Acute oral toxicity evaluation of extracts of Hydrocotyle sibthorpioides in wister albino rats as per OECD 425 TG

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Toxicity was studied for Hydrocotyle sibthorpioides.

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LD₅₀ was found to be greater than 2000 mg/kg of body weight.

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Petroleum ether extract showed increase in somatomotor activity for short time.

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Methanolic and aqueous extract exhibited some change in Haematological parameters.

Hydrocotyle sibthorpioides (Family: Apiaceae) is a medicinal plant and is been a part of traditional cuisine. Hence, an acute toxicity study was performed to confirm its safety profile. Female rats (n=5) were randomly divided into 5 groups. One group served as the control and the other groups were been administered with the petroleum ether, chloroform, methanolic and aqueous extract of Hydrocotyle sibthorpioides at 2000 mg/kg body weight. Blood was collected at certain intervals to measure the haematological and biochemical parameters. The vital organs were isolated and preserved for histopathological examinations.

The result suggested that the LD₅₀ of all the extracts are greater than 2000 mg/kg body weight. There was no significant change in body weight, Behaviour, Renal Function test, Liver function test and Lipid profile. In haematological evaluation, there was an increase in RBC count and haemoglobin production post administration of methanolic and aqueous extract. The study suggested that the LD₅₀ of the plant is greater than 2000 mg/kg body weight of rats in all the extracts.

The complete chloroplast genome sequence of Hydrocotyle sibthorpioides (Apiales: araliaceae)

Hydrocotyle sibthorpioides Lam. is a widespread and important Chinese medicinal plant. In this study, we have sequenced the complete chloroplast genome of H. sibthorpioides, which is 152,880 bp in length with large (LSC 84,064 bp) and small (SSC 18,690 bp) single-copy regions separated by a pair of inverted repeats (IRs 25,063 bp) and contains 113 unique genes with 17 genes duplicated in the IR making a total of 130 genes. The phylogenetic analysis strongly supports the position of H. sibthorpioides and indicates it belongs to the Araliaceae family, potential to facilitate a better understanding of population and phylogenetic studies in Apiales.

Protective effect of madecassoside against cognitive impairment induced by D-galactose in mice

This study was designed to investigate the protective effect of madecassoside from Hydrocotyle sibthorpioides against cognitive impairment induced by D-galactose (D-gal) in mice. The result revealed that treatment with madecassoside significantly reversed D-gal-induced learning and memory impairments, as measured by the Morris water-maze test. Studies on the potential mechanisms of this action showed that madecassoside significantly reduced oxidative stress and suppress inflammatory responses via blocking NF-κB and ERK/p38 MAPK pathways. Moreover, madecassoside markedly attenuated the content and deposition of β-amyloid peptide by inducing a decrease in the expression of amyloid protein precursor, β-site amyloid cleaving enzyme-1 and cathepsin B and an increase in the levels of neprilysin and insulin-degrading enzyme. Madecassoside significantly increased the expression of synapse plasticity-related proteins in the hippocampus, such as postsynaptic density 95, long-term potentiation, N-methyl-D-aspartic acid receptors, Ca(2+)/calmodulin-dependent protein kinase II, NMDA receptor subunit 1, protein kinase C, protein kinase A, cAMP-response element binding protein, and brain-derived neurotrophic factor. In addition, madecassoside significantly increased the levels of acetylcholine but decreased cholinesterase activity. In conclusion, the protective effect of madecassoside against d-gal-induced cognitive impairment was mainly due to its ability to reduce oxidative damage, improve synaptic plasticity and restore cholinergic function. These findings suggest that madecassoside can be considered as a potential agent for preventing cognitive impairment.

Isolation and identification of an anti-hepatitis B virus compound from Hydrocotyle sibthorpioides Lam

ETHNOPHARMACOLOGICAL RELEVANCE

Hydrocotyle sibthorpioides (Apiaceae) have been used as a folk remedy for the treatment of fever, edema, detoxication, throat pain, psoriasis and hepatitis B virus infections in China. The aim of this study is to isolate and identify an anti-HBV compound from this herb.

MATERIALS AND METHODS

A compound (saponin) was isolated from the active ethanol extract using bioassay-guided screening. The structure of the saponin was elucidated by spectroscopic methods and compared with published data. The anti-HBV activity of the saponin was evaluated by detecting the levels of HBV antigens, extracellular HBV DNA, nuclear covalent closed circular DNA (cccDNA) and five HBV promoters in HepG2.2.15 cells. In addition, the levels of serum HBsAg/HBeAg, DHBV DNA, ALT/AST and hepatic pathological changes were analyzed in DHBV-infected ducks.

RESULTS

The chemical analysis indicated that the saponin isolated from Hydrocotyle sibthorpioides is asiaticoside. The pharmacodynamics experimental studies showed that asiaticoside effectively suppressed the levels of HBsAg/HBeAg, extracellular HBV DNA and intracellular cccDNA in a dose-dependent manner. Furthermore, experiments demonstrated that asiaticoside markedly reduced viral DNA transcription and replication by inhibiting the activities of core, s1, s2, and X gene promoters. In addition, asiaticoside markedly reduced DHBV replication without any obvious signs of toxicity. The levels of serum DHBV DNA, HBsAg/HBeAg were increased 3 days after drug withdrawal, but the levels rebounded slightly in the asiaticoside treatment groups compared with the 3TC treatment group. Moreover, analysis of the serum ALT/AST levels and the liver pathological changes indicated that asiaticoside could alleviate liver damage.

CONCLUSIONS

Our results show that asiaticoside could efficiently inhibit HBV replication both in vitro and in vivo, and asiaticoside may be a major bioactive ingredient in Hydrocotyle sibthorpioides.