Protective Effects of Platycodon grandiflorum Aqueous Extract on Thioacetamide-induced Fulminant Hepatic Failure in Mice

Platycodon grandiflorum (Jacq.) A. DC.: A review of phytochemistry, pharmacology, toxicology and traditional use

BACKGROUND

The traditional Chinese medicine Platycodon grandiflorum (Jacq.) A. DC. (PG, balloon flower) has medicinal and culinary value. It consists of a variety of chemical components including triterpenoid saponins, polysaccharides, flavonoids, polyphenols, polyethylene glycols, volatile oils and mineral components, which have medicinal and edible value.

PURPOSE

The ultimate goal of this review is to summarize the phytochemistry, pharmacological activities, safety and uses of PG in local and traditional medicine.

METHODS

A comprehensive search of published literature up to March 2022 was conducted using the PubMed, China Knowledge Network and Web of Science databases to identify original research related to PG, its active ingredients and pharmacological activities.

RESULTS

Triterpene saponins are the primary bioactive compounds of PG. To date, 76 triterpene saponin compounds have been isolated and identified from PG. In addition, there are other biological components, such as flavonoids, polyacetylene and phenolic acids. These extracts possess antitussive, immunostimulatory, anti-inflammatory, antioxidant, antitumor, antiobesity, antidepressant, and cardiovascular system activities. The mechanisms of expression of these pharmacological effects include inhibition of the expression of proteins such as MDM and p53, inhibition of the activation of enzymes, such as AKT, the secretion of inflammatory factors, such as IFN-γ, TNF-α, IL-2 and IL-1β, and activation of the AMPK pathway.

CONCLUSION

This review summarizes the chemical composition, pharmacological activities, molecular mechanism, toxicity and uses of PG in local and traditional medicine over the last 12 years. PG contains a wide range of chemical components, among which triterpene saponins, especially platycoside D (PD), play a strong role in pharmacological activity, representing a natural phytomedicine with low toxicity that has applications in food, animal feed and cosmetics. Therefore, PG has value for exploitation and is an excellent choice for treating various diseases.

Medicinal plants used against hepatic disorders in Bangladesh: A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Liver disease is a major cause of illness and death worldwide which accounts for approximately 2 million deaths per year worldwide, 1 million due to complications of cirrhosis and 1 million due to viral hepatitis and hepatocellular carcinoma. That's why it is seeking the researchers' attention to find out the effective treatment strategies. Phytochemicals from natural resources are the main leads for the development of noble hepatoprotective drugs. The majority of the natural sources whose active compounds are currently employed actually have an ethnomedical use. Ethnopharmacological research is essential for the development of these bioactive compounds. These studies not only provide scientific evidence on medicinal plants utilized for particular therapeutic purposes, but they also ensure cultural heritage preservation. Plenty of experimental studies have been well-documented that the ethnomedicinal plants are of therapeutics' interest for the advanced pharmacological intervention in terms of hepatic disorders.

AIM OF THE STUDY

This study summarizes the processes of hepatotoxicity induced by various toxins and explores identified hepatoprotective plants and their phytoconstituents, which can guide the extraction of novel phytochemical constituents from plants to treat liver injury. This review aimed to summarize the hepatoprotective activity of Bangladeshi medicinal plants where the bioactive compounds may be leads for the drug discovery in future.

MATERIALS AND METHODS

Literature searches in electronic databases, such as Web of Science, Science Direct, SpringerLink, PubMed, Google Scholar, Semantic Scholar, Scopus, BanglaJOL, and so on, were performed using the keywords 'Bangladesh', 'ethnomedicinal plants', 'Hepatoprotective agents' as for primary searches, and secondary search terms were used as follows, either alone or in combination: traditional medicine, medicinal plants, folk medicine, liver, hepatitis, therapeutic uses, and anti-inflammatory. Besides, several books, including the book entitled "Medicinal plants of Bangladesh: chemical constituents and uses" authored by Abdul Ghani, were carefully considered, which contained pharmacological properties and phytoconstituents of many medicinal plants growing and traditionally available in Bangladesh. Among them, the most promising plant species with their latest therapeutic effects against hepatic disorders were deeply considered in this review.

