The Informant Consensus Factor (FIC) represents independent variables that contribute to the agreement and consent in international scientific opinion. It was determined as previously described by Hassan et al. [8].

FIC = ( N u r − N t ) / ( N u r − 1 ) (1)

with: N_ur, scientific articles related to the therapeutic use of the plant;

N_t, plant species and for calculations, N_t= 10.

Data were analyzed on Microsoft Excel 2013 and FIC values range from 0 to 1, where 1 indicates the highest level of consensus. The thresholds for this data analysis have been set at 5% (α = 0.05) which represent the probability of similar use in therapeutics claimed worldwide.

Fidelity Level (FL) represents the accuracy of the claimed medicinal use [9].

FL = [ ( X 1 + X 2 + X 3 ) / Y ] × 100 . (2)

with: X₁, scientific articles combining plant and joint pain; X₂, scientific articles combining plant and anti-inflammatory; X₃, scientific articles combining plant and antirheumatic; Y, number of all citations for the name of the plant only.

Data was analyzed on Microsoft Excel 2013, and thresholds for data analysis have been set at 25% which represent the strength of fidelity showing that this indication is well recognized for this plant.

Analgesics and anti-inflammatories drugs used in the treatment of rheumatic pathologies presented a basic chemical skeleton like C₆-C₁, C₆-C₂ and C₆-C₃ type (Table 3), close to those of plant phenolic compounds [13]. Study of chemical compounds found in plants with the highest level of agreement for inflammatory joint pain care also indicates the presence of compounds showing similar basic skeletons C₆-C₁ and C₆-C₃ type.

1) C₆-C₁ Basic Chemical Skeleton Molecules

Trichiliaemetica Vahl contains C₆-C₁ phenolic acids such as gallic acid (1) (Figure 1) in the root bark [14]. Gallic acid shows anti-inflammatory properties by decrease expression and release of pro-inflammatory and inflammatory mediators, such as bradykinine, substance P, Cyclooxygenase 2 (COX-2), Nuclear Factor-kappa B (NF-κB), Interleukin-2 (IL-2), Interleukin-4 (IL-4), Interleukin-5 (IL-5), Interferon gamma (IFN-γ) and Tumor Necrosis Factor α (TNF-α). It also inhibits polymorphonuclear agents involved in the inflammatory response and decreases the activity of myeloperoxidase (MPO) [15] [16]. Root also contains ferulic acid (2) (Figure 1) [17]. Ferulic acid showed promising anti-inflammatory activity (inhibition of TNF-α, Interleukin-6 (IL-6) and COX-2). Gallic acid, ferulic acid demonstrated inhibition of xanthine oxidase [14]. Guierasenegalensis J.F.G.mel contains nine galloylquinic acids, namely 3-O-, 5-O-, 1,3-di-O-, 3,4-di-O-,3,5-di-O-,4,5-di-O-,1,3,4-tri-O-,3,4,5-tri-O- and 1,3,4,5-tetra-O-galloylquinic isolated by column chromatography and HPLC from different plant parts. Among these nine (09) galloylquinic acids, 3,4,5-tri-O-galloylquinic is a new ethyl ester of polyphenol acid (3) (Figure 1). Gallic acid has also been isolated from leaves [18]. In addition, 3,4,5-tri-O-galloylquinic acid isolated from Guierasenegalensis J.F.G.mel. has showed to exhibit anti-HIV activity [19]. Phenols are present in leaves of Calotropisprocera (Ait) Ait.F. and in Crescientiacujete L. fruits [10]. It is recognized that phenolic compounds proceed in the same way as NSAIDs, and some of them inhibit other pro-inflammatory mediators [13].

2) C₆-C₃ Basic Chemical Skeleton Molecules

Guierasenegalensis J.F.G.mel. leaves extracts contain coumarin (4) and flavonoids such as quercetin (5) and rutin (6) (Figure 1) [19]. Trichiliaemetica Vahl root barks also contain flavonoids such as rutin (6) [20]. Calotropisprocera (Ait) Ait.F. leaves and barks contain flavonoids, mainly rutin (6) [20] which exhibit anti-inflammatory properties by reduction of the production of pro-inflammatory cytokines and inhibition of xanthine oxidase. In vivo, quercetin (5) has been shown to have anti-inflammatory properties by attenuating lipid peroxidation, platelet aggregation and capillary permeability. It also inhibits cyclooxygenases (COX), lipoxygenase (LOX) and lipopolysaccharide (LPS) which induces the production of TNF-α in macrophages and the production of IL-8 [21]. Crescientiacujete L. contains flavonoids in these fruits [22] which have anti-inflammatory properties [21].

Drugs used in inflammatory joint pain care present basic chemical skeletons close to steroid-like triterpene derivatives as corticosteroids and their derivatives (Table 4). Scientific publications indicate that many plant-derived triterpenes have anti-inflammatory properties [23].

Study of chemical compounds found in plants with the highest level of agreement for inflammatory joint pain care also indicates the presence of compounds showing similar basic skeletons of terpenoids. Steroid-like triterpene compounds have been identified in Trichiliaemetica Vahl [24], Guierasenegalensis J.F.G.mel. [25], Calotropisprocera (Ait) Ait.F. [26]. Similarly, limonoid type, a modified triterpenic compounds such as tetranortriterpenoids trichiline (7) (Figure 1) were found in the root bark of Trichiliaemetica Vahl [24] and saponoside type were found in Crescientiacujete L. fruits [22]. Limonoids showed a strong anti-inflammatory activity [23].

Observations of chemical structures indicated that morphine and piroxicam have basic chemical skeletons of C₆-C₂-N type while colchicine would be of C₆-C₃-N type (Table 3) close to phenylalanine-derived compounds. Many alkaloids, especially the iso-quinoline alkaloids, exhibiting the same basic skeletons, are known to have anti-inflammatory and analgesic properties [27].

Study of chemical compounds found in plants with the highest level of agreement for inflammatory joint pain care also indicates the presence of nitrogen

compounds in three (03) plants in exception of Trichiliaemetica Vahl. Basic chemical skeletons of C₆-C₂-N and C₆-C₃-N type, similar to nitrogen compounds have not been identified in Guierasenegalensis J.F.G.mel. [18], Calotropisprocera (Ait) Ait.F. [10], and Crescientiacujete L. [11]. Nevertheless, we noted in Guierasenegalensis J. F. G. mel the presence of indolic alkaloids β-carboline type as harmalane, harmane and tetrahydroharmane (Figure 2) [28]. These compounds demonstrated anti-inflammatory activities by suppressing nitric oxide production and secretion of pro-inflammatory cytokines [29]. Similarly, nitrogen compounds like choline has been identified in the latex of the leaves of Calotropisprocera (Ait) Ait.F. Choline is a quaternary ammonium-like proto-alkaloid [30] that showed anti-inflammatory effects. We could not identify structural analogies between these nitrogen molecules, which potent anti-inflammatory properties have been already demonstrated and modern antirheumatics.