WHAT DOES CURRENT RESEARCH REVEAL ABOUT THE EFFECT MUSHROOMS HAVE ON BLOOD PRESSURE?
High blood pressure (hypertension) is a medical condition that, according to the CDC, affects 1 in every 3 adults. It causes the heart to work harder than normal and it increases the risk of stroke, heart attack, and the development of aneurysms.
Like water flowing through a hose, blood in the circulatory system exerts a force against the walls of blood vessels. Increasing the volume of blood or decreasing the size of a blood vessel will raise blood pressure. High blood sugar and a buildup of cholesterol plaque in the arteries can increase blood pressure, but hypertension can also occur in individuals with healthy levels of sugar and cholesterol in the circulatory system. Diet and exercise can influence blood pressure, but at the cellular and biochemical level, the renin-angiotensin-aldosterone system (RAAS) is the control system. Antihypertensive drugs designed to treat hypertension often act on the enzymes in the RAAS. By inhibiting certain enzymes, the formation of regulatory hormones is suppressed and blood pressure is reduced.
Angiotensin II is considered one of the most important hormones in the RAAS. Its presence either directly or indirectly stimulates sodium reabsorption, water retention, vasoconstriction (tightening of blood vessels), and increased thirst and appetite for salt. Angiotensin II is like the inlet of a five-way valve. Nothing can happen downstream if the inlet is closed. Opening the inlet increases blood pressure, and hypertension is reduced when the valve is closed. Angiotensin-converting enzyme (ACE) is what makes angiotensin II; it alone has the ability to close or open the valve. Therefore drugs that inhibit ACE can have significant antihypertensive effects. Interestingly, a few species of mushrooms contain bioactive molecules that may inhibit ACE and prevent the formation of angiotensin II.
According to the Mushroom Research Center at the University of Malaya, molecules in mushrooms might physically block the active site of ACE, like a piece of wood jammed in a lock. A study published in the Chemical and Pharmaceutical Bulletin found that the triterpenoids in reishi mushrooms were ACE inhibitors, but other studies have demonstrated that small protein chains in mushrooms also have a great effect. Patents have been filed to cover the extraction and use of antihypertensive molecules in oyster mushrooms, and researchers have been working to optimize the production of similar molecules from pioppino mushrooms. Not all of the molecules of interest target ACE, however. In fact, studies have shown the bioactive constituents of mushrooms may also lower blood pressure by decreasing platelet accumulation, blood clot formation, blood sugar levels, and cholesterol plaque formation.
The bioactive components of some mushrooms appear to have antihypertensive properties. The prospect of targeting the RAAS and inhibiting ACE seems like an effective strategy for lowering blood pressure, and it is exciting that the proteins and triterpenoids in mushrooms may impact this biochemical system. However, many factors appear to be involved, and the molecules in mushrooms may affect more than just the RAAS. More research should be conducted to better understand the mechanisms involved and the efficacy of mushrooms to affect blood pressure. The consumption of mushrooms to lower blood pressure is not approved or recommended by the Food and Drug Administration (FDA). Although the antihypertensive properties of mushrooms are not recognized by the FDA, we would like to advise caution to individuals with preexisting low blood pressure. Some species of mushrooms may decrease blood pressure and or interfere with medication prescribed to increase blood pressure.
Aneurysms: Bulges in blood vessels that can rupture when too much pressure accumulates.
Angiotensin II: A major hormone in the RAAS. It is formed when angiotensin I is shortened by ACE. Angiotensin II directly or indirectly stimulates sodium reabsorption, water retention, vasoconstriction (tightening of blood vessels), and increased thirst and appetite for salt. Angiotensin II’s actions increase blood pressure.
Angiotensin-Converting Enzyme: The enzyme that transforms angiotensin I into angiotensin II. Without ACE, angiotensin II cannot be formed. Antihypertensive drugs often inhibit ACE to prevent the formation of angiotensin II and the subsequent hypertensive actions downstream.
