Thunbergia alata inhibits inflammatory responses through the inactivation of ERK and STAT3 in macrophages

Folk medicine, biological activity, and chemical profiles of Brazilian Acanthaceae (Lamiales) - A review

INTRODUCTION

The botanical family Acanthaceae (order Lamiales) potentially comprises 4900 species in 191 genera with extensive morphological, habit and habitat diversity. The family is widely distributed throughout the world but is especially rich in tropical and subtropical regions. Many of its species have great ornamental importance and are broadly used for medicinal purposes in several countries of Asia and Africa. Brazil is a main center of diversity of the family, where they are distributed across all its biomes, mainly in the herbaceous-shrub stratum. Medicinal investigations about Brazilian species are scarce, the exception being a single native species, Justicia pectoralis Jacq., that is widely used and studied chemically.

AIM OF THE REVIEW

This work compiled studies that indicated folk medicinal use, investigated biological activity, or evaluated the chemical composition of Brazilian species of Acanthaceae.

MATERIAL AND METHODS

Medicinal uses, investigations of biological activities and chemical data were collected and summarized through bibliographic surveys. Tables were compiled to standardize the information and the appropriate references were gathered for each species. Registration of chemical components used in the treatment of ailments and in preserving health were emphasized with the aim of stimulating future investigations.

RESULTS

The breadths of habitats and morphologies of the family are directly related to its chemical diversity, as confirmed here for Brazilian species. Although the investigated species represent less than 9% of the total richness of the family in Brazil, they encompass a great diversity of chemical substances. The data indicated folk medicinal uses for 26 species and biological tests for 23, while 30 species were investigated chemically. Ruellia and Justicia were the most researched genera with 12 and 11 species, representing approximately 14% and 7% of Brazilian species of each genus, respectively. Two species are native to other countries but become naturalized in Brazil. Studies of native species were carried out in different countries around the world, with many reports of medicinal uses and biological tests. Examples of uses include anticancer and antidepressant actions, as well as activities against respiratory problems and other diseases.

CONCLUSIONS

This work highlights the chemical and biological diversity of the studied Brazilian species of Acanthaceae, which emphasizes the need to expand studies with native Brazilian species.

Ethnobotanical study of medicinal plants used by the people of Mosop, Nandi County in Kenya

Background: Throughout the history, nature has provided mankind with most of their basic needs, which include food, shelter, medicine, clothes, flavours, scents as well as raw materials. Given that they are an integral part of cultural heritage, medicinal plants have played a significant role in human healthcare systems around the world. Investigating various biological resources for use as medicines requires ethnomedicinal studies. Methods: Data on utilization of ethnomedicinal plants from local healers in Kenya's Mosop Sub-County in Nandi County was documented through open-ended, semi-structured questionnaires. A number of quantitative indices, such as the Use Citation (UC), Informant Consensus Factor (ICF), Use Value (UV), Frequency of Citation (FoC) and Relative Frequency of Citation (RFC) were used to convey the potential medical benefits, vitality and variety of the ethnomedicine. Results: 102 informants provided information on 253 ethnomedicinal plant species, classified into 74 families. There were 249 native plant species identified, along with few exotic species: Senegalia senegal (L.) Britton, Persea americana Mill, Carica papaya L. and Solanum betaceum Cav. Of all recorded species, 32% and 27% were herbs and trees, respectively. Among plant parts, leaves were most frequently utilized (27%) and roots (26%), while decoctions (21%) were the most widely used formulations. The dominant family was Asteraceae, with 28 species, followed by Lamiaceae, with 19 species. The highest ICF value was 0.778 for a number of parasitic and infectious illnesses, including ringworms, athlete's foot rot, tetanus, typhoid, intestinal parasites, abscesses, malaria, and amoebiasis. The study's data validates the region's widespread use of traditional medicinal plant remedies. Conclusion: The current study will lay a foundation of knowledge for future research investigations. The abundance of knowledge regarding ethnomedicinal species and their medicinal applications will stimulate further phytochemical and pharmacological research, which could lead to the discovery of potentially significant pharmaceuticals.

Regulation of anti-inflammatory and antioxidant responses by methanol extract of Mikania cordata (Burm. f.) B. L. Rob. leaves via the inactivation of NF-κB and MAPK signaling pathways and activation of Nrf2 in LPS-induced RAW 264.7 macrophages

