responsive biopolymer-silica composites (Chi-SiO2, Chi-CMC-SiO2) were developed. These two types of composites presented a different swelling behavior due to the environmental pH. Moreover, the nanocomposites were loaded with aqueous Larrea divaricata Cav. extract (Ld), a South American plant which presents antioxidant properties suitable for the treatment of gingivoperiodontal diseases. Chi-CMC-SiO2 composites showed the highest incorporation and reached the 100% of extract release in almost 4 days while they preserved their antioxidant properties. In this study, thermal and swelling behavior were pointed out to show the distinct water-composite interaction and therefore to evaluate their mucoadhesivity. Furthermore, a cytotoxicity test with 3T3 fibroblasts was assessed, showing that in both composites the addition of Larrea divaricata Cav. extract increased fibroblast proliferation. Lastly, preliminary in vitro studies were performed with simulated body fluids. Indeed, SEM-EDS analysis indicated that only chi-SiO2 composite may provide an environment for possible biomineralization while the addition of CMC to the composites discouraged calcium accumulation. In conclusion, the development of bioactive composites could promote the regeneration of periodontal tissue damaged throughout periodontal disease and the presence of silica nanoparticles could provide an environment for biomineralization.

Larrea divaricata Cav: scientific evidence showing its beneficial effects and its wide potential application / Larrea divaricata Cav: evidencia específica mostrando sus efectos beneficiosos y su amplia aplicación potencial

Larrea divaricata Cav. (jarilla) (Zygophyllaceae) is used in Argentinean folk medicine. It contains nordihydroguaiaretic acid (NDGA), a lignan with nefrotoxic and hepatotoxic effects. The presence of NDGA converts controversial the use of L. divaricata. The amount of NDGA is higher in alcoholic extracts than in aqueous extracts (AE). The last 20 years had a great advance on the use of AE to treat different conditions in a safe manner. In this review, we present the scientific results tending to confirm the potential beneficial effects of the AE on human health. The anti-proliferative effects of AE of L. divaricata have been assayed on a tumor lymphoid line (BW 5147) and the pathways involved in such effects were described. The anti-microbial activity was determined by tests for bacteria and fungus. The anti-inflammatory activity was assayed by using carrageen and TPA induced-inflammation tests. The Immunomodulatory effects were investigated ¯in vivo and ¯in vitro on mice. Sub-fractions of aqueous extracts were obtained and analyzed. The immunogenicity of proteins from crude AE was characterized and antioxidant and nutritional activity were studied. The effect of an AE on hair loss was assayed. In summary, AE from L. divaricata has pharmacological activities including anti-microbial, anti-inflammatory, anti-cancer effects.

Larrea divaricata Cav. (Jarilla) (Zygophyllaceae) es utilizada en medicina popular Argentina. Contiene ácido nordihidroguaiarético (NDGA), un lignano con efectos nefrotóxicos y hepatotóxicos. La presencia de NDGA hace controvertido el uso de L. divaricata. La cantidad de NDGA es mayor en extractos alcohólicos que en extractos acuosos (EA). Los últimos 20 años han tenido un gran avance en el uso de EA para el tratamiento de diferentes condiciones en forma segura. En esta revisión se presentan resultados científicos que confirman los efectos potencialmente beneficiosos de los EA sobre la salud humana. Los efectos anti-proliferativos se han ensayado en una línea de tumor linfoide, así como los mecanismos involucrados. La actividad anti-microbiana se determinó usando pruebas para bacterias y hongos. La actividad anti-inflamatoria fue evaluada mediante el uso de inflamación inducida por carragenina y TPA. Los efectos inmunomoduladores fueron investigados "in vivo" e "in vitro" en ratones. Sub-fracciones de los EA fueron obtenidos y analizados. La inmunogenicidad de las proteínas del EA crudo se caracterizaron y se estudiaron las actividades antioxidantes nutricionales. Además, se ensayó el efecto del EA en la caída del cabello. En resumen, los EA de L. divaricata presentan actividades farmacológicas como por ejemplo, anti-microbiana, anti-inflamatoria y efectos anti-cancerígenos.