Promising roles of Zingiber officinale roscoe, Curcuma longa L., and Momordica charantia L. as immunity modulators against COVID-19: A bibliometric analysis.

Zingiber officinale, Curcuma longa, and Momordica charantia are medicinal plants that are commonly used in the form of herbal tea, which is formulated to strengthen the immune system, especially against COVID-19 infection. Excellent antioxidant, anti-inflammatory, and immunostimulatory properties have been reported for their bioactive compounds, which have been shown to aid in stimulating immune systems as well as lowering the risk of severe COVID-19 such as lung injury. Yet, no bibliometric study on the subject is available. Hence, the purpose of this study is to quantitatively examine the existing articles related to the therapeutic potential of these three herbs, as well as their mechanisms of action in combating the SARS-CoV-2 virus. A total of 121 papers were retrieved from Scopus database up to 14th March 2023. The bibliometric analysis was conducted using VOSviewer software. Based on the literature search, Z. officinale was the most researched plant. India appeared as the most prolific country, with the highest number of articles contributed by two authors from India (Rathi, R. and Gayatri Devi, R.). In terms of keywords, the plants were associated with immune modulation, management of symptoms, antioxidant, anti-inflammatory and antiviral activities. Several important bioactive compounds were responsible for these effects such as gingerol, paradol, shogaol, curcumin, calebin A, momordicoside, karaviloside and cucurbitadienol. These compounds were hypothesized to prevent and cure COVID-19 by regulating inflammatory response, downregulating oxidative stress and modulating immunostimulatory activity. This review paper therefore supports the potential of Z. officinale, C. longa, and M. charantia to be formulated as a herbal blend for treating and preventing COVID-19 infection.

Dual actions of gallic acid and andrographolide trigger AdipoR1 to stimulate insulin secretion in a streptozotocin-induced diabetes rat model.

Common treatments for the management of diabetes have limitations due to side effects, hence the need for continuous research to discover new remedies with better therapeutic efficacy. Previously, we have reported that the combination treatment of gallic acid (20 mg/kg) and andrographolide (10 mg/kg) for 15 days demonstrated synergistic hypoglycemic activity in the streptozotocin (STZ)-induced insulin-deficient diabetes rat model. Here, we attempt to further elucidate the effect of this combination therapy at the biochemical, histological and molecular levels. Our biochemical analyses showed that the combination treatment significantly increased the serum insulin level and decreased the total cholesterol and triglyceride level of the diabetic animals. Histological examinations of H&E stained pancreas, liver, kidney and adipose tissues of combination-treated diabetic animals showed restoration to the normalcy of the tissues. Besides, the combination treatment significantly enhanced the level of glucose transporter-4 (GLUT4) protein expression in the skeletal muscle of treated diabetic animals compared to single compound treated and untreated diabetic animals. The molecular docking analysis on the interaction of gallic acid and/or andrographolide with the adiponectin receptor 1 (AdipoR1), a key component in the regulation of pancreatic insulin secretion, revealed a greater binding affinity of AdipoR1 to both compounds compared to individual compounds. Taken together, these findings suggest the combination of gallic acid and andrographolide as a potent therapy for the management of diabetes mellitus.