Antihypertension Medication: Medication that has a blood pressure-lowering effect.
Enzymes: Proteins that catalyze reactions by lowering the amount of energy needed for a reaction to occur. If the reactions that take place in our bodies were to be repeated in the laboratory without the use of enzymes, many of them would require extremely high heat–energy. Enzymes are very efficient, produce no waste, and keep us alive.
Hypertension: A medical term that describes high blood pressure. The opposite condition, low blood pressure, is called hypotension.
Renin-Angiotensin-Aldosterone System: Controls blood pressure, water, and sodium retention and excretion and stimulates thirst and hunger for salt. The RAAS is controlled by hormones secreted by the kidney, liver, lungs, and cells within blood vessels. An overactive RAAS can cause high blood pressure and disrupting the pathway can decrease blood pressure.
Triterpenoids: Molecules that are the building blocks for many important biological molecules including all steroids, not just anabolic ones. Terpenoids have been shown to interact with proteins.
Selected Research and Highlights:
Kim, J. H., Lee, D. H., Lee, S. H., Choi, S. Y., & Lee, J. S. (2004). Effect of Ganoderma lucidum on the quality and functionality of Korean traditional rice wine, yakju. Journal of Bioscience and Bioengineering, 97(1), 24-28.
“Adding 0.1% G. lucidum into the mash showed the best acceptability, and its angio- tensin I-converting enzyme (ACE) inhibitory activity and SOD-like activity were 63% and 42%, respectively, both of which are higher than those of yakju. The high ACE inhibitory activity of G. lucidum GL-1 yakju was found to result from ganoderic acid K in G. lucidum on the basis of phys- ical and spectral data. However, the fibrinolytic activity and antioxidant activity of G. lucidum GL-1 yakju were very low, while tyrosinase inhibitory activity was not determined. From these re- sults, G. lucidum GL-1 yakju may become a new functional Korean traditional rice wine with an- tihypertensive properties.”
“Comparison of the ACE inhibitory activities of the new G. lucidum GL-1 yakju of this study and other medicinal plant-yakjus revealed that G. lucidum GL-1 yakju had a greater antihypertensive effect.”
Tam, S., Yip, K., Fung, K., & Chang, S. (1986). Hypotensive and renal effects of an extract of the edible mushroom Pleurotus sajor-caju. Life Sciences, 38(13), 1155-1161.
“An aqueous extract of Pleurotus sajor-caju was found to have a hypotensive effect in rats. Intravenous infusion of the extract into rats caused a decrease of the mean systemic blood pressure in a dose dependent manner. A typical dose of 25 mg of the extract decreased the mean systemic blood pressure from 110 mm Hg to 70 mm Hg. The systolic and diastolic pressure changed proportionally with minimal alteration in heart rate.”
Lau, C., Abdullah, N., Shuib, A., & Aminudin, N. (2012). Proteomic analysis of antihypertensive proteins in edible mushrooms. Journal of Agricultural Food Chemistry, 60(80), 12341-12348.
“In conclusion, mushrooms are a good source of antihypertensive proteins. The ACE inhibitory activity of water extracts from the nine mushroom species were tested at a concentration of 10 mg/mL. The highest ACE inhibitions were exhibited by F. velutipes and L.edodes.”
Choudhury, M., Rahman, T., Kakon, A., Hoque, N., Akhtaruzzaman, M., Begum, M., et al. (2013). Effects of Pleurotus ostreatus on blood pressure and glycemic status of hypertensive diabetic male volunteers. Bangladesh Journal of Medical Biochemistry, 6(1), 5-10.
“The study showed that after 3 months of regular intake of Pleurotus ostreatus mushroom, both systolic and diastolic blood pressure decreased significantly (p<0.001). It was also observed that, Pleurotus ostreatus decreased fasting plasma glucose level significantly (p<0.001). Reduction of HbA1c % observed after 3 months of mushroom intake was found to be significant (p<0.001). But there was no significant change of plasma creatinine level (p>0.05) indicating Pleurotus ostreatus has no detrimental effect on renal system. From the study, it can be said that, Pleurotus ostreatus mushroom intake improves glycemic status and blood pressure control in diabetic hypertensive subjects.”
