Published online Oct 7, 2020. doi: 10.3748/wjg.v26.i37.5629
Peer-review started: June 12, 2020
First decision: July 25, 2020
Revised: July 28, 2020
Accepted: September 9, 2020
Article in press: September 9, 2020
Published online: October 7, 2020
Processing time: 108 Days and 5.9 Hours
Many natural products confer health benefits against diverse diseases through their antioxidant activities. Carbon tetrachloride (CCl4) is often used in animal experiments to study the effects of substances on liver injury and the related mechanisms of action, among which oxidative stress is a major pathogenic factor.
The antioxidant activities of ten herbs were evaluated both in vitro and in vivo. Their hepatoprotective effects were also evaluated in order to elect more effective natural products for direct consumption and the development of nutraceuticals or therapeutics to manage oxidative stress-related diseases.
To compare antioxidant and hepatoprotective activities of ten herbs and identify and quantify phytochemicals for the one with strongest hepatoprotection, which could be helpful in the prevention and treatment of oxidative liver injury.
The antioxidant activity of ten medicinal herbs was determined by both ferric-reducing antioxidant power and Trolox equivalent antioxidant capacity assays. The total phenolic and flavonoid contents were determined by Folin–Ciocalteu method and aluminum chloride colorimetry, respectively. Their effects on CCl4-induced oxidative liver injury were evaluated and compared in a mouse model by administrating each water extract [(0.15 g/mL, 10 mL/kg) once per day] for seven consecutive days and a dose of CCl4 solution in olive oil (8%, v/v, 10 mL/kg). The herb with the strongest hepatoprotective performance was analyzed for the detailed bioactive components by using high-performance liquid chromatography-electrospray ionization source-ion trap tandem mass spectrometry.
The results revealed that all tested herbs attenuated CCl4-induced oxidative liver injury; each resulted in significant decreases in levels of serum alanine transaminase, aspartate transaminase, alkaline phosphatase, and triacylglycerols. In addition, most herbs restored hepatic superoxide dismutase and catalase activities, glutathione levels, and reduced malondialdehyde levels. Sanguisorba officinalis (S. officinalis) L., Coptis chinensis Franch., and Pueraria lobata (Willd.) Ohwi root were the three most effective herbs, and S. officinalis L. exhibited the strongest hepatoprotective effect. Nine active components were identified in S. officinalis, and gallic acid and (+)-catechin were quantified (7.86 ± 0.45 mg/g and 8.19 ± 0.57 mg/g dried weight, respectively). Furthermore, the tested herbs displayed a range of in vitro antioxidant activities proportional to their phenolic content; the strongest activities were also found for S. officinalis L.
The results of this study indicated that all ten medicinal foods and herbs could individually protect against CCl4-induced oxidative liver injury, and S. officinalis L., C. chinensis Franch., and P. lobata (Willd.) Ohwi root were more effective than the others. In addition, S. officinalis L. exhibited the strongest hepatoprotective effect, and nine components of its decoction were identified, among which gallic acid and (+)-catechin were quantified. It was also revealed that the tested materials exhibited various in vitro antioxidant activities proportionate to their phenolic content, and that the highest values were found in S. officinalis L. The results are valuable for the selection of more effective natural products to be consumed directly or developed into nutraceuticals or therapeutics for the prevention and treatment of oxidative stress-related diseases.
This study is of value to assist the selection of more effective natural products for direct consumption and the development of nutraceuticals or therapeutics to manage oxidative stress-related diseases. In the future, methods to identify and quantify the phytochemical compounds in medicinal herbs must be investigated more comprehensively. The bioavailability, desirable dose range, and side effects should also be clarified.