Triterpene glycoside from Terminalia arjuna

Perspective of Secondary Metabolites in Respect of Multidrug Resistance (MDR): A Review

Aberrant and haphazard use of antibiotics has created the development of antimicrobial resistance which is a bizarre challenge for human civilization. This emerging crisis of antibiotic resistance for microbial pathogens is alarming all the nations posing a global threat to human health. It is difficult to treat bacterial infections as they develop resistance to all antimicrobial resistance. Currently used antibacterial agents inhibit a variety of essential metabolic pathways in bacteria, including macro-molecular synthesis (MMS) pathways (e.g. protein, DNA, RNA, cell wall) most often by targeting a specific enzyme or subcellular component e.g. DNA gyrase, RNA polymerase, ribosomes, transpeptidase. Despite the availability of diverse synthetic molecules, there are still many complications in managing progressive and severe antimicrobial resistance. Currently not even a single antimicrobial agent is available for which the microbes do not show resistance. Thus, the lack of efficient drug molecules for combating microbial resistance requires continuous research efforts to overcome the problem of multidrug-resistant bacteria. The phytochemicals from various plants have the potential to combat the microbial resistance produced by bacteria, fungi, protozoa and viruses without producing any side effects. This review is a concerted effort to identify some of the major active phytoconstituents from various medicinal plants which might have the potential to be used as an alternative and effective strategy to fight against microbial resistance and can promote research for the treatment of MDR.

Antibacterial and Anti-Inflammatory Potential of Polyherbal Formulation Used in Chronic Wound Healing

Objective

Polyherbal formulations Jathyadi Thailam and Jatyadi Ghritam (JT) are used in Indian traditional medicine for diabetic chronic wounds, fistula, fissure, eczema, and burn management. We aimed to investigate the antibacterial and anti-inflammatory properties of crude hexane and ethanol extracts of JT formulations.

Methods

Antibacterial activity of JT extracts was tested to estimate minimum inhibitory concentrations (MICs) against nine reference bacterial strains, including one methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant (MDR) Pseudomonas aeruginosa, and clinical strains of methicillin-susceptible S.aureus (MSSA), all involved in diabetic foot infection. The anti-inflammatory activity of plant extracts was evaluated in LPS-treated macrophage cells by measuring the mRNA levels and secretion of inflammatory mediators.

Results

The antibacterial activity of JT extracts was higher against Gram (+) bacteria, with the MICs varying from 1.95 to 62.5 mg/mL. Gram (−) bacteria were only susceptible to ethanol extracts of JT. Plant extracts were found to be the most active against the reference and clinical strains of MSSA, MRSA, and biofilm-forming S. epidermidis. JT extracts efficiently inhibited in a dose-dependent manner the mRNA expression and protein secretion of proinflammatory cytokines IL-6 and IL-1β, and chemokines MCP-1 and CXCL10 in LPS-challenged macrophages.

Conclusion

In the present study, we have shown that extracts of JT formulations possess potent antibacterial and anti-inflammatory properties that could be involved in chronic wound healing activity and has the potential to be used as external add-on therapy in the management of multidrug-resistant bacterial infections at the wound.

The Genus Terminalia (Combretaceae): An Ethnopharmacological, Phytochemical and Pharmacological Review

Terminalia Linn, a genus of mostly medium or large trees in the family Combretaceae with about 250 species in the world, is distributed mainly in southern Asia, Himalayas, Madagascar, Australia, and the tropical and subtropical regions of Africa. Many species are used widely in many traditional medicinal systems, e.g., traditional Chinese medicine, Tibetan medicine, and Indian Ayurvedic medicine practices. So far, about 39 species have been phytochemically studied, which led to the identification of 368 compounds, including terpenoids, tannins, flavonoids, phenylpropanoids, simple phenolics and so on. Some of the isolates showed various bioactivities, in vitro or in vivo, such as antitumor, anti HIV-1, antifungal, antimicrobial, antimalarial, antioxidant, diarrhea and analgesic. This review covers research articles from 1934 to 2018, retrieved from SciFinder, Wikipedia, Google Scholar, Chinese Knowledge Network and Baidu Scholar by using "Terminalia" as the search term ("all fields") with no specific time frame setting for the search. Thirty-nine important medicinal and edible Terminalia species were selected and summarized on their geographical distribution, traditional uses, phytochemistry and related pharmacological activities.

