Table 2: An overview of complement inhibitors in extracts from plant species.

Plant L.Part of plant (extract)Mode of action Beneficial effectsReferences

Achyrocline flaccida  
(Yellow Marcela)
Aerial partsCP inhibition.  
Antispasmodic, antipyretic, antihelmintic, antibacterial, antiviral. Stimulant, emmenagogue, excitant.[61]

Aloe vera LeavesAP activation, resulting in consumption of C3.Antibacterial, antifungal, antiparasitic, antitumor, laxative. Used for seborrheic dermatitis, radiation dermatitis, psoriasis vulgaris, genital herpes, burn wounds, diabetes, HIV infection, ulcerative colitis, pressure ulcers, mucositis, aphthous stomatitis, acne vulgaris, lichen planus, frostbite, alopecia, systemic lupus erythematosus, arthritis, tic douloureux.[62, 63]

Apeiba tibourbou  
(Monkey comb)
LeavesCP and AP inhibition.Antispasmodic, mucilaginous, and pectoral properties. Used for rheumatism.[64]

Artemisia species  
(A. dracunculus, A. montana, A. princeps, A. rubripes, A. tripartita)
LeavesCP inhibition.
Used for colic pain, vomiting, diarrhea, dysmenorrhea.[6568]

Ascophyllum nodosum  
(Brown seaweed)
LeavesCP inhibition. Fucoidan binds C1q and prevents the formation of active C1. It forms a complex with C4Anti-inflammatory, antiangiogenic, anticoagulant, antiadhesive.[69, 70]

Astronium urundeuva Stem barkCP and AP inhibition.
IC50 (CP) = 64 μg/mL
IC50 (AP) = 111 μg/mL
Used for wound healing, bone healing, inflamed sores, gastric ulcers, uterine hemorrhages, metrorragias, cervicitis.[71]

Avicennia marina  
(Evergreen shrub)
Stem barkCP inhibition.
IC50 (CP) = 23–248 μg/mL
Antitumor, anti-inflammatory, antiviral. Used for skin diseases, wound healing, rheumatism, smallpox, ulcers, malaria.[72]

Biophytum petersianum Klotsch Aerial partsCP inhibition.
IC50 (CP) 2–86 μg/mL
Used for wound healing, inflammation.[65, 73]

Boswellia serrata  
(Frankincense)
Oleogum resinCP inhibition, it inhibits C3 convertaseAntihelminthic, antiseptic, haemostatic, analgesic, cardiotonic, diuretic, aphrodisiac, laxative. Used for Crohn’s disease, ulcerative colitis, bronchial asthma, rheumatoid arthritis, osteoarthritis, wound cleaning, reducing fat, diarrhea, improving menstruation.[74, 75]

Bridelia ferruginea Stem barkCP and AP inhibition. Inhibition of C1 and terminal complex.Used for rheumatism.[76]

Cochlospermum vitifolium  (silk cotton tree)Stem barkCP and AP inhibition.
IC50 (CP) = 104 μg/mL
IC50 (AP) = 135 μg/mL
Used for diabetes, hepatobiliary and cardiovascular diseases, hypertension, pain, kidney diseases, ulcers.[71, 77]

Croton draco LatexCP and AP inhibition.
IC50 (CP) = 430–590 μg/mL
IC50 (AP) = 680–930 μg/mL
Antibacterial, antitumor, antiviral. Used for wound healing, inflammation.[78]

Entada africana RootsCP inhibition.
IC50 (CP) = 75–370 μg/mL
Hepatoprotective, haemostatic, antipyretic, antiseptic, diuretic, antigonococci, antisyphilitic, antiparasitic, abortifacient. Used for wound healing, malaria, respiratory diseases, psoriasis, rheumatism, cataract, dysentery.[79]

Eugenia malaccensis  
(Malay rose apple)
Stem barkCP inhibition: IC50 (CP) = 12 μg/mL
AP was activated: 50 % activation at 6 μg/mL
Used for general debility, sore throat, wound healing, candidiasis, venereal diseases, tuberculosis, digestive tract disorders.[80]

Eupatorium arnottianum Aerial partsCP and AP inhibition.
IC50 (CP) = 5.0–155.9 μg/mL
IC50 (AP) = 101.3 μg/mL
Antimicrobial, antiviral, antinociceptive. Used for gastric pain.[61]

Eupatorium buniifolium Aerial partsCP inhibition.
IC50 (CP) = 44.1–66.7 μg/mL
Hepatoprotective, antiviral, antiseptic.[61]

Euterpe precatoria  
(Açai)
RootsCP and AP inhibition.
IC50 (CP) = 105 μg/mL
IC50 (AP) = 147 μg/mL
Antioxidant. Used for muscular pain, sciatic pain, liver and kidney diseases, wound healing, skin ulcers, edema, inflammatory diseases. [71]

Glycine max  
(Soyabean)
SeedsIn vitro it inhibits synthesis and secretion of C2 and C4 by guinea pig peritoneal macrophagesAntioxidant, anti-inflammatory, antitumor, antioestrogenic, antifungal, insulinotropic. Used for atherosclerosis, skin whitening, [81, 82]

