Inhibitory effect of Eucommia ulmoides Oliv. on oxidative DNA damage in lymphocytes induced by H2O2

Cytoprotective, antimutagenic/antirecombinogenic and antibacterial properties of Lallemantia iberica extracts

BACKGROUND

Plants have important chemical compounds to protect organisms from many mutagens but they may also have dangerous toxic substances that must be tested before use. Lallemantia iberica has been used by local people for treatment of some diseases but it was never tested for its cell protective and antimutagenic/antirecombinogenic properties. In this study, it was aimed to determine the cytoprotective, antimutagenic/antirecombinogenic, antibacterial, antioxidant and phenolic profile of L. iberica by MTS assay, micronucleus test/somatic mutation recombination test (SMART), disc diffusion method, ABTS/DPPH tests and liquid chromatography (LC), respectively.

RESULTS

MTS assay results showed that both of the extracts supported the normal growth of healthy human lymphocytes and there was no significant difference between extracts. Although there was no significant increase in micronucleus concentration (‰) of the cultures treated with ethanol or methanol extracts, methanol extract caused slightly lower micronucleus concentration (12.64 ± 3.65‰) than the ethanol extract (24.46 ± 4.50‰). SMART results showed that ethanol and methanol extracts prevented harmful mitotic recombination. Lallemantia iberica also showed antibacterial activity against all of the strains tested, and the largest inhibition zones were observed with Pseudomonas aeruginosa (17.9 mm) and Enterobacter aerogenes (13.8 mm). Methanol extracts showed better antioxidant activities (ABTS IC₅₀ : 104.07 μg mL^-1 , DPPH IC₅₀ : 58.8 μg mL^-1 ) than ethanol extracts (ABTS IC₅₀ : 344.03 μg mL^-1 , DPPH IC₅₀ : 233.7 μg mL^-1 ). According to the LC results, the most abundant phenolic compounds were rutin hydrate (1796.4 ± 62.9 mg kg^-1 ) and p-coumaric acid (228.1 ± 7.60 mg kg^-1 ).

CONCLUSION

Lallemantia iberica extracts had cell-protective, antimutagenic/antirecombinogenic, antibacterial and strong antioxidant characteristics in relation to their rich phenolic content. © 2022 Society of Chemical Industry.

Potential therapeutic effects and applications of Eucommiae Folium in secondary hypertension

Eucommiae Folium (EF), a traditional Chinese medicine, has been used to treat secondary hypertension, including renal hypertension and salt-sensitive hypertension, as well as hypertension caused by thoracic aortic endothelial dysfunction, a high-fat diet, and oxidized low-density lipoprotein. The antihypertensive components of EF are divided into four categories: flavonoids, iridoids, lignans, and phenylpropanoids, such as chlorogenic acid, geniposide acid and pinoresinol diglucoside. EF regulates the occurrence and development of hypertension by regulating biological processes, such as inhibiting inflammation, regulating the nitric oxide synthase pathway, reducing oxidative stress levels, regulating endothelial vasoactive factors, and lowering blood pressure. However, its molecular antihypertensive mechanisms are still unclear and require further investigation. In this review, by consulting the relevant literature on the antihypertensive effects of EF and using network pharmacology, we summarized the active ingredients and pharmacological mechanisms of EF in the treatment of hypertension to clarify how EF is associated with secondary hypertension, the related components, and underlying mechanisms. The results of the network pharmacology analysis indicated that EF treats hypertension through a multi-component, multi-target and multi-pathway mechanism. In particular, we discussed the role of EF targets in the treatment of hypertension, including epithelial sodium channel, heat shock protein70, rho-associated protein kinase 1, catalase, and superoxide dismutase. The relevant signal transduction pathways, the ras homolog family member A (RhoA)/Rho-associated protein kinase (ROCK) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase/eNOS/NO/Ca²⁺ pathways, are also discussed.

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Eucommiae Folium (EF) treats secondary hypertension via the RhoA/ROCK1 and NO/sGC/cGMP pathways.

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EF inhibits oxidative stress and improves endothelial dysfunction to treat hypertension.

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EF's antihypertensive components are phenylpropanoids, flavonoids, lignans, iridoids.

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KEGG analysis showed EF treated hypertension through the MAPK and TNF signaling pathways.

Mechanism of the Inhibitory Effects of Eucommia ulmoides Oliv. Cortex Extracts (EUCE) in the CCl 4 -Induced Acute Liver Lipid Accumulation in Rats

Eucommia ulmoides Oliv. (EU) has been used for treatment of liver diseases. The protective effects of Eucommia Ulmoides Oliv. cortex extracts (EUCE) on the carbon tetrachloride- (CCl4-) induced hepatic lipid accumulation were examined in this study. Rats were orally treated with EUCE in different doses prior to an intraperitoneal injection of 1 mg/kg CCl4. Acute injection of CCl4 decreased plasma triglyceride but increased hepatic triglyceride and cholesterol as compared to control rats. On the other hand, the pretreatment with EUCE diminished these effects at a dose-dependent manner. CCl4 treatment decreased glutathione (GSH) and increased malondialdehyde (MDA) accompanied by activated P450 2E1. The pretreatment with EUCE significantly improved these deleterious effects of CCl4. CCl4 treatment increased P450 2E1 activation and ApoB accumulation. Pretreatment with EUCE reversed these effects. ER stress response was significantly increased by CCl4, which was inhibited by EUCE. One of the possible ER stress regulatory mechanisms, lysosomal activity, was examined. CCl4 reduced lysosomal enzymes that were reversed with the EUCE. The results indicate that oral pretreatment with EUCE may protect liver against CCl4-induced hepatic lipid accumulation. ER stress and its related ROS regulation are suggested as a possible mechanism in the antidyslipidemic effect of EUCE.

