Orostachys japonicus A. Berger (Crassulaceae) Exerts Antidiabetic Activity by Improving Glucose and Lipid Levels in Type 2 Diabetic Mice

Anti-cancer effects of the aqueous extract of Orostachys japonica A. Berger on 5-fluorouracil-resistant colorectal cancer via MAPK signalling pathways in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Orostachys japonica A. Berger, also known as Wa-song in Korea, has traditionally been used as a folk medicine, but the potential anti-cancer effects of aqueous extract of Orostachys japonica (OJe) have not yet been thoroughly investigated.

AIM OF THE STUDY

To evaluate the anti-cancer effects of OJe, its possible mechanisms of action were investigated in 5-fluorouracil (5-FU) resistant SNU-C5/5-FUR colorectal cancer cells.

MATERIALS AND METHODS

The functional compounds of OJe were identified with high performance liquid chromatography. The anti-cancer effects of OJe in SNU-C5/5-FUR cells were investigated by a cell viability assays, flow cytometry analysis, and a subcutaneous xenograft model employing BALB/c-nude mice. Possible signalling pathways were assayed with Western blotting.

RESULTS

OJe (250 μg/ml) showed anti-cancer effects in SNU-C5/5-FUR cells, that were mediated via apoptosis as well as cell cycle arrest at the G0/G1 phase. Gallic acid and (-)-epicatechin, the major functional components of OJe, induced cell cycle arrest. OJe treatment (250 mg/kg, p.o.) produced a significant anti-proliferative effect in the xenograft model via decreased β-catenin/GSK3β and increased p27 expression. OJe treatment significantly activated ERK and p38 both in vitro and in vivo.

CONCLUSIONS

These results suggest that OJe has anti-proliferative effects on 5-FU-resistant colorectal cancer cells via regulation of MAPK signalling pathways.

A comprehensive review of herbacetin: From chemistry to pharmacological activities

ETHNOPHARMACOLOGICAL RELEVANCE

Herbacetin is an active constituent of traditional Chinese medicines such as Ephedra sinica Stapf (MaHuang) and Sedum roseum (L.). Scop. (Hong JingTian). MaHuang was used to treat cough, asthma, fever, and edema for more than 5000 years, while Hong JingTian was used to treat depression, fatigue, cancers, and cardiovascular disease. Recent studies indicate that herbacetin and its glycosides play a critical role in the pharmacological activities of these herbs. However, currently, no comprehensive review on herbacetin has been published yet.

AIM OF THE STUDY

This review aimed to summarize information on the chemistry, natural sources, and pharmacokinetic features of herbacetin, with an emphasis on its pharmacological activities and possible mechanisms of action.

MATERIALS AND METHODS

A literature search was performed on the Web of Science, PubMed, and China Knowledge Resource Integrated databases (CNKI) using the search term "herbacetin" ("all fields") from 1935 to 2020. Information was also obtained from classic books of Chinese herbal medicine, Chinese pharmacopeia, and the database "The Plant List" (www.theplantlist.org). Studies have been analyzed and summarized in this review if they dealt with chemistry, taxonomy, pharmacokinetic, and pharmacological activity.

RESULTS

Herbacetin is distributed in various plants and can be extracted or synthesized. It showed diverse pharmacological activities including antioxidant, antiviral, anti-inflammatory, anticancer, antidiabetic, and anticholinesterase. It is thought to have great potential in cancer treatment, especially colon and skin cancers. However, the bioavailability of herbacetin is low and the toxicity of herbacetin has not been studied. Thus, more studies are required to solve these problems.

CONCLUSIONS

Herbacetin shows promising pharmacological activities against multiple diseases. Future research should focus on improving bioavailability, further studying its pharmacological mechanism, evaluating its toxicity and optimal dose, and performing the clinical assessment. We hope that the present review will serve as a guideline for future research on herbacetin.

Ethanol Extract of Orostachys japonicus A. Berger (Crassulaceae) Protects Against Type 2 Diabetes by Reducing Insulin Resistance and Hepatic Inflammation in Mice

Type 2 diabetes (T2D) is a threaten human health problem, and accompanied by hyperglycemia and disorder of insulin secretion, is a major cause of abnormalities in maintaining blood glucose homeostasis. Also, low-grade inflammation, as well as insulin resistance (IR), is a common feature in patients with T2D. Numerous causes of the outbreak of T2D have been suggested by researchers, who indicate that genetic background and epigenetic predisposition, such as overnutrition and deficient physical activity, hasten the promotion of T2D milieu. Orostachys japonicus A. Berger (O. japonicus) is a herbal and remedial plant whose various activities include hemostatic, antidotal, febrile, and anti-inflammatory. Hence, we designed to evaluate the antidiabetic efficacy of ethanol extracts of O. japonicus (OJE). Six-week-old C57BL/Ksj-db/db (db/db) mice were used. The results showed that mice given various concentrations of OJE (0, 50, 100, and 200 mg/kg per day) for 8 weeks showed significantly reduced hyperglycemia, IR, and liver injury, confirmed by measuring diabetic parameters, serum, and hepatic biochemicals. Furthermore, the treatment of OJE markedly decreased the mRNA levels of proinflammatory cytokines, lipid accumulation, and gluconeogenesis-related genes. Consistently, western blot analysis indicated that mice treated with OJE showed increased levels of phospho-c-Jun N-terminal kinase, phospho-Akt, glucose transporters 2 and 4 (GLUT2 and GLUT4) in T2D mice. Likewise, much the same results were obtained in in vitro experiments. Taken together, OJE had hopeful advantage in sustaining the glucose homeostasis and diminishing IR, and could be a safe alternative remedy for treating T2D.

Orostachys japonicus ethanol extract inhibits 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin lesions in NC/Nga mice and TNF-α/IFN-γ-induced TARC expression in HaCaT cells

The risk of atopic dermatitis (AD)-like skin lesions has increased due to the elevated levels of allergens worldwide. Natural-origin agents, which are effective and safe, show promise for the prevention and treatment of inflammatory conditions. Orostachys japonicus (OJ) A. Berger is an ingredient of traditional herbal medicines for fever, gingivitis, and cancer in Korea, China, and Japan. However, the effect of OJ on AD-like skin lesions is unknown. Therefore, we investigated the effect of OJ ethanol extract (OJEE) on AD-like skin symptoms in mice and cells. OJEE reduced the 2,4-dinitrochlorobenzene-induced AD severity, serum levels of IgE and TARC, and mRNA levels of TARC, TNF-α, and IL-4 in NC/Nga mice. Histopathological analysis showed that OJEE reduced the thickness of the epidermis/dermis and dermal infiltration of inflammatory cells in ear tissue. Furthermore, OJEE suppressed the TNF-α/IFN-γ-increased TARC mRNA level by inhibiting NF-κB and STAT1 activation in HaCaT cells. Taken together, our findings show that OJEE reduced the risk of AD-like skin symptoms by decreasing TARC expression via inhibiting NF-κB and STAT1 activation in skin keratinocytes and thus shows promise as an alternative therapy for AD-like skin lesions.