Two new bioactive oleanane triterpene glycosides from Terminalia arjuna

Therapeutic potential and industrial applications of Terminalia arjuna bark

ETHNOPHARMACOLOGICAL RELEVANCE

Terminalia arjuna (Roxb. ex DC.) Wight & Arnot (Combretaceae) is one of the most frequently used medicinal trees in Indian traditional medicinal systems. It is used for the treatment of a variety of diseases including cardiovascular disorders.

AIM OF THE STUDY

The purpose of this review was to provide a comprehensive overview of the phytochemistry, medicinal uses, toxicity, and industrial applications of T. arjuna bark (BTA), as well as to identify gaps in research and applications of this important tree. It also aimed to analyze trends and future research paths to utilize the full potential of this tree.

MATERIALS AND METHODS

Extensive bibliographic research on the T. arjuna tree was carried out using scientific research engines and databases such as Google Scholar, PubMed, and Web of Science, covering all relevant English-language articles. The database "World Flora Online (WFO)" (http://www.worldfloraonline.org) was used to confirm plant taxonomy.

RESULTS

To date, BTA has been traditionally employed for several disorders such as snakebites, scorpion stings, gleets, earaches, dysentery, sexual disorders, and urinary tract infections along with the cardioprotective activity. About 38 phytocompounds were identified from BTA and were classified as triterpenoids, tannins, flavonoids, and glycosides. A wide range of in vitro and in vivo pharmacological effects of BTA were reported such as anti-cancer, antimicrobial, antiviral, anti-inflammatory, antioxidant, hepatoprotective, anti-allergic, anti-diabetic, and wound healing activities. The oral administration of BTA (500 mg/kg) per day did not result in any toxicity in humans. The in vivo acute and sub-acute toxicity analysis of the methanol extract of BTA and one of its major compounds, 7-methyl gallate, did not produce any adverse effects up to a dose of 1000 mg/kg.

CONCLUSIONS

This comprehensive review highlights various aspects of traditional knowledge, phytochemicals, and pharmacological significance of BTA. The review covered safety information on employing BTA in pharmaceutical dosage forms. Despite its long history of medicinal benefit, more studies are needed to understand the molecular mechanisms, structure-activity relationship, and potential synergistic and antagonistic effects of its phytocompounds, drug administration, drug-drug interactions, and toxicological effects.

Isolation of two new triterpene glycoside from the fruits of Terminalia arjuna and their in vitro and in silico studies

Two new triterpene glycoside, Arjunoglycoside VI (1) and Arjunursglycoside I (2) alone with five previously known analogues (3-7) were isolated from methanolic extract of the fruits of Terminalia arjuna. The structures were elucidated by extensive spectroscopic studies (1 D and 2 D NMR and mass). Compound 1 and 2 showed moderate activity on α-chymotrypsin enzyme inhibition with IC₅₀ values 53.8 ± 1.39 and 64.27 ± 1.27 µg/mL respectively. Molecular docking was performed for compound 1 and 2 with the 1CGI co crystals of α-chymotrypsin enzyme protein of Bovine from protein data bank showed -7.7 and -7.6 kcal/mol binding energy, respectively.

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.

Structural elucidations and spectral assigments of two novel triterpene glycosides from Cephalaria paphlagonica

Two novel triterpene glycosides, paphlagonoside A (1) and B (2), were characterised as 28-O-[beta-D-glucopyranosyl(1 --> 2)-alpha-L-arabinopyranosyl(1 --> 4)-beta-D-glucopyranosyl]-hederagenin (1) and 28-O-[beta-D-xylopyranosyl(1 --> 4)-alpha-L-rhamnopyranosyl(1 --> 3)-beta-D-xylopyranosyl (1 --> 6)-beta-D-glucopyranosyl(1 --> 2)-beta-D-glucopyranosyl]-hederagenin (2) from Cephalaria paphlagonica (Dipsacaceae). In addition to these, a common natural product (hederagenin) (3) was also isolated. The structures of all compounds were identified by spectroscopic and chemical methods. The antimicrobial and antioxidant activities of the plant extracts were examined by MIC and DPPH activity methods, respectively.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids including squalene derivatives, protostanes, lanostanes, holostanes, cycloartanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, lupanes, oleananes, friedelanes, ursanes, hopanes, isomalabaricanes and saponins; 574 references are cited.