RESULTS

The results of this study revealed that in most cases, therapy using plant extracts stabilized altered hepatic biochemical markers induced by hepatotoxins. Initially, we investigated 32 plant species for hepatoprotective activity, however after extensive literature searching; we observed that 20 plants offer good pharmacological evidence of hepatoprotective function. Consequently, most bioactive compounds derived from the herbs including berberine, thymoquinone, andrographolide, ursolic acid, luteolin, naringenin, genistein, quercetin, troxerutin, morin, epigallocatechin-3-gallate, chlorogenic acid, emodin, curcumin, resveratrol, capsaicin, ellagic acid, etc. are appeared to be effective against hepatic disorders.

CONCLUSIONS

Flavonoids, phenolic acids, monoterpenoids, diterpenoids, triterpenoids, alkaloids, chromenes, capsaicinoids, curcuminoids, and anthraquinones are among the phytoconstituents were appraised to have hepatoprotective activities. All the actions displayed by these ethnomedicinal plants could make them serve as leads in the formulation of drugs with higher efficacy to treat hepatic disorders.

Improved hepatoprotective activity of Beta vulgaris L. leaf extract loaded self-nanoemulsifying drug delivery system (SNEDDS): in vitro and in vivo evaluation

OBJECTIVE

Beta vulgaris L. (beetroot) is a vegetable plant rich in phytochemical compounds such as phenolic acids, carotenoids and flavonoids. The objective of the current study is the development and optimization of self-nanoemulsifying drug delivery systems (SNEDDSs) to enhance the hepatoprotective activity of beet leaf (BL) extract.

METHODS

Total flavonoids content was estimated in the BL extract and its solubility was evaluated in various vehicles to select proper component combinations. Pseudo-ternary phase diagrams were constructed employing olive, linseed, castor and sesame oils (oil phase), Tween^® 20 (Tw20) and Tween^® 80 (Tw80) (surfactants (SAs)) as well as dimethyl sulfoxide (DMSO) and propylene glycol (PG) (co-surfactants (Co-SAs)). Optimization of formulations from the phase diagrams took place through testing their thermodynamic stability, dispersibility and robustness to dilution.

RESULTS

Four optimized BL-SNEDDS formulations, comprising linseed oil or olive oil, Tw80 and DMSO at two SA/Co-SA ratios (2:1 or 3:1) were chosen. They exhibited high cloud point and percentage transmittance values with spherical morphology of mean droplet sizes ranging from 14.67 to 16.06 nm and monodisperse distribution with negatively charged zeta potential < -9.51 mV. The in vitro release profiles of the optimized formulations in pH 1.2 and 6.8 were nearly similar, with a non-Fickian release mechanism. In vivo evaluation of BL-SNEDDSs hepatoprotective activity in a thioacetamide-induced hepatotoxicity rat model depicted promoted liver functions, inflammatory markers and histopathological findings, most prominently in the group treated by F7.

CONCLUSION

The results indicate that SNEDDS, as a nanocarrier system, has potential to improve the hepatoprotective activity of the BL extract.

Xue-fu-Zhu-Yu decoction protects rats against retinal ischemia by downregulation of HIF-1α and VEGF via inhibition of RBP2 and PKM2

BACKGROUND

Retinal ischemia-related eye diseases result in visual dysfunction. This study investigates the protective effects and mechanisms of Xue-Fu-Zhu-Yu decoction (XFZYD) with respect to retinal ischemia.

METHODS

Retinal ischemia (I) was induced in Wistar rats by a high intraocular pressure (HIOP) of 120 mmHg for 1 h, which was followed by reperfusion of the ischemic eye; the fellow untreated eye acted as a control. Electroretinogram (ERG), biochemistry and histopathology investigations were performed.

