A comparative assessment of acute oral toxicity and traditional pharmacological activities between extracts of Fritillaria cirrhosae Bulbus and Fritillaria pallidiflora Bulbus.

Fritillariae Bulbus ("Beimu" in Chinese) is a famous traditional Chinese medicine used to treat cough, expectoration and asthma for more than 2000 years, which belongs to the Fritillaria genus in Liliaceae family. Bulbs of Fritillaria cirrhosa D.Don (BFC) and bulbs of Fritillaria pallidiflora Schrenk (BFP) are two important drugs of Beimu. Due to the significant similarities in their outward appearance characters and chemical profiles, BFC has often been adulterated with BFP in Chinese Traditional Medicine markets.This study aims to compare the oral acute toxicity and the traditional pharmacological activities including antitussive, expectorant and anti-inflammatory effects between the extract of BFC and BFP, to clear and definite if the BFP can be used as a substitute of the BFC in the application of traditional medicine.The extracts were prepared through refluxing with 80% ethanol solvent. For the acute toxicity tests, graded doses of BFP extracts and the maximum dose of BFC extracts were administered orally to mice. The animals were observed for toxic symptoms and mortality daily for 14 days. For the pharmacological activities tests, graded doses of BFP and BFC extracts were administered orally to mice. To observe the effects relieving cough, expelling phlegm and lessening the ear swelling of BFC extracts and BFP extracts through ammonia liquor inducing cough, phenol red apophlegmating in mice and the xylene-induced auricular swelling of mouse, respectively.

In the acute toxicity study, the LD₅₀ value of BFP in mice was calculated to be 213.57 g/kg body weight, and the maximum feasible dose (MFD) value of BFC in mice was 452.14 g/kg. Histopathological analysis has shown inflammatory cells infiltration and cells edema in liver, multinucleated giant cell proliferation in spleen, perivascular exudate and hemorrhage in lung, glomerulus atrophy in kidney of mice after oral administrations of BFP extracts. But only liver cells edema was observed in BFC group. Both BFC extract and BFP extract significantly increased latent period of cough and inhibited cough frequency in mice induced by ammonia. Besides, the two extracts also obviously enhanced mice's tracheal phenol red output in expectorant assessment and inhibited the development of ear edema in anti-inflammatory evaluation assay.

To summarize, the BFP has the significant similarities in morphological characteristics, chemical profiles and traditional pharmacological activities compared with the BFC. The result of this study provide some valid scientific support for using BFP as a plant substitute of the BFC, but considering the toxicity of BFP is much higher than BFC, we don't recommend long-term oral administration of BFP or exceeding recommended dosage of Chinese Pharmacopoeia 2015.