Eucommia ulmoides Oliv. Bark. protects against hydrogen peroxide-induced neuronal cell death in SH-SY5Y cells

ETHNOPHARMACOLOGICAL RELEVANCE

Eucommia ulmoides Oliv. Bark. (EUE), has commonly been used to fortify the muscles and lungs, lower blood pressure, prevent miscarriage, improve the tone of liver and kidneys, and promote longevity the traditional tonic medicines of Korea, China, and Japan.

AIM OF THE STUDY

In this study, we investigated that the neuroprotective activities and possible mechanisms of EUE aqueous extract in hydrogen peroxide (H(2)O(2))-induced neuronal cell death in human SH-SY5Y neuroblastoma cells.

MATERIAL AND METHOD

We examined the effects of EUE against H(2)O(2)-induced cytotoxicity, DNA condensation, the production of reactive oxygen species (ROS), loss of mitochondria membrane potential (MMP), the proteolysis of cleaved poly-ADP-ribose polymerase (PARP), and the expression of Bcl-2, Bcl-xL, cleaved caspase-3, and release of cytochrome c. Moreover, we attempted to determine whether EUE suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase 1/2 (ERK 1/2), and phosphoinositide 3-kinase (PI3K)/Akt.

RESULTS

Pretreatment with EUE increased cell viability and inhibited cytotoxicity and DNA condensation. EUE also attenuated the increase in ROS production and MMP reduction. Western blot data revealed that EUE inhibited H(2)O(2)-induced up- or down-regulation of cleaved PARP, cleaved caspase-3, Bcl-2, and Bcl-xL. The EUE inhibited release of cytochrome c from mitochondria to the cytosol, and significantly attenuated H(2)O(2)-induced phosphorylation of JNK, p38 MAPK, ERK 1/2, and PI3K/Akt.

CONCLUSION

The potent neuroprotective capacity of EUE, shown in these experiments, may potentially be applied in the prevention or treatment of neurodegenerative diseases such as Alzheimer's disease (AD).

Eucommia ulmoides Oliv. antagonizes H2O2-induced rat osteoblastic MC3T3-E1 apoptosis by inhibiting expressions of caspases 3, 6, 7, and 9

Eucommia ulmoides Oliv. (EuO), also known as Duzhong, native to China, has been reported to have antioxidative function, but its cellular mechanism is not fully examined yet. We investigated inhibitory effects of EuO leaf ethanol extracts on H(2)O(2)-induced apoptosis in rat osteoblastic MC3T3-E1 cells and underlying mechanisms. Locally-grown Duzhong leaves were extracted with ethanol. MC3T3-E1 cells were treated with EuO (6.25, 12.5, 25, 50, and 100 µg/ml) for 24 h, and then H(2)O(2) (800 µmol/L) for an additional 24 h. Cell survival rate, percentage of apoptosis, and expressions of caspases 3, 6, 7, and 9 were examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, microscopic analysis, Western blotting, and reverse transcription polymerase chain reaction (RT-PCR). The final EuO leaf ethanol extract powder was detected to contain caffeotannic acid at 58 mg/g and geniposide at 3.45 mg/g by high performance liquid chromatography (HPLC). EuO remarkably restrained cell oxidative damage and increased cell survival rate in a dose-dependent manner: 0 µg/ml, 0.21; 6.25 µg/ml, 0. 28; 12.5 µg/ml, 0.31; 25 µg/ml, 0.48; 50 µg/ml, 0.54; and 100 µg/ml, 0.66 (P<0.05), with the half-effective concentration being around 25 µg/ml. MTT results were confirmed by microscopic analysis. Western blotting and RT-PCR analyses showed that the expressions of caspases 3, 6, 7, and 9 were significantly decreased in the EuO-treated cells compared with the control (EuO- and H(2)O(2)-free) (P<0.05), with the half-effective concentration of EuO ranging from 12.5 to 25 µg/ml. We conclude that the ethanol-extracted EuO leaf extracts promoted the growth of MC3T3-E1 cells, and suppressed the H(2)O(2)-induced apoptosis in a rat MC3T3-E1 osteogenic cell model, likely due to the inhibition of caspases' activities. The results indicate that EuO is a potent antioxidant, which may contribute to its many cellular protective functions, including the promotion of bone growth.