RESULTS

Significant ischemic changes occurred after ischemia including decreased ERG b-wave ratios, less numerous retinal ganglion cells (RGCs), reduced inner retinal thickness, fewer choline acetyltransferase (ChAT) labeled amacrine cell bodies, increased glial fibrillary acidic protein (GFAP) immunoreactivity and increased vimentin Müller immunolabeling. These were accompanied by significant increases in the mRNA/protein concentrations of vascular endothelium growth factor, hypoxia-inducible factor-1α, pyruvate kinase M2 and retinoblastoma-binding protein 2. The ischemic changes were concentration-dependently and significantly altered when XFZYD was given for seven consecutive days before or after retina ischemia, compared to vehicle. These alterations included enhanced ERG b-wave amplitudes, more numerous RGCs, enhanced inner retinal thickness, a greater number of ChAT immunolabeled amacrine cell bodies and decreased GFAP/vimentin immunoreactivity. Furthermore, decreased mRNA levels of VEGF, HIF-1α, PKM2, and RBP2 were also found. Reduced protein concentrations of VEGF, HIF-1α, PKM2, and RBP2 were also demonstrated. Furthermore, there was an inhibition of the ischemia-associated increased ratios (target protein/β-actin) in the protein levels of VEGF, HIF-1α, PKM2, and RBP2, which were induced by Shikonin, JIB-04 or Avastin.

CONCLUSION

XFZYD would seem to protect against well-known retinal ischemic changes via a synergistic inhibition of RBP2 and PKM2, as well as down-regulation of HIF-1α and a reduction in VEGF secretion.

Protective effect of olive and juniper leaves extracts on nephrotoxicity induced by thioacetamide in male mice

This study, for the first time, evaluates the effect of olive and juniper leaves extracts and their combination on thioacetamide (TAA)-induced nephrotoxicity in male mice. The experimental mice were divided into eight groups. Group 1 was served as control. Group 2 was exposed to TAA. Group 3 was treated with TAA and olive leaves extract. Group 4 was subjected to TAA and juniper leaves extract. Group 5 was exposed to TAA and olive and juniper leaves extracts. Groups 6, 7 and 8 were treated with olive, juniper, and olive and juniper leaves extracts respectively. In mice treated with only TAA, significant increases of blood urea nitrogen and uric acid were observed after six weeks. Moreover, levels of serum creatinine, blood urea nitrogen and uric acid were statistically increased in mice administrated with only TAA for twelve weeks. Insignificant alterations in levels of these haematobiochemical parameters were noted in other treated groups after six and twelve weeks. Histopathological evaluations of renal sections from mice treated with only TAA for twelve weeks showed severe damage of the renal corpuscles. Furthermore, the renal sections from mice treated with TAA and olive leaves extract, TAA and juniper leaves extract, TAA and olive and juniper leaves extracts, olive leaves extract, juniper leaves extract, and olive and juniper leaves extracts showed normal structures. In addition, it is conceivable therefore, that these extracts exhibit protective influences against TAA-induced nephrotoxicity, probably mediated through the antioxidative pathway roles.

Platycodin D isolated from the aerial parts of Platycodon grandiflorum protects alcohol-induced liver injury in mice

Platycodin D (PD) is the main active saponin of Platycodon grandiflorum (PG) and is reported to exhibit multiple biological effects, including anti-tumor, anti-inflammation, and anti-obesity properties.

Aquaporin-4 deletion in mice reduces encephalopathy and brain edema in experimental acute liver failure

Brain edema and associated astrocyte swelling leading to increased intracranial pressure are hallmarks of acute liver failure (ALF). Elevated blood and brain levels of ammonia have been implicated in the development of brain edema in ALF. Cultured astrocytes treated with ammonia have been shown to undergo cell swelling and such swelling was associated with an increase in the plasma membrane expression of aquaporin-4 (AQP4) protein. Further, silencing the AQP4 gene in cultured astrocytes was shown to prevent the ammonia-induced cell swelling. Here, we examined the evolution of brain edema in AQP4-null mice and their wild type counterparts (WT-mice) in different models of ALF induced by thioacetamide (TAA) or acetaminophen (APAP). Induction of ALF with TAA or APAP significantly increased brain water content in WT mice (by 1.6% ± 0.3 and 2.3 ± 0.4%, respectively). AQP4 protein was significantly increased in brain plasma membranes of WT mice with ALF induced by either TAA or APAP. In contrast to WT-mice, brain water content did not increase in AQP4-null mice. Additionally, AQP4-null mice treated with either TAA or APAP showed a remarkably lesser degree of neurological deficits as compared to WT mice; the latter displayed an inability to maintain proper gait, and demonstrated a markedly reduced exploratory behavior, with the mice remaining in one corner of the cage with its head tilted downwards. These results support a central role of AQP4 in the brain edema associated with ALF.