Glycyrrhiza glabra  (Licorice)Roots and rhizomesGlycyrrhizin binds to C3a and C3. It induces conformational changes in C3 and it inhibits CP at the level of C2.Anti-inflammatory, antiviral, antimicrobial, antioxidative, antitumor, immunomodulatory, hepatoprotective, cardioprotective, diuretic, anabolic, laxative, contraceptive. Used for wound healing, cystitis, diabetes, cough, stomachache, tuberculosis, nefrolitiasis, lung ailment, Addison’s disease, gastric ulcers, improvement of voice, improvement of male sexual function.[83, 84]

Isopyrum thalictroides Roots and aerial partsCP inhibition. Ca2+ and Mg2+ dependent complement inhibition. It inhibits C1 formation.Rheumatism, neuralgia, silicosis, malaria.[81]

Jatropha multifida/Jatropha curcas  (Coral plant)LatexCP inhibition, mediated by Ca2+ depletionUsed for infected wounds.[81, 85]

Lithraea molleoides LeavesCP inhibition.
IC50 (CP) = 59.0–86.1 μg/mL
arthritic, haemostatic, diuretic, tonic. Used for respiratory diseases. It causes allergic contact dermatitis.[61]

Opilia celtidifolia LeavesCP inhibition.
IC50 (CP) = 0.5–29 μg/mL
Haemostatic. Used for wound healing.[73]
Piper kadsura  
(Japanese pepper)
Stem barkIt inhibits C5a-induced chemotaxis and decreased the stimulated production of TNF-α and IL-1-βAsthma, rheumatic arthritis[86]

Phyllanthus sellowianus Leaves and stemsCP and AP inhibition.
IC50 (CP) = 11.2–22.0 μg/mL
IC50 (AP) = 280.6 μg/mL
Hypoglycemic, diuretic, laxative, antiseptic, antinociceptic.
[61, 87]

Rosmarinus officinalis/Melissa officinalis  (Rosemary)LeavesCP and AP inhibition. It binds C3 and inhibits C5 convertase. C5a generation is decreased. IC50 (CP) = 2 μg/mLAntispasmodic, choleretic, hepatoprotective, anti-inflammatory, antitumor, antioxidant. Used for renal colic pain, dysmenorrhea, respiratory disorder (bronchial asthma), stimulation of hair growth, relaxation of smooth muscles of trachea and intestine, peptic ulcers, atherosclerosis, ischaemic heart disease, cataract, improvement of sperm motility. [81, 88, 89]

Trichilia emetica  
(Natal mahogany)
LeavesCP inhibition.
IC50 (CP) = <15–62.5 μg/mL
Antipyretic, antiepileptic, antigonococci, antisyphilitic, anti-parasitic. Used for wound healing, dysmenorrhea, asthma, vomiting, hepatitis, improvement of fertility (women), gastric diseases, malaria, hypertension, rheumatism, lumbago.[90]

Triplaris americana  
(Ant tree)
Stem barkCP and AP inhibition.
IC50 (CP) = 74 μg/mL
IC50 (AP) = 89 μg/mL
Antioxidant, parturifacient. Used for metrorragias, diarrhea, stomachache, intestinal worms, leishmaniasis, skin ulcers.[71]

Ulex europaeus  (Common gorse)SeedsIt attenuates MBL binding on human endothelial cells and inhibited C3 deposition. The dcreased LP activation resulted in less complement-dependent neutrophil chemotaxis.
IC50 = 10 pmol/L
None.[91]

Uncaria tomentosa  (Cat’s claw)Stem barkCP and AP inhibition.
IC50 (CP) = 124 μg/mL
IC50 (AP) = 151 μg/mL
inflammatory, antiviral, immunostimulating, antimutagenic, antioxidant. Used for gastritis, dermic and urogenital inflammations, asthma, rheumatism, irregular menstruation, digestive, liver and kidney diseases, adjuvant therapy for breast cancer.[71, 92]

CP: classical pathway; AP: alternative pathway; LP: Lectin Pathway; IC50: concentration required for 50% complement inhibition. Most of these complement inhibition tests were performed using complement haemolytic activity assays. Compounds in these plant species inhibiting the complement system are e.g. flavonoids, glucosides, polysaccharides, terpenes, iridoids, polymers, peptides, alkaloids, and oils [81]. Other complement inhibitors from plants are found in Acanthus ilicifolius[72], Atractylodes lancea[73], Angelica acutiloba [73, 81, 93], Azadirachta indica [81], Bupleurum falcatum [94], Cedrela lilloi [81], Centaurium spicatum [81], Cochlospermum tinctorium[95], Crataegus sinaica [81], Crataeva nurvala [81], Curcuma longa [96], Dendropanax morbifera Leveille [97], Glinus oppositifolius [79], Juglans mandshurica [98], Ligularia taquetii [99], Litsea japonica [100], Ligustrum vulgare [81], Lithospermum euchromum [81], Magnolia fargesii [101], Melothria maderaspatana [102], Morinda morindoides [81], Olea europaea [81], Osbeckia octandra [102], Ocimum basilicum [66], Osbeckia aspera [81], Panax ginseng [103], Paulownia tomentosa var. tomentosa [104], Persicaria lapathifolia [81], Petasites hybridus [81], Phillyrea latifolia [81], Phyllanthus debilis [102], Picria fel-terrae [105], Plantago major [81], Sorghum bicolor [106], Terminalia amazonia [71], Thymus vulgaris [66], Tinospora cordifolia [81], Trichilia elegans [90], Trichilia glabra [81, 90], Vernonia Kotschyana [72, 73, 95], Wedelia chinensis [107], and Woodfoidra fruticosa [81].