Efficacy and effects of raw rhubarb and contraindications

Raw rhubarb is a valuable herbal medicine, it has many efficacy and effects, in the history of Chinese medicine is widely used, with more clinical application of rhubarb, mainly summarized the following efficacy and effects and contraindications.

Relieving dampness and reducing yellow

It can be used in combination with other herbs to treat dysentery caused by damp-heat stagnation in the intestinal tract, jaundice caused by damp-heat accumulation in the liver and gallbladder, and urinary redness.

Relieving heat and relaxing the bowels

It is used for dry stools, stagnant diarrhea and dysentery, and constipation due to heat and heat, and yellow fur. It is used in combination with mangosteen, houpu and heliotrope.

Relieving toxins and canker sores

It is used for detoxifying and eliminating carbuncles. It is used in treating hyperthermia, overflowing of blood, painful red eyes and feverish sores. Used in combination with Huang Lian, Scutellaria, Dan Pi and Red Peony.

Promoting blood stasis and clearing menstruation

For postpartum abdominal pain due to stagnation of blood stasis, menstrual disorders, bruises and injuries, and painful stasis. It should be used in combination with drugs that activate blood circulation and promote blood stasis, such as peach kernel, red peony and safflower. In addition, rhubarb can also be used to clear damp heat and jaundice, clinical application with Yin Chen, Gardenia, etc.; such as the powdered product, can also be used as a topical medicine for burns and heat sores, with the effect of clearing heat and detoxification.

Pharmacological effects

Choleretic effect

The decoction of rhubarb given to the duodenum of anesthetized dogs can increase bile secretion and reduce the tension of the sphincter of Oddi. In anesthetized rats, rhubarb decoction or hydroalcoholic extract was given to duodenum, and the secretion of bile and pancreatic juice increased within 30 minutes, while the activity of pancreatic amylase decreased. Rhubarb not only promotes bile secretion, but also increases the content of bilirubin and bile acids. In human, taking 15g of rhubarb decoction, the gallbladder was significantly enlarged (measured by ultrasound). It is consistent with the results of animal experiments.

Hepatoprotective effect

Rhubarb has a significant protective effect on experimental liver injury. Experimental evidence: rhubarb does have preventive and therapeutic effects on liver injury caused by carbon tetrachloride. In vitro experiments have proved that rhubarb decoction has obvious inhibitory effect on hepatitis B antigen (HBsAg), and the effect is weakened or disappeared after removing the tannin, and also proved that the intention quinones and rhodopsin in rhubarb do not have inhibitory effect on HBsAg.

Anti-gastric and duodenal ulcers

Experiments using ethanol-induced gastric mucous membrane damage model showed that rhubarb decoction 1g/kg, 0.5g/kg and 0.25g/kg had significant protective effect on gastric mucous membrane, and also increased the content of prostaglandin E2 (PGE2) in gastric wall to prevent ethanol damage to gastric mucous membrane.

Effects on smooth muscle of intestinal tube

Electrophysiological studies have shown that rhubarb has a significant excitatory effect on the electrical activity of the colon, characterized by clustered discharge, significantly faster peak electrical frequency, significantly higher amplitude, and enhanced contractile activity, and atropine can block the excitatory effect of rhubarb on the colon. Atropine can block the excitatory effect of rhubarb on the colon, prevent the absorption of water in the colon, accelerate the discharge of dissolved substances in the colon and exert its laxative effect. It is suggested that the laxative effect of rhubarb is through M receptors in the intestinal tube.

Action on pathogenic microorganisms

It has been proved through various experiments that: the mechanism of antibacterial effect of rhubarb lies in the inhibition of nucleic acid and protein synthesis and sugar metabolism of bacterial cells; rhubarb decoction and water, alcohol and ether extracts have inhibitory effect on some pathogenic fungi in vitro; rhubarb decoction has strong inhibitory effect on influenza virus.

Anti-tumor effect

Intraperitoneal injection of rhubarb acid and rhubarbin has strong inhibitory effect on melanoma in mice; rhubarb acid also has inhibitory effect on Ehrlich ascites carcinoma, but has no obvious effect on sarcoma S180 and subcutaneous type of Ehrlich carcinoma; rhubarbin also has inhibitory effect on breast cancer, and its mechanism of action is mainly to inhibit the oxidation and dehydrogenation of cancer cells. Rhubarb acid also has an inhibitory effect on the enzymolysis of cancer cells.

Anti-inflammatory effect

Rhubarb has a significant inhibitory effect on experimental inflammation in a variety of animals. Gavage of rhubarb decoction to mice can significantly inhibit the acute exudative inflammation of ear Guo in mice caused by croton oil. It also inhibited formaldehyde and egg white foot metatarsal swelling in rats, and cotton ball granuloma proliferation in mice and rats.

Effects on microcirculation

After gavage of rhubarb alcoholic extract to mice, the microcirculation (arterial and venous diameters) of otocerebrocytes had no obvious effect, but it could slow down the blood flow, and granular erythrocyte aggregates appeared, the most obvious in the microvein, local drip could not change the constriction of mesenteric microvessels induced by epinephrine, and there was no obvious dilating effect on microartery and microvein of gastric wall, and more obvious granular flocculation appeared, especially in the microvein. The effect of rhubarb on microcirculation is mainly the slowing down of blood flow, the aggregation of red blood cells, and the increase of local blood viscosity without local vasodilation, thus strengthening the local hemostatic process.

Hypolipidemic effect

For experimental hypercholesterolemia, rhubarb alcohol or aqueous extract can significantly reduce total serum cholesterol, while petroleum ether extract is ineffective.

Diuretic effect

In rabbits infused with rhubarbin and rhubarb acid 30mg/kg, the urine volume, sodium and potassium excretion reached the highest peak after 2-4 hours, which was significantly increased than the control warp. The effect of Aloe vera rhodopsin and rhododol was weaker. Rhodopsin, rhodolic acid and aloe rhodopsin had a strong competitive inhibitory effect on Na+, K+-ATPase in the free kidney medulla.

Contraindications of rhubarb

It should be taken with caution in all cases of unresolved superficial evidence, blood deficiency and qi weakness, spleen and stomach deficiency and coldness, without actual heat, stagnation and stasis, as well as in the prenatal and postnatal periods. In the Materia Medica Huiyan: "Do not use rhubarb lightly for people who are sick in the qi part of the body, have cold stomach and blood deficiency, and after pregnancy and delivery, as well as for those who have been sick for a long time and are old." Ben Jing Feng Yuan: "It should not be used for kidney deficiency and gangrene."