Anti-hypertensive effect of the dongchunghacho, isaria sinclairii, in the spontaneously hypertensive rats

Abstract

The present study examined the effect of the methanol extract of Isaria sinclairii, a kind of Donchunghacho (Tochukaso), on blood pressure in spontaneously hypertensive rats (SHR). Blood pressure and heart rate were measured after treatment with the methanol extract of I. sinclairii by the indirect tail-cuff method and the direct in vivo model. Starting at 12 weeks of age, male SHR were treated with the extracts for 2 or 4 weeks. We found that, when compared to untreated control SHR, oral treatment with I. sinclairii methanol extract (30 mg/kg/day) remarkably decreased systolic blood pressure from 200 to 112 mmHg and decreased diastolic blood pressure from 114 to 88 mmHg. Furthermore, efficacy of methanol extract of I. sinclairii was superior to captopril (30 mg/kg/mL, positive control), an angiotensin-converting enzyme inhibitor, with a lowering effect that dropped systolic blood pressure from 201 to 130 mmHg and diastolic blood pressure from 102 to 92 mmHg. However, in normal Wistar Kyoto rats, I. sinclairii methanol extract did not significantly change the normal blood pressure, suggesting that this type of Dongchunghacho has a selective effect against hypertension. Therefore, methanol extract of I. sinclairii may be used as an anti-hypertensive food/agent. Furthermore, this extract also has multiple actions such as No production in endothelial cells, inhibiting thrombin-induced blood coagulation by thrombin and mildly decreasing in prostaglandin E2 levels in cultured macrophage cells, all of which might contribute to protection against atherogenesis and thrombus formation. HPLC and MS analysis of methanol extract of I. sinclairii revealed the presence of adenosine.

Anti-diabetic activities of Paecilomyces tenuipes N45 extract in alloxan-induced diabetic mice

“…Paecilomyces tenuipes, a well-known Chinese medicinal entomopathogenic fungi, has been traditionally used in folk medicine in Japan, Korea and China for years (13). Paecilomyces tenuipes, containing polysaccharides, adenosine, cordycepin, sterol and cyclopeptide, is increasingly notable for its antidepressant, antitumor and immunomodulatory effects (14,15). However, the regulatory effects of a polysaccharide-enriched fraction of Paecilomyces tenuipes on diabetic mice has not been reported previously.…”

Fatty Acid Composition of Adipose Tissues in Obese Mice and SD Rats Fed with Isaria sinclairii Powder

“…Recently, it was reported that the primary pharmacological activities of I. sinclairii include selective antihypertensive activity (Ahn et al ., 2007c) and anti-obesity activity in rats (Ahn et al ., 2007b) . However, I. sinclairii contains polyhydroxylated alkaloids such as 1-deoxynojirimycin (DNJ) that are metabolized from silkworm nutrients (Asano et al ., 2001) , and a synthetic long-chain N-alkylated immini sugar, N -buthyl-deoxynojirimycin, was reported, where its membrane disruption and cytotoxicity were dependent on the inhibition of protein and lipid glycosylation, reducing hepatitis virus (Mellor et al ., 2003) which might be responsible for the increase in conjugated poly saturated fatty acid level.…”

“…In very rare situations,human obesity is caused by an absence of the leptin signal (mutations of the leptin gene or leptin receptor gene) , which produces the internal perception of starvation, results in the chronic stimulation of excessive food intake (Jéquier 2002) .Recently, many natural products can help control the bodyweight through specific mechanisms, such as ion channel regulation by AMPK (AMP-activated protein kinase) (Vong et al ., 2009) , dyslipidemia action of acetyl-CoA carboxylase (ACC) (Kim and Kim, 2009) and the promotion of glucagons-like peptide-1 secretion (Chen and Reimer, 2009) . Among the Dongchunghachoes, Isaria sinclairii (Cicada Dongchunghacho) exhibited possesses selective antihypertensive activity in a spontaneously hypertensive rat (SHR) model (Ahn et al ., 2007c) . A previous report suggested that I. sinclairii powder (IS) reduces obesity in Zucker-fa/fa rats by reducing the serum total cholesterol, triglyceride and LDL levels, and by increasing the leptin levels.…”

Anti-aging Effect and Gene Expression Profiling of Aged Rats Treated with G. bimaculatus Extract

“…Measurement of blood pressure. Measurement of the direct model in vivo and the tail-cuff method (indirect) was performed on a weekly basis according to a previous report (10) . Using a blood monitoring system (Japan Muromachi Co., MK-100), we monitored WKY rats that had received a single daily dose of Gb extract (100 mg/kg) orally (diluted in saline) over one month.…”