The effect of ginseng (genus Panax) on blood pressure: a systematic review and meta-analysis of randomized controlled clinical trials

Pre-clinical evidence indicates the potential for ginseng to reduce cardiovascular disease risk and acutely aid in blood pressure (BP) control. Clinical evidence evaluating repeated ginseng exposure, however, is controversial, triggering consumer and clinician concern. A systematic review and meta-analysis were conducted to assess whether ginseng has an effect on BP. MEDLINE, EMBASE, Cochrane and CINAHL were searched for relevant randomized controlled trials ⩾4 weeks that compared the effect of ginseng on systolic (SBP), diastolic (DBP) and/or mean arterial (MAP) BPs to control. Two independent reviewers extracted data and assessed methodological quality and risk of bias. Data were pooled using random-effects models and expressed as mean differences (MD) with 95% confidence intervals (CIs). Heterogeneity was assessed and quantified. Seventeen studies satisfied eligibility criteria (n=1381). No significant effect of ginseng on SBP, DBP and MAP was found. Stratified analysis, although not significant, appears to favour systolic BP improvement in diabetes, metabolic syndrome and obesity (MD=-2.76 mm Hg (95% CI=-6.40, 0.87); P=0.14). A priori subgroup analyses revealed significant association between body mass index and treatment differences (β=-0.95 mm Hg (95% CI=-1.56, -0.34); P=0.007). Ginseng appears to have neutral vascular affects; therefore, should not be discouraged for concern of increased BP. More high-quality, randomized, controlled trials assessing BP as a primary end point, and use of standardized ginseng root or extracts are warranted to limit evidence of heterogeneity in ginseng research and to better understand its cardiovascular health potential.

Effect of fructose on markers of non-alcoholic fatty liver disease (NAFLD): a systematic review and meta-analysis of controlled feeding trials

BACKGROUND/OBJECTIVES

In the absence of consistent clinical evidence, there are concerns that fructose contributes to non-alcoholic fatty liver disease (NAFLD). To determine the effect of fructose on markers of NAFLD, we conducted a systematic review and meta-analysis of controlled feeding trials.

SUBJECTS/METHODS

We searched MEDLINE, EMBASE, CINAHL and the Cochrane Library (through 3 September 2013). We included relevant trials that involved a follow-up of ≥ 7 days. Two reviewers independently extracted relevant data. Data were pooled by the generic inverse variance method using random effects models and expressed as standardized mean difference (SMD) for intrahepatocellular lipids (IHCL) and mean difference (MD) for alanine aminotransferase (ALT). Inter-study heterogeneity was assessed (Cochran Q statistic) and quantified (I(2) statistic).

RESULTS

Eligibility criteria were met by eight reports containing 13 trials in 260 healthy participants: seven isocaloric trials, in which fructose was exchanged isocalorically for other carbohydrates, and six hypercaloric trials, in which the diet was supplemented with excess energy (+21-35% energy) from high-dose fructose (+104-220 g/day). Although there was no effect of fructose in isocaloric trials, fructose in hypercaloric trials increased both IHCL (SMD=0.45 (95% confidence interval (CI): 0.18, 0.72)) and ALT (MD=4.94 U/l (95% CI: 0.03, 9.85)).

LIMITATIONS

Few trials were available for inclusion, most of which were small, short (≤ 4 weeks), and of poor quality.

CONCLUSIONS

Isocaloric exchange of fructose for other carbohydrates does not induce NAFLD changes in healthy participants. Fructose providing excess energy at extreme doses, however, does raise IHCL and ALT, an effect that may be more attributable to excess energy than fructose. Larger, longer and higher-quality trials of the effect of fructose on histopathological NAFLD changes are required.

Inhibition of prostasin-induced ENaC activities by PN-1 and regulation of PN-1 expression by TGF-beta1 and aldosterone

Prostasin has been shown to regulate sodium handling in the kidney. Recently, a serine protease inhibitor, protease nexin-1 (PN-1), was identified as an endogenous inhibitor for prostasin. Therefore, we hypothesized that PN-1 may regulate sodium reabsorption by reducing prostasin activity, and that expression of PN-1 was regulated by transforming growth factor-beta1 (TGF-beta1) or aldosterone, like prostasin. cRNAs for epithelial sodium channel (ENaC), prostasin, and PN-1 were expressed in Xenopus oocytes, and the amiloride-sensitive sodium currents (I(Na)) were measured. The effect of TGF-beta1 and aldosterone on the mRNA and protein abundance of PN-1 and ENaC was detected by real-time polymerase chain reaction and immunoblotting in M-1 cells. Expression of PN-1 substantially decreased prostasin-induced I(Na) by approximately 68% in oocytes. Treatment of M-1 cells with 20 ng/ml TGF-beta1 significantly increased protein expression of PN-1 by 3.8+/-0.5-fold, whereas administration of 10(-6) M aldosterone markedly decreased protein expression of PN-1 to 53.7+/-6.7%. Basolateral, but not apical, application of TGF-beta1 significantly reduced I(eq). To elucidate the involvement of PN-1 in basal ENaC activity, we silenced the expression of PN-1 by using short-interfering RNA. This increased I(eq) by 1.6+/-0.1-fold. Our study indicates that PN-1 could have a natriuretic role by inhibiting prostasin activity and suggests the possibility that aldosterone and TGF-beta reciprocally regulate the expression of PN-1 in renal epithelial cells contributing to salt retention or natriuresis, respectively by an additional mechanism. PN-1 could represent a new factor that contributes to regulation of ENaC activity in the kidney.