Morigiwa, A., Kitabatake, K., Fujimoto, Y., & Ibekawa, N. (1986). Angiotensin converting enzyme-inhibitory triterpenes from Ganoderma lucidum. Chemical Pharmaceutical Bulletin, 34(7), 3025-3028.
“The 70% MeOH extract of Ganoderma lucidum had an inhibitory effect on angiotensin coverting enzyme activity, and from this extract, five new triterpenses, named ganoderal A, ganoderols A and B, and ganoderic acids K and S, were isolated.”
Mori, K., Kikuchi, H., Obara, Y., Iwashita, M., Azumi, Y., Kinugasa, S., et al. (2010). Inhibitory effect of hericenone B from Hericium erinaceus on collagen-induced platelet aggregation. Phytomedicine, 17(14), 1082-1085.
“Platelet aggregation in the blood vessel causes thrombosis. Therefore, inhibitors of platelet aggregation promise to be preventive or therapeutic agents of various vascular diseases, including myocardial infarction and stroke. In the present study, we found that hericenone B had a strong anti-platelet activity and it might be a novel compound for antithrombotic therapy possessing a novel mechanism. Therefore, hericenone B was considered to block collagen signaling from integrin α2/β1 to arachidonic acid release. Moreover, we found that collagen-induced aggregation was inhibited by hericenone B in human platelets, similar to in rabbit platelets.”
Wu, S., Sun, H., Sun, J., & Liao, D. (2010). Technical optimization for extracting hypotensive active peptides from Agrocybe aegerita. Nan Fang Yi Ke Da Xue Xue Bao, 30(6), 1264-1267.
“Optimal extraction of the hypotensive active peptides from Agrocybe aegerita was achieved with the liquid/solid ratio of 40:1, extraction time of 3 h, extraction temperature at 30 degrees Celsius;, and pH=8 of the initial liquid. The EP of the hypotensive active peptides from Agrocybe aegerita could reach 87.7% with IP of the extracts on angiotensin I-converting enzyme of 54.0%.
CONCLUSION: This method is simple and efficient for extracting hypotensive active peptides from Agrocybe aegerita.”
Kumaran, S., Palani, P., Nishanthi, R., & Kaviyarasan, V. (2011). Studies on screening, isolation and purification of a fibrinolytic protease from an isolate (VK12) of Ganoderma lucidum and evaluation of its antithrombotic activity. Medical Mycology Journal, 52(2), 153-162.
“Antithrombotic activity of a protease purified from a medicinal mushroom, Ganoderma lucidum, has been evaluated platelet aggregation in vitro and pulmonary thrombosis in vivo. The purified protease exhibited concentration dependent inhibitory effects on platelet aggregation induced by ADP (adenosine diphosphate), with an IC50 value of 2.4 mg/mL. The purified protease protected mice against thrombotic death or paralysis induced by collagen and epinephrine in a dose-dependent manner when administered orally. It produced a significant inhibition of thrombotic death or paralysis at 60 μg/kg body weight, while aspirin produced a significant inhibition of thrombosis at 10-20 mg/kg body weight. The purified protease also has showed fibrinolytic activity and alters coagulation parameters such as activated partial thromboplastin time(APTT), and thrombin time(TT)in rat platelet.”