Mikania cordata (Burm. f.) B.L. Rob. has been traditionally used in tropical countries throughout Asia and Africa to treat gastric ulcers, dyspepsia, and dysentery. However, the mechanisms responsible for its anti-inflammatory and antioxidant activities are not fully understood. Therefore, this study sought to investigate the anti-inflammatory and antioxidant effects of methanol extracts of M. cordata (MMC) on inflammation and oxidative stress in lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophages and elucidate its underlying regulatory mechanism. MMC significantly suppressed the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated RAW 264.7 macrophages by downregulating the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) at both the mRNA and protein levels. Moreover, MMC effectively reduced the mRNA expression levels and production of pro-inflammatory cytokines, including interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α). These suppressive effects of MMC on pro-inflammatory mediators and cytokines were mediated through the inhibition of transforming growth factor beta-activated kinase 1 (TAK1), which subsequently blocked the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs). MMC also upregulated the nuclear factor erythroid-2-related factor 2 (Nrf2) by inducing the degradation of Kelch-like ECH-related protein 1 (Keap1), an Nrf2-specific E3 ligase. Accordingly, MMC enhanced Nrf2 target gene expression of anti-oxidative regulators such as heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1). However, it had minimal effect on the DPPH radical scavenging capacity in vitro. Collectively, these findings demonstrate that MMC holds promise as a potential therapeutic agent for alleviating inflammation-related diseases and oxidative stress.

Efficient micropropagation of Thunbergia coccinea Wall. and genetic homogeneity assessment through RAPD and ISSR markers

Thunbergia coccinea Wall. ex D. Don being a rare, ornamental and medicinal plant of India, is needed to propagate for conserving the germplasm and analyzing its phytochemical compounds in the future. A reliable protocol for direct in vitro propagation using nodal shoot meristem of T. coccinea as explant was standardized. The highest number of shoots per explant (22.17 ± 0.54) with maximum shoot length (2.36 ± 0.28) in cm was obtained in Murashige and Skoog (MS) medium supplemented with 9.70 µM of 6-furfurylaminopurine (Kinetin) and 0.053 µM of α-naphthaleneacetic acid (NAA) combination, among all the different plant growth regulators (PGR’s) and concentrations tested. The aforesaid PGR’s combination was optimum for axillary shoot bud induction and multiplication in T. coccinea. The best rooting was observed on the half-strength MS medium fortified with 2.68 µM NAA with the highest number of roots per shoot (3.75 ± 0.12) and maximum length (5.22 ± 0.32) in cm. All the in vitro raised plantlets were acclimatized in sterile sand and soil mixture (1:1) with a survival rate of 70% on earthen pots under greenhouse conditions. PCR-based RAPD (Random Amplified Polymorphic DNA) and ISSR (Inter-Simple Sequence Repeat) molecular markers were employed to determine the genetic homogeneity amongst the plantlets. Twelve (12) RAPD and nine (9) ISSR primers developed a total of 104 and 91 scorable bands, respectively. The band profiles of micropropagated plantlets were monomorphic to the mother, donor in vivo plant, and similarity values varied from 0.9542–1.000. The dendrogram generated through UPGMA (unweighted pair group method with arithmetic mean) showed 99% similarities amongst all tested plants confirming the genetic uniformity of in vitro raised plants.

Synedrella nodiflora (Linn.) Gaertn. inhibits inflammatory responses through the regulation of Syk in RAW 264.7 macrophages

Synedrella nodiflora (Linn.) Gaertn. (S. nodiflora) has long been used for the treatment of inflammatory diseases, including liver disease, asthma, rheumatism and earache, in tropical countries throughout America, Asia and Africa. However, the biological effects of S. nodiflora have not been extensively studied at the molecular level. Notably, it remains unclear how S. nodiflora exerts anti-inflammatory activity. In the present study, the anti-inflammatory mechanism of a methanol extract of S. nodiflora (MSN) in RAW 264.7 macrophages activated by lipopolysaccharide (LPS) was investigated. Non-cytotoxic concentrations of MSN (≤400 µg/ml) decreased the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), which resulted in a decrease in nitric oxide and prostaglandin E₂ (PGE₂) production. The mRNA expression of pro-inflammatory cytokines such as interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α was reduced upon MSN treatment. In addition, the activation of spleen tyrosine kinase (Syk) and Akt was suppressed by MSN. Taken together, these findings recommend the traditional medicinal application of S. nodiflora in the treatment of several inflammation-associated diseases and indicate the possibility of MSN as a novel therapeutic reagent of inflammation-related diseases.

Anti-inflammatory effects of a novel compound, MPQP, through the inhibition of IRAK1 signaling pathways in LPS-stimulated RAW 264.7 macrophages

Small-molecule inhibitors are widely used to treat a variety of inflammatory diseases. In this study, we found a novel anti-inflammatory compound, 1-[(2R,4S)-2-methyl-4-(phenylamino)-1,2,3,4-tetrahydroquinolin-1-yl]prop-2-en-1-one (MPQP). It showed strong anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. These effects were exerted through the inhibition of the production of NO and pro-inflammatory cytokines, such as interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α). Furthermore, MPQP decreased the expression levels of inducible NO synthase (iNOS) and cyclooxygenase 2 (COX-2). Additionally, it mediated the inhibition of the phosphorylation of p38, c-Jun N-terminal kinase (JNK), the inhibitor of κBα (IκBα), and their upstream kinases, IκB kinase (IKK) α/β, mitogen-activated protein kinase kinase (MKK) 3/6, and MKK4. Furthermore, the expression of IL-1 receptor-associated kinase 1 (IRAK1) that regulates NF-κB, p38, and the JNK signaling pathways, was also increased by MPQP. These results indicate that MPQP regulates the IRAK1-mediated inflammatory signaling pathways by targeting IRAK1 or its upstream factors.