Quantitation of bacteria in bone marrow from patients with typhoid fever: relationship between counts and clinical features

Enteric fever is the only bacterial infection of humans for which bone marrow examination is routinely recommended. A prospective study of the concentrations of bacteria in the bone marrow and their relationship to clinical features was conducted with 120 Vietnamese patients with suspected enteric fever, of whom 89 had confirmed typhoid fever. Ninety-three percent of the Salmonella enterica serovar Typhi samples isolated were resistant to ampicillin, chloramphenicol, and co-trimoxazole. For 81 patients with uncomplicated typhoid and satisfactory bone marrow aspirates, the number of serovar Typhi CFU in bone marrow aspirates was a median value of 9 (interquartile range [IQR], 1 to 85; range, 0.1 to 1,580) compared to 0.3 (IQR, 0.1 to 10; range, 0.1 to 399) CFU/ml in simultaneously sampled blood. The ratio of individual blood counts to bone marrow counts was 10 (IQR, 2.3 to 97.5). The number of bacteria in blood but not bone marrow was correlated inversely with the duration of preceding fever. Thus, with increasing duration of illness the ratio of bone marrow-to-blood bacterial concentrations increased; the median ratio was 4.8 (IQR, 1 to 27.5) during the first week compared with 158 (IQR, 60 to 397) during the third week. After lysing the host cells, the median ratio of viable bone marrow to blood increased, reflecting the higher concentration of intracellular serovar Typhi in the bone marrow. Effective antibiotic pretreatment had a significantly greater effect in reducing blood counts compared to bone marrow counts (P < 0.001). Thus, bacteria in the bone marrow of typhoid patients are less affected by antibiotic treatment than bacteria in the blood. The numbers of bacteria in bone marrow correlated negatively with the white blood cell (R = -0.3, P = 0.006) and platelet counts (R = -0.32, P = 0.01) and positively with fever clearance time after treatment (R = 0.4, P < 0.001). The bacterial load in bone marrow therefore may reflect the clinical course of the infection, and high levels may suppress neutrophil proliferation.

Severe and complicated malaria treated with artemisinin, artesunate or artemether in Viet Nam

One hundred and seventy five Vietnamese adults with severe and complicated malaria admitted to a rural district hospital were entered into an open randomized comparative study to compare 4 treatment regimens based on artemisinin and its derivatives. The median time of defervescence was 48 h (95% confident interval [CI] 38-58 h) in those given intramuscular (i.m.) artemether, 42 h (95% CI 36-48 h) in those given artemisinin suppositories, 36 h (95% CI 30-42 h) in those receiving artesunate (i.m.) and 30 h (95% CI 18-42 h) in those receiving intravenous artesunate (P = 0.13). The respective median parasite clearance times were 30 h (95% CI 26-34 h), 30 h (95% CI 24-36 h), 24 h (95% CI 15-33 h), and 24 h (95% CI 15-33 h) (P = 0.30); the median times for recovery of consciousness were 47 h (95% CI 31-63 h), 24 h (95% CI 18-30 h), 30 h (95% CI 18-42 h), and 24 h (95% CI 4-44 h) (P = 0.18); and the mortality rates were 11.1%, 17.6%, 10.2% and 16.6%, respectively (P = 0.64). There was no significant difference in efficacy between the 4 treatments.

A controlled trial of artemether or quinine in Vietnamese adults with severe falciparum malaria

BACKGROUND

Artemisinin (qinghaosu) and its derivatives are rapidly effective antimalarial drugs derived from a Chinese plant. Preliminary studies suggest that these drugs may be more effective than quinine in the treatment of severe malaria. We studied artemether in Vietnam, where Plasmodium falciparum has reduced sensitivity to quinine.

METHODS

We conducted a randomized, double-blind trial in 560 adults with severe falciparum malaria. Two hundred seventy-six received intramuscular quinine dihydrochloride (20 mg per kilogram of body weight followed by 10 mg per kilogram every eight hours), and 284 received intramuscular artemether (4 mg per kilogram followed by 2 mg per kilogram every eight hours). Both drugs were given for a minimum of 72 hours.

