METHODS: We performed a systematic search using PubMed, Scopus, Cochrane Library, Web of Science for randomised controlled trials (RCTs), published until March 17, 2021. The quality assessment was carried out using the Cochrane Collaboration risk of bias tool. The Q-test and I 2 tests were used for the determination of heterogeneity of the included studies. Data were pooled using a random-effects model, and weighted mean difference (WMD) was used for the overall effect size.
RESULTS: Pooled findings of the five RCTs demonstrated that ginger supplementations had significantly reduced hs-CRP (WMD -0.42 mg/L; 95% CI, -0.78, -0.05, P = 0.03), TNF-α (-2.13 pg/mL; 95% CI: -3.41, -0.86, P = 0.001), and IL-6 (WMD: -0.61 pg/mL; 95% CI: -0.92, -0.30, P = 0.001) levels in patients with T2DM. The quality assessment of the studies showed that all of the included studies were at high risk of bias.
CONCLUSIONS: The meta-analysis shows that ginger supplementations reduced inflammatory parameters in patients with T2DM. Nonetheless, the reduction is relatively small, and its meaningful clinical effects are unknown. Future high-quality RCTs are needed to confirm the beneficial effects of ginger supplementation in patients with T2DM.
METHODS: CINAHL, PubMed, and EBSCO Host and Science Direct databases were searched for articles related to the use of EOs and/or aromatherapy for nausea and vomiting. Only articles using English as a language of publication were included. Eligible articles included all forms of evidence (nonexperimental, experimental, case report). Interventions were limited to the use of EOs by inhalation of their vapors to treat symptoms of nausea and vomiting in various conditions regardless of age group. Studies where the intervention did not utilize EOs or were concerned with only alcohol inhalation and trials that combined the use of aromatherapy with other treatments (massage, relaxations, or acupressure) were excluded.
RESULTS: Five (5) articles met the inclusion criteria encompassing trials with 328 respondents. Their results suggest that the inhaled vapor of peppermint or ginger essential oils not only reduced the incidence and severity of nausea and vomiting but also decreased antiemetic requirements and consequently improved patient satisfaction. However, a definitive conclusion could not be drawn due to methodological flaws in the existing research articles and an acute lack of additional research in this area.
CONCLUSIONS: The existing evidence is encouraging but yet not compelling. Hence, further well-designed large trials are needed before confirmation of EOs effectiveness in treating nausea and vomiting can be strongly substantiated.
DESIGN: Single-blind, controlled, randomized cross-over study. Patients received 5-day aromatherapy treatment using either ginger essential oil or fragrance-matched artificial placebo (ginger fragrance oil) which was instilled in a necklace in an order dictated by the treatment group sequence.
SETTING: Two oncology clinics in the East Coast of Peninsular Malaysia.
MAIN OUTCOME MEASURES: VAS nausea score, frequency of vomiting and HRQoL profile (EORTC QLQ-C30 scores).
RESULTS: Sixty female patients completed the study (age=47.3±9.26 years; Malay=98.3%; on highly emetogenic chemotherapy=86.7%). The VAS nausea score was significantly lower after ginger essential oil inhalation compared to placebo during acute phase (P=0.040) but not sustained for overall treatment effect (treatment effect: F=1.82, P=0.183; time effect: F=43.98, P<0.001; treatment×time effect: F=2.04; P=0.102). Similarly, there was no significant effect of aromatherapy on vomiting [F(1, 58)=0.29, P=0.594]. However, a statistically significant change from baseline for global health status (P<0.001) was detected after ginger essential oil inhalation. A clinically relevant 10 points improvement on role functioning (P=0.002) and appetite loss (P<0.001) were also documented while patients were on ginger essential oil.
CONCLUSION: At present time, the evidence derived from this study is not sufficiently convincing that inhaled ginger aromatherapy is an effective complementary therapy for CINV. The findings for HRQoL were however encouraging with significant improvement in several domains.
AIM: The present study was conducted to investigate the possible mechanism of actions underlying the systemic antinociception activity of the essential oil of Zingiber zerumbet (EOZZ) in chemical-induced nociception tests in mice.