Du-Zhong (Eucommia ulmoides Oliv.) cortex extract prevent OVX-induced osteoporosis in rats

Du-Zhong, rich in polyphenolic compounds such as lignans, phenolic acid, and flavonoids, is a kidney-tonifying herbal medicine with a long history of safe use for treatment of bone fractures and joint diseases in China. In the present study, we examined whether Du-Zhong cortex extract (DZCE) with graded doses exerted its preventive effects on estrogen deficiency-induced osteoporosis. Eighty 3-month-old female Sprague-Dawley rats were used and randomly assigned into sham-operated group (Sham) and five ovariectomy (OVX) subgroups, i.e. OVX with vehicle (OVX); OVX with 17alpha-ethinylestradiol (E(2), 25 microg/kg/day); OVX with DZCE of graded doses (100, 300, or 500 mg/kg/day). Daily oral administration of DZCE or E(2) started on week 4 after OVX for 16 weeks. Treatment with DZCE at higher doses (300 or 500 mg/kg/day) was found to be able to significantly prevent OVX-induced decrease in biomechanical quality of femur such as maximum stress and Young's modulus. The mechanical changes were associated with the prevention of a further bone mineral density (BMD) decrease or even with some improvements in microarchitecture. DZCE dose-dependently inhibited total BMD decrease in the femur caused by OVX, which was accompanied by a significant decrease in skeletal remodeling, as was evidenced by the decreased levels of the bone turnover markers osteocalcin (OC), alkaline phosphatese (ALP), deoxypyridinoline (DPD), and urinary Ca and P excretions. muCT analysis of the femoral metaphysis showed that DZCE at the highest doses (500 mg/kg/day) significantly prevents decrease in bone volume/tissue volume (BV/TV), connect density (Conn.D), trabecula number (Tb.N) and trabecula thickness (Tb.Th), and increase in trabecula separation (Tb.Sp) and structure model index (SMI) in OVX rats. We conclude that 16 weeks of DZCE treatment improves bone biomechanical quality through modifications of BMD, and trabecular microarchitecture without hyperplastic effect on uterus, and it might be a potential alternative medicine for treatment of postmenopausal osteoporosis.

Antioxidant protection of edible oils

The ability of different cooking oils to withstand oxidation was investigated in relation to their native antioxidant capacity [measured as the Ferric Reducing/Antioxidant Power (FRAP) value]. The antiperoxidation effect of the presence of the Chinese herbs, du-zhong (Cortex Eucommia ulmoides) and ginseng (Panax ginseng C.A. Mayer) in corn oil was also investigated over 26 days' storage at 55 degrees C. Results showed that sesame oil had the highest FRAP value (803 microM), followed by canola oil (400 microM), and sunflower, peanut, corn and olive oils (100-153 microM). Oils with higher intrinsic antioxidant content showed higher resistance to oxidation, although this was not statistically significant. Corn oil to which was added the herbs du-zhong, ginseng or both had increased resistance to oxidation (conjugated diene level and lipid peroxide formation) over 26 days. FRAP values of the oil/herb mixtures decreased during this time, implying utilisation of herbal antioxidants. Results have implications for increasing the shelf-life and usage time of cooking oils by addition of herbs which can increase resistance of the oil to oxidation. Results have implications also for health, as it is possible that ingestion of these herbs could increase resistance of polyunsaturated fatty acids of cell membranes and lipoproteins to oxidation within the body.

Du-Zhong (Eucommia ulmoides Oliv.) leaves inhibits CCl4-induced hepatic damage in rats

The protective effects of water extract of Du-Zhong (Eucommia ulmoides Oliv.) leaves (WEDZ) and its active compound (protocatechuic acid; PCA) on liver damage were evaluated by carbon tetrachloride (CCl4)-induced chronic hepatotoxicity in rats. Wistar rats were orally treated with WEDZ (0.1, 0.5, and 1.0 g/kg bw) or PCA (0.1 g/kg bw) with administration of CCl4 (0.5 ml/rat, 20% CCl4 in olive oil) for 28 consecutive days. It showed that CCl4-treated rats increased the relative organ weights of liver and kidney. CCl4-induced rats liver damage and significantly (p<0.05) increased the GOT, GPT, LDH and ALP levels in serum as compared with the control group. Treatment with WEDZ or PCA could decrease the GOT, GPT, LDH and ALP levels in serum when compared with CCl4-treated group. CCl4-treated rats also significantly (p<0.05) decreased the GSH content in liver and trolox equivalent antioxidant capacity (TEAC) in serum whereas increased (p<0.05) MDA content in liver as compared with the control group. Treatment with WEDZ or PCA also significantly (p<0.05) increased the GSH content and significantly (p<0.05) decreased the MDA content in liver. Administration of WEDZ or PCA could increase the activities of GPx, GRd and GST in liver. Liver histopathology showed that WEDZ or PCA reduced the incidence of liver lesions including hepatic cells cloudy swelling, lymphocytes infiltration, cytoplasmic vacuolization, hepatic necrosis and fibrous connective tissue proliferated induced by CCl4 in rats. The data suggest that oral administration with WEDZ for 28 consecutive days significantly decrease the intensity of hepatic damage induced by CCl4 in rats.