Gotu Kola (Centella asiatica) and Swelling / fluid retention: evidence and sources

Background Chronic venous insufficiency (CVI) is a condition in which veins are unable to transport blood unidirectionally towards the heart. CVI usually occurs in the lower limbs. It might result in considerable discomfort, with symptoms such as pain, itchiness and tiredness in the legs. Patients with CVI may also experience swelling and ulcers. Phlebotonics are a class of drugs often used to treat CVI. This is the second update of a review first published in 2005. Objectives To assess the efficacy and safety of phlebotonics administered orally or topically for treatment of signs and symptoms of lower extremity CVI. Search methods The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and Clinicaltrials.gov trials register up to 12 November 2019. We searched the reference lists of the articles retrieved by electronic searches for additional citations. We also contacted authors of unpublished studies. Selection criteria We included randomised, double-blind, placebo-controlled trials (RCTs) assessing the efficacy of phlebotonics (rutosides, hidrosmine, diosmine, calcium dobesilate, chromocarbe, Centella asiatica, disodium flavodate, French maritime pine bark extract, grape seed extract and aminaftone) in patients with CVI at any stage of the disease. Data collection and analysis Two review authors independently extracted data and assessed the quality of included RCTs. We estimated the effects of treatment by using risk ratios (RRs), mean differences (MDs) and standardized mean differences (SMDs), according to the outcome assessed. We calculated 95% confidence intervals (CIs) and percentage of heterogeneity (I 2 ). Outcomes of interest were oedema, quality of life (QoL), assessment of CVI and adverse events. We used GRADE criteria to assess the certainty of the evidence. Main results We identified three new studies for this update. In total, 69 RCTs of oral phlebotonics were included, but only 56 studies (7690 participants, mean age 50 years) provided quantifiable data for the efficacy analysis. These studies used different phlebotonics (28 on rutosides, 11 on hidrosmine and diosmine, 10 on calcium dobesilate, two on Centella asiatica, two on aminaftone, two on French maritime pine bark extract and one on grape seed extract). No studies evaluating topical phlebotonics, chromocarbe, naftazone or disodium flavodate fulfilled the inclusion criteria. Moderate-certainty evidence suggests that phlebotonics probably reduce oedema slightly in the lower legs, compared with placebo (RR 0.70, 95% CI 0.63 to 0.78; 13 studies; 1245 participants); and probably reduce ankle circumference (MD -4.27 mm, 95% CI -5.61 to -2.93 mm; 15 studies; 2010 participants). Moderate-certainty evidence shows that phlebotonics probably make little or no difference in QoL compared with placebo (SMD -0.06, 95% CI -0.22 to 0.10; five studies; 1639 participants); and similarly, may have little or no effect on ulcer healing (RR 0.94, 95% CI 0.79 to 1.13; six studies; 461 participants; low-certainty evidence). Thirty-seven studies reported on adverse events. Pooled data suggest that phlebotonics probably increase adverse events slightly, compared to placebo (RR 1.14, 95% CI 1.02 to 1.27; 37 studies; 5789 participants; moderate-certainty evidence). Gastrointestinal disorders were the most frequently reported adverse events. We downgraded our certainty in the evidence from 'high' to 'moderate' because of risk of bias concerns, and further to 'low' because of imprecision. Authors' conclusions There is moderate-certainty evidence that phlebotonics probably reduce oedema slightly, compared to placebo; moderate-certainty evidence of little or no difference in QoL; and low-certainty evidence that these drugs do not influence ulcer healing. Moderate-certainty evidence suggests that phlebotonics are probably associated with a higher risk of adverse events than placebo. Studies included in this systematic review provided only short-term safety data; therefore, the medium- and long-term safety of phlebotonics could not be estimated. Findings for specific groups of phlebotonics are limited due to small study numbers and heterogeneous results. Additional high-quality RCTs focusing on clinically important outcomes are needed to improve the evidence base.

We aimed to assess the efficacy of Centella asiatica for improvement of the signs and symptoms of chronic venous insufficiency (CVI). We searched 13 electronic databases including the Cochrane Central Register of Controlled Trials for randomised controlled trials assessing the efficacy of Centella asiatica for CVI. Two review authors independently selected studies, assessed the risks of bias of included studies and extracted data. The treatment effects of similar studies were pooled whenever appropriate. Eight studies met the inclusion criteria. The pooling of data of similar studies showed that Centella asiatica significantly improved microcirculatory parameters such as transcutaneous partial pressure of CO2 and O2, rate of ankle swelling and venoarteriolar response. Three out of the eight studies did not provide quantitative data. However, these studies reported that patients treated with Centella asiatica showed significant improvement in CVI signs such as leg heaviness, pain and oedema. Our results show that Centella asiatica may be beneficial for improving signs and symptoms of CVI but this conclusion needs to be interpreted with caution as most of the studies were characterised by inadequate reporting and thus had unclear risks of bias, which may threaten the validity of the conclusions.

Plant-derived elements used for pharmacological applications constitute an increasing research field. Centella asiatica is widely used mainly as an extract (TECA). Triterpenic fractions, the primary constituents of Centella asiatica, produce a wide range of preventive and therapeutic effects. The modulation of collagen production and deposition in wound healing is of primary importance. TECA is also used to treat several microcirculatory problems, inflammatory skin conditions (leprosy, lupus, varicose ulcers, eczema, atopic dermatitis, psoriasis) and also intestinal problems, fever, amenorrhea and genitourinary conditions. Cognitive functions, anxiety and mental impairment may be also affected by TECA administration. New applications in neurology include nerve growth factor enhancement and applications in neurological degenerative conditions. Interaction with other products is also indicated in this document. The multiplicity of actions of TECA is associated to six important mechanisms, all inter-connected and modulating each other: 1) edema - and capillary filtration - control; 2) a strong antioxidant power, effective on several forms of oxidative stress associated to inflammation or infections and synergic with other antioxidant products; 3) an anti-inflammatory action; 4) a modulation of the collagen production avoiding slower scarring or faster, hyperthrophic scarring and cheloids; 5) a modulating action of local growth factors; 6) a modulation of angiogenesis. This "status" paper - resulting from an expert meeting held in Cobham, Surrey, indicates most of the therapeutic potential of TECA, still to be explored in further studies. The status paper constitutes the basis for a consensus document on TECA to be developed in the next future. This "status" paper opens a new window on an ancient but still partially unexplored product that may become an important value in prevention and treatment of several pre-clinical and risk conditions and in clinically significant disease both as a single products and in association with other 'natural' products.