Abdullah, N., Ismail, S. M., Aminudin, N., Shuib, A. S., & Lau, B. F. (2011). Evaluation of selected culinary-medicinal mushrooms for antioxidant and ACE inhibitory activities. Evidence-based Complementary and Alternative Medicine, 2012. Retrieved January 1, 2013, from http://www.ncbi.nlm.nih.gov/pubmed/21716693)
“Considering the importance of diet in prevention of oxidative stress-related diseases including hypertension, this study was undertaken to evaluate the in vitro antioxidant and ACE inhibitory activities of selected culinary-medicinal mushrooms extracted by boiling in water for 30 min. Antioxidant capacity was measured using the following assays: DPPH free radical scavenging activity, β-carotene bleaching, inhibition of lipid peroxidation, reducing power ability, and cupric ion reducing antioxidant capacity (CUPRAC). Antioxidant potential of each mushroom species was calculated based on the average percentages relative to quercetin and summarized as Antioxidant Index (AI). Ganoderma lucidum (30.1%), Schizophyllum commune (27.6%), and Hericium erinaceus (17.7%) showed relatively high AI. Total phenolics in these mushrooms varied between 6.19 to 63.51 mg GAE/g extract. In the ACE inhibitory assay, G. lucidum was shown to be the most potent species (IC50 = 50 μg/mL). Based on our findings, culinary-medicinal mushrooms can be considered as potential source of dietary antioxidant and ACE inhibitory agents.”
Kumakura, K., Kumakura, H., Ogura, M., & Eguchi, F. (2008). Pharmacological effects of Ganoderma lucidum collected from ume (Japanese apricot) trees. Journal of Wood Science, 54(6), 502-508.
“G. lucidum might accumulate high levels of triterpenoids as the effective component of ACE inhibition or might contain a new constituent. Given that 30% methanol was used for extraction in this study, water-soluble polysaccharides, proteins, or peptides would have been present in the extract. Many kinds of food-derived peptides have been reported to inhibit ACE and some are obtained from mushrooms.23,24 Orally administered hot-water extracts of Mycoleptodonoides aitchisonii exhibit hypotensive effects on SHR, and ACE inhibitory activity was related to the hypotensive mechanism,25 which suggests that polysaccharides, proteins, or peptides in G. lucidum may be involved in ACE inhibition.”
Choi, H., Cho, H., Yang, H., Ra, K., & Suh, H. (2001). Angiotensin I-converting enzyme inhibitor from Grifola frondosa. Food Research International, 34(2-3), 177-182.
“The most potent ACE inhibitory activity (58.7%) was detected in a cold water extract of Grifola frondosa, with an IC50 of 0.95 mg. The ACE inhibitory activities of the cold and hot water extracts increased as the extraction time increased but decreased slightly 15 h and 90 min, respectively, after extraction. After the purification of ACE inhibitory peptides with acetone fractionation and column chromatography, we obtained an active fraction with an IC50 of 0.13 mg and a yield of 0.7%. The purified inhibitor showed competitive inhibition on ACE and this peptide maintained inhibitory activity even after digestion by intestinal proteases.”
 Abdullah, N., Ismail, S. M., Aminudin, N., Shuib, A. S., & Lau, B. F. (2011). Evaluation of selected culinary-medicinal mushrooms for antioxidant and ACE inhibitory activities. Evidence-based Complementary and Alternative Medicine, 2012. Retrieved January 1, 2013, from http://www.ncbi.nlm.nih.gov/pubmed/21716693)
 Morigiwa, A., Kitabatake, K., Fujimoto, Y., & Ibekawa, N. (1986). Angiotensin converting enzyme-inhibitory triterpenes from Ganoderma lucidum. Chemical Pharmaceutical Bulletin, 34(7), 3025-3028.
 Wu, S., Sun, H., Sun, J., & Liao, D. (2010). Technical optimization for extracting hypotensive active peptides from Agrocybe aegerita. Nan Fang Yi Ke Da Xue Xue Bao, 30(6), 1264-1267.
 Mori, K., Kikuchi, H., Obara, Y., Iwashita, M., Azumi, Y., Kinugasa, S., et al. (2010). Inhibitory effect of hericenone B from Hericium erinaceus on collagen-induced platelet aggregation. Phytomedicine, 17(14), 1082-1085.