RESULTS

There were 36 deaths in the artemether group (13 percent) and 47 in the quinine group (17 percent; P = 0.16; relative risk of death in the patients given artemether, 0.74; 95 percent confidence interval, 0.5 to 1.11). The parasites were cleared more quickly from the blood in the artemether group (mean, 72 vs. 90 hours; P < 0.001); however, in this group fever resolved more slowly (127 vs. 90 hours, P < 0.001), the time to recovery from coma was longer (66 vs. 48 hours, P = 0.003), and the hospitalization was longer (288 vs. 240 hours, P = 0.005). Quinine treatment was associated with a higher risk of hypoglycemia (relative risk, 2.7; 95 percent confidence interval, 1.7 to 4.4; P < 0.001), but there were no other serious side effects in either group.

CONCLUSIONS

Artemether is a satisfactory alternative to quinine for the treatment of severe malaria in adults.

Sequence analysis of a cDNA for lysyl hydroxylase isolated from human skin fibroblasts from a normal donor: differences from human placental lysyl hydroxylase cDNA

Using polymerase chain reaction, we have isolated and sequenced a 3-kb cDNA for lysyl hydroxylase (LH) from human skin fibroblasts from an normal donor. Apart from two polymorphic sites, no differences were observed between the 2184 nt coding regions of LH cDNA from fibroblasts and placenta. However, four differences were observed in the 3' non-coding regions of the two cDNAs; three were single base changes and the fourth a deletion of a single base. The absence of the single nucleotide in the LH cDNA from fibroblasts resulted in the loss of an HpaII site that is present in the placental LH cDNA; this was confirmed in HpaII digests of fibroblast and placental LH cDNAs from the same donor. Northern blots showed that the LH gene was strongly expressed in fibroblasts and placenta and, to a lesser extent, in aorta, lung, vein, cartilage, and artery.

Regulation of lysyl oxidase mRNA in dermal fibroblasts from normal donors and patients with inherited connective tissue disorders

Lysyl oxidase (LO) is an extracellular copper-dependent enzyme that catalyzes the initial reaction in the formation of lysine or hydroxylysine-derived crosslinks during collagen biosynthesis. We have isolated a cDNA for human LO from skin fibroblast poly(A+)RNA by PCR using primers based on the recently published sequence of human LO. This cDNA probe detects a major mRNA of 4.2 kb on Northern blots of RNA from normal fibroblasts. The level of LO mRNA was not significantly affected by cell density or by ascorbate treatment. Treatment of skin fibroblasts with hydralazine (50 microM), which increases the mRNAs for both the alpha and the beta subunits of prolyl hydroxylase (PH) and the mRNAs for lysyl hydroxylase, also increased LO mRNA by fourfold over a 72-h time course. In contrast, hydralazine dramatically decreased the mRNAs for alpha 1(I) collagen. Administration of minoxidil (500 microM), which specifically decreases LH activity without affecting PH activity or collagen biosynthesis in skin fibroblasts, stimulated the level of LO mRNA. Neither the administration of penicillamine (100 microM), which interferes with collagen cross-linking, nor the administration of beta-aminopropionitrile, which is a strong irreversible inhibitor of LO, to fibroblasts significantly changed the levels of LO mRNA over a 72-h time course. However, bleomycin (0.6 microgram/ml) significantly decreased the 4.2-kb LO mRNA in contrast to the levels of the alpha 1(I) collagen mRNAs, which were unchanged. No significant change was observed in the steady-state levels of LO mRNAs in fibroblasts isolated from patients with certain connective tissue disorders, including Marfan syndrome, Menkes disease, cutis laxa, and pseudoxanthoma elasticum.

Characterization of a partial cDNA for lysyl hydroxylase from human skin fibroblasts; lysyl hydroxylase mRNAs are regulated differently by minoxidil derivatives and hydralazine

Lysyl hydroxylase (LH) is an essential enzyme in collagen biosynthesis that catalyzes the formation of hydroxylysine required for intermolecular crosslinking of collagen. We have isolated a partial (2.2-kb) cDNA for LH from human skin fibroblasts using PCR. DNA sequencing revealed 72% homology of the human coding sequence with the chick LH sequence at the nucleotide level and 76% homology predicted at the amino acid level. The LH cDNA hybridized strongly with two mRNA species of 2.4 and 3.4 kb on Northern blots of normal fibroblast RNA. Administration of minoxidil decreased both mRNA species without affecting levels of the mRNAs for the beta subunit of prolyl 4-hydroxylase (PH) or alpha 1(I) collagen. Two derivatives of minoxidil (3' hydroxyminoxidil and 4' hydroxyminoxidil) produced similar decreases in LH mRNAs. In contrast hydralazine increased the mRNAs for LH in parallel with its previously reported effect on the mRNA for the beta subunit of PH. This effect is accompanied by virtual elimination of the alpha 1(I) collagen mRNAs. These results on the action of minoxidil and hydralazine at the pretranslational level correlate well with their previously reported effect on enzyme activity and collagen biosynthesis and indicate that changes in steady-state mRNA levels can account directly for changes at the protein level. Moreover, the unique action of minoxidil in specifically decreasing LH mRNAs contrasts with the less specific stimulatory effects of hydralazine and suggests that these pharmaceuticals are regulating expression of LH at a pretranslational level by different mechanisms.