MATERIALS AND METHODS: Acetic acid-induced abdominal constriction, capsaicin-, glutamate- and phorbol 12-myristate 13-acetate-induced paw licking tests in mice were employed in the study. In all experiments, EOZZ was administered systemically at the doses of 50, 100, 200 and 300 mg/kg.
RESULTS: It was shown that EOZZ given to mice via intraperitoneal and oral routes at 50, 100, 200 and 300 mg/kg produced significant dose dependent antinociception when assessed using acetic acid-induced abdominal writing test with calculated mean ID(50) values of 88.84 mg/kg (80.88-97.57 mg/kg) and 118.8 mg/kg (102.5-137.8 mg/kg), respectively. Likewise, intraperitoneal administration of EOZZ at similar doses produced significant dose dependent inhibition of neurogenic pain induced by intraplantar injection of capsaicin (1.6 μg/paw), glutamate (10 μmol/paw) and phorbol 12-myristate 13-acetate (1.6μg/paw) with calculated mean ID(50) of 128.8 mg/kg (118.6-139.9 mg/kg), 124.8 mg/kg (111.4-139.7 mg/kg) and 40.29 (35.39-45.86) mg/kg, respectively. It was also demonstrated that pretreatment with l-arginine (100mg/kg, i.p.), a nitric oxide precursor significantly reversed antinociception produced by EOZZ suggesting the involvement of l-arginine/nitric oxide pathway. In addition, methylene blue (20mg/kg, i.p.) significantly enhanced antinociception produced by EOZZ. Administration of glibenclamide (10mg/kg, i.p.), an ATP-sensitive K(+) channel antagonist significantly reversed antinociceptive activity induced by EOZZ.
CONCLUSION: Together, the present results suggested that EOZZ-induced antinociceptive activity was possibly related to its ability to inhibit glutamatergic system, TRPV1 receptors as well as through activation of l-arginine/nitric oxide/cGMP/protein kinase C/ATP-sensitive K(+) channel pathway.
METHODS: Three extracts of ginger (Zingiber officinale) rhizome prepared by maceration using the respective solvents and 6-shogoal were reconstituted in normal saline with 0.2% DMSO. Thirty C57BL/6 15-week-old mice were divided into 5 groups: Group 1, saline; Group 2, 70% methanol extract; Group 3, 80% ethanol extract; Group 4, 100% DMSO extract; and Group 5, 6-shogaol. The baseline pilocarpine-stimulated salivary flow rate was measured at the age of 15 weeks (15th week), and treatment solutions were administered by intraperitoneal injection from the 16th to 18th week. The stimulated salivary flow rate during treatment weeks was recorded for each group, and its difference with baseline was analysed using paired-sample t test. The change in salivary flow rate between the treatment groups and the control group was analysed using one-way analysis of variance.
RESULTS: Groups 2, 3, 4, and 5 showed a significant increase in salivary flow rate when compared to baseline (P < .05). The increase in salivary flow rate in all 4 treatment groups was significant when compared to the control group (P < .05). Group 4 produced the highest increase in salivary flow rate; however, the differences amongst the treatment groups did not reach statistical significance (P > .05).
CONCLUSIONS: All GR extracts (70% methanol, 80% ethanol, 100% DMSO) and 6-shogaol were equally effective in increasing the pilocarpine-stimulated salivary flow rate in C57BL/6 mice when administered systemically as a sustained dose for 3 weeks.
METHODS: A structured electronic search on worldwide accepted scientific databases (Web of Science, PubMed, Google Scholar, Science Direct, SciFinder, Wiley Online Library) was carried out to compile the relevant information. Some information was obtained from books and database on medicinal plants used in various countries.
RESULTS: About 60 metabolites, mainly polyphenols, and terpenoids have been isolated and identified. However, most of the reported pharmacological studies were based on crude extracts, and only a few of those isolated metabolites, particularly zerumbone have been investigated for biological and pharmacological activities. Many of the mechanistic studies to understand the pharmacological effects of the plant are limited by many considerations with regard to design, experimentation and interpretation.
CONCLUSION: The bioactive metabolites should be further investigated on their safety and more elaborate preclinical studies before clinical trials can be undertaken.