Protective effect of the roots extract of Platycodon grandiflorum on bile duct ligation-induced hepatic fibrosis in rats

The aim of the present study was to evaluate the protective effect of aqueous extract from Platycodon grandiflorum (BC703) on bile duct ligation (BDL)-induced hepatic fibrosis in rats. BDL rats were divided into three groups, which orally received distilled water or BC703 (10 or 50 mg/kg/day) for consecutive 28 days. Antifibrotic effects of BC703 on BDL-induced hepatic fibrosis in rats were estimated by assessing serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), blood urea nitrogen (BUN), transforming growth factor-beta 1 (TGF-β1) and hepatic levels of malondialdehyde (MDA), glutathione (GSH), total superoxide dismutase (SOD) and nitric oxide (NO). The biochemical observations were supplemented by histopathological examination of liver samples stained with hematoxylin and eosin and Masson’s trichrome stain. ALT, AST, TBIL and BUN were elevated in the group treated with BDL alone than in the sham-operated group. These elevations were significantly decreased by BC703 treatment. Hepatic GSH and SOD levels, depressed by BDL, were also increased in the BC703 group. In addition, increases in hepatic MDA and NO levels in the BDL-induced cholestasis were attenuated by BC703 treatment. Furthermore, BC703 treatment significantly reduced the serum level of fibrogenic cytokine, TGF-β1. Histopathological studies further substantiated the protective effect of BC703 on BDL-induced hepatic fibrosis in rat. BC703 may have beneficial effects not only on hepatic fibrosis by cholestasis but also on hepatic fibrosis development in patients with chronic hepatic disease.

Two new oleanane-type triterpenoids from Platycodi Radix and anti-proliferative activity in HSC-T6 cells

Two new oleanane-type triterpenoids, named platycodonoids A and B (1, 2), together with five known saponins, including platycodin D (3), deapioplatycodin D (4), 3-O-β-D-glucopyranosyl polygalacic acid (5), 3-O-β-D-glucopyranosyl platycodigenin (6) and polygalacin D (7), were isolated from the roots of Platycodon grandiflorum. On the basis of spectral data and chemical evidence, the structures of the new compounds were elucidated as 2β,3β,23,24-tetrahydroxy-28-nor-olean-12-en-16-one (1) and 2β,3β,23,24- tetrahydroxy-28-nor-olean-12-en-16-one-3-O-β-D-glucopyranoside (2). Compounds 1-7 were evaluated for their in vitro anti-proliferative activity against the HSC-T6 cell line.

Protective effect of the aqueous extract from the root of Platycodon grandiflorum on cholestasis-induced hepatic injury in mice

CONTEXT

The root of Platycodon grandiflorum (Jacq.) A. DC. (Campanulaceae) has been widely studied for its hepatoprotective effects against various hepatotoxicants.

OBJECTIVE

The present study evaluated the protective effect of the standardized aqueous extract of P. grandiflorum (BC703) on cholestasis-induced hepatic injury in mice.

MATERIALS AND METHODS

BC703 is a standardized aqueous extract of P. grandiflorum in reference to platycodin D (at least 0.8%). The mice were allocated into five groups as follows: Sham-operated, bile duct ligation (BDL) alone, and BDL with BC703 (1, 5, and 10 mg/kg BW) treated group. BC703 was given for 3 consecutive days before BDL operation. The animals were sacrificed by CO₂ anesthesia post-24 h of BDL operations.

RESULTS AND DISCUSSION

Serum alanine aminotransferase and serum aspartate aminotransferase increased to 395.2 ± 90.0 and 266.0 ± 45.6 Unit/L in the BDL alone group and decreased with BC703 in a dose-dependent manner. Especially the 10 mg/kg of BC703-treated mice showed a 77% decrease of serum alanine aminotransferase and 56% of aspartate aminotransferase as compared with BDL alone. Decreased antioxidant enzyme levels in BDL alone group were elevated in BC703-treated groups ranging from 7 to 29% for glutathione and from 13 to 25% for superoxide dismutase. BC703 treatment also attenuated malondialdehyde (from 3 to 32%) and nitric oxide levels (from 32 to 50%) as compared with BDL alone. Histopathological studies further confirmed the hepatoprotective effect of BC703 in BDL-induced cholestesis.

CONCLUSION

BC703 could attenuate liver injury by BDL in mice, and test results indicate that BC703 might be useful in cholestatic liver injury.