Table 2.

Summary on the advantages, disadvantages, benefits, and pitfall of up-to-date in vitro, in vivo and clinical toxicology studies on Garcinia/HCA.

Methodology	Study target	Summary	Advantages	Disadvantages	Benefits	Pitfall of experiment
In vitro cytotoxicity	3T3 fibroblast [21]	G. indica was cytotoxic on 3T3	Rapid test	Not fully representative compared to animal/human subject.	First line screening	Poor methodology, only Balb/c 3T3 was screened.
In vitro genotoxicity ~Ames test ~Chromosomal aberration test	~Salmonella typhimuriumi, ~Chinese hamster ovarian cell [22]	HCA-SX did not induced mutagenic activity	Rapid test	Not fully representative compared to animal/human subject.	First line screening
In vivo genotoxicity Micronucleus test	8 weeks old ICR mice [22]	Micronucleated polychromatic erythrocytes in bone marrow cell	Better representation than in vitro cell line study	Variation among animal.	Preclinical screening	i.p. injection with DMSO as vehicle not suitable; no prior i.p. LD50 predetermination; 12,500 μmol/kg exceed the highest dose, poor statistic analysis [23].
In vivo acute toxicity	Albino rat [12]	HCA SX LD50 > 5 g/kg body weight	High dosage (233X higher than maximum dose of 1.5 g/day in human)	Single administration.	Understand acute toxic effect at high concentration	Only LD50, gross necropsy and body weight were recorded. No blood biochemical profiling and full blood count.
In vivo subchronic	Rat [24, 25]	HCA-SX reduced body weight, feed intake but no effect on other parameters.	Experiment was design to represent actual recommended dosage.	—	Good reference to support the entry of clinical studies.	—
In vivo skin irritation	Albino rabbit [12]	HCA-SX was none irritating with primary irritation index = 0.	More representative than in vitro test.	Single exposure.		This study only tested the irritative potential with single exposure.
In vivo eye irritation	Albino rabbit [12]	HCA-SX was mild irritant on eye.	More representative than in vitro test.	—	HCA-SX is an oral supplement. Results for in vivo skin and eye irritation can help to strengthen the MSDS.	—
In vivo reproduction toxicity	Rat [36, 40]	HCA-SX did not affect the postnatal maturation, reproductive capacity.	“No observed adverse effect level” of HCA-SX higher than 1.5 mg/kg/day was determined in both parental, offspring generation and HCA-SX was not teratogenic.	—	Good reference to support that HCA was none toxic effect against reproductive system.	—
In vivo reproduction toxicity	Zucker obese rats [26, 27]	G. cambogia powder (containing 41.2 wt% of (−)-HCA, the ratio of free to lactone form is 36.6 to 63.4) impaired spermatogenesis	—	—	—	Zucker rat is not suitable in this study since it has a defect in testicular testosterone production. HCA used in this experiment contains high lactone that may contributed to it the impairment of spermatogenesis [31]
Clinical studies (as stated in Table 1)	873 subjects	Garcinia/HCA is generally none toxic with NOAEL > 4 g HCA	Garcinia/HCA was recorded as none toxic up to 12 weeks consumption.	None of the studies recorded the use of Garcinia/HCA for more than 12 weeks.	Garcinia/HCA is generally safe to consume up to 3 months.	Continue monitoring on the consumers who take Garcinia/HCA for more than 3 months can strengthen the knowledge of long term safety assessment of Garcinia/HCA.