Medicinal properties of Terminalia arjuna (Roxb.) Wight & Arn.: A review

Medicinal plants have been a main source of therapeutic agents from ancient time to cure diseases. Terminalia arjuna (Roxb.) Wight & Arn. (T. arjuna) is one of the most accepted and beneficial medicinal plants in indigenous system of medicine for the treatment of various critical diseases. This comprehensive review provides various aspects of its ethnomedical, phytochemical, pharmacognostical, pharmacological and clinical significance to different diseases particularly in cardiovascular conditions. This plant has a good safety outline when used in combination with other conventional drugs. This review highlights various medicinal properties of T. arjuna through different studies such as antioxidant, hypotensive, anti-atherogenic, anti-inflammatory, anti-carcinogenic, anti-mutagenic and gastro-productive effect.

Terminalia arjuna in coronary artery disease: ethnopharmacology, pre-clinical, clinical & safety evaluation

ETHNOPHARMACOLOGICAL RELEVANCE

Terminalia arjuna (Roxb.) Wight & Arn. is one of the most popular and beneficial medicinal plants in indigenous system of medicine for the treatment of cardiovascular diseases. This comprehensive review provides latest updates on traditional use, phytochemistry, pharmacological and toxicological data, clinical efficacy and safety of Terminalia arjuna as well as outlined strategies for future research and development to scientifically validate the therapeutic potential of this plant.

MATERIALS AND METHODS

Information about Terminalia arjuna was collected via a systematic electronic and library search of various indexed and non-indexed journals, some local books and varied articles published on ethnopharmacology, phytochemistry and traditional uses. Various pre-clinical (2000-2014) and clinical studies (1990-2014) have also been considered regarding efficacy and safety profile of Terminalia arjuna.

RESULTS

Evidence from various in vitro, in vivo and clinical trials reveal the pleiotropic effects of Terminalia arjuna such as anti-atherogenic, hypotensive, inotropic, anti-inflammatory, anti-thrombotic and antioxidant actions for treatment of various cardiovascular disorders. It is clearly documented that this plant has a good safety profile when used in conjunction with other conventional drugs. However, there is a paucity of data regarding the exact molecular mechanism of its action, appropriate form of drug administration, whether whole crude drug or aqueous or alcoholic extract should be used, toxicological studies and its interaction with other drugs.

CONCLUSIONS

In conclusion, this review highlights the importance as well as pleiotropic actions and functional aspects of Terminalia arjuna especially in cardiovascular diseases. Though, various pharmacological studies and clinical trials support its benefit in the CVD as per traditional use, new clinical trials using more rigorous state of the art technology and in a larger population setup are warranted to assess the traditional putative efficacy of Terminalia arjuna.

Effect of Chinese Medicine Danshen and Indian Ayurvedic Medicine Bark of Arjuna Tree on a Relatively New LOCI Digoxin Assay for Application on the Vista 1500 Analyzer

BACKGROUND

Danshen is a traditional Chinese medicine and bark of Arjuna tree is an Ayurvedic medicine both indicated as heart tonic. Interference of Danshen in serum digoxin immunoassays has been reported but potential interference of extract of bark of Arjuna tree has not been reported. We studied potential interferences of Danshen and bark of Arjuna tree on a relatively new LOCI digoxin assay for application on the Vista 1500 analyzer (Siemens Diagnostics).

METHODS

Aliquots of drug-free serum were supplemented with ethyl acetate extract of Danshen (two different brands studied) or aqueous or ethyl alcohol extract of bark of Arjuna tree and apparent digoxin concentrations were measured by the LOCI digoxin assay. In another experiment, aliquots of serum pool containing digoxin were further supplemented with Danshen or bark of Arjuna tree extract and digoxin concentrations were measured again using LOCI digoxin assay.