Repression of GRIM19 expression potentiates cisplatin chemoresistance in advanced bladder cancer cells via disrupting ubiquitination-mediated Bcl-xL degradation

OBJECTIVE

The mainstay of treatment for advanced bladder cancer (BC) is cisplatin (CDDP)-based systematic chemotherapy. However, acquired chemoresistance induced by as yet unidentified mechanisms is encountered frequently and often results in treatment failure and disease progression. The present study was designed to elucidate the expression and potential role of the gene associated with retinoid-interferon-induced mortality-19 (GRIM19) in the pathogenesis of CDDP resistance in BC.

METHODS

RT-qPCR and immunoblotting were employed to evaluate the expression profile of GRIM19 in clinical BC samples and in different BC cells. Using cell viability assay, apoptotic ELISA, xenografts mouse model, and Transwell assay, the effects of GRIM19 inhibition or GRIM19 overexpression on CDDP resistance were determined in different BC cells. Lastly, using co-immunoprecipitation, we provided the molecular evidence for the interaction between GRIM19 and Bcl-xL.

RESULTS

Expression levels of GRIM19 were significantly down-regulated in recurrent BC specimens, and in experimentally induced CDDP-resistant BC cells. Functionally, overexpression of the exogenous GRIM19 potentiated CDDP sensitivity and suppressed the survival and invasion of BC cells in the presence of CDDP challenge. Mechanistically, the compromised CDDP chemosensitization induced by GRIM19 loss was at least partially attributed to the attenuation of Bcl-xL polyubiquitination and subsequent degradation, because (1) GRIM19 colocalized with Bcl-xL in the mitochondria of BC cells and (2) GRIM19 overexpression promoted the ubiquitination of Bcl-xL, and this event could be effectively reversed by pretreatment with inhibitors of p38-MAPK and JNK pathways, indicating that GRIM19 overexpression-induced Bcl-xL ubiquitination may achieve in a p38/JNK-dependent manner. Using the UMUC-3 cells stably depleted of endogenous GRIM19, we further show that inhibition of Bcl-xL rectified GRIM19 deficiency-caused CDDP resistance in BC cells. In addition, BCL2L1 mRNA levels were negatively correlated with GRIM19 mRNA levels in CDDP-associated clinical BC tissues.

CONCLUSIONS

Disruption of GRIM19/Bcl-xL is a key mechanism of CDDP resistance in advanced BC. Therapeutically, enhancement of GRIM19 expression or employment of p38/JNK inhibitors may serve as resensitizing therapies for subgroups of CDDP-resistant or refractory BC patients.

Advanced glycation end products induced IL-6 and VEGF-A production and apoptosis in osteocyte-like MLO-Y4 cells by activating RAGE and ERK1/2, P38 and STAT3 signalling pathways

Advanced glycation end products (AGEs) are involved in osteopenia in people with diabetes and the elderly. Interleukin-6 (IL-6) and vascular endothelial growth factor-A (VEGF-A) are potent regulators of bone metabolism, and in bone tissue, osteocytes are an important source of these regulators. However, whether AGEs can directly regulate IL-6 and VEGF-A secretion by osteocytes is unknown. In this study, we evaluated the effect of AGEs on IL-6 and VEGF- A production as well as apoptosis in osteocyte-like MLO-Y4 cells. We also studied the involvement of receptor for advanced glycation end products (RAGE) and the role of extracellular signal-regulated kinases 1 and 2 (ERK1/2), P38 and signal transducer and activator of transcription 3 (STAT3) signalling pathways. We found that 100μg/ml AGEs significantly induced apoptosis and up-regulated the expression of IL-6 and VEGF-A in MLO-Y4 cells. Additionally, AGEs significantly activated the ERK1/2, P38 and STAT3 signalling pathways. The ERK1/2 inhibitor U0126, the P38 inhibitor SB239063 and the STAT3 inhibitor S3I-201 all attenuated the effects of AGEs on MLO-Y4 cell apoptosis and IL-6 and VEGF-A secretion. Moreover, activation of the three signalling pathways was abolished by their respective inhibitors. Additionally, the AGEs-induced effects, including increased apoptosis, up-regulated expression of IL-6 and VEGF-A and activation of the three signalling pathways, were all abolished by pre-treating the osteocytes with the RAGE antagonist FPS-ZM1. Together, these data convince us that AGEs can activate the ERK1/2, P38 and STAT3 signalling pathways via RAGE and that their activation involves the AGEs-induced up-regulation of IL-6 and VEGF-A production as well as apoptosis in osteocytes. These results highlight the role of osteocytes in the regulation of bone metabolism by AGEs.