Cynatratoside-C efficacy against theronts of Ichthyophthirius multifiliis, and toxicity tests on grass carp and mammal blood cells

A review of the ethnopharmacology, phytochemistry and pharmacology of Cynanchumatratum

ETHNOPHARMACOLOGICAL RELEVANCE

The dried roots and rhizomes of Cynanchum atratum Bunge is named 'Baiwei' according to traditional Chinese medicine theory. It is also named Cynanchi atrati Radix in Chinese Pharmacopoeia. Cynanchi atrati Radix is famous for its medicinal value of clearing away heat, relieving drenching, detoxifying and treating abscesses. It was commonly used in some Asian countries for the treatment of fever, vasoconstrictive syncope, lymphangitis and other diseases, obviously due to the effect of C₂₁ steroidal glycosides.

THE AIM OF THE REVIEW

The review concentrates on the botany, ethnopharmacology, phytochemistry, pharmacology and toxicology of Cynanchum atratum. We also discuss expectations for prospective research and implementation of this herb.

MATERIALS AND METHODS

Relevant information about C. atratum was gained from ancient books and records, Doctoral and master's Theses, Science Direct, Pubmed, Wiley, CNKI, WanFang DATA, Google Scholar and other domestic and foreign literature. Some electronic databases have been included.

RESULTS

As a member of the Apocynaceae family, C. atratum possesses its up-and-coming biological characteristics. It is widely reported for treating of postpartum fatigue, vomiting, urine drops, nephritis, urinary tract infection, edema, bronchitis and rheumatic low back pain. By now, over 100 compounds have been identified from C. atratum, including C₂₁ steroidal glycosides, acetophenones, alkaloids, volatile oil and other ingredients. Activities such as anti-inflammatory, anti-tumor, anti-virus, antibacterial, anti-forgetful and others have been corroborated in vivo and in vitro. In addition, many of the active ingredients, such as Cynatratoside A, Cynanversicoside A, B, D, G, p-hydroxyacetophenone, 2,4-dihydroxyacetophenone and some volatile oils have been used as quality markers.

CONCLUSION

All kinds of research conducted on C.atratum, especially in field of ethnopharmacological use, phytochemicals and pharmacology have been reviewed. The herb has been used over the years in treating nephritis, urinary tract infection, bronchitis and rheumatic lumbocrural pain. Many studies have been carried out to identify compounds that play a leading role in drug activity. However, the mechanism of drug therapy remains unclear. The evidence used to prove the quality standard of medicinal materials is obviously inadequate. Besides, safety evaluation is necessary for clinical medication. Similarly, the separation of steroidal saponins and the development of new drugs will also need further discussion.

Efficacy and antiparasitic mechanism of 10-gingerol isolated from ginger Zingiber officinale against Ichthyophthirius multifiliis in grass carp

Ichthyophthirius multifiliis is a ciliate parasite of freshwater fish with a global distribution and results in severe economic losses in aquaculture. The present study aimed to investigate the efficacy and antiparasitic mechanism of active compounds isolated from Zingiber officinale against I. multifiliis. Three compounds were isolated from the Z. officinale extract and identified as 10-gingerol, 6-dehydroshogaol, and 6-dehydro-10-gingerol. 10-gingerol demonstrated the greatest antiparasitic efficacy in vitro. 10-gingerol resulted in 100% mortalities of theronts, nonencysted tomonts, and encysted tomonts at concentrations of 2, 8, and 16 mg/L, respectively. 10-gingerol significantly reduced theronts infectivity (p < 0.05) at a concentration of 1 mg/L, and it was effective in treating infected grass carp and protecting naïve fish from I. multifiliis infestation at a concentration of 4 mg/L. The antiparasitic mechanism might be attributed to the increase of intracellular osmotic pressure, accumulation of free radicals, and membrane damage of I. multifiliis post 10-gingerol treatment. The study demonstrated that 10-gingerol had the potential as a therapeutic agent against I. multifiliis.

Antiparasitic efficacy of curcumin from Curcuma longa against Ichthyophthirius multifiliis in grass carp

Ichthyophthirius multifiliis is a ciliated parasite that elicits great economic losses in aquaculture. In the present study, a polyphenol compound, curcumin, was obtained from the rhizome of Curcuma longa by bioassay-guided isolation based on the efficacy of anti-I. multifiliis theronts. Anti-I. multifiliis efficacy of curcumin was evaluated in vitro and in vivo. Curcumin resulted in 100% mortality of I. multifiliis theronts at a concentration of 1mg/L within 21.7±1.2min and killed all tomonts at 8mg/L within 31.0±1.0min. Curcumin at 4mg/L for 16h exposure can completely terminate the reproduction of tomonts. The pretreatment with curcumin at concentrations of 0.5, 0.25, and 0.125mg/L for 2h significantly reduced the infectivity of I. multifiliis theronts. Curcumin at 4mg/L completely cured the infected grass carp and protected naive fish from I. multifiliis infection after 10days exposure. The 4h median effective concentration (EC₅₀) of curcumin to I. multifiliis theronts and the 5h EC₅₀ of curcumin to I. multifiliis tomonts were 0.303mg/L and 2.891mg/L, respectively. The 96h median lethal concentration (LC₅₀) of curcumin to grass carp was 56.8mg/L, which was approximately 187.4 times EC₅₀ of curcumin to theronts and 19.6 times EC₅₀ of curcumin to tomonts. The results demonstrated that curcumin has the potential to be a safe and effective therapeutant for controlling ichthyophthiriasis in aquaculture.