RESULTS

Little apparent digoxin concentration was observed when aliquots of drug-free serum pools were supplemented with Danshen or bark of Arjuna tree extract. When aliquots of serum digoxin pool were further supplemented with these extract, we observed statistically significant negative interference but such differences may not be clinically significant.

CONCLUSION

We conclude that LOCI digoxin assay is virtually free from interferences of Danshen and extract of bark of Arjuna tree.

Synthesis and biological evaluation of oleanolic acid derivatives as antitumor agents

Derivatives of oleanolic acid were synthesized and evaluated in vitro for their growth inhibition against human hepatocellular carcinoma cell line (HepG2) and colon cancer cell line (Col-02). Several derivatives exhibited moderate-to-good inhibitory activity, with 3 displaying the most promising inhibition [GI₅₀ = 1.75 μM (HepG2), 0.71 μM (Col-02)]. Structure-activity relationship analyses of these derivatives demonstrated that a 1-en-2-cyano-3-oxo in ring A and a nitro at C-17 were important in retention of the inhibition against HepG2 and Col-02 cells.

Anti-tumor activity of a 3-oxo derivative of oleanolic acid

Oleanolic acid (3beta-hydroxy-olea-12-en-28-oic acid, OA) exists widely in plant kingdom and possesses various pharmacological activities. In recent years, it was found that it had marked anti-tumor effects and exhibited cytotoxic activity towards many cancer cell lines in culture. In this article, the anti-tumor and differentiation-inducing effects of a derivative of OA modified at C-3, 3-oxo oleanolic acid (3-oxo-olea-12-en-28-oic acid, 3-oxo-OA, 3-7-1) was reported. In vitro, 3-7-1 were found to inhibit significantly the growth of cancer cells derived from different tissues. And 3-7-1 had inhibitory effect on melanoma in vivo. This selection may relate to the differentiation induced by 3-7-1. The inhibition of 3-7-1 on B16-BL6 suggests that 3-7-1 may be a useful anti-cancer agent for melanoma.

Effects of ursolic acid and oleanolic acid on human colon carcinoma cell line HCT15

AIM

Ursolic acid (UA) and oleanolic acid (OA) are triperpene acids having a similar chemical structure and are distributed wildly in plants all over the world. In recent years, it was found that they had marked anti-tumor effects. There is little literature currently available regarding their effects on colon carcinoma cells. The present study was designed to investigate their inhibitory effects on human colon carcinoma cell line HCT15.

METHODS

HCT15 cells were cultured with different drugs. The treated cells were stained with hematoxylin-eosin and their morphologic changes observed under a light microscope. The cytotoxicity of these drugs was evaluated by tetrazolium dye assay. Cell cycle analysis was performed by flow cytometry (FCM). Data were expressed as means +/-SEM and Analysis of variance and Student' t-test for individual comparisons.

RESULTS

Twenty-four to 72 h after UA or OA 60 micromol/L treatment, the numbers of dead cells and cell fragments were increased and most cells were dead at the 72nd hour. The cytotoxicity of UA was stronger than that of OA. Seventy-eight hours after 30 micromol/L of UA or OA treatment, a number of cells were degenerated, but cell fragments were rarely seen. The IC(50) values for UA and OA were 30 and 60 micromol/L, respectively. Proliferation assay showed that proliferation of UA and OA-treated cells was slightly increased at 24h and significantly decreased at 48 h and 60 h, whereas untreated control cells maintained an exponential growth curve. Cell cycle analysis by FCM showed HCT15 cells treated with UA 30 and OA 60 for 36 h and 72 h gradually accumulated in G(0)/G(1) phase (both drugs P<0.05 for 72 h), with a concomitant decrease of cell populations in S phase (both drugs P<0.01 for 72 h) and no detectable apoptotic fraction.

CONCLUSION

UA and OA have significant anti-tumor activity. The effect of UA is stronger than that of OA. The possible mechanism of action is that both drugs have an inhibitory effect on tumor cell proliferation through cell-cycle arrest.