Boerhavia diffusa L. ethanol extract suppresses inflammatory responses via inhibition of Src/Syk/TRAF6

Anti-inflammatory effect of Barringtonia angusta methanol extract is mediated by targeting of Src in the NF-κB signalling pathway

CONTEXT

Among the plants in the genus Barringtonia (Lecythidaceae) used as traditional medicines to treat arthralgia, chest pain, and haemorrhoids in Indonesia, Barringtonia racemosa L. and Barringtonia acutangula (L.) Gaertn. have demonstrated anti-inflammatory activity in systemic inflammatory models.

OBJECTIVE

The anti-inflammatory activity of Barringtonia angusta Kurz has not been investigated. We prepared a methanol extract of the leaves and stems of B. angusta (Ba-ME) and systemically evaluated its anti-inflammatory effects in vitro and in vivo.

MATERIALS AND METHODS

RAW264.7 cells stimulated with LPS or Pam3CSK4 for 24 h were treated with Ba-ME (12.5, 25, 50, 100, and 150 µg/mL), and NO production and mRNA levels of inflammatory genes were evaluated. Luciferase reporter gene assay, western blot analysis, overexpression experiments, and cellular thermal shift assay were conducted to explore the mechanism of Ba-ME. In addition, the anti-gastritis activity of Ba-ME (50 and 100 mg/kg, administered twice per day for two days) was evaluated using an HCl/EtOH-induced gastritis mouse model.

RESULTS

Ba-ME dose-dependently suppressed NO production [IC₅₀ = 123.33 µg/mL (LPS) and 46.89 µg/mL (Pam3CSK4)] without affecting cell viability. Transcriptional expression of iNOS, IL-1β, COX-2, IL-6, and TNF-α and phosphorylation of Src, IκBα, p50/105, and p65 were inhibited by Ba-ME. The extract specifically targeted the Src protein by binding to its SH2 domain. Moreover, Ba-ME significantly ameliorated inflammatory lesions in the HCl/EtOH-induced gastritis model.

DISCUSSION AND CONCLUSIONS

The anti-inflammatory activity of Ba-ME is mediated by targeting of the Src/NF-κB signalling pathway, and B. angusta has potential as an anti-inflammatory drug.

Attenuation of oxidative stress and artificial wound closure in C2C12 myoblasts induced by sequential extracts of Boerhavia diffusa

OBJECTIVES

Whole plants of Boerhavia diffusa L. are widely used medicine in Ghana and other tropical countries, for the treatment of wounds and other ailments. The aim of the study was to determine the ability of sequential extracts of B. diffusa to influence oxidation and wound closure in myoblast cells in vitro.

METHODS

Sequential extracts were prepared from the whole plant using four solvents of increasing polarity (hexane, ethyl acetate, methanol and water). Cytotoxicity was determined using the sulforhodamine B staining assay, phase-contrast microscopy, plasDIC microscopy and live-dead staining. Extracts were tested for their ability to reduce 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidation and mediate cell migration after artificial wound generation in C2C12 myoblast cells using the scratch wound assay.

KEY FINDINGS

All extracts indicated negligible cytotoxicity (IC₅₀  > 100 μg/ml), and microscopic evaluation showed no difference from negative controls. AAPH induced a 2.87-fold increase in reactive oxygen species compared to the negative control. Pretreatment with 100 μg/ml of the extracts reduced AAPH-induced oxidation to 1.70-fold of the untreated controls (P < 0.001). Wound closures in the methanol and water extract treatments were 18.08% and 20.76% higher than the negative control, respectively (P < 0.01).

CONCLUSIONS

These findings indicate that the hexane, methanol and water extracts of B. diffusa whole plant promote artificial wound healing and protection against oxidation in vitro and therefore warrant further research into its mechanisms of wound healing.

Safety assessment and attenuation of cisplatin induced nephrotoxicity by tuberous roots of Boerhaavia diffusa

Cisplatin (Cis-diaminedichloroplatinum II) is a chemotherapeutic agent having well documented adverse effect as nephrotoxicity. This study was designed to evaluate the nephroprotective role of Boerhaavia diffusa in cisplatin-induced acute kidney injury. Wistar rats (n = 6) were allocated into six groups constituting normal control, cisplatin-induced, Boerhaavia diffusa root extract in doses 50, 100 and 200 mg/kg and Boerhaavia diffusa per se group, administered orally for a period of ten days. Intraperitoneal injection of cisplatin was administered on day 7, to all groups except normal control and Boerhaavia diffusa per se group. On day 10, cisplatin resulted in substantial nephrotoxicity in Wistar rats with significant (p < 0.001) elevation in serum creatinine and blood urea nitrogen, decline in the concentrations of reduced glutathione and superoxide dismutase, elevation in TNF-α level in renal tissues. Boerhaavia diffusa at a dose of 200 mg/kg body weight significantly (p < 0.001) ameliorates increased in serum creatinine, blood urea nitrogen, oxidative stress and inflammatory markers. In parallel to this, it also exhibits antiapoptotic activity through the reduction of active caspase-3 expression in kidneys. Findings indicate that Boerhaavia diffusa is effective in mitigating cisplatin-induced nephrotoxicity and thus, for this the acute and sub-acute toxicity studies conducted to evaluate the safety profile of Boerhaavia diffusa. The no-observed adverse effect level (NOAEL) of tuberous roots of Boerhaavia diffusa root extract was 1000 mg/kg.

Ethnomedicinal uses, phytochemistry and pharmacological properties of the genus Boerhavia

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Boerhavia is widely distributed in tropical, subtropical and temperate regions of the world including Mexico, America, Africa, Asia, Indian Ocean Islands, Pacific Islands and Australia. The genus Boerhavia is extensively used by local peoples and medicinal practitioners for treatments of hepatitis, urinary disorders, gastro intestinal diseases, inflammations, skin problems, infectious diseases and asthma. Present review focused on traditional uses, phytochemistry, pharmacology and toxicology of Boerhavia genus to support potential scope for advance ethnopharmacological study.

MATERIALS AND METHODS

Information on the Boerhavia species was collected from classical books on medicinal plants, pharmacopoeias and scientific databases like PubMed, Scopus, GoogleScholar, Web of Science and others. Also scientific literatures based on ethnomedicinal surveys, Ph.D. and M.Sc. dissertations, published papers from Elsevier, Taylor and Francis, Springer, ACS as well as Wiley publishers and reports by government bodies and documentations were assessed.

RESULTS

A total of 180 compounds from Boerhavia genus were isolated of which B. diffusa alone shared around 131 compounds and for most of which it is currently an exclusive source. In the genus, phenolic glycosides and flavonoids contribute approximately 97 compounds. These includes eupalitin, rotenoids like boeravinones, coccineons, alkaloid i.e. betanin and punarnavine etc., showing vital pharmaceutical activities such as anticancer, anti-inflammatory, antioxidant and immunomodulatory.

CONCLUSION

Boerhavia is an important genus with wide range of medicinal uses. However, most of the available scientific literatures have lacked relevant doses, duration and positive controls for examining bioefficacy of extracts and its active compounds. In some studies, taxonomic errors were encountered. Moreover, there is need for accurate methods in testing the safety and ethnomedicinal validity of Boerhavia species.